Engineering Characteristics of Light-weight Foamed CLSM Using Coal Ash according to Final Mixing Time and Dilution Ratio

摘要

Controlled low strength material (CLSM) using coal ash, which has theadvantages of self-leveling, self-compacting, flowability, and easy reexcavation,has been developed. In this study, CLSM additionallymixed with foaming agent for structural backfill material, aimed atlightness of materials, was developed called light-weight foamedCLSM. As the basic study of this material, to determine the optimumfinal mixing time and dilution ratio of existing light-weight foamedCLSM, flow, slurry unit weight and unconfined compressive strengthtest according to each impact factor were performed at the standard mixproportion. As the results of tests, CASE N(Final mixing time 4 min,dilution ratio 2%), CASE O(Final mixing time 3 min, foam agents ratio3%, dilution ratio 2%) were satisfied with the standard of flowtest(above 20cm), slurry unit weight test(12～15kN/m~3) and unconfinedcompressive strength test(800kPa～1200kPa). These results will indicatethe standard optimum final mixing time and dilution ratio of lightweightfoamed CLSM for structural backfill.