Technology of Ultra-High Strength / High Performance Concrete Applied to Guangzhou Xita Tower Construction

This paper introduces development and application of ultra-high strength/high performance concrete in construction of the Xita tower high-rise building at Zhujiang New City of Guangzhou, China. The goal of the concrete construction in the Xita Tower project will be realized via research of mix proportion and optimization of pumping equipment. In regard to mix proportion of concrete, low water/cement (W/C) ratio, low water content lower than 150 kg/m3 and employment of superplasticizer are essential to acquire high strength. A series of parameters have been measured to research workability of concrete from C70 to C90, such slump, slump flow, flow time from inverted cone, L-box flow, and bleeding under pressure et al. Properties of hardened concrete should also be considered, including durability, autogenous shrinkage caused cracking, and fire resistance.