This paper presents an innovative method of prestressing carbon fibre reinforced polymer (CFRP) plates used as externally bonded reinforcement for flexural strengthening of reinforced concrete (RC) beams. The proposed method aims to achieve self-anchorage of the prestressed CFRP plate and thus eliminate the need for conventional mechanical anchorage at its ends. Experimental tests of RC beams in four-point bending were conducted to investigate the strengthening efficiency of the self-anchored prestressed CFRP plate. The experimental results showed that using the self-anchored prestressed CFRP significantly improved the flexural performance of the strengthened beam in terms of bending stiffness, crack widths, and load-carrying capacity. The utilisation ratio of the prestressed CFRP plate reached 81% at its debonding. Numerical analyses using nonlinear finite element (FE) method were conducted to model the tested specimens. Based on the reliable simulation of flexural cracks and crack-induced CFRP debonding, parametric studies were conducted using FE analyses, in order to investigate the effect of prestressing levels and the CFRP plate's stiffness on the flexural behaviour. Recommendations were then made for selecting a proper prestressing level and the mechanical properties of CFRP plates.

For reinforced concrete (RC) slabs without shear reinforcement, shear and punching can be the governing failure mode at the ultimate limit state if subjected to large concentrated loads. Shear and punching of RC slabs without shear reinforcement has been a challenging problem in assessment based on current standards. To examine a previously developed enhanced analysis approach, this study was conducted by applying a multilevel assessment strategy to a 55-year old RC bridge deck slab subjected to concentrated loads near the main girder in a field failure test. This strategy clearly provides the engineering community a framework for using successively improved structural analysis methods for enhanced assessment in a straightforward manner. The differences between analysis methods at different levels of assessment were discussed regarding one-way shear and punching shear behavior of the slab. The influences of parameters, such as boundary conditions, location of concentrated loads, and shear force distribution, were investigated.