MTRD ICT
MINISTRY OF TRANSPORT AND INFRASTRUCTURE
STATE DEPARTMENT OF INFRASTRUCTURE
MATERIALS TESTING AND RESEARCH DIVISION(MTRD)
DETAILED INSPECTION OF BRIDGES ALONG NAKURU-NYAHURURU-
NYERI –MARUA ROAD(B5)
MTRD REPORT NO.1233
MAY,2015
CHIEF ENGINEER (MATERIALS )P.O. BOX 11873-00400
NAIROBI
INTERNATIONAL CONSULTANTS AND TECHNOCRATS(ICT) PVT LTDA-8, GREEN PARK NEW DELHI -
110016, INDIA
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
1.0 INTRODUCTIONThis bridge inspection report is in response to a request made by M/S International Consultants and Technocrats (ICT) Pvt Ltd of A-8, Green Park New Delhi -110016, and India to undertake inspection of structures along road B5. This was done under the project: “Consultancy Services for a Feasibility Study, EIA, SIA and Detailed Designs Including Tender Documents for Rehabilitation of Nakuru-Nyahururu-Nyeri –Marua Road”.
A total of seven structures had been targeted for detailed inspection as listed below.
i. Bridge at Km 60+030ii. Bridge at Km 84+520iii. Bridge at Km 93+380iv. Bridge at Km 102+510v. Bridge at Km 125+670vi. Bridge at Km 142+450vii.Bridge at Km 173+120
This report contains a description of the structures, visual observations, description of testing methods, test results for various parameters based on different Non-Destructive Testing methods, conclusions and recommendations.
The report is factual and dwells mainly on the status of structural elements and their material components.
The primary results of these inspections are given and the critical problems have been highlighted.
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1.1 Scope of workThe scope of work as shown below involved testing of structural elements in both the superstructures and substructures for each of the seven bridges for several parameters using various Non-Destructive Testing methods.Table 1: Scope of work
Item no. Structural
elementParameters tested Inspection details/methods
1 Abutments
Appearance Carry out visual inspectionRe-bar details Carry out electromagnetic
testsInsitu Concrete strength Carry out Schmidt hammer
testsQuality, homogeneity and internal defects of concrete matrix
Carry out ultrasonic pulse velocity tests
Deterioration status of the concrete matrix
i. Corrosionii. Remaining effective
good covers
i. Carry out resistivity/half cell potential tests
ii. Carry out carbonation depth tests
Crack profilingi. Widthii. Depthiii. length
i. Use of crack width microscope to measure crack widths
ii. Carry out ultrasonic tests to measure crack depths
2Piers
i. Wall type ii. Column
typeDitto Ditto
3 Deck slab Ditto Ditto
4 Steel Girders
Laminations Carry out ultrasonic testsCorrosion Carry out visual inspection
and ultrasonic thickness testsPlate thicknesses Carry out ultrasonic tests
Continuity of critical welds if any
Carry out radiographic tests
5
Ancillary Fixturesi. bearingsii. expansion
gapsAppearance Carry out visual inspections
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3.0 SUMMARY OF TEST RESULTSGenerally the findings from all the tests done indicate a lot of similarity for six structures in terms of re-bar distribution for various structural elements, cracking patterns, steel girder types ,numbers & sizes, type of ancillary fixtures and concrete deterioration status.
The findings for bridge at km173+120 (at Marua) were different from those of other structures.
Inspection results have been summarized for each structure and are presented below.
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3.1 BRIDGE AT KM 60+030…This is a single span structure comprising a composite deck with 5 no. steel beams, wall type RC abutments and wing walls.
Photo 1: A side view of bridge at km 60+030
3.1.1 ABUTMENTS3.1.1.1 Visual Inspection
Two vertical cracks running full height were found on the Nyeri side abutment. The cracks appear approximately midway between the beam supports at the abutment cap. The crack widths vary from 0.8-1.4mm
Fig. 1: showing crack profiles for Nyeri side abutment
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BRIDGE AT KM 60+030
Photo 2: a vertical crack on an abutment wall
One vertical crack was found on the Nyahururu side abutment. The crack appearednear the inner RHS beam support at the abutment cap and propagated the full height of the abutment wall. The maximum crack width recorded was.1.0 mm
Fig. 1: showing crack profiles for Nyeri side abutment
3.1.1.2 Steel Reinforcement details for the Abutments
The reinforcement details as gathered through electromagnetic method revealed the spacing of the reinforcement bars in the abutment walls on
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either side of the bridge was not uniform in the vertical and horizontal directions, varying between 400mm- 450mm and 380-450mm respectively . The vertical re-bars were 25 mm diameter while the horizontal were 16 mm diameter.
BRIDGE AT KM 60+030Steel Reinforcement details for the Abutments
The average covers were varying at different points on either abutment with the lowest at 33 mm and the highest at 71 mm.
3.1.1.3 Concrete strength, quality and homogeneity for the Abutments
The concrete strength as measured through rebound (Schmidt) hammer method recorded strengths of between 44.0N/mm2 to 54.0N/mm2
The concrete matrix was generally homogeneous as revealed through ultrasonic method except at locations where cracks appeared.
3.1.1.4 Crack depths for the Abutments
The crack depths were ultrasonically determined and found to be106mm at the widest points.
3.1.1.5 Concrete Deterioration for the Abutments
Two methods were employed i.e. carbonation and resistivity potential to indicate the level of deterioration of concrete.
The highest carbonation depth recorded was 6mm indicating a remaining good cover of 27mm (least cover recorded was 33mm). This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 111.4kΩcm.
3.1.2 DECK SLAB3.1.2.1 Visual inspection of the Deck Slab
Deck slab thickness was 200mm.
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There were several multi directional cracks appearing from the soffit of the deck. The cracks were distributed all over the deck soffit.
Maximum crack width was 1mm.
3.1.2.2 Steel Reinforcement details of the Deck Slab
The reinforcement details as gathered through electromagnetic method revealed that the distribution of the reinforcement bars in the deck slab was uniform both in both longitudinal and transverse directions. The longitudinal re-bars were 20 mm diameter at an average spacing of 400mm while the transverse were 16 mm diameter at an average spacing of 300 mm. The average covers were 50mm and 35mm for longitudinal re-bars and transverse re-bars respectively.
3.1.2.3 Concrete strength, quality and homogeneity
The concrete strength as measured through rebound (Schmidt) hammer method recorded an average strength of between 56N/mm2 62N/mm2
The concrete matrix was inhomogeneous as revealed through ultrasonic method. This could be due to cracking on the deck slab soffit.
3.1.2.4 Crack depths
The crack depths were ultrasonically determined and found to be “through cracks”
3.1.2.5 Concrete Deterioration of Deck Slab
Two methods were employed i.e. carbonation and resistivity potential to indicate the level of deterioration of concrete.
The highest carbonation depth recorded was 6mm indicating a remaining good cover of 29mm (least cover recorded was 35mm).This was an indication of low level deterioration.
Deterioration in this case refers to chemical effects and not physical.
Probability of corrosion activity was insignificant as indicated by high resistivity potential of 110.2DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
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BRIDGE AT KM 60+0303.1.4 WING WALLS3.1.4.1 Visual Inspection of the Wing Walls
There were no visual structural defects on the wing walls
3.1.4.2 Steel Reinforcement Details for the Wing Walls
The reinforcement details as gathered through electromagnetic method revealed the spacing of the reinforcement bars in the wing walls on either side of the bridge not to be uniform in the vertical and horizontal directions, varying between 380mm- 480mm and 390-470 mm respectively. The vertical re-bars were 20 mm diameter while the horizontal were 16 mm. The average covers were varying at different points on either side with the lowest at 26 mm and the highest at 71 mm.
3.1.4.3 Concrete strength, quality and homogeneity for the wing walls
The concrete strength as measured through rebound (Schmidt) hammer method recorded an average strength of 58.0N/mm2
The concrete matrix was generally homogeneous as revealed through ultrasonic method.
3.1.5 STEEL GIRDERS 3.1.5.1 Visual Inspection of Steel Girders
There were spots of paint peeling off from the bracings and beams.
The top flanges near the abutment supports had started to corrode as revealed by red/brown colouration stains at the slab soffit joint. However the corrosion was at an early stage without causing any significant reduction in thickness of the steel plate.
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There was accumulation of soil at the abutment caps which covered the bottom flanges of the steel girders causing the paint to peel off resulting in early stages of corrosion.
BRIDGE AT KM 60+030Visual Inspection of Steel Girders
The bolts and nuts for all the joints were in good condition.
There were no critical welded joints.
3.1.5.2 Ultrasonic Thickness Tests for Steel Girders
There was no delaminating of the plates as determined ultrasonically. The thicknesses for the flange and web plates were determined ultrasonically and found to be uniform.
3.1.6 BEARINGSThe bearing type was elastomeric of approximate size 400x280x 30 mm and was in good condition.
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3.2 BRIDGE AT KM 93+380This is a single span structure comprising a composite deck with 5 no. steel beams, wall type RC abutments and wing walls.
Photo 3: A side view of bridge at km 93+380
3.2.1 ABUTMENTS3.2.1.1 Visual Inspection Abutments
There were four regularly spaced vertical cracks running full height on the Nyeri side abutment. The cracks appeared approximately midway between the beam supports at the abutment cap.
Fig 3: sketch showing the crack profiles on the Nyeri side abutment wall
The crack widths varied from 0.6-1mm.
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3.2 BRIDGE AT KM 93+380Three regularly spaced vertical cracks running full height were found on the Nyahururu side abutment. The cracks appeared approximately midway between the beam supports for the inner LHS& RHS beams and the centre beam.
Fig 4: showing crack profiles for Nyahururu side abutment-measurement in mm
Photo 4: Showing a vertical crack on an abutment
3.2.1.2 Steel Reinforcement details for the Abutments
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The reinforcement details as gathered through electromagnetic method revealed the distribution of the reinforcement bars in the abutment walls on either side of the bridge to be uniform in the vertical and horizontal directions.
BRIDGE AT KM 93+380Steel Reinforcement details for the AbutmentsThe vertical s re-bars were 25 mm diameter at an average spacing of 450mm while the horizontal were 16 mm diameter at an average spacing of 450 mm. The average covers were varying at different points on either abutment with the lowest at 28 mm and highest at 66 mm.
3.2.1.3 Concrete strength, quality and homogeneity for the Abutments
The concrete strength as measured through rebound (Schmidt) hammer method recorded strengths between 40.0 N/mm2 to 60N/mm2 for six test points.
The concrete matrix was generally homogeneous as revealed through ultrasonic method except at locations where cracks appeared.
3.2.1.3 Crack depths
The crack depths were ultrasonically determined and found to be 61mm at the widest points.
3.2.1.4 Concrete Deterioration for the Abutments
Two methods were employed i.e. carbonation and resistivity potential to indicate the level of deterioration of concrete.
The highest carbonation depth recorded was 5mm indicating a remaining good cover of 23mm (least cover recorded was 28mm).This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 110.6kΩcm.
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BRIDGE AT KM 93+3803.2.2 DECK SLAB3.2.2.1 Visual inspection Of the Deck Slab
Deck slab thickness was 200mm.There were several multi directional cracks appearing from the soffit of the deck. The cracks were distributed all over the deck soffit. There were two major cracks that ran full width on each half of the Nyeri side and Nyahururu side of the deck at approximatetly1500mm from the cross bracing. There were leakage stains along these cracks, an indication that the cracks were through hence the risk of exposure of re-bars to corrosion due to water ingress at the locations. (See photos below)
Photo 5: showing a transverse crack on the deck of bridge at km 93+380
Photo 6: a closer view of the crack in photo 5 above
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Maximum crack width was 1mm.
BRIDGE AT KM 93+3803.2.2.2 Steel Reinforcement details for the Deck Slab
The reinforcement details as gathered through electromagnetic method revealed that the distribution of the reinforcement bars in the deck slab was uniform both in both longitudinal and transverse directions. The longitudinal re-bars were 20 mm diameter at an average spacing of 400mm while the transverse were 16 mm diameter at an average spacing of 300 mm. The average covers were 50mm and 34mm for longitudinal re-bars and transverse re-bars respectively.
3.2.2.3 Concrete strength, quality and homogeneity for the Deck Slab
The concrete strength as measured through rebound (Schmidt) hammer method recorded an average strength of 55N/mm2 for three test locations.
The concrete matrix was inhomogeneous as revealed through ultrasonic method. This was especially due to numerous multi directional cracks on the deck slab soffit.
3.2.2.4 Crack depths
The crack depths for the major transverse cracks were ultrasonically determined and found to be through cracks at the widest points.
3.2.2.5 Concrete Deterioration
Two methods were employed i.e. carbonation and resistivity potential to indicate the level of deterioration of concrete.
The highest carbonation depth recorded was 5mm indicating a remaining good cover of 29mm (least cover recorded was 34mm).This was an indication of low level deterioration.
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Deterioration in this case refers to chemical effects, not physical.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential 108.6
BRIDGE AT KM 93+3803.2.3 WING WALLSVisual Inspection of the Wing Walls
There were no visible structural defects on the wing walls.
3.3.3.1 Steel Reinforcement Details
The reinforcement details as gathered through electromagnetic method revealed the distribution of the reinforcement bars in the wing walls on either side of the bridge to be uniform the vertical and horizontal directions. The vertical re-bars were 220 mm diameter at an average spacing of 450mm while the horizontal were 16 mm diameter at an average spacing of 350mm. The average covers were varying at different points on either side with the lowest at 37 mm and the highest at 68 mm.
3.2.3.2 Concrete strength, quality and homogeneity
The concrete strength as measured through rebound (Schmidt) hammer method recorded strengths of between 58.0N/mm2 to 65N/mm2.
The concrete matrix was generally homogeneous as revealed through ultrasonic method.
3.3.4 STEEL GIRDERS 3.2.4.1 Visual inspection of Steel Girders
There were spots of paint peeling off from the bracings and girders.
The top flanges near the abutments had started to corrode for approximately 700 mm length. However the corrosion was at an early stage without causing any significant reduction in thickness of the steel plates.
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Photo 1: showing spots of paint peeling off a bracing on bridge at km 93+380
BRIDGE AT KM 93+380There was accumulation of soil at the abutment caps which covered the bottom flanges of the steel girders causing the paint to peel off resulting in early stages of corrosion.
The bolts and nuts for all the joints were in good condition.
There were no critical welded joints.
3.2.4.2 Thickness Tests for Girder Plates
There was no delaminating of the plates as determined ultrasonically. The thicknesses for the flange and web plates were determined ultrasonically and found to be uniform.
3.3.5 BEARINGSThe bearing type is elastomeric of approxsize400x280.30 while loaded and were in good condition.
photo 8:showing a bridge bearing for bridge at km 93+380
3.3.6 OTHER BRIDGE FITTINGSThe guard rails were in good condition.
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photo 2:showing guardrails for bridge at km 93+380
3.3 BRIDGE AT KM 84+520This is a three span structure comprising a composite deck with 5 no. steel girders for each span, wall type RC abutments, column type RC piers and wing walls.
Photo 9:Showing the Approach for bridge at km 84+520
Photo 10: showing the soffit of bridge at km 84+520
3.3.1 ABUTMENTS3.3.1.1 Visual Inspection of Abutments
Two vertical cracks running from mid way the height downwards were found on the Nyahururu side abutment. The crack widths ranged between 0.6-1.0mm.
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Fig 5:showing crack profiles on the nyahururu side abutment
BRIDGE AT KM 84+520One vertical crack running from mid-way the height downwards was found on the Nyeri side abutment. The crack width was 0.8mm at the widest point.
3.3.1.2 Steel Reinforcement details for the Abutments
The reinforcement details as gathered through electromagnetic method revealed the spacing of the reinforcement bars in the abutment walls on either side of the bridge not to be uniform in the vertical and horizontal directions, varying between 480mm- 520mm and 360-440mm respectively. The vertical re-bars were 25 mm diameter while the horizontal were 16 mm diameter. The average covers were varying at different points on either abutment with the lowest at 36 mm and the highest at 66mm.
3.3.1.3 Concrete strength, quality and homogeneity for the Abutments
The concrete strength as measured through rebound (Schmidt) Hammer method recorded average strengths of 50.0N/mm2 and 54.0N/mm2 for the Nyeri and Nyahururu sides respectively.
The concrete matrix was generally homogeneous as revealed through ultrasonic method.
3.3.1.4 Crack depths for the abutment walls
The crack depths were ultrasonically determined and found to be 27 mm at the widest points.
3.3.1.5 Concrete Deterioration
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The highest carbonation depth recorded was 3 mm indicating a remaining good cover of 29mm (least cover recorded was 32mm.This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 111.6 kΩcm
BRIDGE AT KM 84+520
3.3.2 DECK SLAB3.3.2.1 Visual Inspection of the Deck Slab
Deck slab thickness was 200mm.There were several multi directional cracks appearing from the soffit of the deck. The cracks were distributed all over the deck soffit. There were two major cracks that ran full width on each quarter of each span at approximately 1500mm from the transverse bracing. There were leakage stains along these cracks, an indication that the cracks were through hence the risk of exposure of re-bars to corrosion due to water ingress at the locations.Othermulti directional cracks are distributed over the entire deck slab soffit.
Photo 11: showing a transverse crack on the deck slab of bridge at km 84+520
Maximum crack width was 1mm.
3.3.2.2 Steel Reinforcement Details for the Deck Slab
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The reinforcement details as gathered through electromagnetic method revealed the distribution of the reinforcement bars in the deck slab to be uniform in the longitudinal and transverse directions. The longitudinal re-bars were 20 mm diameter at an average spacing of 400mm while the transverse were 16 mm diameter at an average spacing of 300 mm. The average covers were 45mm and 27mm for longitudinal re-bars and transverse re-bars respectively.
BRIDGE AT KM 84+520
3.3.2.1 Concrete strength, quality and homogeneity for the Deck Slab
The concrete strength as measured through rebound (Schmidt) hammer method recorded an average strength of 46N/mm2
The concrete matrix was inhomogeneous as revealed through ultrasonic method. This could be attributed to numerous multi directional cracks on the deck slab soffit.
3.3.2.2 Crack depths for the Deck Slab
The crack depths were ultrasonically and visually determined and found to through at the widest points.
3.3.2.1 Concrete Deterioration for the Deck Slab
The highest carbonation depth recorded was 3mm indicating a remaining good cover of 24mm (least cover recorded was 27 mm).This was an indication of low level deterioration.
Deterioration in this case refers to chemical effects rather than physical.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 111.6.
3.3.3 WING WALLS3.3.3.1 Visual Inspection of the Wing Walls
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There were no visual structural defects on the wing walls.
3.3.3.2 Steel Reinforcement Details for the Wing Walls
The reinforcement details as gathered through electromagnetic method revealed the spacing of the reinforcement bars in the wing walls on either side of the bridge not to be uniform in the vertical and horizontal directions, varying between 350mm- 470mm and 260-370mm respectively. The vertical re-bars were 20 mm in diameter while the horizontal were 16 mm .The average covers were varying at different points on either side with the lowest at 36 mm and highest at 64 mm.
BRIDGE AT KM 84+5203.3.3.3 Concrete Strength, Quality and Homogeneity of the Wing Walls
The concrete strength as measured through rebound (Schmidt) hammer method recorded an average strength of 55.0N/mm2 and 54.0N/mm2 for Nyeri and Nyahururu side respectively.
The concrete matrix was generally homogeneous as revealed through ultrasonic method.
3.3.4STEEL GIRDERS 3.3.4.1 Visual Inspection of Steel Girders
The girders were generally in good condition.There were no critical welded joints along the entire length of the girders.
The bolts and nuts for all the joints were in good condition.
There were mud stains at the abutment support, causing early stages of corrosion to the LHS girder near the abutment support for a length of approximately 1m.
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Photo 12:showing stains on a bottom flange of a steel girder for bridge at km 84+520
3.3.4.2 Ultrasonic Thickness Tests for Steel Girders
There was no delaminating of the plates as determined ultrasonically. The thicknesses for the flange and web plates were determined ultrasonically and found to be uniform.
BRIDGE AT KM 84+5203.3.5 PIER COLUMNS
3.3.5.1 Visual Inspection of Pier Columns
The pier columns were generally in good condition.
Photo 13: showing part of a pier column for bridge at km 84+520
3.3.5.2 Steel Reinforcement details
There were 2 No. pier columns on either side of the river channel where the central span is supported.The columns sizes were 750x600mm.
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The reinforcement details as gathered through electromagnetic method revealed 8 no.32mm diameter re-bars in each column. The average covers were varying at different points on the faces of each column with the lowest at 40 mm and highest at 70 mm.
3.3.5.3 Concrete strength, quality and homogeneity
The concrete strength as measured through rebound (Schmidt) hammer method recorded average strengths of 55 N/mm2 and 62 N/mm2 for Nyahururu side and 48N/mm2 and 54.0N/mm2 for Nyeri side.
The concrete matrix was generally homogeneous as revealed through ultrasonic method. The quality of concrete was also found to be good through direct transmission mode of ultrasonic pulses where an average velocity of 4.2 km/s was recorded.
BRIDGE AT KM 84+5203.3.5.4 Concrete matrix Deterioration for pier columns
The highest carbonation depth recorded was 3 mm indicating a remaining good cover of 37mm (least cover recorded was 40mm. This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 111.6 kΩcm.
3.3.5.5 BEARINGSThe bearing type is elastomeric of approximate size400x280x30mm. They were in good condition.
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Photo 14: Showing a bridge bearing for bridge at km 84+520
3.3.6 OTHER BRIDGE FITTINGSThe guard rails were in good condition.
photo 15:showing bridge fittings for bridge at km 84+52
3.4 BRIDGE AT KM 102+510The structure comprises a composite deck with 5 no. steel beams, wall type RC abutments and wing walls.
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Photo 16: showing a side view of bridge at km 102+510
3.4.1 ABUTMENTS3.4.1.1 Visual inspection for the Abutments
Four vertical cracks running from approximately quarter the height of the abutment downwards were found on the Nyeri side abutment. The cracks appeared along a line approximately midway between the beam supports at the abutment cap. The crack widths varied from 0.4-1.2mm.
Fig 6: sketch showing crack profiles for Nyeri side abutment for bridge at km 102+510
Two vertical cracks from approximately mid height down wards were found on the Nyahururu side abutment. The cracks appeared along a line approximately midway between the two RHS beam supports and between the LHS and centre beam supports.DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
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Fig 6: sketch showing crack profiles for Nyahururu side abutment for bridge at km 102+510
Photo 17: showing a vertical crack on an abutment wall for bridge at km 102+510
There was scouring of the Nyeri side abutment bottom level up to 1400mm high reducing the re-bar covers along this line which is mostly submerged when water levels are high.
Photo 19: showing a scoured surface at the bottom of the abutment for bridge at km 102+510
BRIDGE AT KM 102+510
3.4.1.2 Steel Reinforcement details for the Abutments
The reinforcement details as gathered through electromagnetic method revealed the distribution of the reinforcement bars in the abutment walls on
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either side of the bridge to be uniform in the vertical and horizontal directions. The vertical re-bars were 25 mm in diameter at an average spacing of 450mm while the horizontal were 16 mm diameter at an average spacing of 400mm. The average covers were varying at different points on either abutment with the lowest at 26 mm and highest at 60 mm.
3.4.1.3 Concrete strength, quality and homogeneity for the Abutments
The concrete strength as measured through rebound (Schmidt) hammer method recorded strengths of between 40.0 N/mm2 to 59.0N/mm2.
The concrete matrix was generally homogeneous as revealed through ultrasonic method except at locations where cracks appeared.
3.4.1.4 Crack depths
The crack depths were ultrasonically determined and found to be 42 mm at the widest points.
3.4.1.5 Concrete Deterioration for the abutments
The highest carbonation depth recorded was 4mm indicating a remaining good cover of 22mm (least cover recorded was 26mm), see table ... for calculation of balance of carbonation depth).This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 110.8.
BRIDGE AT KM 102+510
3.4.2 DECK SLAB3.4.2.1 Visual inspection of the Deck
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Deck slab thickness was 200mm.There were several multi directional cracks appearing from the soffit of the deck. The cracks were distributed all over the deck soffit. There were two major cracks that ran full width on either half of the Nyeri side and Nyahururu side of the deck at approx1, 500 mm from the transverse bracing. There were leakage stains along these cracks, an indication that the cracks were through hence the risk of exposure of re-bars to corrosion due to water ingress at the locations. (See photos below).
Photo 20: showing cracks on the deck slab of bridge at km 102+510
Maximum crack width was 0.8 mm.
3.4.2.2 Steel Reinforcement details for the Deck Slab
The reinforcement details gathered through electromagnetic method revealed that the distribution of the reinforcement bars in the deck slab to be uniform in the longitudinal and transverse directions. The longitudinal re-bars were 20 mm in diameter at an average spacing of 400mm while the transverse were 16 mm diameter at an average spacing of 300 mm. The average covers were 45 mm and 60mm for longitudinal and transverse re-bars respectively. 3.4.2.3 Concrete strength, quality and homogeneity for the Deck Slab
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The concrete strength measured through rebound (Schmidt) hammer method recorded an average strength of 55.5N/mm2.
The concrete matrix was inhomogeneous as revealed through ultrasonic method. This could be attributed to numerous multi directional cracks on the deck slab soffit.
3.4.2.4 Crack depths
The crack depths were ultrasonically determined and found to be 42mm at the widest points.
3.4.2.5 Concrete Deterioration
The highest carbonation depth recorded was 5mm indicating a remaining good cover of 40mm (least cover recorded was 45mm). This was an indication of no deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 110.8 kΩcm.
3.4.3 WING WALLS3.4.3.1 Visual Inspection of Wing Walls
There were no visible structural defects on the wing walls
3.4.3.1 Steel Reinforcement Details for wing walls
The reinforcement details gathered through electromagnetic method revealed the distribution of the reinforcement bars in the wing walls on either side of the bridge to be uniform in the vertical and horizontal directions. The vertical re-bars were 20 mm diameter at an average spacing of 500mm while the horizontal were 16 mm diameter at an average spacing of 400mm. The average covers were varying at different points on either side with the lowest at 29 mm and highest at 55 mm.
BRIDGE AT KM 102+510
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3.4.3.2 Concrete strength, quality and homogeneity for Wing Walls
The concrete strength as measured through rebound (Schmidt) hammer method recorded strengths between of 49.0N/mm2 to 60.0N/mm2.
The concrete matrix was generally homogeneous as revealed through ultrasonic method.
3.4.4 STEEL GIRDERS 3.4.4.1 Visual
There were spots of paint peeling off on the bracings and beams
Photo 21: showing a point where paint has peeled off a bottom flange plate of a girder for bridge at km 102+510
There was accumulation of soil at the abutment caps which covered the bottom flanges of the steel girders causing the paint to peel off resulting in early stages of corrosion.
The bolts and nuts for all the joints were in good condition.
There were no critical welded joints.
3.4.4.2 Ultrasonic Plate Thickness Tests for Steel Girders
There was no delaminating of the plates as determined ultrasonically. The thicknesses for the flange and web plates were determined ultrasonically and found to be uniform.
BRIDGE AT KM 102+510
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3.4.4.3 BEARINGSThe bearing type was elastomeric of approximate size300x280.30 and were in good condition.
3.4.4.4 OTHER BRIDGE FITTINGSThe guard rails were intact and in good condition.
Photo 22: showing the guardrails for bridge at km 102+510
3.5 BRIDGE AT KM 125+670
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This is a three span structure comprising a composite deck with 5 no. steel girders which are continuous through the three spans, wall type RC abutments, and wall type RC piers .There were no wing walls-gabion boxes had been used instead.
Photo 3: A side view of bridge at km 125+670
3.5.1 ABUTMENTS3.5.2 Visual Inspection of Abutments
The abutments could not be accessed due to protection works (stone pitching)
3.5.3 DECK SLAB3.5.3.1 Visual inspection of the Deck Slab
Deck slab thickness was 200mm.There were numerous (dense) multi directional cracks appearing from the soffit of the deck. The cracks were distributed all over the deck soffit. There were two major cracks that ran full width on each quarter of the span at the transverse bracings.
There were leakage stains along these cracks, an indication that the cracks were through hence the risk of exposure of re-bars to corrosion due to water ingress at the locations.(see photos below)
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Photo 23: showing cracks on the deck slab of bridge at km 125+670
Vibrations could be felt midspan upon movement of vehicles on the deck.
Maximum crack width was 1mm.
3.5.3.2 Steel Reinforcement details for the deck slab
The reinforcement details gathered through electromagnetic method revealed that the distribution of the reinforcement bars in the deck slab to be uniform in the longitudinal and transverse directions. The longitudinal re-bars were 20 mm in diameter at an average spacing of 400mm while the transverse were 12 mm diameter at an average spacing of 300 mm. The average covers were 25mm and 45 mm for longitudinal and transverse re-bars respectively.
3.5.3.3 Concrete strength, quality and homogeneity for the Deck Slab
The concrete strength measured through rebound (Schmidt) hammer method recorded a strength ranging between 40N/mm2 to 46.0N/mm2.
The concrete matrix was slightly inhomogeneous as revealed through ultrasonic method. This could be attributed to cracks on the deck slab soffit.
3.5.3.4 Crack depths for the Deck Slab
The crack depths were ultrasonically and visually determined and found to be through cracks at the widest points.
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BRIDGE AT KM 125+670
3.5.3.5 Concrete Deterioration for the Deck Slab
The highest carbonation depth recorded was 4mm indicating a remaining good cover of 21mm (least cover recorded was 25 mm).This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 112.3.
3.5.4 PIER WALLS3.5.4.1 Visual inspection of the Pier Walls
There were two vertical cracks on the Nyeri side pier wall.
The protection works near the bases of the pier walls and for the Nyeri side back fill were damaged.
The walls’ thicknesses were 600mm.
3.5.4.2 Steel Reinforcement Details for the Pier Walls
The reinforcement details gathered through electromagnetic method revealed the spacing of the reinforcement bars in the pier walls on either side of the bridge to be uniform the vertical and horizontal directions at 300 and 450 mm respectively. The vertical re-bars were 25 mm in diameter while the horizontal were 16 mm .The average covers were varying at different points on either side with the lowest at 40 mm and the highest at 67 mm.
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BRIDGE AT KM 125+6703.5.4.3 Concrete Strength, Quality and Homogeneity of the pier walls
The concrete strength measured through rebound (Schmidt) hammer method recorded an average strength of 51.0N/mm2and 53.0 N/mm2 for Nyeri and Nyahururu side respectively.
The concrete matrix was generally homogeneous as revealed through ultrasonic method. Direct transmission of ultrasonic pulses gave an average ultrasonic velocity of 4.3 km/s, an indication of good quality concrete.
3.5.5 STEEL GIRDERS 3.5.5.1 Visual Inspection of Steel Girders
The paint had peeled off the bottom flanges of the steel girders near the abutment supports.
Photo 24: showing paint peeling off the bottom flange and web pates
Three bracings-two on Nyeri side and one on Nyahururu side-were missing, probably stolen. The beams were reachable near the abutments making it easy for vandals to remove bolts and steal the bracings.
Photo 25: Showing a missing bracing on bridge at km 125+670
There were no critical welded joints along the entire length of the girders.
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The bolts and nuts for all the joints were in good condition.
BRIDGE AT KM 125+670
3.5.6 BEARINGS
The bearings were elastomeric measuring 400x280x 30 mm and were in good condition.
Photo 26: Showing a bridge bearing for bridge at km 125+670
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3.6 BRIDGE AT KM 142+450(NEAR MWEIGA TOWNSHIP)The structure comprises a composite deck with 5 no. steel beams, wall type RC abutments and wing walls.
Photo 27: showing a side view of bridge at km 142+450
3.6.1 ABUTMENTS3.6.1.1 Visual inspection of the Abutments
Three vertical cracks running mid-way the height from the abutment cap were found on the Nyahururu side abutment. One of the cracks appeared approximately midway between the two RHS beam supports while the other one propagated from the centre beam support at the abutment cap downwards.
Photo 28: Showing a vertical crack on the abutment wall for bridge at km 142+450
The maximum crack width was 1.1 mm
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BRIDGE AT KM 142+450(NEAR MWEIGA TOWNSHIP)3.6.1.2 Steel Reinforcement details for the Abutments
The reinforcement details gathered through electromagnetic method revealed the distribution of the reinforcement bars in the abutment walls on either side of the bridge to be uniform in the vertical and horizontal directions. The vertical re-bars were 25 mm in diameter at an average spacing of 450mm while the horizontal were 16 mm diameter at an average spacing of 400 mm. The average covers were varying at different points on either abutment wall with the lowest at 27 mm and highest at 67 mm.
3.6.1.3 Concrete strength, quality and homogeneity for The Abutments
The concrete strength measured through rebound (Schmidt) hammer method recorded strengths of between 54 N/mm2 to 64 N/mm2.
The concrete matrix was homogeneous except for LHS of Nyahururu side, though with no visible defects on the surface. This infers the likelihood of internal defects within the concrete matrix at the tested location.
3.6.1.4 Crack depths
The crack depths were ultrasonically determined and found to be 42mm at the widest points.
3.6.1.5 Concrete Deterioration
The highest carbonation depth recorded was 7mm indicating a remaining good cover of 20mm (least cover recorded was 27mm).This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by high resistivity potential 111.5.
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BRIDGE AT KM 142+450(NEAR MWEIGA TOWNSHIP)3.6.2 DECK SLAB3.6.2.1 Visual inspection of the deck slab
Deck slab thickness was 200mm.There were longitudinal cracks propagating from both Nyeri side and Nyahururu side towards the middle of the span.
Photo 29: showing longitudinal cracks on the deck of bridge at km 142+450
There were also other multi directional cracks distributed on the deck slab soffit.
Maximum crack width was 1.0mm.
There was lime like substance on the surface of the deck slab soffit which appeared prominently along the location of the re-bars forming a similar pattern to that of the re-bars layout.
Photo 30: showing lime stains on the deck soffit
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BRIDGE AT KM 142+450(NEAR MWEIGA TOWNSHIP)3.6.2.3 Steel Reinforcement details for the Deck Slab
The reinforcement details gathered through electromagnetic method revealed the distribution of the reinforcement bars in the deck slab to be uniform in the longitudinal and transverse directions. The longitudinal re-bars were 20 mm diameter at an average spacing of 400mm while the transverse were 12 mm diameter at an average spacing of 300 mm. The average covers were 45mm and 33 mm for longitudinal and transverse re-bars respectively.
3.6.2.4 Concrete strength, quality and homogeneity for the Deck Slab
The concrete strength as measured through rebound (Schmidt) hammer method recorded an average strength of 53.3N/mm2 (see details at various point in table no....)
3.6.2.5 Crack depths
The crack depths were ultrasonically determined and found to be 65 mm at the widest points.
3.6.2.6 Concrete Deterioration
Two methods were employed i.e. carbonation and resistivity potential to indicate the level of deterioration of concrete.
The highest carbonation depth recorded was 6mm indicating a remaining good cover of 27mm .This was an indication of low level deterioration.
Probability of corrosion activity was insignificant as indicated by high resistivity potential of 111.3.
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BRIDGE AT KM 142+450(NEAR MWEIGA TOWNSHIP)3.6.3 WING WALLS3.6.3.1 Visual inspection of the Wing Walls
There were no visual structural defects on the wing walls
3.6.3.2 Steel Reinforcement Details for the Wing Walls
The reinforcement details gathered through electromagnetic method revealed the spacing of the reinforcement bars in the abutment walls on either side of the bridge not to be uniform in both vertical and horizontal directions varying between 300mm- 450mm and 400-450mm respectively. The vertical re-bars were 20 mm diameter while the horizontal were 16 mm diameter the average covers were varying at different points on either abutment with the lowest at 40 mm and the highest at 68 mm.
3.6.3.3 Concrete strength, quality and homogeneity for the wing walls
The concrete strength measured through rebound (Schmidt) hammer method recorded strengths between 55.0N/mm2 to 62.0 N/mm2.
The concrete matrix was slightly inhomogeneous as revealed through ultrasonic method.
3.6.4 STEEL GIRDERS 3.6.4.1 Visual inspection of Steel Girders
There were spots of paint peeling off on the beams signalling early stages of corrosion. The LHS girder had a large spot where paint had peeled off on the bottom flange.
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Photo 31: showing spots of paint peeling off from the steel girders
BRIDGE AT KM 142+450(NEAR MWEIGA TOWNSHIP)
There was accumulation of soil at the abutment caps covering the bottom flanges of the steel girders causing the paint to peel off resulting in early stages of corrosion.
The bolts and nuts for the joints were in good condition.
There were no critical welded joints.
3.6.4.2 Thickness tests
There was no delaminating of the plates as determined ultrasonically. The thicknesses for the flange and web plates were determined ultrasonically and found to be uniform.
3.6.5 BEARINGSThe bearing type was elastomeric of size 400x280x 30 mm and was in good condition.
Photo 32:showing a bridge bearing for bridge at km 142+450
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3.7 BRIDGE AT KM 173+120(MARUA)This is a three span structure comprising a composite deck with 4 no. steel girders for each span, column type RC abutments and column type RC piers
Photo 33: a side view of bridge at km 173+120
3.7.1 ABUTMENTS3.7.2 Visual Inspection of the abutments
The abutments could not be accessed due to gabion box protection works
Photo34: showing gabion boxes which prevented access to the abutment columns
3.7.3 DECK SLAB
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3.7.2.1 Visual Inspection of the Deck Slab
The deck slab is in good condition. No structural defects were visible
BRIDGE AT KM 173+120(MARUA)3.7.2.2 Steel Reinforcement details for the Deck Slab
The reinforcement details gathered through electromagnetic method revealed that the distribution of the reinforcement bars in the deck slab to be uniform in the longitudinal and transverse directions. The longitudinal re-bars were 16 mm diameter at an average spacing of 150mm while the transverse were 12 mm diameter at an average spacing of 130 mm. The average covers were 20 mm and 10mm for longitudinal re-bars and transverse re-bars respectively.
3.7.2.3 Concrete strength, quality and homogeneity for the Deck Slab
The concrete strength measured through rebound (Schmidt) hammer method recorded an average strength of between 30.0 N/mm2 and 55.0 N/mm2.
The concrete matrix was slightly inhomogeneous as revealed through ultrasonic method.
3.7.2.4 Concrete Deterioration of the Deck Slab
The highest carbonation depth recorded was 3mm indicating a remaining good cover of 4mm (least cover recorded was 6 mm).This was an indication of high level deterioration. It should be noted that the little balance of effective good cover is contributed to by small initial covers and not due to deep carbonation.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 111.4kΩcm.
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3.7.3 STEEL GIRDERS 3.7.3.1 Visual inspection of steel girders
The girders were generally in good condition along the spans. There was accumulation of soil through the expansion joint at the abutment caps which upon removal revealed a serious corrosion attack for the bottom flanges, mounting bolts, anchor plates and stiffening plates at the abutment caps supports.
BRIDGE AT KM 173+120(MARUA)The Nyeri side girders’ mounting bolts, stiffener plates and the anchor plates were severely corroded and had started to peel off. See photos below.
Photo 35: showing corrode mounting bolt and bottom flange plate
Photo 36: showing a corroded mounting bolts and a stiffening plate.
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Photo 37: showing corroded mounting bolt ,nut ,bottom flange plate and stiffener plate. Notice the peel off
BRIDGE AT KM 173+120(MARUA)Corrosion at early stages was also observed at the mid span joints.
See photo below
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Photo 38: showing corrosion at early stages at the midspan joint
3.7.4 PIER COLUMNS
3.7.4.1 Visual inspection of pier columns
The pier columns are generally in good condition.
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Photo 39: showing a column pier for bridge at km 173+120
BRIDGE AT KM 173+120(MARUA)3.7.4.2 Steel Reinforcement details for Pier Columns
There were 4 No. pier columns on either side of the river channel where the central span is suspended.The columns sizes were 450x600mm.The reinforcement details as gathered through electromagnetic method revealed 8 No.32mm diameter re-bars in each column. The average covers were varying at different points on the faces of the columns with the lowest at 18mm and highest at 36 mm.The links were spaced at 250mm.
3.7.4.3 Concrete strength, quality and homogeneity for Pier Columns
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The concrete strength measured through rebound (Schmidt) hammer method recorded average strengths of 32 N/mm2 and 45 N/mm2 for Nyeri side and 43.0N/mm2 and 55.0N/mm2 for Karatina side. The concrete matrix was generally homogeneous as revealed through ultrasonic method. The quality of concrete was also found to be good through direct transmission of mode of ultrasonic method where an average ultrasonic pulse velocity of 4.4 km/s was recorded.
3.7.4.4 Concrete Deterioration for Pier Columns
The highest carbonation depth recorded was 6 mm indicating a remaining good cover of 12mm (least cover recorded was 18mm).This was an indication of medium level deterioration.
Probability of corrosion activity was insignificant as indicated by a high resistivity potential of 111.4 kΩcm.
3.7.4.5 BEARINGS
The bearing type was found to be steel plate laminations which had started to corrode.
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photo 40& 41:showing laminated metallic bearing on the Nyeri side abutment cap support
4.0 CONCLUSIONSFrom the results obtained, the following conclusions can be made:
i. There is severe cracking of the deck slabs
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ii. The steel girders for the structures except bridge at km 173+120 are in good condition but may need repainting.
iii. The concrete strengths recorded for the structural elements are structurally okay.
iv. The concrete covers for the abutments and wing walls vary considerably at different points on these structural elements.
v. The danger of re-bar corrosion is minimal except at locations where the crack depths are greater than the concrete covers where water can get to the re-bars.
vi. There is adequate effective good cover for steel reinforcement bars-carbonation effect is minimal except forbridge at km 173+120 deck slab.
vii.The bearings for the structures are in good condition-except for bridge at km 173+120
viii. The deck slab forbridge at km 173+120 is in good conditionix. The steel girders for bridge at km 173+120(Marua Bridge) are
damaged by corrosion at the abutment capsupport. This is the same case with the mounting bolts and anchor plates-immediate attention is needed.
5.0 RECOMMENDATIONS1) An action plan is needed to address the following
i. Cracking on the deck slabs and abutmentsii. Damaged protection works for bridge at km125+670iii. Vandalism and theft of bracings for bridge at km 125+670iv. Lime accumulation for bridge at km 142+450.v. Severe corrosion of anchor plates, mounting bolts and bottom
flange edges at the abutment caps for bridge at km 173+120vi. Damage or lack of bearings for bridge at km 173+120
2) Development of a periodic inspection plan to monitor any further deterioration or performance of any rehabilitation worksthat may be implemented in response to no.1 above.
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3) The custodians of the structuresshould maintain proper records for the structures in future to enable comparison of status during inspection and original design requirements.
6.0 TESTS DONE
Seven tests were done namely:
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i) Visual Inspection to ascertain the extent of wear and tear of the structure.
ii) Ultrasonic Test to determine the homogeneity, quality, and internal defects in the concrete matrix.
iii) Ultrasonic test to determine steel plate thicknesses and test for delamination.
iv) Electromagnetic Test to establish the steel reinforcement details for reinforced concrete.
v) Schmidt Hammer Test to determine the concrete strength insitu.
vi) Carbonation test to determine the effective good cover to the reinforcement.
vii) Resistivity potential to determine the probability of corrosion of the re-bars.
4.1 Test Method Principles4.1.1 Visual InspectionVisual Inspection is used in maintenance of facilities, inspection of equipment and structures using either or all of human senses such as vision, hearing, touch and smell. Visual Inspection typically means inspection using human senses and/or any non-specialized inspection equipment.
4.1.2 Schmidt Hammer TestThis method is based on the principle that the rebound of an elastic mass depends on the hardness of the surface that it strikes. The rebound number obtained from the Schmidt Hammer is correlated with
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concrete cube crushing strength, whose calibration curves for 7 days and 28 days curing periods are contained in the digital instrument
4.1.3 Electromagnetic TestThis method is employed for locating steel in concrete using an Electromagnetic Covermeter. The principle method of test is by electromagnetic induction. When a probe carrying an alternating field is brought close to steel, eddy magnetic fields are generated by the steel, which reduces the primary field of the probe. At maximum induction level depicted by audio signals and reduction in minimum cover measurement, the location and orientation of a reinforcement bar can be established. After appropriate calibration, the technique is used to determine concrete cover, location and diameter of reinforcement bars (when reinforcement bars are parallel to the surface of the probe).Normally, closely packed reinforcement bars influence the accuracy of this method while determining the bar size. The accuracy of the method employed for bar size determination is ±2mm. 4.1.4 Ultrasonic Pulse velocity Test
The velocity of ultrasonic pulses traveling through a solid material depends on the density and the elastic properties of that material. Ultrasonic pulse velocity testing using low frequency pulses of 54 kHz is employed as a Non Destructive testing technique to determine the quality and homogeneity of concrete. This is given by the velocity at which the pulses will travel through the concrete. Regions of cracks or damaged material will have a corresponding reduction in the pulse velocity due to their high acoustic impedance.
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In this case two modes of transmission were employed namely:
a) Direct transmission to determine the pulse velocity in km/s hence the quality of concrete.
b) Indirect transmission method was employed to determine the homogeneity of concrete. A straight line graph of transit time against distance indicates a homogeneous concrete matrix. Deviations from the straight line are indications of inhomogeneity.
4.1.5 Carbonation Test.
The drilling method is used to determine the depth of carbonation. The drilled out material at prescribed depth is then analyzed for carbonation using phenolphthalein reagent. Presence of carbonation is depicted by no color change while the color changes to pink in the absence of carbonation.
A deterioration degree is judged based on the balance of carbonation depth as shown in the table below.
Based on this table, the degree of reinforcement corrosion is “None” for the results of tests having more than 30 mm depth for the balance of carbonation depth.
Table 2: Evaluation of Carbonation Depth
Deterioration degree
Balance of Carbonation Depth
Degree of reinforcement
corrosionHigh T < 0 mm Large
Medium 0 mm ≤ T < 10 mm MediumLow 10 mm≤ T < 30 mm LowNone 30 mm≤ T None
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4.1.6 Reinforcement Corrosion Investigation (Resistivity potential method)
The time at which corrosion of steel may commence and the rate at which it may proceed is dependent upon the properties of the cement paste and the permeability of the concrete. Since the electrical conductivity of concrete is an electrolysis process, which takes place by ionic movement in the aqueous pore solution of the cement matrix, it follows that a highly permeable concrete will have a high conductivity and low electrical resistance.
The knowledge of the electrical resistance of concrete can provide a measure of the possible corrosion of steel embedded in it as shown below
Table 3: Resistivity Level vs Possible Corrosion Rate
Resistivity Level(k ohm cm) Possible Corrosion Rate<5 Very high
5-10 high10-20 moderate to low>20 insignificant
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DETAILED RESULTS DATA SHEETS
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BRIDGE AT KM 60+030ABUTMENTSElectromagnetic test results for the abutments
Test Element/Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Abutment wall
Thickness(mm)
A1 –Nyeri Side
At abutment cap
LHS Vertical:350Horizontal:400
Vertical:45Horizontal:65
Vertical:25Horizontal:16
700
Centre Vertical:450Horizontal:400
Vertical:42Horizontal:63
Vertical:25Horizontal:16
RHS Horizontal:480Horizontal: 400
Vertical: 35Horizontal:60
Vertical: 25Horizontal:16
Along the middle line
LHS Vertical:350Horizontal:450
Vertical:45Horizontal:60
Vertical:25Horizontal:16
Centre Vertical:450Horizontal:400
Vertical:36Horizontal:60
Vertical:25Horizontal:16
RHS Horizontal:480Horizontal: 400
Vertical: 35Horizontal:60
Vertical: 25Horizontal:16
A2 –Nyahururu Side
At abutment cap
LHS Vertical:450Horizontal:500
Vertical:45Horizontal:75
Vertical:25Horizontal:16
Centre Vertical:400Horizontal:470
Vertical:35Horizontal:65
Vertical:25Horizontal:16
RHS Horizontal:380Horizontal:450
Vertical: 61Horizontal:33
Vertical:25Horizontal:16
Along the middle line
LHS Vertical:450Horizontal:420
Vertical: 52Horizontal:66
Vertical: 25Horizontal:16
Centre Vertical:400Horizontal:400
Vertical:38Horizontal:73
Vertical:25Horizontal:16
RHS Horizontal:400Horizontal:400
Vertical: 33Horizontal:71
Vertical:25Horizontal:16
Schmidt Hammer Test Results for the Abutments
Test Element/LocationAverage concrete
strength (N/mm2)
A1 –Nyeri SideAt abutment cap
LHS 49.5Centre 53.1
RHS 53.1
Along the middle line
LHS 41.3Centre 44.1
RHS 44.0
A2 –Nyahururu Side
At abutment capLHS 54.0
Centre 48.0RHS 44.0
Along the middle line
LHS 48.0Centre 43.0
RHS 45.0
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BRIDGE AT KM 60+030Ultrasonic Pulse Velocity Results for the Abutments
Test Element/Location Homogeneity of concrete matrix
A1 –Nyeri Side
LHS Homogeneous Centre Homogeneous
RHS HomogeneousLHS Homogeneous
Centre HomogeneousRHS Homogeneous
A2 –Nyahururu Side
LHS HomogeneousCentre Homogeneous
RHS HomogeneousLHS Homogeneous
Centre HomogeneousRHS Homogeneous
Carbonation Test Results for the AbutmentsTest
Element/LocationCarbonation
depth(mm)
Least cover recorded
(mm)
Balance of carbonation
depth(mm)
Remarks
A1-Nyeri side 6 35 29Low
deterioration degree
A2-Nyahururu side 6 33 27
Resistivity Test Results for the AbutmentsTest
Element/LocationResistivity
(kΩcm)Remarks
A1-Nyeri side 111.3 Probability of corrosion is insignificant
A2-Nyahururu side 111.5
Crack Profiles for the AbutmentsTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
A1-Nyeri sideCr.1 Full height of the
abutment wall1.4 160
Cr.2 Full height of the abutment wall
0.8 76
A2-Nyahururuside
Cr.1 Full height of the abutment wall 0.8 70
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BRIDGE AT KM 60+030DECK SLABElectromagnetic Test Results for the Deck Slab
Test Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Deck slab Thickness
(mm)
DS1-Nyeri Side Longitudinal:400Transverse:300
Longitudinal:50Transverse:35
Longitudinal:20Transverse:16
250DS3-Nyahururu side
Longitudinal:400Transverse:300
Longitudinal:55Transverse:37
Longitudinal:20Transverse:16
Schmidt hammer Test Results for the Deck Slab
Test LocationAverage concrete strength
(N/mm2)
DS1-Nyeri Side 56.1
DS2 –Mid Span 59.6DS3-Nyahururu side
62.0
Ultrasonic Pulse Velocity Results for the Deck SlabTest Element/Location Homogeneity of concrete matrix
DS1-Nyeri SideNot homogenous-transmission of ultrasonic pulses not consistent
DS2-Nyahururu side Not homogenous-transmission of ultrasonic pulses not consistent
Carbonation Test Results for the Deck SlabTest
Element/Location
Carbonation depth(mm)
Least cover recorded
(mm)
Balance of carbonation
depth(mm)
Remarks
DS1-Nyeri Side 6 35 29Low deterioration degree
DS3-Nyahururu side 6 37 31
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BRIDGE AT KM 60+030DECK SLABResistivity Test Results for the Deck Slab
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
DS1-Nyeri Side111.2
Probability of corrosion is insignificantDS2-Nyahururu
side109.1
Crack profiles For the Deck SlabTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
DS1-Nyeri side Cr.1 9.9-Full width 1.0 Through crackDS3-Nyahururu side
Cr.1 9.9-Full width 1.0 Through crack
WING WALLSElectromagnetic Test Results for the Wing Walls
Test Element/Location
Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Nyeri Side LHS Vertical:380Horizontal:460
Vertical:39Horizontal:53
Vertical:20Horizontal:16
Nyahururu Side LHS
Vertical:480Horizontal:470
Vertical:45Horizontal:60
Vertical:20Horizontal:16
Schmidt Hammer Test Results for the Wing Walls
Test Element/LocationAverage concrete strength
(N/mm2)Nyeri Side
LHS 56.0
Nyahururu Side LHS 60.0
Ultrasonic Pulse Velocity Results for the Wing WallsTest Element/Location Homogeneity of concrete
matrix
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Nyeri Side LHS Homogeneous
Nyahururu Side LHS
BRIDGE AT KM 60+030Carbonation Test Results for the Wing Walls
Test Element/Locatio
n
Carbonation depth(mm)
Least cover recorded
(mm)
Balance of carbonation
depth(mm)
Remarks
Nyeri side 6 26 20Low deterioration degreeNyahururu side
6 31 25
Resistivity test results for the Wing WallsTest
Element/Location
Resistivity (kΩcm)
Remarks
Nyeri side 110.2Probability of corrosion is insignificant
Nyahururu side108.2
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 60+030STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination for steel girders
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 LHSNo Delamination
SG2 LHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.7
13.7
600
MTRD ICT
BRIDGE AT KM 60+030STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination for steel girders
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG3 CentreNo Delamination
SG2 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.6
14.5
600
22.4
14.0
600
MTRD ICT
BRIDGE AT KM 60+030STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination for steel girders
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.5
14.0
600
MTRD ICT
BRIDGE AT KM 84+520-NDARAGWAABUTMENTSElectromagnetic test results for the abutments
Test Element/Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Abutment wall
Thickness
(mm)
A1 –Nyeri Side
At abutment cap
LHS Vertical:500Horizontal:450
Vertical:45Horizontal:66
Vertical:25Horizontal:16
770Centre Vertical:470Horizontal:370
Vertical:40Horizontal:60
Vertical:25Horizontal:16
RHS Vertical:480Horizontal:360
Vertical:36Horizontal:54
Vertical:25Horizontal:16
Along the middle line
LHS Vertical:500Horizontal:400
Vertical:40Horizontal:60
Vertical:25Horizontal:16
Centre Vertical:520Horizontal:400
Vertical:40Horizontal:60
Vertical:25Horizontal:16
RHS Vertical:480Horizontal:400
Vertical:37Horizontal:60
Vertical:25Horizontal:16
A2 –Nyahururu Side
At abutment cap
LHS Vertical:450Horizontal:400
Vertical:45Horizontal:65
Vertical:25Horizontal:16
770
Centre Vertical:400Horizontal:440
Vertical:37Horizontal:60
Vertical:25Horizontal:16
RHS Vertical:500Horizontal:400
Vertical:35Horizontal:60
Vertical:25Horizontal:16
Along the middle line
LHS Vertical:450Horizontal:380
Vertical:40Horizontal:65
Vertical:25Horizontal:16
Centre Vertical:400Horizontal:450
Vertical:36Horizontal:60
Vertical:25Horizontal:16
RHS Vertical:500Horizontal:400
Vertical:36Horizontal:60
Vertical:25Horizontal:16
Schmidt Hammer Test Results for the Abutments
Test Element/LocationAverage concrete
strength (N/mm2)
A1 –Nyeri SideAt abutment cap
LHS 51.7Centre 41.1
RHS 54.9
Along the middle line
LHS 54.1Centre 48.8
RHS 53.8
A2 –Nyahururu Side
At abutment capLHS 48.1
Centre 55.7RHS 52.5
Along the middle line
LHS 57.6Centre 53.3
RHS 54.9
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 84+520Ultrasonic Pulse Velocity Results for the Abutments
Test Element/Location Homogeneity of concrete matrix
A1 –Nyeri Side
LHS HomogeneousCentre Homogeneous
RHS HomogeneousLHS Homogeneous
Centre HomogeneousRHS Homogeneous
A2 –Nyahururu Side
LHS HomogeneousCentre Homogeneous
RHS HomogeneousLHS Homogeneous
Centre HomogeneousRHS Homogeneous
Carbonation Test Results for the AbutmentsTest
Element/Location
Carbonation depth(mm)
Least cover
recorded
(mm)
Balance of carbonatio
n depth(mm)
Remarks/deterioration degree
A1-Nyeri side 3 32 29 Low A2-Nyahururu side 3 36 33 None
Resistivity Test Results for the AbutmentsTest
Element/LocationResistivity
(kΩcm)Remarks
A1-Nyeri side111.7
Probability of corrosion is insignificantA2-Nyahururu side 111.5
Crack Profiles for the AbutmentsTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
A1-Nyeri side Cr.1 2000 0.8 25A2-Nyahururuside
Cr.1 1500 1.0 27Cr.2 1500 0.6 22
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 84+520DECK SLABElectromagnetic Test Results for the Deck Slab
Test Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Deck slab Thickness
(mm)
DS1-Nyeri Side Longitudinal:400Transverse:300
Longitudinal:45Transverse:27
Longitudinal:20Transverse:16
220DS3-Nyahururu side
Longitudinal:400Transverse:300
Longitudinal:45Transverse:34
Longitudinal:20Transverse:16
Schmidt hammer Test Results for the Deck Slab
Test LocationAverage concrete strength
(N/mm2)
DS1-Nyeri Side 46.0
DS2-Nyahururu side 47.9
Ultrasonic Pulse Velocity Results for the Deck SlabTest Element/Location Homogeneity of concrete matrix
DS1-Nyeri SideSlightly inhomogeneous
DS2-Nyahururu side Slightly inhomogeneous
Carbonation Test Results for the Deck SlabTest
Element/Location
Carbonation depth(mm)
Least cover recorded
(mm)
Balance of carbonation
depth(mm)
Remarks/degree of
deterioration
DS1-Nyeri Side 3 24 21 lowDS2-Nyahururu
side 3 33 30 low
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 84+520DECK SLABResistivity Test Results for the Deck Slab
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
DS1-Nyeri Side 110.7 Probability of corrosion is insignificantDS3-Nyahururu
side 110.9
Crack Profiles for the Deck SlabTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
DS1-Nyeri side Cr.1 Full width 1.2Through cracksCr.2 Full width 1.0
DS2-Nyahururu side
Cr.1 Full width 1.2Cr.2 Full width 1.2
WING WALLSElectromagnetic Test Results for the Wing Walls
Test Element/LocationRe-bar spacing
(mm)Average covers(mm)
Re-bar size(mm)
Nyeri Side RHSVertical:470
Horizontal:450Vertical:40
Horizontal:61Vertical:20
Horizontal:16
Nyahururu Side LHSVertical:350
Horizontal:260,370Vertical:60
Horizontal:75Vertical:20
Horizontal:16
Schmidt Hammer Test Results for the Wing Walls
Test Element/LocationAverage concrete strength
(N/mm2)
Nyeri SideRHS 56.4
LHS 54.0
Nyahururu Side
LHS 53.9
RHS 55.0
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 84+520Ultrasonic Pulse Velocity Results for the Wing Walls
Test Element/Location Homogeneity of concrete matrix
Nyeri SideLHS Homogeneous
RHS Homogeneous
Nyahururu Side LHS Homogeneous
RHS Homogeneous
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 84+520STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 LHSNo Delamination
SG2 LHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
23.5
14.2600
23.7
14.2
600
MTRD ICT
BRIDGE AT KM 84+520STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG3 CentreNo Delamination
SG2 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.6
14.3600
22.3
14.1
600
MTRD ICT
BRIDGE AT KM 84+520STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.4
13.9600
MTRD ICT
BRIDGE AT KM 84+520PIER COLUMNSElectromagnetic Test Results for the Pier Columns
Test element /location
Column Size(mm), No. & Arrangement of re-bars
Re-bar size
(mm)
Average covers(mm)
Link Details(mm)
PC 1-Nyeri sideLHS 32
Side A:50Side B:63Side C:70Side D:55
size:10Spacing:300
PC 2-Nyeri sideRHS 32
Side A:53Side B:56Side C:56Side D:50
size:10Spacing:300
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
D
200 200
250250
600
750
A
B
C
D
D
200 200
250250
600
750
A
B
C
D
MTRD ICT
BRIDGE AT KM 84+520Test
element /location
Column Size(mm), No. & Arrangement of re-bars
Re-bar size
(mm)
Average covers(mm)
Link Details(mm)
PC 1-Nyahururu
sideLHS
32Side A:58Side B:56Side C:51Side D:60
size:10Spacing:300
PC 1-Nyahururu
sideLHS
32Side A:55Side B:56Side C:50Side D:50
size:10Spacing:300
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
B
D
200 200
250250
600
750
A
B
C
D
MTRD ICT
BRIDGE AT KM 84+520Schmidt Hammer Test Results for the Pier Columns
Test Element/LocationAverage concrete strength
(N/mm2)
Nyeri SideRHS 55.0
LHS 61.6
Nyahururu Side
LHS 48.0
RHS 54.0
Ultrasonic Pulse Velocity Results for the Pier Columns for homogeneityTest Element/Location Homogeneity of concrete matrix
Nyeri Side
LHS Homogeneous
RHS Homogeneous
Nyahururu Side LHSHomogeneous
RHSHomogeneous
Ultrasonic Pulse Velocity Results for the Pier Columns for quality of concrete
Test Element/LocationTransit
time(µs)
Distance (mm)
Pulse velocity(km/s)
remarks
Nyeri SideLHS 144 600 4.16 Good quality
concreteRHS 148 600 4.05
Nyahururu Side LHS 137 600 4.40
RHS 142 600 4.22
Carbonation Test Results for the Pier ColumnsTest
Element/Location
Carbonation depth(mm)
Least cover
recorded
(mm)
Balance of carbonatio
n depth(mm)
Remarks/deterioration degree
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Nyeri side 3 49 46 None Nyahururu side
3 40 37
BRIDGE AT KM 84+520Resistivity Test Results for the Pier Columns
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
Nyeri side111.6
Probability of corrosion is insignificantNyahururu side
111.6
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 93+380ABUTMENTSElectromagnetic Test Results for the Abutments
Test Element/Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Abutment wall
Thickness(mm)
A1 –Nyeri Side
At abutment cap
LHS Vertical:450Horizontal:400
Vertical:30Horizontal:55
Vertical:25Horizontal:16
700
Centre Vertical:450Horizontal:500
Vertical:32Horizontal:55
Vertical:25Horizontal:16
RHS vertical:450Horizontal:440
Vertical:40Horizontal:65
Vertical:25Horizontal:16
Along the middle line
LHS Vertical:450Horizontal:400
Vertical:40Horizontal:70
Vertical:25Horizontal:16
Centre Vertical:450Horizontal:400
Vertical:36Horizontal:50
Vertical:25Horizontal:16
RHS Vertical :450Horizontal:420
Vertical:40Horizontal:65
Vertical:25Horizontal:16
A2 –Nyahururu Side
At abutment cap
LHS Vertical:430Horizontal:400
Vertical:28Horizontal:55
Vertical:25Horizontal:16
700
Centre Vertical:440Horizontal:400
Vertical:35Horizontal:60
Vertical:25Horizontal:16
RHS Vertical :450Horizontal:400
Vertical:54Horizontal:72
Vertical:25Horizontal:16
Along the middle line
LHS Vertical:450Horizontal:400
Vertical:30Horizontal:55
Vertical:25Horizontal:16
Centre Vertical:440Horizontal:400
Vertical:30Horizontal:55
Vertical:25Horizontal:16
RHS Vertical :450Horizontal:400
Vertical:40Horizontal:66
Vertical:25Horizontal:16
Schmidt Hammer Test Results for the Abutments
Test Element/LocationAverage concrete
strength (N/mm2)
A1 –Nyeri SideAt abutment cap
LHS 45.5Centre 60.3
RHS 43.2
Along the middle line
LHS 57.6Centre 43.8
RHS 44.2
A2 –Nyahururu At abutment cap
LHS 40.1Centre 58.7
RHS 48.2
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Side Along the middle line
LHS 51.1Centre 56.2
RHS 45.8
BRIDGE AT KM 93+380ABUTMENTSUltrasonic Pulse Velocity Results for the Abutments
Test Element/Location Homogeneity of concrete matrix
A1 –Nyeri Side
LHS Homogeneous Centre Homogeneous
RHS HomogeneousRHS Homogeneous
A2 –Nyahururu Side
LHS HomogeneousCentre Homogeneous
RHS HomogeneousCentre Homogeneous
RHS Homogeneous
Carbonation Test Results for the AbutmentsTest
Element/Location
Carbonation depth(mm)
Least cover
recorded
(mm)
Balance of carbonatio
n depth(mm)
Remarks/deterioration degree
A1-Nyeri side 5 30 25 Low A2-Nyahururu side 5 28 23 Low
Resistivity Test Results for the AbutmentsTest
Element/LocationResistivity
(kΩcm)Remarks
A1-Nyeri side110.8
Probability of corrosion is insignificantA2-Nyahururu side 110.4
Crack Profiles for the AbutmentsTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
A1-Nyeri sideCr.1 Full height of
abutment wall 1.0 61
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Cr.2 Full height of abutment wall 1.0 60
Cr.3 Full height of abutment wall 0.8 48
Cr.4 Full height of abutment wall 0.6 40
BRIDGE AT KM 93+380Crack Profiles for the Abutments
Test Element/Locatio
n
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
A2-Nyahururuside
Cr.1 Full height of abutment wall
1.055
Cr.2 Full height of abutment wall 1.0 41
Cr,3 Full height of abutment wall 0.6 33
DECK SLABElectromagnetic Test Results for the Deck Slab
Test Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Deck slab Thickness
(mm)
DS1-Nyeri Side Longitudinal:400Transverse:300
Longitudinal:54Transverse:34
Longitudinal:20Transverse:16
200DS2 –Mid Span
Longitudinal:400Transverse:300
Longitudinal:35Transverse:50
Longitudinal:20Transverse:16
DS3-Nyahururu side
Longitudinal:400Transverse:300
Longitudinal:34Transverse:48
Longitudinal:20Transverse:16
Schmidt Hammer Test Results for the Deck Slab
Test LocationAverage concrete strength
(N/mm2)
DS1-Nyeri Side 54.5
DS2 –Mid Span 56.6
DS3-Nyahururu side 56.1
Ultrasonic Pulse Velocity Results for the Deck SlabTest Element/Location Homogeneity of concrete matrix
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
DS1-Nyeri SideHomogeneous
DS2 –Mid SpanHomogeneous
DS3-Nyahururu side Homogeneous
BRIDGE AT KM 93+380Carbonation Test Results for the Deck Slab
Test Element/Locatio
n
Carbonation depth(mm)
Least cover
recorded(mm)
Balance of carbonation
depth(mm)
Remarks/degree of
deterioration
DS1-Nyeri Side 5 34 29 Low
DS2 –Mid Span 5 35 30DS3-Nyahururu
side 5 34 29
DECK SLABResistivity Test Results for the Deck Slab
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
DS1-Nyeri Side 106.8 Probability of corrosion is insignificant
DS2 –Mid Span 108.8DS3-Nyahururu
side 110.2
Crack profiles For the Deck SlabTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
DS1-Nyeri side Cr.1 11600-full width 1.0 Through crackDS3-Nyahururu side
Cr.1 11600-full width 1.0 Through crack
WING WALLSElectromagnetic Test Results for the Wing WallsDETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Test Element/LocationRe-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Nyeri Side LHSVertical:450Horizontal:350
Vertical:37Horizontal:60
Vertical:20Horizontal:16
Nyahururu Side RHSVertical:450Horizontal:350
Vertical:45Horizontal:68
Vertical:20Horizontal:16
BRIDGE AT KM 93+380Schmidt Hammer Test Results for the Wing Walls
Test Element/LocationAverage concrete strength
(N/mm2)
Nyeri Side LHS 57.9
RHS 57.7
Nyahururu Side RHS 65.0
LHS 60.2
Ultrasonic Pulse Velocity Results for the Wing WallsTest Element/Location Homogeneity of concrete matrix
Nyeri SideLHS
Homogeneous
RHSHomogeneous
Nyahururu Side LHSHomogeneous
RHSHomogeneous
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 93+380STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 LHSNo Delamination
SG2 LHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.1
14.2
600
22.0
14.2
600
MTRD ICT
BRIDGE AT KM 93+380Steel Girder
No.Section Dimensions
(mm)Continuity Across
Plate Thickness
SG3 CentreNo Delamination
SG2 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.5
14.0
600
22.4
14.2
600
MTRD ICT
BRIDGE AT KM 93+380Steel Girder
No.Section Dimensions
(mm)Continuity Across
Plate Thickness
SG1 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.1
14.0
600
MTRD ICT
BRIDGE AT KM 102+510ABUTMENTSElectromagnetic Test Results for the Abutments
Test Element/LocationRe-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Abutment wall
Thickness(mm)
A1 –Nyeri Side
LHS Vertical:450Horizontal:400
Vertical:45Horizontal:60
Vertical:25Horizontal:16
Centre Vertical:450Horizontal:400
Vertical:40Horizontal:50
Vertical:25Horizontal:16
RHS vertical:450Horizontal:400
Vertical:26Horizontal:57
Vertical:25Horizontal:16
A2 –Nyahururu Side
LHS Vertical:450Horizontal:400
Vertical:40Horizontal:55
Vertical:25Horizontal:16
Centre Vertical:450Horizontal:400
Vertical:37Horizontal:51
Vertical:25Horizontal:16
RHS vertical:450Horizontal:400
Vertical:30Horizontal:55
Vertical:25Horizontal:16
Schmidt Hammer Test Results for the Abutments
Test Element/LocationAverage concrete strength
(N/mm2)
A1 –Nyeri Side
LHS 59.1Centre 57.7
RHS 51.0Side A2 –Nyahururu
LHS 40.8Centre 52.4
RHS 55.8
ABUTMENTSUltrasonic Pulse Velocity Results for the Abutments
Test Element/Location Homogeneity of concrete matrix
A1 –Nyeri Side
LHS Homogeneous Centre Homogeneous
RHS Homogeneous
A2 –Nyahururu Side
LHS HomogeneousCentre Homogeneous
RHS Homogeneous
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 102+510Carbonation Test Results for the Abutments
Test Element/Location
Carbonation depth(mm)
Least cover
recorded(mm)
Balance of carbonation
depth(mm)
Remarks/deterioration degree
A1-Nyeri side 4 26 22Low
A2-Nyahururu side 4 30 26 Low
Resistivity Test Results for the AbutmentsTest
Element/LocationResistivity
(kΩcm)Remarks
A1-Nyeri side110.8
Probability of corrosion is insignificant
A2-Nyahururu side 110.8
Crack Profiles for the AbutmentsTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
A1-Nyeri side Cr.1 1400 0.4 20Cr.2 1400 0.7 33Cr.3 1400 1.2 42Cr.4 1400 1.2 40
A2-Nyahururuside
Cr.1 2000 0.8 35Cr.2 2000 1.0 38
DECK SLABElectromagnetic Test Results for the Deck Slab
Test Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Deck slab Thickness
(mm)
DS1-Nyeri Side Longitudinal:400Transverse:300
Longitudinal:45Transverse:30
Longitudinal:20Transverse:16 200
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
DS2 –Mid SpanLongitudinal:400Transverse:300
Longitudinal:45Transverse:60
Longitudinal:20Transverse:16
DS3-Nyahururu side
Longitudinal:400Transverse:300
Longitudinal:33Transverse:45
Longitudinal:20Transverse:16
BRIDGE AT KM 102+510Schmidt hammer Test Results for the Deck Slab
Test LocationAverage concrete strength
(N/mm2)
DS1-Nyeri Side 55.4
DS2 –Mid Span 57.7DS3-Nyahururu side
54.6
Ultrasonic Pulse Velocity Results for the Deck SlabTest Element/Location Homogeneity of concrete matrix
DS1-Nyeri SideInhomogeneous
DS2 –Mid SpanInhomogeneous
DS3-Nyahururu side Inhomogeneous
Carbonation Test Results for the Deck SlabTest
Element/Location
Carbonation depth(mm)
Least cover
recorded(mm)
Balance of carbonation
depth(mm)
Remarks/deterioration degree
DS1-Nyeri Side 5 30 25 Low
DS2 –Mid Span 5 45 40None
DS3-Nyahururu side 5 33 28
None
DECK SLABResistivity Test Results for the Deck Slab
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
DS1-Nyeri Side110.8
Probability of corrosion is insignificant
DS2 –Mid Span110.8
DS3-Nyahururu side
110.8
BRIDGE AT KM 102+510Crack profiles For the Deck Slab
Test Element/Locatio
n
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
DS1-Nyeri side Cr.1 Full width of the deck
0.8 Through
DS3-Nyahururu side
Cr.1 Full width of the deck
0.8 Through
WING WALLSElectromagnetic Test Results for the Wing Walls
Test Element/LocationRe-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Nyeri Side RHSVertical:500Horizontal:400
Vertical: 29Horizontal:50
Vertical: 20Horizontal:16
Nyahururu Side LHSVertical:500Horizontal:450
Vertical: 35Horizontal:55
Vertical: 20Horizontal:16
Schmidt Hammer Test Results for the Wing Walls
Test Element/LocationAverage concrete strength
(N/mm2)
Nyeri SideRHS
59.1
LHS60.1
Nyahururu Side
LHS48.8
RHS55.8
Ultrasonic Pulse Velocity Results for the Wing WallsTest Element/Location Homogeneity of concrete matrix
Nyeri Side
LHS Homogeneous
RHS HomogeneousHomogeneous
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Nyahururu Side LHS
RHSHomogeneous
BRIDGE AT KM 102+510STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 LHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
SG2 LHSNo Delamination
BRIDGE AT KM 102+510Steel Girder
No.Section Dimensions
(mm)Continuity Across
Plate Thickness
SG3 CentreNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.7
14.1
600
21.9
14.3
600
MTRD ICT
SG2 RHSNo Delamination
BRIDGE AT KM 102+510Steel Girder
No.Section Dimensions
(mm)Continuity Across
Plate Thickness
SG1 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.4
14.0
600
MTRD ICT
BRIDGE AT KM 125+670DECK SLABElectromagnetic Test Results for the Deck Slab
Test Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Deck slab Thickness
(mm)
DS1-Nyeri Side Longitudinal:400Transverse:300
Longitudinal:45Transverse:32
Longitudinal:20Transverse:12
200DS2 –Mid Span
Longitudinal:400Transverse:300
Longitudinal:45Transverse:25
Longitudinal:20Transverse:12
DS3-Nyahururu side
Longitudinal:400Transverse:300
Longitudinal:51Transverse:38
Longitudinal:20Transverse:12
Schmidt Hammer Test Results for the Deck Slab
Test LocationAverage concrete strength
(N/mm2)
DS1-Nyeri Side 40.2
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
DS2 –Mid Span 43.4DS3-Nyahururu side
46.5
Ultrasonic Pulse Velocity Results for the Deck SlabTest Element/Location Homogeneity of concrete matrix
DS1-Nyeri SideInhomogeneous
DS2 –Mid SpanInhomogeneous
DS3-Nyahururu side Inhomogeneous
Carbonation Test Results for the Deck SlabTest
Element/Location
Carbonation depth(mm)
Least cover
recorded
(mm)
Balance of carbonatio
n depth(mm)
Remarks/deterioration degree
DS1-Nyeri Side 4 25 21Low
DS2-Nyahururu side 4 38 34
None
BRIDGE AT KM 102+510DECK SLABResistivity Test Results for the Deck Slab
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
DS1-Nyeri Side112.3
Probability of corrosion is insignificant
DS2 –Mid Span 118.8DS2-Nyahururu
side 110.8
Crack Profiles for the Deck SlabTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
DS1-Nyeri side Cr.1 Full width of the deck
1.0
Through cracks
Cr.2 Full width of deck
1.0
DS2-Mid span Cr.1 Full width of deck
0.8
Cr.2 Full width of deck
1.0
DS3-Nyahururu side
Cr.1 Full width of deck
1.0
Cr.2 Full width of deck
1.0
BRIDGE AT KM 102+510STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
SG1 LHSNo Delamination
SG2 LHSNo Delamination
BRIDGE AT KM 102+510Ultrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
22.5
13.5
600
MTRD ICT
SG3 CentreNo Delamination
SG2 RHSNo Delamination
BRIDGE AT KM 102+510Ultrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
21.5
13.4
600
MTRD ICT
SG1 RHSNo Delamination
BRIDGE AT KM 102+510PIER WALLSElectromagnetic Test Results for the Pier Walls
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Test Element/LocationRe-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Pier wall Thickness
(mm)
Nyeri SideRHS
Vertical:300Horizontal:450
Vertical: 53Horizontal:67
Vertical:25 Horizontal:16
600
Centre Vertical:300Horizontal:450
Vertical: 48Horizontal:69
Vertical: 25Horizontal:16
LHS Vertical:300Horizontal:450
Vertical:55Horizontal:67
Vertical:25Horizontal:16
Nyahururu Side
LHSVertical:300Horizontal:450
Vertical: 42Horizontal:57
Vertical: 25Horizontal:16
Centre Vertical:300Horizontal:450
Vertical: 52Horizontal:66
Vertical: 25Horizontal:16
RHS Vertical:300Horizontal:450
Vertical:50Horizontal:64
Vertical:25Horizontal:16
Schmidt Hammer Test Results for the Pier Walls
Test Element/LocationAverage concrete strength
(N/mm2)
Nyeri Side
RHS 50.0
Centre 52.4
LHS 51.0
Nyahururu Side
LHS 53.8
Centre 56.4
RHS48.1
Ultrasonic Pulse Velocity Results for the Pier WallsTest Element/Location Homogeneity of concrete matrix
Nyeri Side
LHS Homogeneous
Centre Homogeneous
RHS Homogeneous
Nyahururu SideLHS
Homogeneous
Centre Homogeneous
RHSHomogeneous
BRIDGE AT KM 102+510Ultrasonic Pulse Velocity Results for the Pier walls for quality of concrete
Test Element/Location Transit time
Distance (mm)
Pulse velocity(km/s)
Remarks
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
(µs)
Nyeri Side LHS 133 600 4.5 Good quality concrete
Nyahururu Side LHS 139 6004.3
Carbonation Test Results for the Pier WallsTest
Element/Location
Carbonation depth(mm)
Least cover
recorded(mm)
Balance of carbonation
depth(mm)
Remarks/deterioration degree
Nyeri side 8 48 40None
Nyahururu side 4 42 38None
Resistivity Test Results for the Pier WallsTest
Element/Location
Resistivity(kΩcm)
Remarks
Nyeri side 111.3 Probability of corrosion is insignificant
Nyahururu side 112.3
BRIDGE AT KM 142+450ABUTMENTS
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Electromagnetic Test Results for the Abutments
Test Element/LocationRe-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Abutment wall
Thickness(mm)
A1 –Nyeri Side
LHS Vertical:450Horizontal:400
Vertical:27Horizontal:50
Vertical:25Horizontal:16
900Centre Vertical:450Horizontal:400
Vertical:27Horizontal:50
Vertical:25Horizontal:16
RHS vertical:450Horizontal:400
Vertical:26Horizontal:57
Vertical:25Horizontal:16
A2 –Nyahururu Side
LHS Vertical:450Horizontal:400
Vertical:42Horizontal:60
Vertical:25Horizontal:16
900Centre Vertical:430Horizontal:420
Vertical:36Horizontal:55
Vertical:25Horizontal:16
RHS vertical:450Horizontal:400
Vertical:41Horizontal:67
Vertical:25Horizontal:16
Schmidt Hammer Test Results for the Abutments
Test Element/LocationAverage concrete strength
(N/mm2)
A1 –Nyeri Side
LHS 60.8Centre 64.8
RHS 63.9Side A2 –Nyahururu
LHS 60.7Centre 60.9
RHS 54.6
ABUTMENTSUltrasonic Pulse Velocity Results for the Abutments
Test Element/Location Homogeneity of concrete matrix
A1 –Nyeri Side
LHS Homogeneous Centre Homogeneous
RHS Homogeneous
A2 –Nyahururu Side
LHS HomogeneousCentre Homogeneous
RHS Homogeneous
BRIDGE AT KM 142+450Carbonation Test Results for the Abutments
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Test Element/Location
Carbonation depth(mm)
Least cover
recorded(mm)
Balance of carbonation
depth(mm)
Remarks/deterioration degree
A1-Nyeri side 7 26 19Low
A2-Nyahururu side 7 30 23 Low
Resistivity Test Results for the AbutmentsTest
Element/LocationResistivity
(kΩcm)Remarks
A1-Nyeri side111.8
Probability of corrosion is insignificant
A2-Nyahururu side 111.3
Crack Profiles for the AbutmentsTest
Element/Location
Crack no.
Crack length(mm)
Crack width(mm)
Crack depth(mm)
A1-Nyeri side Cr.1 3500 1.2 41Cr.2 3500 1.2 42Cr.3 2000 1.0 30
DECK SLABElectromagnetic Test Results for the Deck Slab
Test LocationRe-bar spacing
(mm)Average covers(mm)
Re-bar size(mm)
Deck slab Thickness
(mm)DS1-Nyeri Side Longitudinal:400
Transverse:300Longitudinal:41Transverse:29
Longitudinal:20Transverse:12
200DS2 –Mid Span
Longitudinal:400Transverse:300
Longitudinal:47Transverse:33
Longitudinal:20Transverse:12
DS3-Nyahururu side
Longitudinal:400Transverse:300
Longitudinal:45Transverse:30
Longitudinal:20Transverse:12
BRIDGE AT KM 142+450Schmidt hammer Test Results for the Deck SlabDETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Test LocationAverage concrete strength
(N/mm2)
DS1-Nyeri Side 53.3
DS2 –Mid Span52.1
DS3-Nyahururu side 48.8
Ultrasonic Pulse Velocity Results for the Deck SlabTest Element/Location Homogeneity of concrete matrix
DS1-Nyeri SideInhomogeneous
DS2 –Mid SpanInhomogeneous
DS3-Nyahururu side Inhomogeneous
Carbonation Test Results for the Deck SlabTest
Element/Location
Carbonation depth(mm)
Least cover
recorded
(mm)
Balance of carbonatio
n depth(mm)
Remarks/deterioration degree
DS1-Nyeri Side 6.0 29 23 Low DS3-Nyahururu
side 6.0 30 24 Low
DECK SLABResistivity Test Results for the Deck Slab
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
DS1-Nyeri Side110.0
Probability of corrosion is insignificant
DS2 –Mid Span 111.3DS3-Nyahururu
side 111.1
BRIDGE AT KM 142+450
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
WING WALLSElectromagnetic Test Results for the Wing Walls
Test Element/LocationRe-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Nyeri Side LHS Vertical:300Horizontal:300
Vertical:68Horizontal:45
Vertical:20Horizontal:6
Nyahururu Side LHSVertical:450
Horizontal:450Vertical:33
Horizontal:45Vertical:20
Horizontal:16
Schmidt Hammer Test Results for the Wing Walls
Test Element/LocationAverage concrete strength
(N/mm2)
Nyeri SideRHS 59.4
LHS 62.0
Nyahururu Side
LHS 53.2
RHS 55.0
Ultrasonic Pulse Velocity Results for the Wing WallsTest Element/Location Homogeneity of concrete matrix
Nyeri Side
LHS Homogeneous
RHS Homogeneous
Nyahururu Side LHS Homogeneous
RHS Homogeneous
Carbonation Test Results for the Wing WallsTest
Element/Location
Carbonation depth(mm)
Least cover
recorded
(mm)
Balance of carbonatio
n depth(mm)
Remarks/deterioration degree
Nyeri side 7 33 28 LowNyahururu side
7 45 38 None
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 142+450Resistivity test results for the Wing Walls
Test Element/Locatio
n
Resistivity (kΩcm)
Remarks
Nyeri side110.0
Probability of corrosion is insignificantNyahururu side 111.5
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
BRIDGE AT KM 142+450STEEL GIRDERSUltrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 LHSNo Delamination
SG2 LHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
14.5
25
600
MTRD ICT
BRIDGE AT KM 142+450Ultrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG3 CentreNo Delamination
SG2 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
14.3
23.2
14.5
23.5
600600
MTRD ICT
BRIDGE AT KM 142+450Ultrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 RHSNo Delamination
BRIDGE AT KM 173+120DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
14.0
22.4
600
MTRD ICT
DECK SLABElectromagnetic Test Results for the Deck Slab
Test Location Re-bar spacing(mm)
Average covers(mm)
Re-bar size(mm)
Deck slab Thickness
(mm)
DS1-Nyeri SideRHS
Longitudinal:150Transverse:130
Longitudinal:20Transverse:10
Longitudinal:16Transverse:12
DS2 –Nyeri Side Centre
Longitudinal:150Transverse:120
Longitudinal:20Transverse:12
Longitudinal:16Transverse:12
DS3-Nyeri Side LHS
Longitudinal:150Transverse:130
Longitudinal:20Transverse:10
Longitudinal:16Transverse:12
Schmidt hammer Test Results for the Deck Slab
Test LocationAverage concrete strength
(N/mm2)
DS1-Nyeri Side LHS 30.7
DS1-Nyeri Side Centre 40.4
DS1-Nyeri Side RHS 55.2
DS2-Karatina side LHS 52.1
DS2-Karatina side Centre 51.3
DS2-Karatina side RHS 40.6
Ultrasonic Pulse Velocity Results for the Deck SlabTest Element/Location Homogeneity of concrete matrix
DS1-Nyeri SideRHS Slightly Inhomogeneous
DS2 –Nyeri Side Centre Slightly Inhomogeneous
DS3-Nyeri Side LHSSlightly Inhomogeneous
Carbonation Test Results for the Deck SlabTest
Element/Location
Carbonation depth(mm)
Least cover
recorded(mm)
Balance of carbonation
depth(mm)
Remarks/Deterioration degree
DS1-Nyeri Side 6 10 4 High BRIDGE AT KM 173+120
DECK SLABDETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Resistivity Test Results for the Deck SlabTest
Element/Location
Resistivity (kΩcm)
Remarks
DS1-Nyeri Side 111.4Probability of corrosion is insignificant
PIER COLUMNSTest
element /location
Column Size(mm), No.& Arrangement of re-bars
Re-bar size
(mm)
Average
covers(mm)
Link Details(mm)
PC 1-Nyeri sideLHS 32
Side A:53Side B:23Side C:26Side D:36
size:10Spacing:250
PC 2-Nyeri sideLHS 32
Side A:20Side B:18Side C:25Side D:22
size:10Spacing:250
BRIDGE AT KM 173+120PIER COLUMNSDETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
A
600
350
500
450
A
B
C
D
MTRD ICT
Test element /location
Column Size(mm), No.& Arrangement of re-bars
Re-bar size
(mm)
Average
covers(mm)
Link Details(mm)
PC 1-Nyeri sideRHS 32
Side A:31Side B:32Side C:24Side D:30
size:10Spacing:250
PC 2-Nyeri sideRHS 32
Side A:35Side B:30Side C:36Side D:25
size:10Spacing:250
BRIDGE AT KM 173+120Schmidt Hammer Test Results for the Pier Columns
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
A
600
350
500
450
A
B
C
D
A
600
350
500
450
A
B
C
D
MTRD ICT
Test Element/LocationAverage concrete strength
(N/mm2)
Nyeri SidePC1LHS 45.0
PC2LHS 32.0
PC1RHS 41.8
PC2RHS 45.0
Karatina Side
PC1LHS 43.0
PC2LHS 50.0
PC1RHS 52.1
PC2RHS 55.0
Carbonation Test Results for the Pier ColumnsTest
Element/LocationCarbonation
depth(mm)
Least cover
recorded(mm)
Balance of carbonatio
n depth(mm)
Remarks/deterioration
degree
Nyeri sidePC1LHS 6 23 17 Low
PC2LHS 6 18 12 Low
PC1RHS 6 24 18 Low
PC2RHS 6 25 19 Low
Resistivity test results for the Pier ColumnsTest
Element/LocationResistivity
(kΩcm)Remarks
Nyeri sidePC2 RHS 111.4
Probability of corrosion is insignificant
BRIDGE AT KM 173+120STEEL GIRDERSDETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
MTRD ICT
Ultrasonic Tests for Plate Thickness & Lamination
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG1 LHSNo Delamination
SG2 LHSNo Delamination
BRIDGE AT KM 173+120Ultrasonic Tests for Plate Thickness & Lamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
16.5
23
870
MTRD ICT
Steel Girder No.
Section Dimensions (mm)
Continuity Across Plate Thickness
SG3 CentreNo Delamination
SG2 RHSNo Delamination
DETAILED INSPECTION REPORT FOR BRIDGES ALONG ROAD B5
16.5
23.5
16.0
22.5
870600