表观密度对水泥基材料塑性收缩开裂性能及强度的影响  

Effect of Apparent Density on the Plastic Shrinkage Cracking and Strength of the Cement-based Materials

作　　者：马一平[1] 刘静静[1] 杨晓杰[1] 谭畅[1] 郭建平[1] 

机构地区：[1]同济大学先进土木工程材料教育部重点实验室,上海201804

出　　处：《材料导报》2014年第2期133-139,共7页Materials Reports

基　　金：国家重点基础研究发展计划(973)(2009CB623104-5);国家自然科学基金(51308406);中央高校基本科研业务费专项资金资助项目(0500219143)

摘　　要：采用物理发泡的方法研究影响轻质水泥基材料制备的因素,在水灰比为0.3、PCS-2速凝剂掺量14%、CaCl2掺量2.0%时,可制得轻质水泥基材料,其28d表观密度为85.9kg/m3时,抗压强度为0.063MPa;28d表观密度为97.7kg/m3时,抗压强度为0.077MPa;28d表观密度为113kg/m3时,抗压强度为0.12MPa;28d表观密度为144.5kg/m3时,抗压强度为0.25MPa。并探讨水泥基材料的表观密度对其收缩开裂性能的影响。结果表明:在一定范围内表观密度的下降可抑制其塑性收缩开裂;但密度低于276kg/m3,其收缩开裂程度严重。掺入0.6kg/m3的PP纤维,减裂率可达89.2%。The factors affecting the preparation of lightweight cement-based materials were investigated by physical foaming.Lightweight cement based materials were prepared,and their apparent density and compressive strength for 28 d reached to 85.9 kg/m3 and 0.063 MPa,97.7 kg/m3 and 0.077 MPa,113 kg/m3 and 0.12 MPa,144.5 kg/rn3 and 0.25 MPa,respectively,with the water-cement ratio of 0.3,PCS-2 accelerator of 14%,CaCl2 of2.0%.And the effects of cement-based materials＇ apparent density on its plastic shrinkage were discussed.The results indicated that the lower density of lightweight cement-based materials could reduce the degree of plastic shrinkage cracking within a certain range.However,the degree of shrinkage cracking became serious when the density was lower than 276 kg/m3.Using PP fiber of 0.6 kg/m3,the reducing rate of plastic shrinkage cracking could be up to 89.2%.

关 键 词：泡沫混凝土 塑性收缩开裂 表观密度 纤维 

分 类 号：TU525[建筑科学—建筑技术科学]