Date of Award

Spring 2020

Document Type

Open Access Thesis

Department

Civil and Environmental Engineering

First Advisor

Paul Ziehl

Abstract

The objective of this thesis is to investigate different (non-destructive) evaluation methods to assess the effects of reactive aggregate size and reinforcement on ASR affected concrete. It has been shown in previous literature that reactive coarse aggregates lead to more expansion as opposed to reactive fine aggregates. However, there is a lack in the literature exhibiting this relationship using different evaluation methods, such as acoustic emission (AE) and ultrasonic pulse velocity (UPV). Also, the literature does not emphasize the role this relationship plays when the concrete is imposed with stress boundary conditions. Non-destructive test methods, including acoustic emission, are becoming a more widely used method of testing concrete, so this thesis will investigate how these nondestructive evaluation methods reflect early ASR damage in concrete; the methods will also help to further understand the roles aggregate size and reinforcement play in ASR infected concrete’s degradation process.

The tests elaborated on in this thesis were completed over two and a half years. Each test has one confined, one unconfined, and one control specimen. The confined specimen is fitted with steel reinforcement. The coarse reactive coarse aggregate concrete was initially tested to understand the affect boundary conditions have on the ASR reaction. The results of this thesis show that the unconfined reactive fine specimen experienced isotropic expansion. In addition, the effect of reinforcement is more pronounced in the reactive coarse aggregate specimens than in the reactive fine specimens. When evaluating the non-destructive test methods in terms of contrasting damage between the reactive and vi control specimens, the evaluation methods are ranked as follows (largest difference to smallest difference): acoustic emission (cumulative signal strength), expansion measurements, visual crack measurements, followed by UPV.

The novelty of this thesis comes from the innovative method of evaluating the accuracy of different non-destructive test methods for ASR affected concrete, as well as investigating the effects of reinforcement and different aggregate sizes on ASR affected concrete with the non-destructive (most notably acoustic emission) test methods.

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