The Study On Durability Of Glass Fiber And Fly Ash Composite Cement Soil

The cement composit soil is the economic, low-carbon and environmental protection materials for construction. It is widely used in many engeering fields, such as canal lining, foundation bedding ect.. This paper is maily about how to improving the cement soil durability by reinforcing glass fiber and fly ash into ordinary cemented soil. According to the data of research and analysis, we can get the durability of reinforcing mechanism of glass fiber and fly ash cemented soil in order to provide relevant scientific basis for applications of this kind of material in practical engeering.Firstly, orthogonal test design is needed. We preferentially selected25experimantal groups with typical characteristic to have orthogonal test. Through a series of statistics theoretical analysis, we calculated the following results:the cement content and age are the two main factors which bring great influnces on the unconfined compressive strength of glass fiber fly ash cemented soil, and the secondary factors are the content of glass fiber and fly ash. And according to the projects requirements, we select the best mix proportion of every material.Secondly, we used different concentrations of sodium sulphate solution to erode the glass fiber fly ash cement soil. Through a seires of analysis, we got the following conclusion:when the concentration of SO42-is very low, it will contribute to the strength of the cement soil. With the concentration of SO42-increasing, the unconfined compressive strength of cement soil will reduct significantly. By means of SEM technology, we analyzed its microstructure and have qualitative analysis for its mechanism. To fit its stress-strain curve equation can qualitatively analyze its strength changes.Thirdly, through the uniaxial and triaxial test under the freezing and thawing cycling and a series of theory analysis research, we can get the following conclusion by mutual confirmation of the two tests:the glass fiber fly ash cement soil’s resistance to freez and thaw is nearly3times higher than normal cement soil. By means of SEM technology, we analyzed its microstructure and have qualitative analysis for its mechanism. To fit its stress-strain curve equation and find the bonding and inner frictional angle curve relations can qualitatively analyze its ability of resistance to freez and thaw.Last, through the long-term following observation, we can get the following conclusions:with aging up, its quality presented a cubic polynomial fuction change trend; its unconfined compressive strength presented a power function development. Its duability is extremely good.