Engineering Commons^™

Assessment Of Bridge Pier Response To Fire, Vehicle Impact, And Air Blast, Chen Fang, Qusai Alomari, Daniel G. Linzell

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Highway bridges exposed to intentional or unintentional fire followed by combined vehicle impact and air blast are at risk of significant damage and, possibly, collapse. Limited studies examining the complex effects of these extreme demands on bridge support elements and parametrizing their response and damage are found in the open literature. Research that is presented is part of an ongoing numerical investigation examining round, multi-column, reinforced concrete (RC), bridge pier behavior subject to multi-hazard scenarios involving fire, vehicle impact, and air blast. Detailed nonlinear finite element analysis models of single columns and multi-column piers supported by a pile foundation system …

Artificial Neural Network And Finite Element Modeling Of Nanoindentation Tests On Silica, Kianoosh Koocheki

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Two major forms of Silica include the crystalline form named Quartz which consist of the sand grains in nature, and amorphous form named Silica Glass or Fused Silica which is commonly known as glass. Fused Silica is an amorphous crystal that can show plastic behavior at micro-scale despite its brittle behavior in large scales. Due to the amorphous and ductile nature of Fused Silica, this behavior may not be explained well using the traditional dislocation-based mechanism of plasticity for crystalline solids. The crystal plasticity happens due to shear stress and stored energy in the material as dislocations which does not …

Hyperelastic Structural Fuses For Improved Earthquake Resilience Of Steel Concentrically-Braced Buildings, Francys López-Mosquera

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Improving structural resilience (i.e., reducing service interruptions and improving rapidity of function restoration) following extreme events is one of the primary contemporary challenges in structural engineering. While massive casualties have successfully been avoided through the adoption of modern building codes, the sole codified performance objective has been limited to the life safety/collapse prevention range of response. Christchurch, NZ, highlighted the insufficiency of this approach, with large sections of the city nonfunctional after a major earthquake, and with subsequent collapses induced by significant aftershocks. Engineering advances to improve building and community resilience are necessary to mitigate hazards from becoming disasters. This …

Effects Of Aggregates On Properties And Performance Of Mastics And Superpave Hot Mix Asphalt Mixtures, Francisco Aragão

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Superpave, a set of advancements in testing devices and specifications for asphalt binders and mixtures, was limited to address the effects of aggregates. Because aggregates represent around 95% in mass of the asphalt mixtures, it is important to understand how these materials affect properties and performance of such mixtures. This research focus on how different types and contents of aggregates affect properties of mastics and asphalt mixtures, and their performance considering the viscoelastic nature of the asphalt material.

Five different types of aggregates and hydrated lime were used for sample fabrication together with two different binders. Several different tests were …