河南省科技攻关项目 黄河中游流域（河南段）土遗址劣化机理及修复技术研究；河南省科技攻关项目 中原地区砖砌体古建筑劣化机理与修复技术研究
1.土木建筑学院;2.College of civil engineering and architecture, Henan University
Research on the deterioration mechanism and restoration technology of earthen sites in the middle reaches of the Yellow River Basin (Henan Section) in Henan Province; deterioration mechanism and restoration technology of ancient brick masonry buildings in Central Plains of Henan Province
There are many earthen sites in the lower reaches of the Yellow River, but they are seriously damaged. The earthen ruins soil is mostly silty clay, which has unfavorable characteristics such as loose structure, low strength, strong capillary action and poor water stability. How to improve the performance of the earthen ruins soil is of great concern. Based on the relevant documents and the principle of biomineralization, the research team selected glutinous rice slurry, quartz sand, alumina and calcium fluoride as the additional materials to improve the silty clay of Qicheng site and prepare the imitated site soil. The mechanical properties, microstructure and color difference of the imitated ruins soil under the concentration of 0%, 1%, 3%, 5%, 7%, and 9% glutinous rice slurry were studied.The research results showed that with the increase of the concentration of glutinous rice slurry, the strength and internal friction angle of soil samples increased first and then decreased, and the cohesion showed a linear increasing trend. Imitated site soil improved by 3% concentration of glutinous rice slurry had the largest shear strength, unconfined compressive strength and internal friction angle, and it showed a more compact microstructure and a better crystallization effect of calcium carbonate. The color difference analysis of the sample showed that the color difference between the imitated site soil, imitated site soil improved by 3% concentration of glutinous rice slurry and the site soil is unobvious. Using glutinous rice slurry to improve the MICP technology, it was found that glutinous rice slurry can increase the activity of bacteria and promote the production of calcium carbonate. Alone with the increase of maintenance days, the strength of modified MICP soil continued to improve, and the biomineralization time was longer.