The unification of light weight and ultra-high strength in LWC: A new homogeneity enhancement approach

Abstract This study proposed a homogeneity improvement approach to solve the contradiction of light weight and high strength in concrete. Specifically, a packing algorithm was used to develop the UHPC matrix, and the response surface methodology (RSM) was performed for the inclusion of light weight aggregate (LWA) and light weight filler (LWF) with reduced particle size. After that, theoretical homogenous structures could be achieved by the blending of high homogenous matrix-UHPC and the LWA with reduced particle size. The experimental results indicated that the homogenous structures were effective in compensating for the strength loss caused by LWA. As a result, two LWCs (LWC 1 with density of 1800 kg/m3, and compressive strength of 121.9 MPa, LWC 2 with density of 1670 kg/m3, and compressive strength of 137.0 MPa) have been designed, confirming the feasibility of homogenous structure fabrication based approach in achieving the unification of light weight and ultra-high strength in LWC. Furthermore, the Peridynamic modelling was employed to uncover the mechanism of homogeneity increase approach, where the results indicated that the high homogeneity altered the crack propagation, facilitated the formation of ductile failure mode, and thereby improved strength. Excitingly, this study also provides ideas for the application of ultra-low strength LWA in the development of ultra-high strength LWC.