Date of Award

2001

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Civil and Environmental Engineering

First Advisor

Abdel-Sayed, G.

Keywords

Engineering, Civil.

Rights

CC BY-NC-ND 4.0

Abstract

Concrete beams reinforced and/or prestressed with steel bars are used in a wide range of structures. However, the deterioration of such structures due to reinforcement corrosion is a major problem. The repair and maintenance of steel reinforced concrete structures, especially highway bridges, is quite costly in locations subject to severe weather conditions of rain and/or snow as in Canada and the USA. In order to overcome this problem, Advanced Composite Materials (ACM), which are produced in the form of Fibre Reinforced Polymers (FRP), are becoming a desirable replacement to the traditional steel reinforcement. While both materials have identical functions, basic differences exist in the mechanical properties between steel and FRP that should be taken into account in the structural design and analysis of concrete beams reinforced and/or prestressed with FRP bars. For example, a ductile failure takes place for steel bars subjected to tensile and/or shear stresses, while brittle failure takes place for FRP bars. Further more, FRP bars provide high tensile strength, while their modulus of elasticity and shear strength are lower than those of steel bars. These variations in properties lead to significant differences in the behaviour between concrete beams reinforced and/or prestressed with FRP bars and those reinforced and/or prestressed with steel bars. The properties of the reinforcing material, in both longitudinal and transverse directions, interact with the characteristics of the formed cracks, i.e. crack geometry and crack width, to determine the beam strength, as well as the mode of failure. Therefore, a reliable study of the behaviour and strength of concrete beams reinforced with FRP bars should include some parameters that used to be neglected in case of steel reinforcement such as crack geometry, crack width, and the mechanical properties of bars in their transverse direction. An experimental program has been conducted at the University of Windsor to study the above mentioned parameters and their effects on the behaviour and strength of both prestressed and non-prestressed concrete beams reinforced with Carbon Fibre Reinforced Polymer (CFRP) bars. The results of the study have been expressed through an analytical model that describes the interactive behaviour between crack progress, and the stresses induced in concrete as well as in both flexural and shear reinforcement. The degree of accuracy in modelling the crack path geometry has been also found to control the reliability of the calculated beam strength. A comparison has been made between the results of the proposed analytical modelling and those obtained from the experimental program mentioned above, as well as from other published test data. A good agreement has been observed between the analytical and experimental results. Another comparison has been made between the experimental beam strength, the strength obtained by the present analytical model, and the strength calculated by the formulas recommended by different design guidelines issued recently for FRP reinforced and/or prestressed concrete structures. The comparison emphasised the necessity of considering the above-mentioned parameters in order to achieve an accurate prediction of beam strength.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2001 .S25. Source: Dissertation Abstracts International, Volume: 62-10, Section: B, page: 4671. Adviser: George Abdel-Sayed. Thesis (Ph.D.)--University of Windsor (Canada), 2001.

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