同流动度下高效减水剂对硫铝酸盐型膨胀剂效能的影响

研究在流动度基本相同的条件下,萘系、氨基及聚羧酸高效减水剂对硫铝酸盐型膨胀剂效能的影响。结果表明,高效减水剂和硫铝酸盐型膨胀剂复合使用时,可提高砂浆28 d抗压强度,但会降低膨胀剂的限制膨胀率,增大水养28 d膨胀指数,从而降低其有效膨胀能。因此,在膨胀剂掺量相同的情况下,复合使用高效减水剂会削弱硫铝酸盐型膨胀剂对混凝土的补偿收缩作用或产生的自应力,故高效减水剂与膨胀剂复合使用时,要达到单掺膨胀剂时的膨胀效果,需适当加大膨胀剂的用量。

Influence of superplasticizer on performance of sulfo-aluminate expansion agent under same fluidity

The influence of naphthalene series,amino sulfonic and polycarboxylate superplasticizer on the performance of sulfo-aluminate expansion agent were investigated under the condition of same fluidity.The results show that superplasticizer used together with sulfo-aluminate expansion agent can enhance the compression strength at 28 d,but reduce restrained-expansion rate of expansion agent,and increase expansion index in water cure at 28 d,thus resulting in the reduction of efficient expansion energy of expansion agent.Therefore with same amount of expansion agent,compound use superplasticizer can decrease the shrinkage-compensation action or self-stress of sulfo-aluminate expansion agent for concrete.When expansion agent is used together with superplasticizer,the amount of expansion agent should be increased suitably in order to obtain the same expansion effect as adding single expansion agent.