水泥和乳化沥青含量对水泥乳化沥青混合料性能的影响

Influence of Cement and Emulsified Asphalt Contents on Performance of Cement Emulsified Asphalt Mixture

为了研究水泥和乳化沥青含量对水泥乳化沥青混合料的性能影响,对不同水泥和乳化沥青掺量的混合料进行了宏观试验和微观观测,包括间接拉伸强度、抗压强度、回弹模量、拉伸强度比、动态稳定性、最大弯曲应变和Cantabro损失。此外,使用扫描电子显微镜(SEM)和计算机断层扫描(CT)获得了具有不同材料成分的水泥乳化沥青混合物的细观图像和空隙特征。结果表明:(1)当水泥含量恒定为3%,乳化沥青含量从6%增加到9%时,间接拉伸强度、抗压强度和弹性模量先增加后减小。在恒定的乳化沥青含量为8%,水泥含量从0增加到4%时,间接拉伸强度先增大后减小,当水泥含量为3%时,抗压强度和回弹模量均达到最大值。水泥的加入可显著提高沥青混合料的高温稳定性和水分稳定性,但不利于其低温性能。当水泥含量在2%和3%之间时,观察到最小的Cantabro磨耗。在水泥乳化沥青混合物中,水泥与沥青破乳后的水分进行反应,AFt与沥青薄膜交织形成网格结构,提高了混合物的水分敏感性和高温稳定性,另外,在不同水泥和乳化沥青含量的混合料中形成细观空隙结构也将影响机械性能和混合物性能。

In order to study the influence of cement and emulsified asphalt contents on the performance of cement emulsified asphalt mixture,the macro experiments and micro observations on the mixtures with different cement and emulsified asphalt contents,including indirect tensile strength,compressive strength,resilience modulus,tensile strength ratio,dynamic stability,maximum bending strain and Cantabro loss,are conducted.In addition,by using scanning electron microscopy(SEM)and computed tomography(CT),the microscopic images and void characteristics of cement emulsified asphalt mixtures with different material compositions are obtained.The result shows that(1)When the cement content is constant at 3%and the emulsified asphalt content increases from 6%to 9%,the indirect tensile strength,the compressive strength and the elastic modulus increase at first and then decrease.When the constant emulsified asphalt content is 8%and the cement content increases from 0 to 4%,the indirect tensile strength increases at first and then decreases.When the cement content is 3%,the compressive strength and the rebound modulus both reach the maximum value.(2)The addition of cement can significantly improve the high temperature stability and moisture stability of the asphalt mixture,but it is not conducive to its low temperature performance.The smallest Cantabro abrasion is observed when the cement content is between 2%and 3%.(3)In the cement emulsified asphalt mixture,cement reacts with the moisture after asphalt demulsification,and AFt interweaves with the asphalt film to form a grid,which improves the moisture sensitivity and high temperature stability of the mixture.The mesoscopic void structure formed in the mixtures with different cement and emulsified asphalt contents will also affect the mechanical properties and mixture properties.