Study On Mechanical Properties And Mechanism Of SAC Solidified Soft Soil

The solidification of marine soft soil is an important link in the construction of offshore infrastructure.Sulphoaluminate cement(SAC)has the characteristics of fast hardening and early strength,hardened paste resistant to seawater erosion,etc.It is suitable for the field of marine engineering.At this stage,there are many studies on the mechanical properties of SAC solidified soil,but the performance optimization methods and gelation mechanism of SAC-based curing agents have not been systematically developed.Based on the macro-mechanical test and micro-test,this paper studies the mechanical properties and solidification mechanism of SAC solidified soil.By changing the amount of gypsum in SAC,the influence of gypsum content on the mechanical properties,hydration product composition and microstructure of SAC solidified soil was analyzed.By comparing the unconfined compressive strength and hydration products of different contents of SAC and ordinary Portland cement(P.O)cured soil,the differences in mechanical properties and curing mechanism of different types of cement cured soil were explored.By analyzing the unconfined compressive strength of SAC and P.O solidified soils at different curing temperatures,the effect of temperature on the early strength development of the solidified soils was studied,and the primary and secondary order that affected the strength of SAC solidified soils was found.The main research results of this article are as follows:(1)The optimal gypsum content of SAC.By changing the admixture of gypsum in SAC,the unconfined compressive strength of SAC solidified soil under different admixtures of gypsum is compared,and the optimal admixture of gypsum is found;(2)The solidification mechanism of SAC solidified soil.By analyzing the changes in mineral composition and microstructure of SAC solidified soil,combined with the results of mechanical tests,the solidification mechanism of SAC solidified soil was explored;(3)The best curing temperature of SAC solidified soil and P.O solidified soil.By comparing the strength of the solidified soil under different curing temperatures,the optimal curing temperature of the solidified soil was found.