Mix design and performance of lightweight ultra high-performance concrete
Jian‐Xin Lu, Peiliang Shen, Hafiz Asad Ali, Chi Sun Poon
Abstract
The inferior mechanical properties and durability of conventional lightweight concrete restrict its wider application. This study intended to design a novel lightweight ultra high-performance concrete (L-UHPC) using a mathematical approach, with a view to achieving low density and excellent performance. Two lightweight materials (i.e. micro-sized glass microsphere and expanded shale aggregates) were introduced in the mix design of L-UHPC. The statistical optimization via Central Composite Design was proved to be an effective method to produce the L-UHPC. The designed L-UHPC showed comparable or even superior functional and durability properties than normal-weight UHPC and high-performance cement mortar. The use of specified lightweight materials played prominent roles in ensuring the mechanical properties of L-UHPC. The high microhardness of paste matrix and the internal curing of lightweight aggregates contributed to the great durability of L-UHPC. The development of L-UHPC can provide a new solution for constructing high-performance lightweight structures and composites.