Construction Engineering and Management Commons^™

Behavior Of Concrete Structures Reinforced With High Strength Steel, Rahman S. Kareem

Graduate Theses and Dissertations

The structural strength and corrosion resistance of concrete members are improved when A1035 steel is used as the main reinforcement. The enhancement of A1035 is achieved by the modification of the composition and microstructure of the steel. Therefore, the behavior of concrete structures reinforced with high-performance steel (A1035) is different from those reinforced with the regular steel (A615). Concrete bridge decks reinforced with different amounts of A1035 were studied in this research program. The structural behavior of twelve concrete bridge decks reinforced with A615 Grade 420 (60 ksi) and A1035 Grade 830 (120 ksi) steel was investigated at both service …

Cement Stabilized Crushed Stone Base Course Strength And Stiffness Analysis, Andrew Deschenes

Graduate Theses and Dissertations

Approximately 70 – 80% of state departments of transportations (DOTs) utilize the 1993 AASTHO Guide for Design of Pavement Structures (1993 AASHTO) [1] for structural design of pavements. A growing portion of DOT’s are beginning to implement the Mechanistic-Empirical Pavement Design Guide (MEPDG), referred to as AASHTOWare Pavement ME [2]. The 1993 AASHTO flexible guide applies empirically derived unitless strength values referred to as structural layer coefficients and structural numbers (SN) to pavement thickness and pavement types. The 1993 AASHTO rigid flexible guide utilizes the depth and strength of the concrete pavement, with the composite spring constant (kc), which is …

Using Bcsa Cement To Repair Waterway Transportation Structures, Anazaria Johanis Ortega Gonzalez

Graduate Theses and Dissertations

Many maritime structures (e.g., locks, dams, ports) in the US are either reaching or are past their design lives, and there are limited funds for the necessary maintenance activities which can lead to repairs that requires closures. These structures are not easy to detour and often require dewatering before repairs can be made, closures can cause delays and business-related losses which can have a large effect on the nation’s economy. Thus, it is advantageous to reduce the repair time for maritime structures. BCSA (belitic calcium sulfoaluminate) cement is a promising material to perform this type of repair due to its …

Seismic Loading Effects Within Orthogonally Connected Steel Lateral Force Resisting Systems, Alhussin Faraj Aliwan

Graduate Theses and Dissertations

Steel buildings located within seismically active regions require special design considerations to ensure public safety and prevent collapse during an extreme seismic event. Two commonly used steel systems are special moment frames (SMFs) and buckling-restrained braced frames (BRBFs). When two seismic systems share a common column in an orthogonal configuration (such as at a building corner), design specifications currently consider a 100+30 rule wherein the shared column is designed for 100% fuse demand in one direction, plus 30% fuse demand from the other direction. While this rule has been shown to be reasonable for elastic building response, a few studies …

Quantifying Workability, Compactability, And Cohesion Gain Of Asphalt Emulsion Cold In-Place Recycling, Sadie Casillas

Graduate Theses and Dissertations

To maximize the life and quality of a pavement, proper maintenance and rehabilitation are essential. Strategies for pavement rehabilitation with many sustainable benefits are pavement recycling. This dissertation focuses on two types of in-situ pavement recycling: Cold in-place recycling (CIR) stabilized with asphalt emulsion and full depth reclamation (FDR) stabilized with asphalt emulsion or foamed asphalt. One white paper (Chapter 2), two accepted peer reviewed journal articles (Chapters 3 and 4), and one submitted peer reviewed journal article (Chapter 5) are presented in this document to create better understanding of the unique material characterization of asphalt emulsion cold recycled materials, …

Verifying The Calcium Oxychloride Threshold In Cementitious Pastes, Fatoumata Traore

Graduate Theses and Dissertations

Calcium oxychloride (CAOXY) formation is a serious deterioration mechanism known to cause joint damage in concrete pavements. CAOXY is the product of a chemical reaction between calcium chloride (CaCl2) or magnesium chloride (MgCl) deicing salts and calcium hydroxide in the cementitious matrix. Currently, the accepted CAOXY threshold at which deterioration is mitigated in cementitious paste is 15 g/100 g paste (15 oz/100 oz paste); however, this limit was developed using flexural strength testing. For this investigation, the current threshold was evaluated using compressive strength and mass change over time in paste specimens exposed to CaCl2. Fly ash is used to …

Examining The Effects Of Reducing The Cement Content Of Portland Cement Concrete Pavement, Bryan Casillas

Graduate Theses and Dissertations

Portland cement is a significant component in a concrete mixture. For concrete used in portland cement concrete pavement (PCCP), the Arkansas Department of Transportation (ARDOT) specifies a minimum cementitious material content of 564 lb/yd3 and a maximum water-cementitious material ratio of 0.45. Prior research conducted at the University of Arkansas, TRC 0603, indicated concrete mixtures used in five bridge decks throughout Arkansas achieved the required 28-day strength at seven days, and the measured compressive strength at 28 days was 30% greater than required. The use of high strength concrete in pavements throughout the state can increase cracking and consequently reduce …

Development Of Multi-Axial Fatigue Retrofits For Lock Gate Components, Logan Verkamp

Graduate Theses and Dissertations

Lock gates are essential infrastructure components to the United State (US) supply chain. They create large cost savings and environmental benefits when compared with traditional methods of transport (freight and rail). Because of the large quantity of goods and dependence on these shipping chains, the US economy can be drastically affected by an unexpected gate closure. Unfortunately, many lock gates within the US have reached or exceeded their designed life. Due to the intensity of cyclic loads and the environment, fatigue cracks have become a prominent issue. Developed cracks near the pintle region (a joint which the gate rotates and …

On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez

Graduate Theses and Dissertations

Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections …

Numerical Simulations Of Spread Foundations Supported On Stone Columns Using The Discrete Element Method, Anibal Enrique Santos Marin

Graduate Theses and Dissertations

The implementation of stone columns as a ground improvement technique has become more popular in geotechnical construction practice as a result of their ability to improve strength, stiffness and permeability characteristics of weak clayey soil deposits. There are several analytical and empirical approaches to estimate the bearing capacity of stone column foundation systems; however, there is notable variation in the performance of these existing methods when compared with full-scale experimental results. For very weak cohesive soils (i.e., undrained shear strength less than 15 kPa), the use of conventional stone columns becomes restricted because of the insufficient confinement that these types …

Numerically Modeling Steel Continuous Bridges For Early Age Concrete Deck Cracking, Abdul Aziz Nabil Salah

Graduate Theses and Dissertations

Early age bridge deck cracking is a common problem throughout the United States. Early age cracking develops shortly after the deck is poured. It reduces the serviceability and lifespan of bridges. Early age cracking can be typically attributed to either of two factors, 1) construction practices, and 2) shrinkage. The Arkansas Department of Transportation (ARDOT) has experienced early age bridge deck cracking. ARDOT currently specifies a sequence deck pour on most of their bridges; however, contractors prefer continuous deck pours because of ease and construction time. During the period of this TRC1903 research project, ARDOT has only approved a few …

Best Practices For Asphalt Emulsion Particle Size Analyses Using A Coulter Counter, Logan P. Kiihnl

Graduate Theses and Dissertations

As asphalt pavements develop distresses, pavement preservation, maintenance, and rehabilitation treatments are used to mitigate distresses and extend the life of the pavement. Many of these treatments utilize asphalt emulsion. Previous research has linked particle size to material properties including viscosity and storage stability. General statements have also been made about particle size influencing emulsion performance while other researchers have identified a trend between particle size and prime coat penetration. Even though literature discusses the importance of particle size, there is little guidance on the best practices of asphalt emulsion particle size analyses, specifically with a Coulter counter.

Data collected …