Development And Application Of The Existing Subgrade Chemical Powder Desiccant

Water content of subgrade within highway operation period，in the dynamicchange of state, and growing. Subgrade soil moisture content above theoptimum moisture content, there was excess water in the subgrade, would leadto the subgrade marshy, lack of stability, a significant impact on the subgradeand pavement. Now, for excess water within subgrade, the mainly rely on thedrainage facilities initial set when subgrade constructed, to guide, seepagedewatering, eliminate; Or use reinforcement treatment technologies, such asgrouting, replacement extrusion pile, when the subgrade seriously damaged.When the subgrade internal soil water content was significantly greater than theoptimum moisture content, but cannot rely on the guidance, seepage and otherdrainage measures exclude, still not enough to use reinforcement treatmenttechnologies, study less. But this part of the water if not timely treatment, cansignificantly affect the subgrade strength and bearing capacity. To this end, forthis part of the water and the problems caused by, should according to principleof simple construction, small bills, to explore the subgrade soil moisture treatment technique.In this study, using chemical dehumidification principle, prepared the SCPdesiccant, used to remove moisture within subgrade of moisture content greaterthan the optimum moisture content, but cannot rely on the drainage facilities toguide to exclude. Through the chemical test, studied the component material,component ratio preparation and nature of the SCP desiccant, derived: the SCPdesiccant were made of calcium oxide, aluminum powder and other fourmaterials, calcium oxide content should be of20%to45%, aluminum contentshould be35%to45%; Using laboratory test simulation of subgrade soilsamples, analyzed impacts of the SCP desiccant on soil moisture, soiltemperature and soil density, obtained: the SCP desiccant could reduce the soilmoisture content, elevated soil temperature, increased soil dry density andstrength, on the basis of it, analyzed the mechanism of action of the SCPdesiccant, that were dehumidification and reinforcement; according toconstruction and observations of test road, presented construction technologiesof plane layout, size requirements, construction process control, inspection afterconstruction, when SCP desiccant Treatment existing subgrade constructed, and analyzed the social and economic benefits of technology of SCP desiccanttreatment of the existing subgrade, established foundation for applications of thetechnology.