Author(s): Li Zhixin, Peng Jiahui, Rong Yantuan, Qiu Xingxing, Zhao Haixin
Pages: 34-36
Year: 2015 Issue:  5
Journal: Non-Metallic Mines
Keyword:  recycled gypsum; hydration process; strength; waterproof properties; change;
Abstract: The hydration process, strength and waterproof properties of recycled gypsum were investigated using temperature increase curves and SEM analysis to reveal the performance change laws of regenerative gypsum. The results showed that the hydration of recycled gypsum was delayed, correspondingly leading to the extending of setting time of recycled gypsum; The strength reduced and waterproof properties became poorer. And the decreasing rate in strength was 45%~55%, the water absorption, dissolution rate and mass loss in dry-wet process increased, but the water saturated strength and dry strength in dry-wet process decreased. The analysis indicates that the main reason of reduction of strength and waterproof properties is that the poorer crystallization and more pores in hardened recycled gypsum.