Effect of Using Geopolymer Flyash on Torsion Capacity of Hybrid High-Strength Reinforced Concrete Beams Containing Fine and Coarse Aggregates Substitution Which Added Iron Ores as Filler
Teuku Budi Aulia (a*), Muttaqin (a), Mochammad Afifuddin (a), Muhammad Zaki (a), Geminingsih Nastiti (a)
University of Syiah Kuala, Banda Aceh 23111, Indonesia
*aulia[at]unsyiah.ac.id
Abstract
High demand for advanced infrastructure leads to the use of high strength concrete. Complex, futuristic and asymmetrical building construction could create dangerous torsional load and moment, mainly due to earthquake. Using large amount of cement makes high strength concrete not environmentally friendly. The use of natural aggregates continuously reduced its availability. Efforts to substitute cement and aggregate from abundant and environmentally friendly natural materials could be smart solution. This study aims to analyze the torsional capacity of high strength cantilever reinforced concrete beams having L configuration with a torque arm. Three hybrid beams were cast with substitution of 15% coal flyash (CFA), 15% palm oil blast furnace slag (POSFA) and 10% pozzolanic flyash (PFA) from cement weight, added with 10% pozzolanic sand as fine aggregate substitution and 40% palm oil blast furnace slag as coarse aggregate substitution. One beam without flyash and aggregate substitution (NPBHSC) was tested as comparison. All four beams added with iron ore as filler. The best torsion capacity achieved by PFA beam with maximum load (P) 2.83 ton, maximum torsion moment (M) 10.4 kNm, maximum torsion angle 0.0225 rad, ductility 3.941 and cylinder compressive strength 59.48 MPa, when compared to NPBHSC beam which produced P = 2.65 ton, M = 9.638 kNm, torsion angle 0.0069 rad, ductility 1.008 and compressive strength 44.40 MPa. POSFA beam followed then by CFA beam resulted in slightly smaller P and M, but generated greater compressive strength, maximum torsion angle and ductility than NPBHSC. It can be concluded that geopolymer flyash can increase compressive strength, torsion capacity and ductility of high strength reinforced concrete beams.
Keywords: Torsion Capacity, High Strength Reinforced Concrete Beam, Geopolymer Flyash, Aggregate Substitution, Iron Ores
Topic: Civil Engineering