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为解决软土地基上修建高速公路时常出现的较大沉降及路桥衔接处差异沉降引起的桥头跳车等工程问题,同时着重考虑节能环保,达到节约建筑材料的目的,提出并设计了泡沫流态粉煤灰这一新型轻质建筑材料。通过系统的试验,在材料配合比初步设计的基础上,分析了泡沫流态粉煤灰的密度、抗压强度、水稳定性、冻融稳定性等技术性能,以及配合比对材料各项技术指标的影响规律,提出了三种推荐采用的泡沫流态粉煤灰配合比。试验结果表明:发泡剂、水泥的掺入量、含水量均对泡沫流态粉煤灰的技术性能具有显著影响;当发泡剂含量从0增加到含水量的1/30时,泡沫流态粉煤灰的干密度、7 d龄期抗压强度、水稳定系数和冻融稳定系数(BDR)分别降低了23%、50%、10%~15%和20%左右;当水泥含量8%提高至20%时,7 d龄期抗压强度、水稳定系数和冻融稳定系数(BDR)分别提高了58.1%、38.2%和20.9%;当含水量从40%提高至60%时,干密度降低了约25%,推荐配合比的泡沫流态粉煤灰干密度比普通土低40%以上。表明泡沫流态粉煤灰是一种良好的轻质建筑材料。
In order to solve the engineering problems such as the large settlement often appearing on the expressway when soft soil foundation is built and the bridgehead jumping caused by the differential settlement between the road and bridge, and considering the energy conservation and environmental protection and saving the building materials, a foam flow regime Fly ash, a new lightweight construction material. Through systematic experiments, based on preliminary design of material mix, the technical performance of foam fluidized fly ash, such as density, compressive strength, water stability, freeze-thaw stability and other technical performance, Indicators of the law of the impact of the proposed three kinds of foam fluidized fly ash with the ratio. The experimental results show that the foaming agent, the incorporation of cement and the water content have a significant effect on the technical performance of foamed fly ash. When the content of foaming agent increases from 0 to 1/30 of the water content, Dry ash density, 7-day age compressive strength, water stability coefficient and freeze-thaw stability coefficient (BDR) decreased by 23%, 50%, 10% -15% and 20% The compressive strength, water stability coefficient and freeze-thaw stability coefficient (BDR) increased by 58.1%, 38.2% and 20.9% at 7 days, respectively, when the moisture content increased from 20% to 20%. When the moisture content increased from 40% to 60% The dry density is reduced by about 25%. It is recommended that the dry density of the fly ash with the compounded ratio is more than 40% lower than ordinary soil. Foam fluidized fly ash is a good lightweight construction material.