RPF November 2004: Roodekrans Trial Sections

Pieter Strauss

Condition Rating after Two Years

• Traffic loading

• Typical structural failures

• Rating by panel of twenty people which included designers, clients and researchers

• Recommendations and the way forward

Traffic Loading

• Design based on conventional design methods

• Intended to get failure within 6 months

• Cum. traffic loading to date (2.7 years)

380 000 E80’s versus 60 000 designed for

• Spread of heavy vehicle types and loading, including Volvo off-road dumpers (16 E80)

Traffic loading: Monthly Statistics

ROODEKRANS - MONTHLY STATISTICSwith Volvo dumpers since 1/9/2002

0

5000

10000

15000

20000

25000

Month

HV Axles E80

(From 12/3/2002)

Traffic loading: E80 per Heavy Vehicle

AVERAGE E80 PER HEAVY VEHICLE BY AXLE CLASS

Roodekrans, from 12 March 2002 till 31 October 2004; 92791 heavy vehiclesAverages: E80/HV = 4.106; E80/AL = 1.322; Axles/HV = 3.107

Number of axles on the heavy vehi cl e2 3 4 5 6 7 8 9

Av

e E

80 p

er

he

avy

ve

hic

le

7.0

6.5

6.0

5.5

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

1.241

5.046 5.047

6.406

4.403

0.908

0

2.864

General Condition

Drying Shrinkage on SFRC

50 mm “CRC”

75 mm “CRC”

100 mm “CRC”

100 mm Butt Jointed on CTS

140 mm Butt Jointed on Gravel

Erosion Below Leave Slab

Condition Rating by Panel

• Average area of sections: 50 square meters

• Percentage area of the section perceived as failed. One out of four panels failed = 25%

• Perception of the rater as a client/designer and as a road user

• The facility being used as a highway, street or hard standing (apron)

1. 75 SFRC on foam

2. 75 SFRC on CTS

3. 75 SFRC on ETB

4. 50 CRC on ETB/CTS

5. 75 CRC on ETB/CTS

6. 100 CRC on CTS

7. 100 butt joint. on CTS

8. 100 butt joint. on AC/CTS

9. 140 plain joint. on G5

10. 140 butt joint. on G5

11. 140 dowel on gravel on G5

1 2 3 4 5 6 7 8 9 10 11

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Designer/Client

Road user

1. 75 SFRC on foam

2. 75 SFRC on CTS

3. 75 SFRC on ETB

4. 50 CRC on ETB/CTS

5. 75 CRC on ETB/CTS

6. 100 CRC on CTS

7. 100 butt joint. on CTS

8. 100 butt joint. on AC/CTS

9. 140 plain joint. on G5

10. 140 butt joint. on G5

11. 140 dowel on gravel on G5

1 2 3 4 5 6 7 8 9 10 11

Highway

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Highway

Street

1. 75 SFRC on foam

2. 75 SFRC on CTS

3. 75 SFRC on ETB

4. 50 CRC on ETB/CTS

5. 75 CRC on ETB/CTS

6. 100 CRC on CTS

7. 100 butt joint. on CTS

8. 100 butt joint. on AC/CTS

9. 140 plain joint. on G5

10. 140 butt joint. on G5

11. 140 dowel on gravel on G5

1 2 3 4 5 6 7 8 9 10 11

Highway

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Highway

Hardstanding

Recommendations and Way Forward

• Keep on monitoring

• Maintain where necessary

• Feedback into cncPave

• Apply knowledge elsewhere especially where slab support is relatively good, traffic loading is moderate and labour intensive construction is considered