养护条件对CA砂浆微观结构及强度的影响规律  

Effect of curing conditions on microstructure and strength of CA mortar

作　　者：金珊珊 赵耀东 张扬 徐增淼 JIN Shanshan;ZHAO Yaodong;ZHANG Yang;XU Zengmiao(School of Civil and Transportation Engineering,Beijing University of Architecture,Beijing 100044,China;Beijing Urban Transportation Infrastructure Engineering Technology Research Center,Beijing 100044,China)

机构地区：[1]北京建筑大学土木与交通工程学院,北京100044 [2]北京市城市交通基础设施建设工程技术研究中心,北京100044

出　　处：《混凝土》2024年第9期157-162,共6页Concrete

基　　金：国家重点研发计划项目(2022YFC3803400);国家重点研发计划项目(2021YFB2601200);北京市教育委员会科学研究计划项目(KM202110016011)。

摘　　要：为探究养护条件对水泥乳化沥青砂浆微观结构及抗压强度的影响规律,设置了干养((25±2)℃,湿度(65±5)%)与湿养((25±2)℃,湿度(90±5)%)2种不同的养护条件,通过抗压强度试验、环境扫描电镜(SEM)、低场核磁共振(NMR)对不同养护条件下的CA砂浆抗压强度、微观形貌、孔隙结构进行了测试。研究结果表明:干养状态下的CA砂浆在各龄期下抗压强度均显著高于湿养状态下的CA砂浆;微观结构测试结果显示养护条件造成的湿度差异以及沥青的综合作用显著影响了CA砂浆的水化过程,在干养的CA砂浆中形成了独特的有机-无机互穿蜂窝结构,使其在较大的孔隙率下,仍能获得较高的抗压强度。因此在实际的工程中,应尽量避免在潮湿的环境下浇筑CA砂浆,以提高成型后CA砂浆的抗压强度。To analyze the influence law of curing conditions on the microstructure and compressive strength of cement emulsified asphalt mortar,two different curing conditions were set,including dry curing condition((25±2)℃,humidity(65±5)%)and wet curing condition((25±2)℃,humidity(90±5)%).The compressive strength,microscopic morphology,and pore radius distribution of CA mortar under different curing conditions were tested by compressive strength test,environmental scanning electron microscopy(SEM),and low-field nuclear magnetic resonance(NMR)respectively.The results showed that the compressive strength of CA mortar under dry curing condition was significantly higher than that of CA mortar under wet curing condition at all curing ages.The microstructure test results showed that both the water content difference of curing condition and the combined effect of asphalt significantly influenced the hydration process of CA mortar.Therefore,a unique organic-inorganic interpenetrating honeycomb structure was formed in the CA mortar under dry curing condition,which enabled it to obtain higher compressive strength even with a large porosity.Therefore,CA mortar should be avoided to be poured under wet environment as far as possible to improve its compressive strength.

关 键 词：水泥乳化沥青砂浆 养护条件 抗压强度 SEM NMR 

分 类 号：TU528.064[建筑科学—建筑技术科学]