Date of Graduation
5-2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Engineering (PhD)
Degree Level
Graduate
Department
Civil Engineering
Advisor/Mentor
Murray, Cameron D.
Committee Member
Hale, W. Micah
Second Committee Member
Prinz, Gary S.
Third Committee Member
Messadi, Tahar
Fourth Committee Member
Feys, Dimitri
Keywords
Alternative cement; Concrete repair; corrosion; self-consolidating concrete
Abstract
Some current building codes for structural concrete allow the use of alternative cement concrete if their structural, durability, and fire performance can be shown to be comparable to portland cement (PC) concrete. One such alternative cement, belitic calcium sulfoaluminate (BCSA) cement, is a promising standalone replacement for portland cement given its lower global warming potential (GWP), fast setting time, and high early age compressive strength. These properties also make it an ideal repair material. But repair materials often need to be highly flowable and easy to consolidate and their performance when used to repair PC concrete structures must be understood. Additional questions remain regarding its durability performance, specifically surrounding its ability to protect reinforcing steel from corrosion. This study developed novel self-consolidating concretes (SCCs) with BCSA cement and characterized their fresh and hardened properties. Cement replacements with fly ash maintained the paste content of SCC mixtures while reducing the cement content. Increased fresh performance with increasing replacement rates were observed but were weighed against decreases in hardened properties. The structural performance of beams repaired with the developed BCSA cement SCC were evaluated in terms of load-deflection behavior, ultimate load, and return of capacity. Beams repaired in the flexural tension zone had capacities within 15% of the all-PC control beams at four hours and within 4% at seven days. Beams with end zone repairs had capacities within 6% and 3% of the PC control beams at four hours and seven days, respectively. To apply repair materials such as the BCSA SCC detailed in this study, the ability of such concrete to provide long term protection from corrosion to steel rebar must also be considered. The corrosion protection provided by BCSA cement concrete was evaluated using a test method developed to compare the effect of admixtures on PC concrete’s corrosion performance. The study’s goals were to examine the role of curing time in the corrosion results for BCSA cement and to measure the effectiveness of different methods to improve corrosion performance such as decreasing the water to cement ratio, increasing cover, and the use of surface sealers. The study found that durability testing of alternative cement concrete should be done considering the maturity of the concrete, rather than arbitrarily selecting a testing age based on PC based standards. Additionally, increasing clear cover depth, lowering w/cm, and using surface coatings such as silane, were effective in increasing corrosion protection.
Citation
Poblete, E. S. (2025). Experimental Study of Novel BCSA SCC Repair Materials and Implications on Corrosion in BCSA Concrete Structures. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/5623
