ORCID Identifier(s)

0000-0001-7517-7693

Graduation Semester and Year

2019

Language

English

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering

Department

Civil Engineering

First Advisor

Shih-Ho Chao

Abstract

The first part of this research presents a new methodology, which enables streets, roads, highways, bridges, and airfields to use an advanced fiber-reinforced concrete material, which can delay or prevent the deterioration of these transportation infrastructure when subjected to traffic and environmental loadings. The major problem of concrete is its considerable deterioration and limited service life due to its brittleness and limited durability. As a result, it requires frequent repair and eventual replacement, which consumes more natural resources. Ultra-high-performance fiber-reinforced concrete (UHP-FRC) introduces significant enhancement in the sustainability of concrete structures due to its dense microstructure and damage-tolerance characteristics. These characteristics can significantly reduce the amount of repair, rehabilitation, and maintenance work, thereby giving the transportation infrastructure a longer service life. This research addresses the strong need to develop fast and sustainable UHP-FRC materials for pavement repair that can be easily cast onsite without special treatments. This avoids any major changes to current concrete production practice and accelerates the use of UHP-FRC materials. This research investigated a new method for concrete repair by combining precast UHP-FRC panels with a small quantity of cast-in-place UHP-FRC for pavement repair without any dowel bars. In this method, a precast UHP-FRC panel is used along with cast-in-place UHP-FRC. The vertical repair surfaces of the existing concrete are roughened on site. The outer edges of the UHP-FRC precast panel are roughened before they are brought to the site (no dowel bars are needed). The depth of the precast UHP-FRC panel is the same as the existing pavement thickness. Only a small cast-in-place UHP-FRC joint (one to two inches wide) is done onsite. The roughened precast UHP-FRC panel is placed in the repair area and cast-in-place UHP-FRC is cast into the joint. Experimental results showed that using a roughened surface (up to about CSP 5) provides a very large bond resistance, which is enough to prevent faulting. For the second part, the research looks into a highly sustainable and efficient reinforced concrete structural members for future infrastructure by utilizing emerging high-performance materials. These materials include ultra-high-performance fiber-reinforced concrete (UHP-FRC) and corrosion resistant high-strength fiber-reinforced polymer (FRP) bars. Four small-scale UHP-FRC specimens were tested under large displacement reversals to prove the proposed new design concept by fully utilizing these ultra-high-performance materials. Micro steel fibers were used for three specimens and ultra-high molecular weight polyethylene fibers was used for one specimen. One specimen with MMFX high-strength steel rebars (100 ksi as per ASTM A1035, 2016), one with high-strength GFRP (glass, 90 ksi) rebars and two with BFRP (basalt) rebars were tested. The beams had a reinforcement ratio of 14% to 15%. The test results conclude that the beams could sustain very large cyclic drift ratios without major damage in the UHP-FRC material, which provided ample shear strength and confinement to the reinforcement throughout the testing. Even with the high amount of reinforcement, UHP-FRC’s superior ductility provided a very stable cyclic behavior up to very large drift ratios. The specimens also exhibited self-centering ability, which considerably reduces the residual displacement after being subject to large displacements. The test results also showed that the high damage resistant and self-centering characteristics of the proposed UHP-FRC columns can provide excellent resilience for building structures.

Keywords

UHP-FRC, FRP, Pavement repair

Disciplines

Civil and Environmental Engineering | Civil Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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