Effect of construction wastes on the rheo-physical behavior of photocatalytic mortar

Herein, the rheological and mechanical performance generated by the incorporation of construction wastes on the photocatalytic mortar were investigated. Construction wastes referred to recycled clay brick sands (RCBS) and recycled clay brick powder (RCBP). First, the RCBP was used as supplementary cementitious material to replace cement by weight percentages of 0, 10, 20, and 30 at fixed water to cement ratio of 0.6. Then, an optimal combination (20% RCBP and 80% cement) considering the yield stress, plastic viscosity, and mechanical performance was used to bind three types of fine aggregates, viz. 100% silica sands, 80% silica sands plus 20% RCBS, and 80% silica sands plus 20% RCBS based composite photocatalysts (RCBS/TiO2). The recycled glass cullet (RGC) and the RGC based composite photocatalyst (RGC/TiO2) were also used as the fine aggregate. Results revealed that the yield stress and the plastic viscosity of RCBS/TiO2 were higher than silica sands and pure RCBSs. Besides, compared with pure RCBS/TiO2, the combination of RCBS/TiO2 and RGC/TiO2 reduced both the yield stress and the plastic viscosity of the mortar. In addition, either RCBS or RCBS/TiO2 with a blending ratio no higher than 20% caused a little effect on the mechanical performance of the mortar.