CA砂浆强度影响因素及强度机理研究

Factors influencing strength of cement asphalt mortar and strength mechanism

为制得满足高速铁路建设的CA砂浆,制备了不同配比的CA砂浆,通过考查CA砂浆的强度并利用扫描电子显微镜观测微观结构,研究砂的级配、砂灰比、乳化沥青与水泥比等因素对CA砂浆固化体不同龄期强度的影响.研究表明:选择粒径为0.15～0.3 mm与0.3～0.6 mm的组合砂能有效地降低高强型CA砂浆材料的分离度,而对CA砂浆28 d的抗压强度的影响不大;随着砂灰比的增大,高强型CA砂浆1 d抗压强度增大,当砂灰比超过1.4时,CA砂浆28 d抗压强度明显降低;随着乳化沥青与水泥质量比的增大,高强型CA砂浆各龄期的抗压强度都显著下降.选择合适粒径的砂,合理的砂灰比和乳化沥青与水泥质量比是制得满足高速铁路建设要求的CA砂浆的前提.

In order to obtain the CA mortar that can satisfy high-speed railway construction, CA mortar with different proportion was prepared. Through studying strength of CA mortar and Observating its microstructure by scan electron microscopy, the strength and its development of CA mortar was studied by changing sand gradation, the ratio of sand to cement and the ratio of asphalt emulsion to cement. Results show that using combination of two kinds of sand with particle size of 0. 15 - 0. 3 mm and 0.3 - 0.6 mm in CA mortar can reduce the material separation greatly while posing little effect on the 28 d compressive strength of high strength CA mortar. With the increment of m （S） / m （ C）, the 1 d compressive strength of high strength CA mortar increa- ses but the 28 d compressive strength doesn＇ t change initially until reaching the critical point 1.4, which drags huge decline for it. The compressive strength of high strength CA mortar of different ages are significantly declining with the increment of m （A） / m （ C ）. Selecting the appropriate size sand, m （S） / m （C） and m（ A）/m （C） is the premise to obtain the CA mortar that can satisfy hizh-sDeed railway construction.