CA砂浆抗冻性能的影响因素研究

Influence Factors on Freezing and Thawing Durability of Cement Asphalt Mortar

为提高CA砂浆的抗冻性能,研究了各组成材料对其抗冻性的影响。结果表明,沥青相对含量越高,抗冻性能越好,沥青乳液与水泥相对质量比(A/C值)从1.4增至1.7时,350次冻融循环相对弹性模量分别降至75%和92%;随着冻融循环次数的增加,CA砂浆质量呈增加趋势,沥青相对含量越高,冻融循环后质量增加率越小;但采用硫铝酸盐水泥(SAC)代替普硅水泥(C)制备的CA砂浆抗冻性较差,350次冻融循环剩余相对弹性模量45%—55%;相对于基准CA砂浆的抗冻性能,加入橡胶粉(CRB)、聚合物胶粉(P3)、有机纤维(FR)和硅灰(SF)能提高CA砂浆的抗冻性能,提高幅度以CRB最大,FR次之,P3更次之,SF最小。

In this paper, freezing and thawing resistance of CA mortar was investigated and statue influential factors such as asphalt emulsion and cement ratio （A/C）, cement types, various additives were also explored. Results indicated that mixtures with a higher A/C performed better in terms of higher relative elastic mcxiuli （REM）. After 350 cycles of freezing and thawing, REM decreased to 75 % and 92 % respectively for mixtures of 1.4-A/C and 1.6-A/C. A gain of mass was observed for every mixture after the test. Mixtures proportioned by partially replacing ordinary Portland cement （C） with sulfoalumninate cement （SAC） underperformed in freezing and thawing property, with a REM of 40%--50% after 350 cycles. Addition of crumb rubber powder （CRB）, redispcrsible powder （P3）, organic fiber （FR） and silica fume （SF） improved the resistance of （TA mortar to freezing and thawing and the effect was in a descending order.