为解决软土地基上修建髙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-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、水泥的掺人量、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、7d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%提髙至20%时,7d龄期抗压强度、水稳定系数和冻融稳定系数(BDR)分别提髙了58.1%、38.2%和20.9%;当含水量从40%提髙至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-种良好的轻质建筑材料.
In order to solve the engineering problems like large settlement that occurred when expressway was constructed on soft ground and bridgehead jump caused by settlement difference between road and b r id g e ,and to save construction materials and energy ,a new type of lightweight construction material named foamed fluid fly ash is proposed. On the basis of preliminary mix design,the technical properties of the foamed fluid fly ash, which include den sity, compressive strength,wear stability and freeze-thaw stabi l ity ,were analyzed through systemic experiments. And the effect of mix proportion on the properties was ana ly zed,too. Three mix proportions of the foamed fluid fly ash were recommended. The test results show that the content of foaming a g en t ,cement and water have a significant effect on the performance of the foamed fluid fly a sh. When the foaming agent content increased from 0 to 1 / 30 ,the dry d en sity,7 d-age compressive strength, water stability coefiicient and freeze-thaw stability coefiicient of the foamed fluid fly ash were reduced by 23 % ,50%,10% -23% and 20%,respectively. When the cement content increased from 8 % to 2 0 % , the 7 dage compressive strength,water stability and freeze-thaw stability coefficient were increased by 58.1%,38.2% and 20. 9%,respectively. When the water content increased from 40% to 60 %,the dry density of the foamed fluid fly ash was decreased by about 25% . The dry density of the foamed fluid fly ash under the recommended mix proportion was 40% lower than that of the ordinary soi l. The foamed fluid fly ash is a nice and lightweight construction material.