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The purpose of this research is to use jacketing of steel wire mesh with steel plates for retrofitting and strengthening of damaged beams completely failed having deformation. Thirteen reinforced concrete beams having a cross section of (100x160) mm and a length of (1250) mm were tested until failure. All specimens were repaired and strengthened with their exiting deformation. The specimens were divided into five groups. Group one consisted of one specimen strengthened with only expanded three plies steel wire mesh. Group two consisted of three specimens strengthened with steel plates (20, 40 and 60 mm) signed inside three plies expanded steel wire mesh. Groups 3, 4 and 5 each consisted of three specimens strengthened with three plies wire mesh with additional external steel plates (20, 40 and 60 mm) fixed with different number (3, 5 and 7) of steel fisher bolts. The strengthened beams were incrementally loaded up to maximum load capacities. The results showed that the effect of strengthening with three plies wire mesh on the ultimate capacity of beams will have an increase about 30%. Also, the increase of cross sections area of steel plates increase the ultimate load capacity from 47% to 60%. The use of different number of fisher bolts contributed to an additional increase in the ultimate load capacity ranging from (2% to 4%). Increase of cross sections of steel plates as well as number of fisher bolts decreases the mid span deflection of beams from (1% to 14%)..

Most international codes in the design of R.C. columns use only the vertical steel bar effect in determining ultimate load capacity. No combination effect of stirrup volumetric ratio with vertical steel bar has been taken in design of the R.C. column. The present study deals with an experimental and analytical analysis of the behavior of reinforced concrete columns with different percentage of vertical steel bars (µ) and stirrups volumetric ratio (ρ v). A total of sixteen R.C. columns with cross-section (250x250x1000) mm were tested and divided into four groups and tested until failure under axial load. Group 1 consisted of four columns with vertical steel bars with (µ) = 0.18% and stirrups (ρ v) = (0.27%, 0.48%, 0.75 and 1.09%). Group 2, 3 and 4 having same stirrups (ρ v) % with vertical bars (µ) = (0.32%, 0.50%, 0.75%) respectively. The test results showed that increasing in the percentage of vertical steel bars (µ) = (0.18% up to 0.73%) give an increase of the ultimate failure load up to 9.7%. Also, increasing percentage of stirrups volumetric ratio (ρ v) = (0.27% up to 1.09 %) gives an increase of the ultimate failure load up to 12.3% and enhancement in ductility of columns Thus, the increase in the ultimate load of columns due to stirrups effect should be taken into consideration in the design of R.C columns. The analytical analysis (FEA) models can be simulate the experimental behavior of tested columns and can be suitable to reduce time and cost.

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