水泥基材料塑性阶段变形特性研究

摘要

利用波纹管研究了水泥基材料塑性阶段的变形行为，同时测试基体的毛细管负压发展规律，分析了变形特性与凝结行为。结果表明：非泌水状态下，浆体的塑性阶段收缩变形呈阶段性发展，存在特征拐点或区域，与毛细管负压发展具有强对应关系。低水灰比浆体的特征拐点更为明显，高水灰比浆体则存在特征区域，据此进行的凝结时间判定与维卡仪测试结果相近。泌水会影响浆体塑性阶段的变形历程，导致变形曲线特征不明显。%Deformation behavior measured by corrugated tube and development of capillary pressure were adopted to describe the defor-mation properties of cement-based materials during plastic stage,the relation between deformation properties and setting time was dis-cussed.Results indicate that plastic shrinkage of cement paste without bleeding is in phased development,the feature turning points and re-gion are observed preferential for cement paste with low and high water cement ratio,respectively,which are well correspondent to the de-velopment of capillary pressure.According to the features,setting time can be determined and the results are in a good agreement with the results obtained by vicat.The process of plastic deformation can be effect significantly by bleeding water,which resulting in indistinct fea-ture of deformation.