Numerical simulation of galvanized rebars pullout

The usage of rebars in construction is the most common method for reinforcing plain concrete and thus bridging the tensile stresses along the concrete crack surfaces. Usually design codes for modelling the bond behaviour of rebars and concrete suggest a local bond stress – slip relationship that comprises distinct reinforcement mechanisms, such as adhesion, friction and mechanical anchorage. In this work, numerical simulations of pullout tests were performed using the finite element method framework. The interaction between rebar and concrete was modelled using cohesive elements. Distinct local bond laws were used and compared with ones proposed by the Model Code 2010. Finally an attempt was made to model the geometry of the rebar ribs in conjunction with a material damaged plasticity model for concrete.

Bond performance in NSM-strengthened masonry brick

The use of Near Surface Mounted (NSM) Fiber Reinforced Polymers (FRPs) for strengthening masonry structures can be a suitable substitute for Externally Bonded Reinforcement (EBR) technique. NSM technique has many advantages such as larger bonded area, better anchorage capacity, higher resistance, higher percentage exploitation of the FRP and reduced installation time. However, information regarding the effectiveness of this strengthening technique for masonry structures is scarce and characterization of the critical mechanisms such as bond behavior is necessary. This paper presents experimental investigation of the bond performance in NSM-strengthened brick specimens. CFRP laminates are used for NSM strengthening of masonry bricks with different bonded lengths. The bond between FRP and masonry substrate is investigated by performing conventional pull-out tests and the experimental results are presented and discussed.

Reforço à flexão de lajes de betão armado com laminados de CFRP pré-esforçados

Dissertação de mestrado integrado em Engenharia Civil (área de especialização em Estruturas e Geotecnia)