Date of Award

11-2016

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Department

Civil and Environmental Engineering

First Advisor

Dr. Tamer El Maaddawy

Second Advisor

Dr. Bilal El-Ariss

Third Advisor

NemkumarBanthia

Abstract

Continuous steel-reinforced concrete structures are vulnerable to corrosion

Damage when exposed to harsh environment. Although replacing conventional steel entirely with basalt fiber-reinforced polymer (BFRP) bars can eliminate corrosion problems, the lower modulus of elasticity of BFRP would reduce serviceability of the structure. The use of hybrid steel-BFRP bars rather than BFRP bars only has a potential to improve the serviceability of continuous concrete

Structures without reducing the deformation capacity. Through experimental testing and numerical simulation, this work aims to examine the structural behavior of two-span concrete specimens internally reinforced with BFRP or hybrid steel-BFRP bars.

A total of 12 two-span specimens were constructed and tested. Six specimens

were over-reinforced and six specimens were under-reinforced. The specimens had different hogging-to-sagging reinforcement ratios. Twelve three-dimensional (3D) finite element (FE) models representing all of the tested specimens were developed using the software package ATENA®. Bond stress-slip models were adopted at the interface between the longitudinal reinforcing bars and the

surrounding concrete. The accuracy and validity of the computational models were examined by comparing their predictions with the experimental results.

Increasing the hogging-to-sagging reinforcement ratio in the BFRP specimens

increased the ultimate load but had an almost no effect on the cracking load. The response of the BFRP under-reinforced specimens was more sensitive to the hogging- to-sagging reinforcement ratio than that of the BFRP over-reinforced specimens. The specimens reinforced with hybrid steel-BFRP bars exhibited less deflections and smaller crack widths at service load than those of their counterparts with BFRP bars only. The use of hybrid steel-BFRP reinforcement rather than BFRP bars only had an almost no effect on the deflection at ultimate load. The behavior of the specimens with BFRP bars only deviated from the elastic response. The deviation increased by decreasing the hogging-to-sagging reinforcement ratio. Specimens with hybrid steel- BFRP bars exhibited less

Deviation from the elastic response comparted with that of their counterparts with BFRP bars only. The FE models developed in the present study simulated the structural behavior of the tested specimens with a good accuracy. The Predicted ultimate loads and corresponding deflections were within a 20% error

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