Experimental Study On Stabilization Of Loess In Shaanxi Province By Adding Fly Ash

Most areas of China are covered with loess,according to the statistics,it covers approximately 640,000 km~2 which nearly 6.6%of China's land area.The loess area has already become the main fields where people exploit in northern and western part of China,so there are a lot of construction engineering and economic activities.Moreover,as the growing demand of the electricity power in China,the total amount of fly ash discharged by the coal-fired power plant as one kind of secondary product is increasing,which put a severe threat to the environment of China.Thus,this research is studying the influences of the amount of fly ash added on the mechanism of loess.Fly ash has recently been demonstrated to be effective for chemical and mechanical stabilization of soils.However,this conclusion is still unclear by without investigated on comparison between submergence and non-submergence.In this research,the influence of fly ash(FA)content(0%,10%,20%,and 30%)on the alteration in the physical and mechanical parameters of loess is investigated.The influences of curing time(0,14,and 28 days)and submergence and non-submergence conditions are investigated likewise.Analysis think through the deviation in Atterberg limits(plasticity index,plastic limit,and liquid limit),compaction parameters(optimum moisture content(OMC)and maximum dry density(MDD)),unconfined compressive strength(UCS)stress,UCS strain,California bearing ratio(CBR)value,and swell potential.Results confirm that the tender of FA stabilized loess(FASL)is effective.1)As the increasing amount of fly ash,liquid limit and plasticity index first increase and then decrease,while the plastic limit shows the opposite trend.And all reach the top when the amount of fly ash is nearly 20%.2)As the increasing of fly ash content,the optimum moisture content(OMC)increases while the maximum dry density(MDD)decreases.The specific gravity of fly ash was lower than that of loess.Thus,the specific gravity of loess mixed with fly ash was decreased with the increase in the amount of fly ash;this condition decreased the maximum dry density.3)As the increasing of fly ash content,the UCS stress increases and the UCS strain decreases.4)As the increasing of fly ash content,the California bearing ratio(CBR)value improves and the swell potential declines.5)The UCS stress and CBR value are improved with the increase in curing time,whereas the UCS strain is negligible.FASL under submergence condition plays an important role in improving the effect of fly ash on the UCS stress and CBR value compared with that in non-submergence condition.The UCS stress and CBR value are more increased and more decreased than the UCS strain in submerged samples.Therefore,the application of FASL in flood areas is important for obtaining sustainable construction materials and ensuring environmental protection.