الفهرس 
Recycled Concrete AggregatesOnly 14 pages are availabe for public view
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Abstract
One of the most frequently used materials in the world is concrete, and thanks to significant improvements in concrete constructions, the natural supplies are gradually replenished. One of the main issues facing the concrete industry is the high cost of raw material supplies. The use of recycled materials in building construction is more important than ever. As a result, it is becoming common practice to replace some of the aggregate in concrete mixes with recycled materials in order to combat global resource depletion and save the environment. These recycled resources include waste aluminum fiber, recycled aggregate and glass powder.
The main goal of current research is to evaluate the effect of recycled materials on the flexural and shear performance of R.C beams. For this goal, fifteen reinforced concrete beams inclusion recycled materials were investigated with dimensions of (250×120×2000 mm). The test specimens were divided into three main groups of five beams each. Recycled materials are recycled coarse aggregate (RCA), glass powder (GP), and waste aluminum fiber (WAF). Five concrete mixes with different percentages of (0, 1, 2, 3%) WAF, (0, 100%) RCA, and 20% GP were investigated. Results showed that using a combination of RCA and WAF has an adverse influence on the slump of concrete mixes. The optimum decrease in slump was occurred by adding 3% of WAF. The compressive strength decreased by fully replacing neutral coarse aggregate (NCA) with RCA. On the other hand, the addition of 1% WAF leads to an improvement in compressive strength. Tensile and flexural strengths of recycled coarse aggregate concrete (RCAC) mixes were decrease also by using RCA but increase when adding WAF, the best enhanced of both tensile and flexural strength was at using 1% WAF. The results indicated that the full replacement of NCA with RCA results in a negative influence on the capacity, initial stiffness, ductility and toughness of tested beams. The addition of WAF in RCAC mixes has enhanced the ultimate moment capacity and ultimate shear strength of tested beams. The optimum proportion of WAF to be added to the concrete as fiber reinforcement is 1% fiber content by volume of concrete which gave all the positive responses from all the tests conducted. Using WAF with different fiber ratios enhances the behavior of reinforced concrete beams in terms of the ultimate load capacity, initial stiffness, toughness and ductility index of RCAC beams. The degree of the enhancement depends on fiber ratio.