Year

2017

Degree Name

Doctor of Philosophy

Department

School of Civil, Mining and Environmental Engineering

Abstract

Strengthening of existing concrete infrastructure has become increasingly important within the construction and building industry throughout the world. The commonly applied methods for strengthening concrete structures are conventional steel reinforcement, steel plates, fibre reinforced polymers (FRP) jackets, steel wire mesh and mortar composite. Using conventional steel reinforcement to strengthen the existing structure leads to a large change in geometry. The FRP jacketing is a widely applied technology for repairing concrete members. However, both FRP jackets and steel plates require epoxy resins. Steel wire mesh and mortar, also considered as ferrocement, is a kind of high performance composite material due to its tensile strength-to-weight ratio and the ability to undergo large deformation (ACI549R 1997). However, wire mesh is commonly applied with low strength mortar or normal strength concrete (NSC). It is well known that the brittleness of concrete will increase with the increase of concrete strength. The need to investigate the potential to extend wire mesh to high strength cementitious matrices and integrate it with different reinforcement materials has arisen.

To address the research gap on applying wire mesh with high strength cementitious matrices, three series of experiments were conducted. In the first experiment, wire mesh and high strength mortar was used to strengthen high strength concrete (HSC) through the wrapping method; in the second experiment, medium strength concrete (MSC) was cast with wire mesh; in the third experiment, wire mesh and modified high strength mortar (MHSM) were used to strengthen NSC. In addition, the composite of wire mesh and MHSM combined with steel hoops at a range of reinforcement volumetric ratios was used to strengthen NSC. The influence of the number of mesh layers (fraction ratio, Vf), steel reinforcement volumetric ratio (ρs), matrix strength and cover thickness were investigated. Cylindrical specimens and square 12.7×12.7 mm galvanised wire mesh (E12.7WM) were used for the three experiments, considering mechanical properties and economic constraints. No longitudinal steel reinforcement was applied.

Download

Share

COinS
 

Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.