Civil Engineering Commons^™

Bridge Deck Cracking Investigation And Repair, Vidal Velez Vargas

UNF Graduate Theses and Dissertations

The focus of this study is to investigate the cracking of concrete bridge decks and the sealants used in repairing transverse cracks. Cracking could occur in both hardened mature concrete and early age concrete. Several factors affect concrete cracking, such as age-dependent material properties, thermal- and moisture-related stresses and strains, material viscoelastic behavior, restraints, concrete expansion and contraction, casting sequence, formwork, material characteristics, and environmental exposure. The causes of early age cracking are primarily attributed to effects such as plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. This deck cracking could greatly reduce durability, lead to a loss of …

Corrosion Of Post-Tensioned Tendons Repaired With Dissimilar Grout, Juan Carlos Rafols

UNF Graduate Theses and Dissertations

A failure associated with steel corrosion was identified in early 2011 in a bridge external post-tensioned tendon, approximately eight years after construction. Large voids in the grout and pockets of non-homogeneous material were identified. The non-homogeneous grout was characterized by high moisture content, and in most cases, the chloride content was lower than conservative threshold values. The non-homogeneous grout also had high pH and high content of sulfates (approximately in the range of 10,000-ppm). As a result, there was an interest in the study of possible corrosion development in repaired systems in which the affected tendons have been re-grouted with …

Correlations Between Index Properties And Unconfined Compressive Strength Of Weathered Ocala Limestone, Raoaa Farah

UNF Graduate Theses and Dissertations

Weathering has a negative effect on both physical and engineering properties of rock specimens and rock masses. When rock masses are weathered it is often difficult to obtain core segments that are the correct size for unconfined compressive strength testing. Thus engineers must use index testing to estimate the strength of specimens for design purposes. This thesis relates the unconfined compressive strength to index strength tests of Ocala limestone. The relationships developed include weathering states of the specimens and proximity of unconfined compressive strength specimens to index specimens.

One hundred and ninety five specimens were classified using International Society for …