Characterization of sustainable ultra-high performance concrete (UHPC) including expanded perlite

Abstract

In this study, the performance of ultra-high performance concrete (UHPC) containing expanded perlite powder (or expanded perlite sand) has been investigated comprehensively. The rheological properties, workability, mechanical properties and durability are determined. Results indicate that the replacement of cement by EP powder significantly reduces the viscosity of UHPC, shortens the V-funnel time, and increases the slump flow. Meanwhile, comparable durability and slightly reduced strength can be obtained with up to 60% EP powder addition. The hydration heat, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) results indicated that EP exhibited pozzolanic activity and promoted the early hydration process. Compared with the effect of the addition of EP powder, the replacement of quartz sand by EP aggregate has no distinct effect on the workability, while leads to a relatively larger strength loss . The more obvious mechanical degradation in specimens with 75% and 100% EP sand is due to the fiber settlement. Additionally, the CO2 emission and cement efficiency value have been calculated, where the results confirm that UHPC containing EP powder as cement replacement (or EP sand as quartz sand replacement) is of remarkable potential to be used as a sustainable building material.