Date of Graduation
Bachelor of Science in Civil Engineering
This research paper details the monitoring of expansion and shear wave velocity for fifteen concrete prisms cast in accordance with ASTM C1293 utilizing five mix designs with varying levels of ASR reactivity. Jobe sand and sodium hydroxide pellets were added in various quantities to increase the reactivity of the prisms. Strain measurements of the prisms were taken according to ASTM C129 and the shear wave velocity of the prisms was measured using ASTM C215. These measurements were taken weekly, then monthly for over a year. It was determined that shear wave velocity of the prisms decrease linearly as strain in the prisms increases with the relationship valid after the initial curing phase of the concrete (i.e., >56 days after casting). However, as cracks and other types of damage become more significant (i.e., individual cracking transitions to map cracking), the concrete can experience a significant loss in shear wave velocity without a proportionate increase in strain. Indicating shear wave velocity may provide a better estimate of concrete condition than strain measurements or visual inspection. For the determination of potentially deleteriously reactive concrete mixes, the shear wave velocity of prisms considered non-reactive (i.e., strain less than 0.04% in 1 year) had incremental increases in shear wave velocity over the 1 year period while prisms considered potentially deleteriously reactive had a decrease in shear wave velocity in the first 100 days. This indicates shear wave velocity may be useful as an alternative monitoring technique for determining potential deleteriously reactive concretes.
Self, Dillon K., "Effectiveness of Small Strain Shear Wave Velocity as a Property for Assessing Damage Associated with Alkali-Silica Reaction in Concrete" (2017). Civil Engineering Undergraduate Honors Theses. 41.