This paper investigates the effect of using near-surface mounted carbon fiber-reinforced polymer (NSM-CFRP) on the shear strengthening of rectangle beams with low strength concrete (f′c = 17 MPa), medium strength concrete (f′c = 32 MPa), and high strength concrete (f′c = 47 MPa). The experimental program was performed by installing NSM-CFRP strips vertically in three different configurations: aligned with the internal stirrups, one vertical NSM-CFRP strip between every two internal stirrups, and two vertical NSM-CFRP strips between every two internal stirrups. All tested beams were simply supported beams and tested under a three-point loading test. The experimental results were compared with the theoretical capacities that were calculated according to the ACI 440.2R-17 and finite element analysis (FEA) that was conducted using ABAQUS software to simulate the behavior of all beams. The experimental results indicated that using NSM-CFRP limited the failure mode of all beams to pure shear failure with no debonding or rapture of the carbon strips. Moreover, the use of NSM-CFRP proved its efficiency by increasing the shear capacity of all beams by a range of 4% to 66%, in which the best enhancement was recorded for the case of using two unaligned NSM-CFRP strips. In general, the experimental shear capacities increased with the increase in the compressive strength of all beams. On the other hand, the ACI 440.2R-17 was conservative in predicting the theoretical shear capacities, and the FEA results agreed well with the experimental results.

The United Kingdom and European codes for the analysis and design of tubular scaffold structures assume that the scaffolds are subjected primarily to vertical loads and to horizontal loads at right-angles to the scaffold. The effects of dynamic loading caused by large winds tend to be ignored and the code analyses often only require static loading on the structures to be considered. To investigate side loads, a scaffold frame built according to the UK standard was made and inserted into a testing rig. Five different load combinations were made to determine the behaviour of the scaffold under different side loads, which were varied cyclically to simulate different wind loads, especially when vertical loads were also applied. The results showed that cyclical loads affected scaffold behaviour, especially when the bases of the scaffold standards were not tied to the base at the bottom of the test rig. Changes should be made to the UK and European codes BS EN 74.1, BS 5975 and BS EN 128 11-1 for the design of scaffold structures to increase safety.

This paper aims to investigate the effect of using different configurations of near-surface mounted carbon-fiber-reinforced polymer (NSM-CFRP) strips on the shear strength of strengthened and rehabilitated reinforced concrete (RC) T-beams with different internal shear stirrup spacing. The internal shear stirrup spacing was 50 and 150 mm. The NSM-CFRP strips were at an inclination of 45° and spaced at 75 and 150 mm. A total of eight beams were tested in this study: two beams without NSM-CFRP as control beams for the purpose of comparison; three beams were strengthened by NSM-CFRP; and three beams were rehabilitated by NSM-CFRP. The experimental shear capacities were compared with the theoretical values predicted by the ACI 440.2R-17. The results indicated that the use of NSM-CFRP strips enhanced the shear capacity for all beams compared to their corresponding control beams. The enhancements in the shear capacity increased with the decrease in the spacing of the internal shear stirrups and NSM-CFRP strips. The ACI 440.2R-17 was conservative in predicting the theoretical shear capacities.