An Experimental Study on Behavior of Sustainable Rubberized Concrete Mixes

In terms of recycling and reuse, today's global generation of waste tire well exceeds its consumption. This has resulted in the accumulation of large stocks of toxic rubber waste that raise health and safety risks. The use of waste tire rubber for the construction of the concrete structure was suggested to combat this challenge. This paper explores tests that were performed with samples of waste tire rubber concrete to evaluate compressive strength, flexural tensile strength, modulus of rupture, and impacts resistance. The main parameters investigated were the rubber ratio as a partial volumetric replacement with fine and coarse aggregate. Chip and crumb rubbers were used to replace coarse and fine aggregate respectively in four different amounts by volume (5%, 10%, 15%, and 20%). Even if the inclusion of waste tire rubber in concrete has specific apparent degradations, the potential benefit seems to overlook the adverse effects and also meet the primary significant value of resolution for rubber waste utilization problems. The results show that the substitution of natural fine or coarse aggregates with crump-chip tier rubber will reduce mechanical properties (compressive, flexural and splitting tensile strength), but increase the impacts resistance to 426% and 396% when 20% coarse aggregates and 20% fine aggregates are replaced by rubber respectively. The proposed mix shows an ability to replace 20% of the aggregate (coarse or fine), and the producing, rubcrete, still structural concrete

Analytical Study of Reinforced Concrete Horizontally Curved Beam of Rectangular Hollow Section

This research is devoted to study the behavior of Horizontally Curved Reinforced Concrete Beam (HCRCB) of hollow and solid section theoretically by finite element method, the 20-node isoparametric brick element has been used to represent the concrete and the reinforcement idealized as an axial members imbedded within the concrete elements, a parametric study of 210 beams with different cross sections had been done included the effect of wall thickness, and the effect of flange depth on the behavior of HCRCB as well as two techniques of rearrangement the concrete in the hollow core to strengthen the beam. From the analytical results it was concluded that rearranging the core area improved the ultimate load capacity for beams with shear span to effective depth ratio (a/d) more than 2 and the effect is reversed for beams with (a/d) less than 2. Also the technique of adding the hollow core area to the top and bottom flange represent the optimal and produce the maximum increment in the ultimate load which equal to 57%. While the technique of adding the hollow core area to the outside perimeter produced 20% increase in the ultimate load. Keywords: Three Dimensional Analysis, Reinforced Concrete Horizontally Curved Beam, Hollow Sectio