土木与环境工程学报

Effect of Silica Fume on the Behavior of Lightweight Rc Beams Made from Crushed Clay Bricks

Abstract

Yahia M.S. Ali and Tarek Abdelaleem

Crushed Over-burnt Clay Bricks (COBB) is a promising alternative to the natural gravel aggregate in Light Weight Concrete (LWC) production because of its high strength-to-weight ratio. In addition, COBCB is considered a green aggregate by solving the problem of disposing of this solid waste. in this paper, a total of fifteen Reinforced Concrete (RC) beams were constructed and tested up to failure. The experimental program was classified to five groups, the first group was casted with Normal Weight Concrete (NWC) as control, and the remaining four groups were casted with LWC. The test parameters were concrete type; reinforcement ratio and silica fume (SF) content. The behavior of beams was evaluated in terms of crack patterns, failure mode, ultimate deflection, and ductility. Based on the experimental results, the resulting concrete showed that it satisfies the requirements of LWC in terms of unit weight and strength. In addition, increasing the reinforcement ratio and silica fume content increased overall beam performance. The results revealed that measurable enhancements to the majority of the performance characteristics of LWC beam by adding SF. Thus, using COBCB as a coarse aggregate has successfully been used to produce good quality lightweight concrete. Both ACI 318-14 and CSA-A23.3-14 give acceptable for predicting cracking moment, ultimate capacity and mid-span deflection.