The admixture for preventing the spalling for enhancing fire-resistance of concrete and the concrete composition that the admixture is included

摘要

A concrete-spalling preventive admixture and a concrete composition including the same are provided to reduce the amount of organic fibers used and to prevent the consistency degradation of high-strength concrete. A concrete-spalling preventive admixture contains waste tire micropowder(10). The minute powder is prepared by thermally decomposing the waste tire. The particle size of the waste tire micropowder is 0.6-3mm. The concrete-spalling preventive admixture additionally contains an organic fiber(20) and a steel fiber(30). A concrete composition contains the concrete-spalling preventive admixture. The 2-4 vol% of the waste tire micropowder is added per unit volume of the concrete.