Date of Award
5-2024
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Civil Engineering
Committee Chair/Advisor
Dr. Prasad Rangaraju
Committee Member
Dr. Brandon Ross
Committee Member
Dr. Amir Poursaee
Abstract
As the state of the US infrastructure continues to deteriorate over time, a prominent issue especially in the field of reinforced concrete structures has been the ability to properly rehabilitate and extend the design service life of these structures. A majority of our existing reinforced concrete bridges were built in the construction boom during the 60’s, 70’s and 80’s, and were originally designed with a service life of approximately 50 years, thus showing that many structures are close to or have already exceeded their intended service life. Additionally, with a poor history of government infrastructure funding, it is seen to be infeasible to fully reconstruct these aging structures on a mass scale. Therefore, the only option engineers are left with is to attempt to extend the service life of these structures through various repair and rehabilitation techniques. However, a common phenomenon experienced throughout the country has been the rapid deterioration of these mitigation strategies, such as repairs, likely due to poor planning, implementation, and lack of material compatibility with the existing substrate.
For concrete bridge deck repair specifically, there are currently several various pre-bagged, repair materials that are readily available on the market. Many of these materials are specially designed for high performance, and exhibit various attributes intended for specific applications. However, the material components are often kept proprietary, and the performance specifications provided are often completed in a controlled lab setting. Thus, restricting knowledge of how these different materials will perform in any given application with different exposure conditions. Additionally, engineers are often forced to make cost-efficient decisions without the proper insight into the makeup of these materials, how they will be affected by the environment, and their compatibility performance as a composite material with existing substrate concrete mixes. All of these factors likely affect the overall performance and longevity of the patching repairs and can ultimately be the direct cause of rapid deterioration before the repair has met its intended design service life.
Literature cites several mechanical and electro-chemical performance properties as direct contributors to a repair’s compatibility with substrate concretes. Properties such as: compressive, flexural, tensile, and bonding strength, elastic and shear moduli, Poisson’s ratio, thermal expansion coefficient, chloride migration resistance and electrical resistivity, all of which are studied and discussed in this thesis. Additionally, several sources directly discuss the impact of environmental exposure conditions during both early and late ages of the repair as potential causes for rapid deterioration of these materials. This thesis studies the hydration reactions and stiffening/hardening behavior and resulting strength performance of these materials in various ambient temperature exposures of 10°C, 23°C and 40°C to simulate material implementation in different geographical areas or during different times of the year.
Results from this in-depth study show the wide range of performance properties of the various materials studied and how the vast difference in these values may affect performance and ultimately lead to the rapid deterioration of the repair or the surrounding substrate concrete. The impact of ambient temperature during the placing and curing of these materials may also be a direct contributor to alterations in expected performance properties and overall durability of the materials. However, each material reacts independently from one another and cannot be treated similarly to each other or to a general Ordinary Portland Cement (OPC) based concrete mix. Therefore, each material must be better understood in terms of its individual performance properties, how it reacts to the environment and how it should be implemented in order to avoid rapid deterioration and ensure that it is able to properly extend the design service life of the existing structure.
Recommended Citation
Roberts, James, "Engineering Sustainable Bridge Deck Rehabilitation: Evaluating Mechanical and Electro-Chemical Properties of Rapid-Set Patching Materials and their Influence on Repair Durability" (2024). All Theses. 4221.
https://open.clemson.edu/all_theses/4221
Author ORCID Identifier
0000-0002-2431-6558
Comments
This thesis covers an in-depth study of various rapid setting concrete repair materials intended for bridge deck repair. The focus of the study was testing numerous mechanical and electro-chemical performance properties to understand their influence on repair/substrate compatibility and durability of the repair.