Shear capacity of hybrid high-strength reinforced concrete beams containing additives and aggregates substitution added with iron ores as filler Teuku Budi Aulia (a*), Yulia Hayati (a), Yunita Idris (a), Cut Fatmawati TA (a)
Syiah Kuala University, Banda Aceh 23111, Indonesia
Abstract
The need for complex infrastructures with high serviceability is rapidly increasing which can be accommodated by the use of high-strength concrete. Indonesia as an earthquake-prone region requires such infrastructures possessing high structural capacity in carrying shear forces. However, the large use of cement in high-strength concretes makes it environmentally-unfriendly. As almost 60% infrastructures development worldwide using concrete, the availability of aggregates originating from natural resources is certainly diminishing. This research purpose was to analyze the shear capacity of hybrid high-strength reinforced concrete beams using substitution of cement, fine and coarse aggregates, i.e., 15% geopolymer coal flyash (CFA) + 10% pozzolanic sand (PZS) + 40% palm oil blast furnace slag (POSA) named H-CPPA; 15% CFA + 20% palm oil blast furnace slag (POSS) + 40% POSA (H-CPSPA); 15% palm oil blast furnace slag ash (POSFA) + 10% PZS + 40% POSA (H-PFPPA); 15% POSFA + 20% POSS + 40% POSA (H-PFPSPA); 10% geopolymer pozzolanic flyash (PFA) + 10% PZS + 40% POSA (H-PZPPA); 10% PFA + 20% POSS + 40% POSA (H-PZPSPA). One beam without substituting flyash and aggregates (H-PB) was casted to compare its capacity. All beams added with nano iron ores as much 6% from cement weight as filler. To guarantee the shear failure, the capacity ratio of flexure to shear was set to 2.292. Based on results, the shear capacity of hybrid high-strength reinforced concrete beams using cement and aggregates substitution ranges 77,98% - 92,28% compared with plain beam, but, generates better the structural ductility in the range of 93,26% - 156,46% and the maximum deflection in amount of 80,82% - 110,33%. It can be summarized that substitution of such geopolymer flyash and industrial wastes can enhance shear capacity of hybrid high-strength reinforced concrete beams, the overall, CPSPA had yielded the best value.
