Evaluation on the Fluidity and Strength of Recycled Aggregate Concrete with High Quality Fly Ash as Industrial Byproduct

Abstract

This study aims to improve the mechanical function of recycled aggregate concrete that applied high-quality fly ash, which presents relatively stable quality by maintaining loss ignition below 1% by eliminating combustible carbon and obtained following results. As a result of the test according to the changes in high-quality fly ash ratio, as the ratio of high-quality fly ash increased, the liquidity enhanced. From the results of strength development of recycled aggregate concrete, compressive strength increased with increasing age and, when high quality fly ash is added, the Pozzolan reaction indicates a high strength increase even after 91 days of age. On the other hand, the reason why compressive strength is reduced due to replacement of recycled aggregates is that the properties of the recycled aggregate itself are lower than those of the natural aggregate, and it is judged that destruction occurs first at the surface prior to destruction of aggregates or mortar. Compressive strength according to the replacement rate of high quality fly ash tends to increase almost linearly. If high quality fly ash is used in recycled aggregate concrete, it is deemed that up to 28 days, the filling effect by the addition of high quality fly ash and the strength enhancement by the Pozzolan reaction is also exerted in 91 days.