Effect of Wind and Temperature on the Macroscopic Properties and Microstructure of Lightweight Cellular Concrete during Pouring

Abstract

Lightweight cellular concrete (LCC) is widely used as a subgrade fill. It is susceptible to environmental factors such as wind and temperature during pouring, and unfavorable environmental factors can lead to deterioration of its performance after curing and molding. However, the effects of wind and temperature during pouring are often neglected. In this paper, the mechanisms of wind and temperature effects on LCC during pouring are revealed in terms of mechanical and microstructural properties. The results indicate that wind speed has a positive correlation with dry density and compressive strength, while it has a negative correlation with water absorption, as long as the wind speed remains below 6 m/s and the duration is within 6 h. Variations in wind speed also affect the average pore size (APS) of LCC, initially increasing and then decreasing. The pore roundness value (PRVs) shows a positive correlation with wind speed, whereas the fractal dimension of pore distribution (FDPD) exhibits a negative correlation. As the temperature rises from −15°C to 70°C, dry density generally decreases in steps; compressive strength decreases and then increases and then decreases. At −10°C and 40°C, LCC shows the highest water absorption, with an increase of 60.8% and 52.3%, respectively, compared with the standard pouring temperature of 20°C. The APS follows a pattern of increase, decrease, and then increase. Moreover, it increases by 51.5% at −5°C and by 21.3% at 70°C. PRV initially increases and then decreases, while FDPD decreases initially and subsequently increases. Macroscopic performance and microporous structure analyses suggest that the recommended temperature range for LCC during pouring is −5°C to 40°C.