水对水泥乳化沥青砂浆静态力学性能的影响

Effect of Water on Static Mechanical Properties of Cement Emulsified Asphalt Mortar

为了研究水对水泥乳化沥青砂浆(SL砂浆)静态力学性能的影响,采用阳离子型(A1)、复合离子型(A2)和阴离子型(A3)3种乳化沥青制备了沥青与水泥质量比(mA/mC)为0.3、0.5、0.7和0.9的SL砂浆圆柱体试件,将其真空吸水饱和后经低湿和恒湿两种干燥方法获得不同饱水度,再对不同饱水度的试件进行抗压试验。结果表明:SL砂浆的饱和体积吸水率均大于10%,且与mA/mC值和乳化沥青种类有关;其抗压强度和弹性模量随饱水度增加而显著降低,且抗压强度降低幅度较大,最大可达40%以上;mA/mC值越大,力学性能降低幅度也越大。3种乳化沥青制备的试件中,A1试件降低幅度最大,A3试件次之,A2试件最小。提高SL砂浆抗水性的关键是增强界面结合力和减小吸水率。

Effect of water on the static mechanical properties of cement emulsified asphalt mortar （SL mortar） was investigated. Some mortar specimens with different mass ratios of asphalt/cement （i.e., mA/mc = 0.3, 0.5, 0.7, 0.9） were prepared by three kinds of emulsi- fied asphalt with cation （A1）, anion （A3） and compound ion （A2）. The mortar specimens were dried in either a low-humidity room or a constant humidity dryer to ensure the moisture content, respectively, after being saturated by water in a vacuum chamber. The com- pressive stress vs strain curve, the compressive strength and elastic modulus of these mortar specimens were obtained. The results show that the saturation moisture content of SL mortar specimens can be greater than 10%, depending on mA/mc and the type of emulsified asphalt. The compressive strength and elastic modulus of the mortar specimens decrease considerably with increasing the moisture content, and the maximum reducing degree of their compressive strength is up to 40%, which is greater than that of elastic modulus. Moreover, it is indicated that the reducing degree of the static mechanical properties of the mortar specimens is correlated to rnA/mc and the type of emulsified asphalt. The greater mA/mc of a mortar specimen, the more its reducing degree will be. Due to the effect of emulsified asphalt on the reducing degree of the static mechanical properties, the emulsion of asphalt with cation occupies firstly, and then the emulsion with anion comes, and finally the emulsion with both cation and anion takes place. The water resistance of SL mortar can be improved via the increase of the adhesion strength of the organic-inorganic phase interfaces and the decrease of the moisture saturation.