The factors responsible for the successful execution of high-rise or large-scale concrete pumping may not be directly visible on the jobsite. Sophisticated machines are only part of these complex operations which require a lot of preparation, starting with identification of the right mix of high-quality concrete with very good pumpability. To achieve this, pump trials are conducted to calculate expected pumping pressures and outputs at the site. The final test results give valuable information about productivity to the jobsite so that the entire site management becomes easier.
Dubai-based ready mix concrete producer Unimix, which has delivered projects such as Maktoum Bridge, Burj Al Arab, Emirates Towers and Burj Khalifa over the past four decades, attributes the success of its concrete pumping operations to extensive testing and preparation for all eventualities.
Having gained a wealth of experience on Burj Khalifa and subsequent projects, which the company executed in partnership with Putzmeister and local dealer German Gulf Enterprises, Unimix seeks to pioneer concrete pumping techniques for the high-rise structures of the future.
Basil Sanuri, general manager, Unimix, points out the current challenges in high-rise concrete pumping in the UAE.
“Dubai’s sustainability vision promotes the use of green and durable concrete. However, the high performance mixes being used at present in the UAE are not always pump friendly as they will have a high replacement of cementitious material which renders them highly viscous. To overcome such challenges, we depend on high-quality pumps with adaptable configurations and accessories to meet almost all our customers’ needs,” says Sanuri.
Sanuri points out that maintaining a consistent product is one of the biggest challenges faced while working on high-rise projects as variations lead to pumping difficulties. This requires extensive preliminary tests and simulations as well as adapting pumps and concrete mixtures to extreme conditions. Overcoming these challenges eventually led to Unimix and Putzmeister setting a new world record in high-rise concrete pumping at over 630m in a single stage, which is valid till date.
“Premium quality can only be guaranteed if the entire supply chain is optimised. The coordination between the technical teams of Unimix and Putzmeister ensured the success of pumping to such high levels,” says Sanuri.
Unimix is upgrading its equipment with new models of Putzmeister truck-mounted and stationary concrete pumps. The latest addition to the Unimix fleet is the BSF 2110 HP-D, called the ‘Moli’. The hybrid machine, a stationary pump mounted on a truck chassis, gives Unimix the required flexibility to cater to various high-rise jobsites at any given time as the machine can be relocated to different sites easily.
Bastian Dreher, regional sales manager and high-rise project consultant, Putzmeister.
Bastian Dreher, regional sales manager and high-rise project consultant, Putzmeister, explains how the company provides guidance on selection of equipment and accessories in order to ensure safe and efficient operations.
“For a project to be successful, it is important that we and our customers work as a team. Putzmeister provides complete solutions, beyond selling machines and accessories. This starts with choosing the right pump for the task, continues with the selection of the right pipeline and fixation and ends with selection of the right placing boom. At every stage, we strive for the best solution from an economical point of view, but more importantly, from a safety perspective. All three components, the pump, pipe, placing boom, have to work together. In particular, the pipeline has to be able to withstand the pressures. Putzmeister also provides support during pump trials, which help determine the pressure levels we could encounter and the right choice of equipment,” says Dreher.
