减缩剂喷涂工艺对水泥基材料的减缩效果

Effect of Spraying Technology of Shrinkage Reducing Agent on the Drying Shrinkage of Cement-Based Materials

探讨了水泥基材料减缩剂喷涂工艺对水泥砂浆的减缩效果.结果表明:减缩剂喷涂对于水泥砂浆有很好的减缩效果.水泥砂浆脱模后在表面连续3 d喷涂3次30%(质量分数)的减缩剂溶液,1 d的减缩效果可以达到45%,28 d为22%.减缩剂喷涂工艺克服了内掺工艺影响水泥基材料强度的缺点,经喷涂减缩剂后的水泥砂浆抗压强度和抗折强度并未降低.另外,减缩剂喷涂工艺可减少减缩剂的使用量,降低成本.

The effect of spraying technology of shrinkage reducing agent （SRA） on the drying shrinkage of cement-based materials was studied. The results show that spraying of SRA on the surface of mortar can significantly reduce the drying shrinkage. After demolding, SRA solution with the concentration of 30% （by mass） was sprayed on the surface of mortar once each day in three days, the shrinkage reducing ratio can reach 45% at the 1st day, and 22% at the 28th day. The spraying of SRA on the surface of mortar overcame the shortcomings of strength decreasing when SRA was added during mortar preparation, however, the strength of the mortar sprayed SRA solution increased a little. In addition the spraying can reduce the usage and cost of SRA.