การใช้เถ้าแกลบ-เปลือกไม้ในคอนกรีตที่ใช้มวลรวมที่ได้จากการย่อยเศษคอนกรีตเก่า

Abstract

In this study, ground rice husk-bark ash (RHBA) was used as a pozzolanic material in concrete containing recycled concrete aggregates. The concrete was prepared by using 100% of coarse recycled concrete aggregate (RCA), then river sand was replaced by fine recycled concrete aggregate (RFA) at 0, 50, and 100% by weight of the fine aggregate (river sand plus fine recycled concrete aggregate). The result revealed that recycled aggregate concrete had lower compressive strength than that of the conventional concrete (concrete made from normal aggregates). In addition, the use of ground RHBA in recycled aggregate concrete gave higher compressive strength than the recycled aggregate concrete without ground RHBA even though it increased the slump loss of concrete. The splitting tensile strength of the tested recycled aggregate concrete was about 8.15% of the compressive strength. Finally, the modulus of elasticity of the tested recycled aggregate concrete was lower than that of the conventional concrete and was about 4% lower than the value predicted by ACI 318.