Cement asphalt emulsion mixture (CAEM) presents low early-age strength and poor flowability, which limits its application range at a certain degree. In this paper, CAEM with high early-age strength and flowability was proposed. The flowability, compressive strength, flexural strength of CAEM at different periods and 28 days elastic modulus of CAEM were investigated. In addition, evolution of composition and microstructure of CAEM was analyzed by X-ray diffraction (XRD), scanning electronic microscope (SEM), and mercury intrusion porosimetry (MIP). The results indicated that the compressive strength of CAEM can be enhanced quickly in several hours. It could achieve 17–24 MPa at 6 h and almost reached 79–90% of the 28 days compressive strength. SEM and XRD analysis found that the hydration products in CAEM at different periods were obviously different. The hydration products of 2 h filled the micro pores of the mixture. After 28 days, the hydration products were connected to each other, resulting in a denser structure. The results of MIP analysis showed that the pore cumulative volume of CAEM was similar for 2 h and 28 days samples. These results testified that CAEM had high early-age strength.

This study proposes a new cement mortar incorporating damping aggregate (DA) and investigates the mechanical properties and damping property of the cement mortar. Four types of DA were prepared, lightweight aggregate presaturated water and three types of polymer emulsion. Further, the effects of polypropylene fiber and rubber powder on the performance of the cement mortar were studied. The experimental results showed that the damping ratio of specimens containing 70% DA was approximately three times higher than that of the reference mortar, with a slight decrease in the mechanical properties. Adding fiber was more effective than rubber powder in improving the damping ratio of the cement mortar, and the optimal dosage of fiber was 0.5%.

In this study, the effects of recycled sand (RS) carrying sulfate corrosion media on mortar drying and autogenous shrinkages were investigated. Four variables were considered, the replacement percentage of RS, water to cement (W/C) ratio, secondary cementitious material, and the corrosion concentration of RS. The test results indicated that the replacement percentage of RS was positively related to the drying and autogenous shrinkages of the mortar. The drying shrinkage of the mortar increased with an increase in the W/C ratio, while the autogenous shrinkage showed an opposite trend. The addition of fly ash (FA) had a significant inhibitory effect on the drying and autogenous shrinkages of the mortar. The drying shrinkage of the mortar was reduced, while the autogenous shrinkage was increased by adding granulated blast-furnace slag (GBFS). The addition of both FA and GBFS caused an increase in the autogenous shrinkage. As the corrosion concentration of RS increased, the drying and autogenous shrinkage values decreased slightly. The scanning electron microscopy and X-ray diffraction analysis results showed that the corrosion products formed by the reaction of sulfate ions carried by RS and cement hydration products filled the internal pores of the mortar and slowed down the shrinkage of the mortar.