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Nine continuous concrete deep beams reinforced with glass fibre reinforced polymer (GFRP) bars were experimentally tested to failure. Three main parameters were investigated, namely, shear span-to-overall depth ratio, web reinforcement and size effect. The experimental results confirmed the impacts of web reinforcement and size effect that were not considered by the strut-and-tie method (STM) of the only code provision, the Canadian S806-12, that addressed such elements. The experimental results were employed to evaluate the applicability of the methods suggested by the American, European and Canadian codes as well as the previous studies to predict the load capacities of continuous deep beams reinforced with GFRP bars. It was found that these methods were unable to reflect the influences of size effect and/or web reinforcement, the impact of which has been confirmed by the current experimental investigation. Therefore, a new effectiveness factor was recommended to be used with the STM. Additionally, an upper-bound analysis was developed to predict the load capacity of the tested specimens considering a reduced bond strength of GFRP bars. A good agreement between the predicted results and the experimental ones was obtained with the mean and coefficient of variation values of 1.02 and 5.9%, respectively, for the STM and 1.03 and 8.6%, respectively, for the upper-bound analysis.

The purpose of this study is to investigate the effects of steel fibers on some properties of light weight concrete. The coarse aggregate used in this study made from crushed clay bricks. Four proportions of steel fibers are used (0.25%, 0.5%, 0.75%, and 1%) by volume of concrete, in addition, to reference mix (without steel fibers). The density obtained from experimental work was 1812 Kg/m³. The results showed that, in general, the adding of steel fibers led to increase the compressive strength of light weight concrete. The enhancement in compressive strength was about (17%-43%) at 7 days and (21%-51%) at 28 days as compared with reference mix. Also, it is deduced that, the proportion (0.75%) of steel fibers is the optimum one. On the other hand, splitting tensile strength increased by about 62.62%, 33.76%, 17.27% and 5.93% for light weight concrete with 1%, 0.75%, 0.5% and 0.25% steel fibers by volume of concrete respectively. Furthermore, flexural strength improved by about 54.24%, 41.67%, 29.25% and 20.91% for light weight concrete with 1%, 0.75%, 0.5% and 0.25% steel fiber by volume of concrete respectively. Finally, the results indicated that, there are significant increases in static modulus of elasticity and absorption for mixes which have steel fibers as compared with others without steel fibers.