乳化沥青干燥过程的影响因素

Influence factors of drying process for emulsified asphalt

基于乳液干燥成膜理论研究乳化沥青干燥过程,分析干燥过程的影响因素,探讨乳化沥青干燥过程与稳定性之间的关联关系。结果表明:乳化剂掺量和皂液pH值对乳化沥青的干燥过程影响较小,而干燥温度和试样厚度对干燥过程影响较大;厚度10 mm的乳化沥青试样与厚度3 mm试样初始干燥速率相近,但3 mm试样干燥至水分临界状态体积分数(φm)的时间是10 mm试样的1.2倍;60℃时乳化沥青试样初始干燥速率约为30℃时的4.2倍,而干燥至φm的时间只需30℃时的约1/4;乳化沥青1 d贮存稳定性越差,平均粒径越大,zeta电位越小,水分临界状态体积分数φm越小,表明乳化沥青越不稳定,越容易破乳,相同条件下水分干燥的越充分。

The drying process of emulsified asphalt was studied on the basis of emulsion drying film theory,and the influencing factors of drying process were analyzed.The relationship between drying process and stability of emulsified asphalt was discussed as well.The results show that the emulsifier content and pH value of soap solution have little effect on the drying process of emulsified asphalt,while the drying temperature and sample thickness present great influence.The initial drying rate of 10 mm thick emulsified asphalt sample is similar to that of 3 mm thick sample.However,the drying time of 3 mm sample to the critical moisture volume fraction(φm)is 1.2 times that of 10 mm sample.The initial drying rate of emulsified asphalt sample at 60℃is about 4.2 times that at 30℃,and the drying time toφm is only about 1/4 of that at 30℃.The worse the 1d storage stability of emulsified asphalt is,the larger the average particle size is,the smaller the zeta potential is,and the smaller the critical state volume fractionφm of asphalt moisture is.It indicates that the more unstable the emulsified asphalt is,the easier the demulsification is,and the more sufficient the moisture is dried under the same conditions.