The influence of alkali-aggregate reactions on reinforced concrete beams strengthening by CFRP

Reinforced concrete (RC) beams are used in structures to transfer flexure and shear stresses from slabs to columns. The alkali-silica reaction (ASR) impacts concrete and reduces its mechanical properties with impact on the performance and remaining load capacity of a deteriorating structure. In this study, we aim to investigate the influence of alkali-aggregate reactions on reinforced concrete beams with CFRP strengthening and different content percentages of reactive sand used. The main experimental parameters for this study are the content of reactive sand in the mixing components and the CFRP sheet. The experimental program included The four groups had reactive sand contents of 0%, 30%, 50%, and 100%. The first group’s concrete beams had a 100% reactive sand content in the mixture, whereas the second and third groups had a 50-30% reactive sand content, respectively. However, the fourth group did not contain any reactive sand. Each group consists of two beams with the same mixing components, reinforced with steel bars in the same proportion. We used the first beam in each group, a solid beam without a CFRP sheet, as the reference. Each group constructed the second beam with a CFRP sheet at the flexure zone on the bottom face, measuring 2000 mm in length and 200 mm in width. The results indicate the effect of reactive sand content and CFRP on load at the first crack and ultimate load in the first, second, and third groups compared with the reference fourth group.