It is found that the proposed formulas can give the most satisfactory results for predicting the ultimate effective width and beam end moments.
However, only the half rib height bar displayed a higher ductility than the standard bar, with significantly greater yield penetration at each crack causing larger ultimate crack widths prior to bar fracture.
Test results were evaluated based on cracking load, crack width, ultimate load, load deflection and load–strain.
The findings of this study have shown that effective slab width for ultimate limit state calculations should be different from that used for serviceability limit states.
They were simply supported and tested in the laboratory under static and cyclic loading conditions to investigate their flexural and shear limit states, including pre-cracking behaviour, cracking pattern and width, deflections, ultimate capacities and strains, and mode of failure.
Table 6 Effect of increasing CFRP number of layers and widths on ultimate loads.
In addition, the maximum crack width and the ultimate bearing capacity were measured.
According to the effective width method, the ultimate strength is obtained when the edge stress approaches the yield stress.
It is found that the effective width at the ultimate strength is larger than that at the serviceability stage and simplified design formulae are correspondingly suggested for the ultimate strength design.
The effect of strengthening technique on several design parameters such as amount and configuration of the FRP sheets around the opening, deflection, strain, opening width and depth, ultimate load and cracking was investigated.
These test results show that the developed system performs superior than steel reinforced system in term of cracking resistance, ultimate load capacity and crack width in the studied period.
