Study on Composition Design and Curing Mechanism of Curing Agent Based on Characteristics of Aeolian Sand

The particles of aeolian sand are round, uniform and small, smooth surface, difficult to compact and it's weak cementation with curing agent, so it is difficult to cure and it's serious shrinkage. By studying the effects of slag size and admixing quantity of slag, modulus and alkali equivalent of alkali activator and SO3admixing quantity of curing agent on the strength and shrinkage of solidified aeolian sand, a special curing agent suitable for aeolian sand was developed, and its action mechanism was revealed by means of XRD, SEM, NMR and MIP. The results show that the strength of solidified aeolian sand can be significantly improved by adding ground slag, introducing alkali excitation system and increasing the admixing quantity of SO3, and its drying shrinkage can be reduced. Compared with ordinary P. 042. 5 water mud, the 28 d uncon-fined compressive strength can be increased by 73. 8%, while the 28 d drying shrinkage strain decreased by 40. 8%. The micro test results show that the curing mechanism of the special curing agent for aeolian sand is that the pores between aeolian sand are filled with ground slag powder to improve the pore structure of solidified aeolian sand and that the cement alkali excitation system is adopted to enhance the cementitious performance of curing agent and improves the interface between the curing agent and aeolian sand and that SO3is introduced to promote the formation of AFt crystal and fills the internal pores of solidified aeolian sand to compensate for shrinkage. © 2022 Cailiao Daobaoshe/ Materials Review. All rights reserved.