Mykolas Daugevičius

RC Beams strengthened with HPFRCC: Experimental and numerical results

AbstractThe study analyses the behaviour of reinforced concrete beams strengthened with high-performance fibre-reinforced cementitious composite (HPFRCC). Six beams were divided into two equal groups and strengthened. In total, nine beams were tested, including three control beams that were not strengthened. Control beams were over-reinforced. The beams of the first group were strengthened in the compressed part while those of the second group were strengthened in the compressed and tensioned parts of the section. The experimental results of all tested beams were compared with numerical results. The positive and negative effects of strengthening the resistance and serviceability of the beams were experimentally determined. The obtained results showed that the load-carrying capacity of all strengthened beams increased and their deflections decreased; however, crack width in the beams of the second group increased while that of the beams of the first group decreased. The width of cracks increased because th...

Crack Width and Load-Carrying Capacity of RC Elements Strengthened with FRP

The present study focuses on a prediction of crack width and load-carrying capacity of flexural reinforced concrete (RC) elements strengthened with fibre-reinforced polymer (FRP) reinforcements. Most studies on cracking phenomena of FRP-strengthened RC structures are directed to empirical corrections of crack-spacing formula given by design norms. Contrary to the design norms, a crack model presented in this paper is based on fracture mechanics of solids and is applied for direct calculation of flexural crack parameters. At the ultimate stage of crack propagation, the load-carrying capacity of the element is achieved; therefore, it is assumed that the load-carrying capacity can be estimated according to the ultimate crack depth (directly measuring concrete’s compressive zone height). An experimental program is presented to verify the accuracy of the proposed model, taking into account anchorage and initial strain effects. The proposed analytical crack model can be used for more precise predictions of flexural crack propagation and load-carrying capacity.