Engineering Commons^™

Durability Of Lightweight Concrete For Bridge Decks, Andrew Mccullough Wagner

Masters Theses

As concrete durability becomes a higher priority for departments of transportation’s acceptability of concrete for bridge decks, consideration of resistance to the penetration of chloride ions has become a key consideration in defining durability. For years the “Rapid Chloride Ion Penetration (RCP) test has been the accepted standard to measure penetrability of concrete to chloride ions. With the movement to use chloride ion penetrability as a part of acceptance criteria for a concrete mix, use of the newer and easier Surface Resistivity (SR) test as an alternative to the slower, more complicated “Rapid Chloride Ion” test became a desirable option. …

Bonded Anchors In Concrete Under Sustained Loading, Douglas Droesch

Masters Theses

Post installed anchors come in either mechanical anchors that develop their strength purely through mechanical interlock with the base concrete, or bonded anchors that develop their strength by bonding anchor rod to the base concrete. Bonded anchors are either grouted, typically cementitious material, or adhesive, typically a chemical material. This thesis presents a current literature review of post-installed bonded anchors, preliminary testing of adhesive bonded anchors, and details of short term and long term test setups for future testing. The purpose of this thesis was to develop the test setups that will be used for future testing on anchors.

Modeling Of Debonding And Crack Propagation In Fibrous Composites Using A Discontinuous Galerkin Approach, Wesley Michael Hicks

Masters Theses

A recently proposed Discontinuous Galerkin (DG) method for modeling debonding and fracture within the context of the finite element method is investigated for problems relating to fiber reinforced composites, namely fiber-matrix interfacial debonding which progresses to matrix fracture. The results are then compared against an existing intrinsic cohesive zone method and a hybrid Discontinuous Galerkin method. The results show that the method can eliminate the problem of artificial compliance that is associated with intrinsic cohesive zone models. Eliminating this stiffness has the positive effect of removing user-defined numerical parameters that are not actually present in the physical system. A key …

Design And Construction Of A Full-Scale Lateral Impact Testing Facility, Cody Aaron Mitchell

Masters Theses

The goal of this work is to design and construct a full scale lateral impact testing facility that is capable of recreating the damage that would be created by an overheight vehicle collision. This was accomplished by impacting a test specimen with an 8000 lbs. impact cart. The impact cart is raised on an elevated track and allowed to roll down the track with a change in height of 10 ft. This change in height is what provides the impact force necessary to recreate an overheight vehicle collision. The track is constructed out of wood and is designed to withstand …

Resilience Of Transportation Infrastructure Systems To Climatic Extreme Events, Alexandra C. Testa

Masters Theses

A topology-based approach has been used to measure the resilience of a highway network to climatic events. Civil infrastructure systems are inarguably critical to the everyday functions of society. Because such systems are regionally distributed, their components undergo a wide range of hazard intensities, often dependent on their relative locations. The ability of an infrastructure system to withstand, adapt to, and rapidly recover from extreme events is paramount to its ability to continuously serve users. The topological properties of a network can provide a good means to assess the resilience of the system which is adequate to comprehend the preparedness …

Structural Vulnerability Assessment Of Bridge Piers In The Event Of Barge Collision, David A. Ribbans

Masters Theses

The inland waterway system in the United States is fundamental to the transportation system as a whole and the success of the nation’s economy. Barge transportation in these waterways levitates congestion on the highway system and is beneficial when comparing barge transportation to other modes of freight transportation in measures of capacity, congestion, emissions, and safety. Unavoidably, the highway system intersects with the waterways, resulting in the risk of vessels collision into bridge structures. Particularly for barge impact, the literature is questioning the accuracy and oversimplification of the current design specifications.

The impact problem was investigated in this research using …

Nano-Scale Investigation Of Mechanical Characteristics Of Main Phases Of Hydrated Cement Paste, Shahin Hajilar

Masters Theses

Hydrated cement paste (HCP), which is present in various cement-based materials, includes a number of constituents with distinct nano-structures. The elastic properties of the HCP crystals are calculated using molecular dynamics (MD) methods. The accuracy of estimated values is verified by comparing them with the results from experimental tests and other atomistic simulation methods. The outcome of MD simulations is then extended to predict the elastic properties of the C-S-H gel by rescaling the values calculated for the individual crystals. To take into account the contribution of porosity, a detailed microporomechanics study is conducted on low- and high-density types of …

Measuring The Resilience Of Transportation Networks Subject To Seismic Risk, Mark N. Furtado

Masters Theses

Transportation networks are critical to the function of modern society but they are vulnerable to extreme events such as earthquakes. Damaged bridges can cost millions of dollars to repair and congestion and detours due to bridge closures leads to indirect costs that are even greater than the cost of repair of damaged bridges. A resilient network however should be able to limit the damage caused by earthquakes and recover in a timely fashion. Resilience of networks has been studying in length from a conceptual standpoint but as quantitative measure, the field has been lacking. This study sets forth to quantify …