Semester

Spring

Date of Graduation

2018

Document Type

Problem/Project Report

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Lane Department of Computer Science and Electrical Engineering

Committee Chair

Roger H.L. Chen

Committee Co-Chair

P.V. Vijay

Committee Member

Kakan Dey

Abstract

The service life of reinforced concrete structures is dependent on the integrity of the steel within the concrete. Over time, due to exposure, chloride and other minerals can penetrate the concrete. Once these materials get to the reinforcing steel, the chloride and oxygen start to corrode and deteriorate the steel. This deterioration will cut the service life of a bridge down dramatically. To prevent this, the permeability of concrete was studied to determine the service life of one of the new Class-M concretes and a Self-Consolidating Concrete (SCC) mix designs; both developed to produce higher quality concrete. This paper looks at the previous research done into the cementitious replacement of sla SCC's an effect on permeability. A replacement of cement with 50% slag was used to create the slag concrete, and a 9% addition of silica fume was used for the SCC concrete. During this study, three different concrete mix designs were included, concrete with 50% slag replacement, an SCC, and an ordinary Portland cement (OPC) concrete. The permeabilities of these three concrete mixes were tested using three different methods. A ponding experiment, which allows salty water to slowly penetrate concrete samples, the Rapid Chloride Penetration Testing, which uses current to push chloride through a concrete sample, and lastly, a Virtual RCPT method, which is a computer model that uses the mix design quantities to predict the permeability of concrete. The diffusion chloride coefficients of the concrete were obtained. These results were then used with the Life 365 software and a NIST service life prediction model to predict the service life of each concrete mix design. The results show that OPC has a service life in the range of 16-22 years. Slag has a service life range between 47-48.5 years, and SCC has a range of 60-252 years. This shows that OPC has the lowest service life range when looking at chloride permeability and that SCC produces the largest service life.

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