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Compression splices are widely used in compression members such as columns in multi- story buildings. There are efficient design equations for compression splice of reinforcement embedded in conventional concrete proposed by design codes of practice. However, there is no design equation for compression splice in compression members made of reactive powder concrete (RPC). So, it is required to introduce a design equation to calculate the steel bars lap splice length of RPC compression members. In this study, an experimental work was conducted to investigate the effect of different variables on compression splices strength. These variables were compressive strength of concrete, transverse reinforcement amount, splice length, yield stress of reinforcement and spliced rebar diameter. The experimental results showed that; Increase in the yield stress of reinforcing bars, length of spliced bars and compressive strength of concrete result in increasing in splice strength. Meanwhile, increase in diameter of reinforcing bars result in decreasing in compression splice strength. The increase in the amount of transverse reinforcement has insignificant effect on compression spliced strength of rebar. Finite element analysis was used to analyze the tested specimens and compared between numerical and experimental result was carried out. The numerical and experimental ultimate load and load-deflection behavior is very close to each other. Finite element method was used to investigate a wide range of experimental variables values through a parametric analysis. A new proposing equation for compression splicing of rebar in RPC column is presented in this research.

Five proposed simply supported RC beams were numerically tested by finite element method using ABAQUS software to investigate their behavior and shear strength when strengthened by embedded through section technique (ETS). All beams have the same dimensions of (160 × 250 ×1140) mm and were insufficient reinforced in shear. One beam is taken as a control beam. While, the other four beams were strengthened ETS CFRP bars and divided into two groups. The first group is with 13mm ETS CFRP bars (one bar per section). While, the second group is with 10mm ETS CFRP bars (two bars per section). For all groups, two styles of ETS inclination are considered, vertical and inclined by 45°. From the numerical tests, it was found that using ETS with 2φ10 inclined CFRP bars is the most effective technique for enhancing both the first cracking load about 100% and ultimate load capacity about 86%.

War, terrorist attacks, explosions, progressive collapse and other unforeseen circumstances have damaged many buildings and bridges. Evidence from studying damaged structures has shown that Reinforced Concrete (RC) slabs, beams, columns, where damaged but not failed, can be strengthened using Carbon Fibre Reinforced Polymer (CFRP) to restore their load carrying capacities and make them serviceable. Currently there is no reliable analytical model that closely represents the true behaviour of the CFRP strengthened elements. This study extends the research on the implementation of model updating techniques on RC beams, to RC beams strengthened with CFRP. Our research shows that it is possible to find analytical models that closely match the experimental results. These analytical models can be used to more accurately predict the behaviour of the damaged structural elements strengthened with CFRP.