Record-breaking raft pour: How YTL Cement spearheaded The Exchange 106’s raft foundation pour within two days
The Edge, Sep 2, 2024
In the heart of Kuala Lumpur, Malaysia’s second-tallest building, The Exchange 106, reaches for the sky as an embodiment of the nation’s ambitions. Designed by Mulia Group Architects and led by its chief development officer Ali Moghaddasi, The Exchange 106 is essentially the centrepiece of the sprawling 70-acre Tun Razak Exchange (TRX) development. What is interesting is that the 454-metre-tall icon is known not just for its towering height and contemporary design, but also for its pioneering engineering feat.
Key players that came together in the groundbreaking project include owner and project manager Mulia Property Development, EDP Consultants, China State Construction and Engineering, IM Technik, and YTL Cement.
YTL Cement was tasked to spearhead the record-breaking largest continuous concrete pour in Malaysia, setting a new benchmark in construction excellence. This monumental achievement not only showcases the innovative spirit and relentless dedication of the team behind The Exchange 106 but also underscores the team’s engineering and construction excellence through the use of some of the most advanced and fast-track construction strategies.
Buildcon (YTL Cement’s concrete arm) senior general manager Lambert Liew and YTL Cement’s Construction Development Lab (CDL) general manager Lim Tze Liang provide some insight into this extraordinary feat.
The Edge: What is a raft pour and why is it important in the construction process?
Liew: A raft foundation is a thick concrete slab reinforced with steel, generally constructed as the foundation of a building. For a building of The Exchange 106’s calibre, we need to keep the integrity of the massive raft. The formation of the foundation slab required a continuous pouring of concrete to spread the weight of the building evenly. Achieving a continuous cement pour of this magnitude required meticulous planning and seamless coordination among various parties.
What is YTL Cement’s role in the raft pour process?
Liew: YTL Cement was tasked to plan, coordinate and execute this challenging process. The raft pour required the pouring of a massive 19,438 cubic metres or 45 million kg of concrete, equivalent to eight Olympic-size swimming pools.
What’s more, the colossal feat had to be completed within two days while maintaining the concrete temperature of below 28°C, which further complicated the process. The success of this pour was crucial as it formed the foundation of the tower, setting the stage for the rest of the construction. At the time, this had never been done before in Malaysia.
Who were the people involved behind the scenes of the extraordinary feat?
Liew: The success of a well-executed plan lies in the planning process. A meticulous plan right down to the smallest detail was crucial in ensuring the success of this feat. The planning process for the raft pour began seven months ahead with collaboration and input from experts from Indonesia, Australia and China.
For us, the biggest challenge was assembling a team of experts with the skills to plan and work together in handling the continuous pour. This involved coordination across various departments. Nevertheless, we managed to pull an extraordinary team of local, regional and international experts, with everyone playing an important part in the success of the pour.
The raft pour required almost 20,000 cubic metres of concrete. How did YTL Cement manage to deliver this quantity?
Lim: Managing the raw materials was indeed a complex task. Nevertheless, as a vertically integrated entity, YTL Cement was able to have full control over the entire production process, from sourcing raw materials to delivering the finished products. This integration enabled us to qualify all materials during the production and reception phases, safeguarding the quality and integrity of our products from start to finish.
To produce the concrete, 3,000 tonnes of cementitious materials were sourced from our facility at Janamanjung, Lumut, and over 35,000 tonnes of manufactured sand and stones were acquired from our Batu Tiga quarries. We also had to coordinate with our manufacturing plants at Padang Rengas and Kuala Kangsar, Batu Caves Depot, as well as five batching plants for tankers to transport the materials.
As a result, we successfully organised the procurement and transport of 5,300 tonnes of cement. By maintaining strict schedules for delivery, routing, safety, and quality standards of raw materials, we ensured that there were no delays in the process.
What were some of the challenges when executing the raft pour?
Liew: One of the main challenges was that we had to address logistical constraints such as traffic in the Kuala Lumpur city centre. To overcome this, the raft pour was scheduled on a long weekend with a public holiday, thereby reducing traffic significantly. Our service centre implemented a real-time monitoring system using GPS and CCTV, coordinating 130 mixer truck deliveries from five batching plants. By meticulously planning the delivery schedule and continuously adjusting based on real-time traffic data, we ensured that concrete deliveries were tracked and monitored effectively. This rigorous coordination allowed the project site to receive materials without any disruptions, ensuring that every part of the operation proceeded seamlessly.
With Malaysia’s weather, we also had to anticipate and overcome potential challenges like heavy rains. Hence, we had layered placing of the concrete to help manage temperatures and drain off rainwater. These techniques were crucial in meeting the project’s technical requirements and ensuring the structural integrity of the foundation.
During the pour, we had to make sure that the temperature was kept at below 28°C. We also sourced 2,000 tonnes of ice from two suppliers to replace part of the water content in the concrete mix to reduce its temperature. Special insulation techniques were designed to prevent thermal stress by controlling temperature gradients.
Monitoring and ensuring the timely delivery of these materials were crucial as everything had to come together like a well-oiled machine to complete the pour in two days.
How did you manage quality control during the raft pours?
Lim: The importance of quality control in construction cannot be underestimated. We conducted numerous joint plant trials and developed temperature modelling processes to ensure compliance with peak temperature requirements.
On the day of the pour, our quality control personnel were stationed at the plants to monitor the fresh concrete’s workability and temperature. Each truck was scrutinised to ensure the concrete temperature was below 28°C. We also took samples during the quality control process to be cast as test cubes, which were later tested for strength development and compliance.
We had to be very strict in ensuring only top-quality concrete was used. Any batch that didn’t meet the standards was rejected.
What were some of the key learnings from this project?
Liew: There were four main factors in accomplishing this extraordinary feat.
First, the machinery. We used four main plants to supply the necessary materials as well as three backup plants. This involved 110 trucks and 220 drivers, plus additional equipment like load loaders, generators and tow trucks on standby.
Second, the manpower. We assigned 40 technicians to the TRX site and an additional 100 general workers to manage ice in all four main plants. Coordination and dedication were vital to the smooth execution of the pour.
Third, the material. Ensuring a continuous supply of raw materials was essential. We carefully monitored and managed procurement and transport to avoid delays or shortages. The products used were our ECOConcrete range, namely, EcoBuild and CoolBuild concrete, as well as our ECOSand.
Lastly, the methodology. We managed to produce 500 cubic metres of concrete per hour, with each plant sharing the load in producing 60 cubic metres for the mass pour. Precise planning and execution were required to meet the high demand within the tight timeframe.
These factors together ensured the pour was completed seamlessly and efficiently.
What does this achievement mean for the construction industry in Malaysia?
Lim: This world-class achievement by our team showcases a significant milestone in Malaysia’s engineering and construction history as well as adds another feather to our cap for delivering complex and technically sophisticated projects. The Exchange 106 not only highlights this accomplishment but also underscores YTL Cement’s integral role in the nation’s construction sector.
We are deeply grateful to the other project stakeholders for their collaboration and trust, which were essential to this achievement. After countless months of dedicated planning and execution, we are proud to have set new records and established a benchmark for future projects, further solidifying our reputation for excellence in engineering and construction.
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