JTK Consult (JTK) was engaged by UEM Builders Berhad to undertake a review of the concrete specifications and understand the significance of blow holes and cracking observed during concrete segment production in meeting the very stringent durability provisions for the Penang Bridge project.
UEM Builders Bhd via a fully owned subsidiary Buildcast Sdn Bhd (BSB) were engaged to manufacture the concrete segments for the construction of the Penang Second Bridge. At the time of JTK engagement there were 800 segments rejected and the project was delayed as the segments could not be launched.
The project concrete specifications, durability requirements and segment production sequencing were reviewed with a view to providing an assessment to see if the concrete being used could be further optimized. Specific needs in terms of durability and quality construction required careful examination and these were considered for the specific micro-environments expected. The 120 year life requirement was considered via durability modelling. A logical course of action was proposed to addressing the problem of concrete defects including undertaking additional concrete trials for concrete optimization and suggestions for the improvements to the physical concrete production process. These findings were presented to the bridge owners Jabatan Kedua Sdn Bhd and the approach to optimization and improvement agreed.
JTK supervised the changes in the production and concrete quality leading to “zero” defects and acceptance of the segments. Following a remedial works programme the majority of the original 800 or so segments which were rejected were accepted and used for construction. This resulted in significant savings to the project avoiding a potential loss of RM 30 million for replacement segments.
Concrete and Construction Materials Technology:
Understrength Concrete Investigation