Abstract：To study the influence of fly ash on the mechanical properties, failure mode, microstructure and mesostructure of Pisha-sandstone cement soil, unconfined compressive tests were carried out on Pisha-sandstone composite cement soil with different fly ash content and different ages, the microstructure and apparent morphology of composite fly ash and Pisha-sandstone cement soil were analyzed and observed by a scanning electron microscope(SEM)and a 3D microscope with super depth of field. The results show that the proper amount of fly ash can promote the formation of the strength of the Pisha-sandstone composite cement soil. The stress-strain curve of composite fly ash and Pisha-sandstone cement soil can be divided into compaction stage, elastic stage, plastic yield stage and failure stage. The incorporation of fly ash is conducive to the increase of the deformation modulus of cementsoil, and can promote the deformation control of Pisha-sandstone composite cementsoil. The scanning electron microscope and super-depth three-dimensional microscope analysis shows that the active material in the fly ash glass body reacts with the cement hydration product calcium hydroxide in a strong alkali environment to generate a dense and stable C-S-H gel and AFt to form a network structure, promote the internal cementation of the specimen to be tighter, and the apparent gully holes are filled and compacted, thereby the strength of the Pisha-sandstone composite cement soil are improved, meanwhile its crack propagation and destruction are inhibited.
杨健,李晓丽*,王辉,耿凯强. 复合粉煤灰砒砂岩水泥土力学性能室内试验研究[J]. 排灌机械工程学报, 2021, 39(12): 1230-1236.
YANG Jian,LI Xiaoli*,WANG Hui,GENG Kaiqiang. Indoor experimental study on mechanical properties of composite fly ash and Pisha-sandstone cement soil. Journal of Drainage and Irrigation Machinery Engin, 2021, 39(12): 1230-1236.
