The need to upgrade the existing structures due to normal change of use, increased demands on the structure, and errors in the design or the construction phase has increased considerably over the last decade. Different methods have been developed over the years for solving different rehabilitation and strengthening problems. The use of near-surface mounted reinforcement (NSMR) technique has been used since the 1940s, where steel reinforcement is placed in slots in the concrete structure and then these slots are grouted. However, the corrosion sensitivity of steel bars and the additional required concrete cover have caused some drawbacks in this technology. Recently, advanced composites used for external bonding in the form of fabrics or laminates have become an accepted method. In most cases, this method is very competitive regarding both structural behaviour and economy. However, there are also some drawbacks. The surface bonded composite material is relatively sensitive to fire, accidents or vandalism. In addition, the pre-treatment is relatively intensive and time consuming. However, if the composite material is placed in slots in the wood or concrete cover some of these drawbacks can be overcome. This technique uses FRP bars embedded in concrete or wood using a bonding material (resin or cement-based adhesive).
For concrete structures, the proposal of using this technique is initiated for the MTQ to be used in rehabilitation and strengthening of concrete deck slabs at the top surface (area of negative moments) where using the externally bonded FRP laminates will be exposed to direct wheel loads. This also can be applied to the negative moment zones in the slabs of parking garage in collaboration with Public Works and Government Services Canada (PWGSC). For wood structures, this technique will be used to enhance the strength and stiffness of laminated wood beams, wood poles (used to carry electricity and phone cables) in collaboration with Hydro-Québec and other industrial partners from Québec. This research activity will be conducted to investigate the flexural strengthening of reinforced concrete and wood structural elements with near surface mounted fibre reinforcement polymer rods. The parameters that will be investigated include, the type of bonding material (polymer cement as bonging agent and epoxy adhesive), size of the groove (depth and width), distance between groves, thickness of adhesive material surrounding the NSMR, and different types and magnitudes of loading during the strengthening process. This study will not be limited to experimental work only but will also include comparisons with test results obtained from the other on-going research on new built structural elements and also from previous research results. The experimental results will be used to verify the analytical modelling that will be carried out using a non-linear finite element analysis. Parametric study taking into account the effect of various parameters such as concrete cover and type of filling material will be performed.