Study On Self-Compacting Light-aggregate High Performance Concrete

Self-compacting light aggregate high performance concrete (abbreviated SCLC ) is a new type of HPC with the dry apparent density of less than 1950 kg/m3,which can be made by replacing ordinary aggregete with light aggregate and adopting a new design of concrete mix on the basis of ordinary self-compacting concrete.In the paper, the main technical indexes of light aggregate used in SCLC were tested and the main characteristics of light aggregate concrete were introduced. Based on the principles of designs of self-compacting and light aggregate concrete mix, SCLC of LC30-LC50 was developed by using absolute volume method. The main factors affecting the workability of SCLC were studied by adopting the modified L-800 fluidity instrument. The results indicate that the key techniques insuring good workability of SCLC are about 30% first-grade fly ash, about 50% volume sand ratio, 2%~6% dosages of silicon fume and compounded superplasticicizers with viscous ingredient. The delamination phenomenon of mixture was studied by adopting the mixture delamination instrument. It is suggested that adding compounded superplasticicizers with viscous ingredient is the main measure preventing mixture from delamination. Mechanical properties and durability of SCLC were studied and contrasted to ordinary concrete. Combining with workability and mechanical properties of SCLC, it is pointed out that light aggregate with coarse surface and rotund shape satisfies the needs of SCLC performance more easily.