Influence of Recycled Concrete Fine Powder on Durability of Cement Mortar

Abstract

In this paper, the durability of cement mortar prepared with a recycled-concrete fine powder (RFP) was examined; including the analysis of a variety of aspects, such as the carbonization, sulfate attack and chloride ion erosion resistance. The results indicate that the influence of RFP on these three aspects is different. The carbonization depth after 30 days and the chloride diffusion coefficient of mortar containing 10% RFP decreased by 13.3% and 28.19%. With a further increase in the RFP content, interconnected pores formed between the RFP particles, leading to an acceleration of the penetration rate of CO2 and Cl-. When the RFP content was less than 50%, the corrosion resistance coefficient of the compressive strength of the mortar was 0.84-1.05 after 90 days of sulfate attack. But the expansion and cracking of the mortar was effectively alleviated due to decrease of the gypsum production. Scanning electron microscope (SEM) analysis has confirmed that 10% RFP contributes to the formation of a dense microstructure in the cement mortar.