基于流变特性的CA砂浆工作性控制指标研究

Research on workability parameters of CA mortar based on the rheological properties

为了解决现有技术规范在CA砂浆施工过程中指导性不强的问题,运用流变学原理,从可灌注性、分离度及泌水3个因素出发,提出了CA砂浆的工作性控制指标。结果表明:剪切应力分别为40.65 Pa和23.13 Pa时流动度与扩展度的关系曲线是CA砂浆难灌注/可灌注和可灌注/易灌注的界限;屈服应力为5.5 Pa是控制CA砂浆离析的临界值,低于该值的砂浆易离析;流动度小于100 s,扩展度大于340 mm是控制CA砂浆泌水的界限。研究结论可为CA砂浆施工提供理论参考。

To solve the problem of weak guidance of existing technical standards in CA mortar construction process,new workability control parameters were proposed by researching perfusion capacity, segregation and bleeding of CA mortar by using the rheology principle. It indicates that the fluidity and expansion curves are unable to infusion boundary and easy to perfusion boundary respectively when shear stress are 40.65 Pa and 23.13 Pa, the yield stress of 5.5 Pa is critical value of controlling segre- gation,and it is easy to segregate when yield stress is lower than the value. Too low fluidity （lower than 100s） and too great ex- pansion degree（greater than 340 ram） lead to bleeding. Conclusions can provide theoretical reference for CA mortar construction.