Post on 24-Oct-2014
Construction Measurement III(SBQ 3314) Pre-Cast and Pre-Stressed Concrete Lecture By Dr Sarajul Fikri Mohamed
Department of Quantity Surveying, FAB, UTM Skudai Johor, Malaysia
29th December 2009
Pre-cast and Pre-stressed Concrete CIVIL WORKS
Electrical Installations
Fire Fighting Installations
Air Conditioning Installations
Unit/Split Package/Central
Landscape Works
Single Phase Three Phase
Gas Installations
ELECTRICAL WORKS
MECHANICAL WORKS
LANDSCAPE WORKS
Hard Landscape Soft Landscape
MAIN COURSE COMPONENTS
© 2009 Sarajul Fikri Mohamed
• Read and check drawing
• Drawing numbering and scale
used.
• Taking off list
• Heading and Description
• Take off
• Annotation / Side Cast
• Query list
• Final checking
BQs FOR PRECAST &
PRESTRESSED WORKS
PROJECT DRAWINGS
Output
3
• Construction technology
• Measurement rules: SMM2
• Description
• Taking Off
• Case Study
KNOWLEDGE
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
© 2009 Sarajul Fikri Mohamed
Table of contents
1. Prestressed concrete in bridgeworks: technological aspects
2. SMM2 measurement rules for pre-cast and pre-stressed concrete
3. Taking off list for pre-stressed concrete
4. Heading and description.
5. Case study: Foot bridge pre-cast and pre-stressed concrete beam
6. Studio work of 'Membina Lebuh Raya Pesisir Pantai Dari Johor
Bahru ke Nusajaya' project.
© 2009 Sarajul Fikri Mohamed
Prestressed concrete in bridgeworks
Types of material # 1
BRIDGEWORKS
Concrete Steel
Masonry Timber
i Simply Supported
ii Continuous
iii Cantilever
System structure #1
BRIDGEWORKS
iv Arch
v Truss
vi Frame
System structure # 2
BRIDGEWORKS
vii Cable Stayed
viii Suspension
ix Culvert
System structure # 3
BRIDGEWORKS
i Reinforced concrete beam
ii Precast reinforced concrete
beam
iii Prestressed concrete beam
Deck types
BRIDGEWORKS
iv Concrete Box Girder
v Voided Concrete Slab
Deck types # 1
BRIDGEWORKS
14
Principles
PRE-CAST & PRE-STRESSED CONCRETE
Without pressing blocks together
With blocks pressed together
15
1) Precast concrete beam 2) Ducting 3) Vents 4) Tendons 5) Anchorages 6) Filling to anchorage pockets 7) Construction joint 8) Temporary support
Pre-cast & pre-stressed concrete
COMPONENTS
16
Pre-cast & pre-stressed concrete
PRE-CAST CONCRETE BEAM
Prestressed concrete beams includes: cast in situ or pre cast, beams or box girders, simply supported or cable stayed.
Two main types which include:
PRE-TENSIONING
The tendon is stressed by jacking against an anchor frame before the concrete is placed.
POST-TENSIONING
The tendon is pulled and stretched using a jack and the resulting force is transferred directly on the hardened concrete through the tender anchor.
Cast in situ beam for construction of a bridge
Pre cast concrete beam from factory transported to site
18
Pre-cast & pre-stressed concrete
WIRES
Individual wires are used in pre-tensioned beams but have become less common in favour of strand; which has better bond characteristics.
Wire diameters are typically between 5mm to 7mm, with a minimum tensile strength of between 1570 and 1860 N/mm2 carrying forces up to 45kN.
WIRE
19
Pre-cast & pre-stressed concrete
STRANDS AND TENDONS The common pre-stressing is 7 wire
strand; made up of individual cold-drawn wires with six outer wires twisted around an inner core wire
For post tensioning, 13mm or
15mm diameter, 7 wire strand is used, either singly for pre-tensioning or in bundles to form multi strand tendons.
The common post-tensioned tendon sizes utilize 7, 12, 19 or 27 strands.
Multi strand tendon live-end
anchor
20
Tendons consists of seven cables
7 wires strand
21
Pre-cast & pre-stressed concrete
DUCTING A duct is used to form a void
through the concrete into which the tendon is placed.
Ducts are made from corrugated steel covered by BS EN523 (1997) with a wall thickness of 0.25mm
Meanwhile, corrugated plastic ducts also cal be used with a wall thickness of 2.5mm to 3.0mm thickness.
External tendons are usually placed inside high-density polyethylene (HDPE) ducts.
Steel duct
22
Ducts and cables for stressing process
23
Pre-cast & pre-stressed concrete
ANCHORAGES # 1 For pre-tensioned strands the
anchorage is by bond and friction of the bare strand cast into concrete
For post-tensioned tendons,
anchorage is achieve by using anchor blocks or an encased dead-end anchor.
Stressing of multi-strand tendons is undertaken using jacks placed over the anchorage and tendon. The jack grips each strand and pulls the tendon until the required force is generated.
Multi strand tendon live-end
anchor
24
Pre-cast & pre-stressed concrete
ANCHORAGES : BEARING PLATE #2
25
Pre-cast & pre-stressed concrete
ANCHORAGES # 3
26
Pre-cast & pre-stressed concrete
EQUIPMENT FOR PLACING TENDONS # 1 For larger and longer multi-strand tendons, special equipment is needed to
position the strand.
In a multi-strand tendon, the strands are positioned by either pushing or pulling the strand into place.
The push-through method involves pushing individual strands into the duct one at a time until the number is in position.
The pull-through method is strands are first cut to length and bundled into a complete tendon at one end of the duct. A steel pulling rope is thread through the duct and connected to a winch at one.
The push-through method
The pull-through method
28
Pre-cast & pre-stressed concrete
THE PUSH THROUGH METHOD
29
Pre-cast & pre-stressed concrete
THE PULL THROUGH METHOD
30
Pre-cast & pre-stressed concrete
STRESSING JACKS The jacks are hydraulically operated
with oil pumped into the piston to apply load to the tendon.
The larger jacks can generate a pulling force in excess of 1200 tonnes. The same jacks are also used to de-stress tendons.
For de-stressing, special tools are used to move the jack back and to give access to the anchor wedge or nut allowing them to be loosened or removed.
Stressing jack
31
Tensioning works in progress
Tendons stressing work are completed
33
Pre-cast & pre-stressed concrete
GROUTING AND VENTS # 1 Grouting mixing on site and these are used to mix the cement, water and
any admixtures required to give a homogeneous grout.
The post-tensioning system have a large hole in the bearing plate to allow the grout to be pumped in via the anchorage cap.
Inlet tubes are needed to allow the grout to be pumped into the duct and should have a minimum internal diameter of 25mm.
A grout pump combined with the mixing pans takes the fluids grout from the pans and pushed it into the duct via the inlet.
All grouting equipment should be duplicated on site to ensure that back-up is always available in case of breakdowns.
Grouting
34
Pre-cast & pre-stressed concrete
GROUTING AND VENTS # 2
Grouting equipment includes mixer and pump in one unit.
Grouting is usually carried out as soon as possible after stressing.
35
Pre-cast & pre-stressed concrete
GROUTING AND VENTS # 3 Outlet tubes are required to vent off the air and to ensure the ducts are full of
grout.
Vents are provided at each low point, both to drain out any standing water and to draw off any trapped air.
A vent is provided at the ‘far’ end of the duct to ensure that the duct is filled along its full length.
Vents should be provided at regular intervals along ducts with long ‘flat’ profiles to remove trapped air that can occur as the grout runs along the bottom of the duct. The maximum vent spacing is less than 15m.
Vent tube
VIDEO PRESENTATION
PROJECT
I-85 BRIDGE, LAGRANGE,
GEORGIA, USA.
Fakulti Alam Bina
© 2009 Sarajul Fikri Mohamed
SMM2 measurement rules
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
39
Related clauses
PRE-CAST & PRE-STRESSED CONCRETE
Clause Description
F.34 F.41-45 F.26 F.35 F.1-7 F.36 F.8-9 F.37 F.10-16 F.38 F.17 F.21 F.23 F.39 F.40
Generally (Prestressed concrete work) Contractor-designed construction Generally (Composite construction) In-situ concrete members Generally (In-situ concrete) Reinforcement to in-situ concrete members Reinforcement Formwork to in-situ concrete members Formwork Precast concrete units Generally (Precast concrete) Standard or purpose-made units Temporary supports Ducts, grooves and pockets Prestressed tendons
40
F.34 GENERALLY
Concrete members classified as prestressed concrete works where a stress is artificially induced in the concrete by means of tendons tensioned working load are applied.
Prestressed concrete work and its reinforcement and associated formwork shall be given under an appropriate heading.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
41
F.34 GENERALLY
Work required to be designed by the Contractor shall be given in accordance with clauses F.41-45.
Work of composite construction shall be given in accordance with clause F.26
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
Lifting of pre-cast concrete beams
Launching of pre-cast beam to the column piers
Cast in-situ pre-stressed concrete beams
44
Pre-stressed concrete beams deliver to site
Loading of pre-stressed concrete beams
PRESTRESSED CONCRETE WORK F.34 Generally
A brief description of the prestressed work stating the method of
tensioning shall be given.
• Location drawings showing the prestressing arrangements shall be provided except where stress is to be applied over the full length of a concrete member by means of continuous tendons running between the ends of the member.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
47
Multistrand system
PRE-CAST & PRE-STRESSED CONCRETE A brief description of the pre-stressed work
48
Standardized tendon units with up to 55 strands of 13mm (0.5”) or 15mm
(0.6”) diameter.
Ducts of steel or polythelene
Grouting with cements mortar or other materials.
Simultaneous stressing of all strands in a tendon but individual locking of
each at the anchorage.
Stressing in any number of steps.
VSL multistrand system components
PRE-CAST & PRE-STRESSED CONCRETE
49
VSL external post tensioning system
PRE-CAST & PRE-STRESSED CONCRETE A brief description of the pre-stressed work
50
VSL monostrand system
PRE-CAST & PRE-STRESSED CONCRETE A brief description of the pre-stressed work
51
Multistrand system
PRE-CAST & PRE-STRESSED CONCRETE Location drawings showing the pre-stressing arrangements shall be provided
52
PRESTRESSED CONCRETE WORK F.34 GENERALLY
Except in the case of standard or stock-pattern members particulars of the following shall be given: a. Materials of which the wires are composed, their diameters and details of any preparatory treatment. b. Numbers of wires to be tensioned simultaneously. c. Amount of tension to be applied to the wires. d. Strength of concrete required at transfer of stress. e. Tests. f. Cutting off and treating the ends of wires.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
53
Types of tendon
1. Wire
2. Standard strand
3. Drawn strand
4. Cable of seven strands
5. Dividing bar
6. Macalloy bar
Types of tendon
PRE-CAST & PRE-STRESSED CONCRETE
54
Typical tendon format
PRE-CAST & PRE-STRESSED CONCRETE
55
Structure of monostrand
PRE-CAST & PRE-STRESSED CONCRETE
56
Two, three and seven wire strands
Number of wire strands
PRE-CAST & PRE-STRESSED CONCRETE
© 2009 Sarajul Fikri Mohamed 57
Akashi Kaiyo Bridge Japan
PRE-CAST & PRE-STRESSED CONCRETE
58
Cable Details
Akashi Kaiyo Bridge Japan
CABLE DETAILS
59
Akashi Kaiyo Bridge Japan
CABLE SPECIFICATIONS
60
Akashi Kaiyo Bridge Japan
STRAND INSTALLATIONS
61
PRESTRESSED CONCRETE WORK F.34 GENERALLY
Where tendons are tensioned after the concrete is cast (post-tensioned) particulars of the following shall be given: a. The type of jack used. b. Details of anchorages and anchorage fittings. C. Whether tensioning is carried out from one or both ends of tendons.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
62
PSC type T jack for multistrands tendon
PRE-CAST & PRE-STRESSED CONCRETE
63
Multistrand system
PRE-CAST & PRE-STRESSED CONCRETE
64
PRESTRESSED CONCRETE WORK F.35 IN-SITU CONCRETE MEMBERS
In-situ concrete member shall be given in accordance with
clauses F.1-7.
Members not cast in a continuous length shall be so described stating the number and average length of separately cast section.
Construction joints between section shall be enumerated -NO
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
65
Construction joint
PRE-CAST & PRE-STRESSED CONCRETE
66
PRESTRESSED CONCRETE WORK F.36 REINFORCEMENT TO IN-SITU CONCRETE MEMBERS
Reinforcement shall be given in accordance with clauses F.8-9.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
67
PRESTRESSED CONCRETE WORK F.37 FORMWORK TO IN-SITU CONCRETE MEMBERS
Formwork shall be given in accordance with clauses F.10-16
subject to the following ;
a) Additional requirement for supporting formwork shall be described.
b)Formwork to pre-tensioned and post-tensioned work shall each be so described.
c)Temporary restraints required for tensioning of items for formwork.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
68
PRESTRESSED CONCRETE WORK F.37 FORMWORK TO IN-SITU CONCRETE MEMBERS
Formwork for ‘anchorage pockets’ shall be enumerated - NO
(stating the size and shape)
Formwork for temporary construction joints shall be enumerated -NO (stating the section profile of the abutting units)
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
69
Anchorage pockets
PRE-CAST & PRE-STRESSED CONCRETE
70
Construction joint
PRE-CAST & PRE-STRESSED CONCRETE
71
PRESTRESSED CONCRETE WORK
F.38 PRECAST CONCRETE UNITS
Precast concrete generally shall be given in accordance with clauses F.17.
Precast concrete units shall be given in accordance with clauses F.21 and F.23.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
72
Pre-cast construction system
PRE-CAST & PRE-STRESSED CONCRETE
73
Pre-cast components
PRE-CAST & PRE-STRESSED CONCRETE
74
PRECAST CONCRETE F.17 GENERALLY
Precast unit including floors shall be given under an appropriate
heading and shall unless otherwise required be enumerated. NO
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
75
PRECAST CONCRETE F.17 GENERALLY
Particular of the following shall be given ; a. Mix or strength requirements of the concrete. b. Kind, quality and size of reinforcement. c. Nature and extent of surface finish. d. Jointing and bedding materials. e. Method of fixing.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
76
PRECAST CONCRETE F.17 GENERALLY
• Formwork or mould for precast units shall be deemed to be
included with the item. • Work required to be designed by the contractor shall be given in
accordance with clauses F.41-45. • Prestressed precast units shall be given in accordance with
clauses F.34-40.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
77
PRECAST CONCRETE
F.21 STANDARD OR PURPOSE-MADE UNITS
The catalogue or other reference number of standard or stock
patterns units shall be given.
Except in the case of items which can be adequately described,
the description of each purpose-made unit shall be
accompanied by drawn information in accordance with clauses
A.5 showing the size and shape of the unit.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
78
PRECAST CONCRETE F.23 TEMPORARY SUPPORTS
Where the design of precast units requires temporary support
after placing in position detail of the requirements shall be given in the description and the condition for the removal of the support stated.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
79
PRESTRESSED CONCRETE WORK F.38 PRECAST CONCRETE UNITS
Precast units shall be classified as follows:
a) Pre-tensioned.
b) Post-tensioned before erection.
c) Post-tensioned after erection. Self-supporting before and after tensioning.
d) Post-tensioning after erection. Self-supporting only after tensioning.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
80
Hollow slab pre-cast construction
PRE-CAST & PRE-STRESSED CONCRETE
81
Pre-cast window unit system
PRE-CAST & PRE-STRESSED CONCRETE
82
PRESTRESSED CONCRETE WORK F.38 PRECAST CONCRETE UNITS
Item description for precast concrete members which are
assembled from sections cast separately shall state whether the sections are assembled before or after erection.
Construction joint between adjacent units shall be enumerated.
Temporary supports for precast units are self-supporting only after tensioning shall be enumerated stating the area of support required and its height where this exceeds 3.50m.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
83
Typical pre-cast beam and floor deck section
PRE-CAST & PRE-STRESSED CONCRETE
84
Construction joint
PRE-CAST & PRE-STRESSED CONCRETE
85
PRESTRESSED CONCRETE WORK
F.39 DUCTS, GROOVES AND POCKETS
Ducts and grooves for post-tensioned prestressing tendons
shall be given in metres (M) stating the number and size.
Particular of the following shall be given: sleeves or sheathing,
temporary supports & mix of grout.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
86
Grouting duct and vent
PRE-CAST & PRE-STRESSED CONCRETE
Vent tube
Steel duct
87
PRESTRESSED CONCRETE WORK
F.39 DUCTS, GROOVES AND POCKETS
Ducts and grooves over 6.00m long shall be so described
stating the length in stages of 3.00m.
Curved ducts shall be described separately.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
88
89
PRESTRESSED CONCRETE WORK
F39.3 DUCTS, GROOVES AND POCKETS- VENTS
• Vents shall be enumerated. NO
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
90
Grouting vent
PRE-CAST & PRE-STRESSED CONCRETE
91
PRESTRESSED CONCRETE WORK
F.39.4 FILLING OF ANCHORAGE POCKETS
Filling of anchorage pockets shall be enumerated (NO) stating
the finish of any exposed surface.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
92
Filling of anchorage pockets shall be enumerated (NO)
93
PRESTRESSED CONCRETE WORK
F.40 PRESTRESSED TENDONS
Prestressed tendons shall be enumerated (NO) stating their length, number of wires, ultimate strength and size of wires, type of core and sheathing.
The lengths of pre-tensioned tendons shall be measured to the surfaces of the concrete members.
Description shall state whether tendons are pre-tensioned or post-tensioned members.
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
94
Pre-stressed tendons shall be enumerated (NO)
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
95
PRESTRESSED CONCRETE WORK F.40.2 ANCHORAGES
Anchorages shall be enumerated (NO) stating their components
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE
96
Measurement rules
PRE-CAST & PRE-STRESSED CONCRETE Anchorages shall be enumerated (NO)
97
Multistrand system
ANCHORAGE
98
SCD seven strand anchorages
ANCHORAGE
99
PSC monostrand anchorage
ANCHORAGE
© 2009 Sarajul Fikri Mohamed
Taking off list
101
Taking off list
PRE-CAST & PRE-STRESSED CONCRETE
1 General Item
2 Precast Concrete System : beam, floor, etc No
3 Reinforcement (insitu) m3
4 Formwork for anchorage pocket No
5 Ducting M
6 Vents No
7 Tendons No
8 Anchorages No
9 Filling to anchorage pockets No
10 Construction joint No
11 Temporary support No
© 2009 Sarajul Fikri Mohamed
Heading and description
103
Description Unit
Precast Concrete Beam
18000 mm long pre-cast beam, Grade 45 with approved type of
reinforcement to engineer’s details with minimum 23 days
concrete works cube strength shall be 50N/mm3 minimum cube
strength at transfer shall be 40N/mm3 including 7-wire super
strands with low relaxation in accordance with ASTMA4160 – 82
per strands
No
Heading and description
PRE-CAST CONCRETE BEAM
104
Description Unit
Ducts and Groove
____ mm thick _____ mm diameter metal sheeting
including temporary supports required, filling in with
cement and sand grouting (1:3) in the formation of the
curved duct exceeding 3.00m but not exceeding 6.00m.
m
Heading and description
DUCTS AND GROOVE
105
Description Unit
Tendons
___ mm long tendons cable conduit of 12 strands per
cable, each strands consist of 7-wires super low
relaxation, ___ mm diameter stressed with minimum of
188 kN per strand.
No
Heading and description
TENDONS
106
Description Unit
Anchorages
Monostrand anchorage including wedges, forge steel
anchorage block with 12 Nos of holes for strand, bearing
plate cast into end of member including socket for steel
duct.
No
Heading and description
TENDONS
107
Description Unit
Filling to Anchorage Pockets
Filling into stressing and anchorage pockets with extreme
size mm x mm including finished with emulsion
paint on all exposed surfaces.
No
Heading and description
FILLING TO ANCHORAGE POCKETS
108
CADANGAN MEMBINA PERSIMPANGAN BERTINGKAT GELANG PATAH DI LALUAN FT001,JOHOR BAHRU.
ITEM DESCRIPTION QTY UNIT RATE AMOUNT
10.4 PRECAST PRESTRESSED
BEAMS AND ANCILLARIES
Excute the proposed works
in accordance with the specification and
as shown in the Drawings.
10.4.1 16.85m long Prestressed
Pretension 'M' beams to site inclusive
of all materials, labour, prestressing,
grouting,lifting, transporting. 56.00 nos 4,800.00 4,800.00
10.4.2 Launch and placing in position 16.85m
long Prestressed Pretension 'M' beams 56.00 nos 330.00 18,480.00
10.4.3 Install 32mm diameter mild
galvanised Dowel Bars,600mm long
with rubber dowel caps as to detail. 12.00 nos 50.00 600.00
10.4.4 Provide 400 X 280 X 59mm thick
laminated elastomeric bearings and
epoxy bedding as to detail. 112.00 nos 145.00 16,240.00
10.4.5 Allow for peliminary tests on
350x200x475mm thick laminated
elastomeric bearings at Rubber Research
Institute of malaysia as specified. 4.00 nos 800.00 3,200.00
TOTAL FOR BILL NO. 10 38,520.00
109
Example of Bill of Quantities
PRE-CAST & PRE-STRESSED CONCRETE
© 2009 Sarajul Fikri Mohamed
Case study of foot bridge construction
CASE STUDY
PROJECT
CONSTRUCTION OF
FOOT BRIDGE
Fakulti Alam Bina
112
Type of Bridge : Pre-stressed Conrete Bridge Overall Length : 22000 metres PRE STRESSING BEAM PARTICULARS 1. No. of Cables Per Beam = 7 nos ( 4 types) 2. Diameter of Strands = 0.5 inch 3. Nos of Strand Per Cable = 7 nos 4. Length of Cables B/w Bearing = Varies(19700-21775) 5. Tension in Cable at Transfer = 82 tonne 6. Gauge Length = Varies(20150-22225) 7. Weight of Beam = 22.35 tonne 8. Concrete Per Beam = 9 m3
General project data
PRE-CAST & PRE-STRESSED CONCRETE
113
Elevation drawing
PRE-CAST & PRE-STRESSED CONCRETE
114
Section drawing at support
PRE-CAST & PRE-STRESSED CONCRETE
115
Section drawing of pre-stressed beam
PRE-CAST & PRE-STRESSED CONCRETE
116
Taking off list
PRE-CAST & PRE-STRESSED CONCRETE
1 Notes To Contractor
2 Pre Cast Concrete Beam No
3 Ducts & Grooves M
4 Filling to anchorage pocket No
5 Tendons No
6 Grouting Vent To Anchorage No
7 Anchorages No
117
Description Unit
Precast Prestressed Concrete Beam
Preambles
The prestressed precast concrete beam shall be post tensioned after erection
(self supporting before and after tensioning) at 4 m height after casting. Post
tensioned beam including al moulds, finished with painting on all exposed
surfaces including 3 nos steel ducting size 65mm diameter with high tensile
reinforcement hoisting and fixing in position. Prestressing of all cables of beam
consist of 3 nos cable including 12 strands of 7 wire strand class 2 relaxation 12.9
mm diameter for each cable which the ultimate tensile strength at 184 KN per
strand. All cable is post tensioned from one end and stressing in 2 stages, which
is in the first stage, tendon strength is 828 KN, 1656 KN in second stage where is
cable A and B is stressed from left side which cable C stressed from right side
using monostrand anchorage with all cable cast iron and bearing plate cast into
end of members after the stressing was done and fill all ducting withgrout and cut
all cable excess end of anchor with vibratedreinforced concrete grade 45.
Heading and description
PREAMBLES
Description Unit Qty Note
Precast Prestressed Concrete Beam
22000m length post tensioned beam, minimum concrete
strenght 45 N/mm3 transfer period and minimum concrete
strenght 50 N/mm3 in 28 days, including 12.7 mm
diameter 7 wire super low relaxation in accordance with
ASTM A4160 - 82 per strand. Each tension stages would
be carried out to 4 strands simultaneously at 2
prestressing stages to total of 138 KN per strand. All
prestressing work shall including testing of each strand
and to form lifting hole and reinforcement all wire end are
cut and holes to be grouted with approved material. All
recesses are to be covered with concrete and make
goods.
No
2
F.34.1- Concrete
member shall be
classified as
prestressed concrete
work where a stress
is artificially induced
in the concrete by
means of tendons
tensioned applied
before working loads
are applied
Heading and description
PRE-STRESSED CONCRETE BEAM
Description Unit Qty Note
Precast Prestressed Concrete Beam
Duct and grooves
M.S ducts and vents for grouting cable positioned at
500 m centres average 110 m including grout mix,
grouting process and make good at access grout
material
M
6
F.39.1 - Ducts and
Grooves for post-
tensioned prestressing
tendons shall be given
in metres stating the
number and size.
Particulars of the
following shall be given
: (a-c)
Heading and description
DUCT AND GROOVES # 1
Description Unit Qty Note
Precast Prestressed Concrete Beam
Duct and grooves
5 mm thick 65 mm diameter flexible mild steel ducting,
including PVC sheating, cement grout and grooves for
tendons each average size 100 mm diameter in 5.0
numbers not exceeding 6.00 length
Ditto, 6.00 - 9.00 m length
Ditto, 9.00 - 12.00 m length
Ditto, 12.00 - 15.00 m length
M
M
6
3
F.39.1 - Ducts and
Grooves for post-
tensioned
prestressing tendons
shall be given in
metres stating the
number and size.
Particulars of the
following shall be
given : (a-c)
Heading and description
DUCT AND GROOVES # 2
Description Unit Qty Note
Precast Prestressed Concrete Beam
Tendons
3 nos of 20.30 tendon consist of 12 nos of strands and
each strand consist of 7 wire superstrand class 2
relaxation 12.9 diameter and ultimate tensile strength at
184 KN per strand
No
6
F.40.1- Prestressed
tendons shall be
enumerated stating
their length, number
of wires, ultimate
strenght and size of
wires, type of
sheeting
Heading and description
TENDONS
Description Unit Qty Note
Precast Prestressed Concrete Beam
Tendons
Post tension tendons at a length of 19.70 m with
minimum 127mm diameter 7 wire super low relaxation
strands with a minimum UTS of 125 psi per strand
Ditto, at a length of 19.71m, ditto, 124 psi per strand
Ditto, at a length of 21.78m, ditto, 133 psi per strand
No
6
F.40.1- Prestressed
tendons shall be
enumerated stating
their length, number
of wires, ultimate
strenght and size of
wires, type of
sheeting
Heading and description
TENDONS
Description Unit Qty Note
Precast Prestressed Concrete Beam
Filling anchorage pocket
Filling into stressing and anchorage pocket to level of
beam ends with approved concrete grout strength
No
6
F.39.4 - Filling of
anchorage pockets
shall be enumerated
stating the finish of
any exposed surface
Heading and description
FILLING ANCHORAGE POCKETS
Description Unit Qty Note
Precast Prestressed Concrete Beam
Vent
Forming 250 mm diameter vent at 5 m centres at side of
the beam including finished on every exposed upon
completion
No
6
F39.3 - Vents shall
be enumerated.
Heading and description
VENTS
Description Unit Qty Note
Precast Prestressed Concrete Beam
Anchorage
Anchorage of both ends of the beam according to
manufactures instructions
No
6
F.40.2 - Anchorage
shall be enumerated
stating their
components
Heading and description
ANCHORAGE
© 2009 Sarajul Fikri Mohamed
Studio work
STUDIO WORK
PROJECT
MEMBINA LEBUHRAYA PESISIR PANTAI
DARI JOHOR BAHRU KE NUSAJAYA
FOR
ISKANDAR REGIONAL DEVELOPMENT
AUTHORITY (IRDA)
Fakulti Alam Bina