聚羧酸减水剂对机制砂混凝土的性能影响

Influence of polycarboxylate superplasticizer on mechanical sand concrete

为研究合成聚羧酸减水剂对大连湾海底隧道建设工程所用机制砂混凝土性能影响,针对合成聚羧酸减水剂不同生产工艺及复配不同实例,对机制砂石粉含量及不同含泥量适应性进行研究,并探究在实际工程中应用效果。针对大连湾海底隧道建设工程主体结构混凝土施工配合比,试验石粉含量对机制砂混凝土物理性能影响。试验结果表明:坍落度随石粉含量增加而减小;同时为保证相同的坍落度及1 h坍落度损失,随石粉含量增加,减水剂的掺量也需适当增加;当石粉含量达到一定限值时,应将该部分石粉计算至胶凝材料中,以确定配合比中减水剂实际使用量。经工程实际应用,EPEG工艺聚羧酸减水剂的混凝土表现出较好的保坍性以及和易性,且具有较好的适应性。

In order to study the influence of synthetic polycarboxylate superplasticizer on the performance of mechanical sand concrete used in the construction project of Dalian Bay Subsea Tunnel,according to different production processes and different cases of synthetic polycarboxylate superplasticizer,the content of mechanical sand stone power and the adaptability of different mud content were studied,and the application effect in practical engineering was explored.Regarding the concrete construction mix ratio of the main structure of the Dalian Bay Subsea Tunnel construction project,the influence of stone powder content on the physical properties of mechanism sand concrete was tested.The test results show the slump decreases with the increase of stone powder content.At the same time,in order to ensure the same slump and 1 hour slump loss,the dosage of water reducing agent needs to be appropriately increased with the increase of stone powder content.When the content of stone powder reaches a certain limit,the portion of stone powder should be calculated into the cementitious material to determine the actual amount of superplasticizer used in the mix proportion.Through practical engineering applications,the concrete treated with EPEG process polycarboxylate superplasticizer exhibits good slump retention and workability,and has good adaptability.