大流动性高性能轻集料混凝土的试验研究

Study of high performance lightweight aggregate concrete with high fluidity

为设计出具有大流动性的高性能轻集料混凝土,分别研究了胶凝材料用量、粉煤灰取代量和体积砂率等因素对轻集料混凝土工作性、密度和抗压强度的影响规律;采用700级粘土陶粒可配制密度等级为1700级,坍落度达200mm的CL30轻集料混凝土.该混凝土28d收缩率仅为45.5×10-6,快速冻融循环可超过300次,RCM法测得的氯离子扩散系数为2.59×10-12m2/s;而且工作性好,基本克服了陶粒的上浮问题.

In order to design high performance lightweight aggregate concrete with high fluidity, the influence of content of cement, content of flying ash, and sand volume ratio on the workability, density and compressive strength of lightweight aggregate concrete are studied. The expanded clay whose density grade is 700 can produce the lightweight aggregate concrete whose density grade is1700, the slump up to 200mm and strength grade is CL.30. The shrinkage rate after 28 days of this concrete is only 45.5 10^-6 ,and it can resist 300 cycles of accelerated freeing-thawing, the coefficient of EL-1 tested by RCM is 2. 59× 10^12 m^2/s. This concrete also has a good workability, and solves the problem of the floating up of lightweight aggregate.