掺轻砂内养护剂的微膨胀混凝土性能研究

Research on Performance of Micro-Expansive Concrete Mixed with Light Sand Internal Curing Agent

为配制地铁车站叠合式墙板低收缩抗裂混凝土,本文在优化配合比基础上,采用内养护剂与膨胀剂的复掺技术,研究了掺内养护剂的C40微膨胀混凝土的工作性、力学性能和变形性能。试验结果表明,优化配合比参数,掺适量的膨胀剂对混凝土工作性和力学性能有明显改善;掺内养护剂对中高强膨胀混凝土具有明显的协同膨胀效应;采用密度大、吸水率高的轻砂内养护剂,可均匀分布于混凝土中,促使膨胀剂和胶凝材料的充分水化,有效提高混凝土的力学性能和变形性能,其内养护效果优于SAP内养护剂。

In order to prepare low-shrinkage and anti-cracking concrete for subway station superposed wall panels, this paper uses the compounding technology of internal curing agent and expansion agent on the basis of optimizing the mix ratio to study the workability and mechanics of C40 micro-expansion concrete with internal curing agent performance and deformation performance. The test results show that optimizing the mixing ratio parameters and adding an appropriate amount of expansive agent can significantly improve the workability and mechanical properties of concrete;adding internal curing agent has obvious synergistic expansion effect on medium and high-strength expansive concrete;adopting light weight with high density and high water absorption, the sand curing agent can be evenly distributed in the concrete to promote the full hydration of the expansion agent and the cementitious material, effectively improving the mechanical properties and deformation properties of the concrete, and its internal curing effect is better than the SAP internal curing agent.