Structural Behavior of Reinforced Concrete Beams Incorporating Waste Glass Powder as Partial Replacement of Cement

Abstract

Concrete is the most used material in construction industry. The construction industry is responsible for some of the most serious sustainability and environmental issues the world is currently facing such as recycled materials in general and Waste Glass (WG) in particular can potentially conserve natural cement, eliminate unnecessary consumption of landfill areas and reduce energy consumption. In this thesis, the research involves the study of different mixes contained waste glass powder as cement replacement and compared to control mixes. Waste glass powder was used as replacement percentages of cement weight (10, 15, 20 and 25%), and the experimental program was divided into two parts: hardened properties and structural behavior. The laboratory program consisted of fifty-four cylinder with the diameter 150mm and length 300mm to test the compressive strength of concrete specimens at 28, 56 and 90 days, and also eighteen cylinders with dimension (300×100mm) to test splitting tensile strength at 28 days. From test results, mixes with 20% of milled glass gave increase of 26, 44 and 53% of 10, 15 and 20% of WGP, respectively, compared to control mixes (with SP) at curing age 28 day. Moreover, these specimens showed increase of 18, 43 and 35% at age 56 day and 14, 38 and 15 % at age 90 day for modified specimens with 10, 15 and 20% of WGP compared to control specimens. It can be concluded that replacement percentage 20% of WGP exhibited higher 21% and 6% than ratios 10 and 15% of milled glass, respectively at 28 days, while the use of 15% WGP is best level among other percentages at 56 and 90 days. In addition, mixes with 10 and 20% of glass powder gave similar compressive strength at curing age 90 days, but specimens with 25% of milled glass demonstrated decrease of compressive strength -15, 20 and 23% at curing age 28,56 and 90 III days, respectively compared control mixes (SP). Test results of splitting tensile strength, mixes contained 15% of waste glass powder showed increase 0.5% and 16% for mixes 10 and 20% of WGP, respectively. Ultrasonic pulse velocity and water absorption tests used cubes specimens that dimensions of 100 mm. From tests results, appeared decrease water absorption capacity -18, 36, 44 and 54% for 10, 15, 20 and 25% WGP compared reference specimens and UPV test showed similar results with compressive strength at 28 days. Flexural test results gave increase +33% of specimens with 15% of glass powder compared to control, while modulus of elasticity demonstrated slight increase for mixes contained with 10 and 15% WGP. The second part was carried out to investigate shear and flexural behavior of concrete incorporated with waste glass powder. Eighteen beams were used in this study, these specimens were 150 mm wide, 150 depth and 900 mm long. For the investigations of structural behavior of concrete with glass powder, these beams were reinforced with different steel ratio (ρmax., ρavg. and ρmin.), also amount of transverse reinforcement ratio (Smin and Smax.). Shear and flexural behavior of reinforced concrete beams made 10 and 15% of waste glass powder (WGP) were investigated. Beams with waste glass powder showed good shear resistance compared with reference beams besides satisfactory flexural performance, but higher ultimate resistance and deflection.