| dc.description.abstract | The development of cracks in Portland Cement Concrete (PCC) and Grout has become a problem of rising concern in a country with an aging infrastructure. A detailed understanding of the causes as well as the behavior of these cracks is vital to preventing future formation and further propagation. This study examines a currently existing structure known as the Watt’s Towers, or The Towers of Simon Rodia which exhibits extensive cracking.
The effects of thermal cycles, both daily and annual, on crack opening and closing for typical cracks were studied using the Towers as an example case. The study is used to determine whether or not thermal cyclical loading plays a significant role in the formation of cracks in mortar. Specifically, an array of cracks located at different sections on the Towers was outfitted with strain gauges, force transducers, and thermocouples to collect data on the crack width as a function of the ambient temperature. Using the Finite Element Analysis program LS-DYNA, a computer model was created to replicate these results. After many simulations a relationship between the thermal loading and the local stressing induced around the cracks was developed. It was determined that Crack gap movement is strongly correlated with temperature. It is an inverse relationship: as the ambient temperature increases, the crack width increases. The cyclical nature of the crack width plays a significant role in the development of local stresses, and ensuing crack formation. | en |
