We were engaged by GAB Robins (M) Sdn Bhd and Crawford & Company Adjusters (M) Sdn Bhd to investigate selected piers and cross heads showing signs of cracking on the 7km Ampang-Kuala Lumpur Elevated Highway. The highway was developed on a design and build basis by Percon in joint venture with Leighton of Australia. The project was initiated in July 1996.
The problems of cracking in a number of piers (2.8m diameter) were apparently identified in mid-2000 and on two cross heads in 2001. The cracking in the piers was thought to have initiated due to temperature differentials and internal restraint in the concrete following formwork stripping. The initial hair line cracks at the concrete surface due to thermal cracking were thought to have opened up at later ages due to long term drying shrinkage effects.
The cracking at the cross heads was due to a combination of effects including:
– Improper concrete mix design to take into consideration heat of hydration effects for mass concreting
– Thermal cracking due to temperature differentials at the time of formwork stripping
– Long term drying shrinkage
– Structural cracking due to inadequate consideration of the complex eccentric load conditions at this location
The assessment formed a basis for the loss adjustors to consider the validity of the claims against the insurance policy.