基于外加剂的水泥砂浆塑性收缩开裂本构关系的研究

Research on Influence of Admixture to the Constitutive Equation of Plastic Shrinkage Cracking of Cement Mortar

研究了水泥常用外加剂对砂浆塑性收缩性能的影响。实验表明，当引气剂掺量在0-200×10^-6时，引气剂掺量与抗裂指数成正比，当掺量达到250×10^-6以上时，砂浆开裂；早强剂不利于减少砂浆塑性收缩开裂；减水剂、保水剂可减缓砂浆塑性开裂；建立了引气剂、早强剂、减水剂、保水剂、缓凝剂掺量与砂浆塑性收缩参数及开裂时间的本构关系。

The influence of admixture to plastic shrinkage cracking was studied. The results show that the content of air-entraining agent and anti cracking index are proportional when the content of air-entraining agent is lower than 200×10^-6. The cement mortar cracks when air-entraining agent content is up to 250×10^-6. Early strength accelerator counts against reducing the plastic shrinkage cracking of cement mortar, water-reducing agent, water-retaining agent and retarder can reduce the plastic shrinkage cracking of cement mortar. The constitutive relations between the content of air-entraining agent, content of early strength accelerator, content of water-reducing agent, content of water-retain agent, content of retarder and its anti-cracking index have been built.