聚羧酸高效减水剂对泡沫混凝土性能影响试验研究

Experimental research on effect of poly carboxylic acid water reducing agent on performance of foamed concrete

以普通硅酸盐水泥为胶凝材料,掺入聚羧酸高效减水剂,采用物理发泡技术制备泡沫混凝土,研究了聚羧酸高效减水剂掺量对泡沫混凝土抗压强度、弹性模量、流值、气孔结构的影响。结果表明:在水灰比不变的条件下,泡沫混凝土的流值随着聚羧酸减水剂掺量的增加而增大,较小的掺量即可使泡沫混凝土获得较大的流值;聚羧酸高效减水剂可显著改善泡沫混凝土的气孔结构,使得气孔细小且分布较均匀,孔壁结构完整;随着水灰比的减小,聚羧酸减水剂掺量的增加,泡沫混凝土的抗压强度和弹性模量均呈现出先增大后减小的趋势,当水灰比为0.5,聚羧酸减水剂掺量为0.08%,较未掺减水剂试样的抗压强度提高44.1%。

Foamed lightweight concrete was prepared by introducing preformed foam into ordinary Portland cement slurry with poly carboxylic acid water reducing agent. The effect of poly carboxylic acid water reducing agent on the compressive strength,e- lastic modulus,flow value, and pore structure were researched. Test results illustrated that the flow value of foamed lightweight con- crete increased with the increment of poly carboxylic acid water reducing agent under the same water cement ratio and foamed lightweight concrete could achieve larger flow value with smaller mixing amount. The poly carboxylic acid water reducing agent had an obvious effect on the pore structure,decreasing the pore diameter, achieving more uniform distribution of air voids and integrat- ing the pore wall. The compressive strength and elastic modulus increased at first then decreased as the decrease of the water ce- ment ratio and increase of poly carboxylic acid water reducing agent. When the water cement ratio was 0.5 and the addition amount of poly carboxylic acid water reducing agent was 0.08%,the compressive strength could be raised by 44.1%.