BEHAVIOUR AND STRENGTH OF SUSTAINABLE RUBBERIZED REINFORCED CONCRETE BEAMS STRENGTHENED BY CFRP

الملخص

The current study is interested in investigating the effect of replacing 50% of sand with textured rubber (Crumb Rubber) that reduced 10% of the specimen's weight, then using the CFRP to strengthen the flexural efficiency of beams. Five specimens with 200x300x2000mm dimensions are investigated. The variables are studied in the installation of CFRP. Three situations of fixing the CFRP, the first is in the area exposed to flattening, the second in both regions of tension and compression, and the last one covered all faces by CFRP. Laboratory results showed that when replacing 50% of sand with crumb rubber the weight of beams decreased by 9% and increased the ductility by 74% also the crack width is reduced by 9% and 38% at yield and ultimate loads respectively. Strengthening by CFRP strips is increase the yield and ultimate load by 40% and 35% on average respectively, but by covering all faces the ratios were increased by 60% and 63%. Using the crumb rubber decreased the deflection by 27% on average and by using CFRP the defection was decreased by 36%, and 19% on average at yield and ultimate load respectively. CFRP increases the strain in the compression face of concrete and the value was greater than the maximum strain of concrete (0.003). Also, the crack width was decreased by 45%, and 23% on average at yield and ultimate loads, respectively.