JTK Consult (JTK) was engaged by Mayjaus Joint Venture (MJS) for materials technology consultancy to conceptually assess the likelihood of early age crack development in core wall casting at the 85 storey Petronas Twin Tower 1 development in Kuala Lumpur. This was the tallest building in the world when completed. The core wall construction covered approximately 22m x 22m in plan and the walls were up to 0.75m thick. The concrete was grade 80 MPa at 28 days which was the highest known strength of concrete to be used in the world at that time. The high concrete strength, thick wall sections and long casting lengths were the reasons we were engaged to assess the likelihood of crack formation.
The scope of work included reviewing the construction details (eg structural and architectural drawings, technical specification, concrete mix design) and the proposed construction sequence. The concrete behaviour at early age was predicted and the likelihood of early age crack formation assessed.
JTK determined the influence on cracking from formwork material, insulation, curing, other building elements in contact with the cast element, formwork removal and the concrete mix. The risk of cracking and the location where cracks were most likely to initiate, were advised. JTK made recommendations on measures to be implemented which would reduce the risk of early age cracking. This included some improvement to the concrete mix design.
Concrete and Construction Materials Technology :
high strength concrete, core wall crack mitigation, construction sequencing thermal modelling and prediction