Engineering Commons^™

An Evaluation Of Models Of Bare Soil Evaporation Formulated With Different Land Surface Boundary Conditions And Assumptions, Kathleen M. Smits, Viet V. Ngo, Abdullah Cihan, Toshihiro Sakaki, Tissa H. Illangasekare

Civil Engineering Faculty Publications

Bare soil evaporation is a key process for water exchange between the land and the atmosphere and an important component of the water balance. However, there is no agreement on the best modeling methodology to determine evaporation under different atmospheric boundary conditions. Also, there is a lack of directly measured soil evaporation data for model validation to compare these methods to establish the validity of their mathematical formulations. Thus, a need exists to systematically compare evaporation estimates using existing methods to experimental observations. The goal of this work is to test different conceptual and mathematical formulations that are used to …

Impact Of Lifetime On U.S. Residential Building Lca Results, Can B. Aktas, M. M. Bilec

Civil Engineering Faculty Publications

Purpose: Many life cycle assessment (LCA) studies do not adequately address the actual lifetime of buildings and building products, but rather assume a typical value. The goal of this study was to determine the impact of lifetime on residential building LCA results. Including accurate lifetime data into LCA allows a better understanding of a product’s environmental impact that would ultimately enhance the accuracy of LCA results.

Methods This study focuses on refining the U.S. residential building lifetime, as well as lifetime of interior renovation products that are commonly used as interior finishes in homes, to improve LCA results. Residential building …

Structural Behavior And Design Of Barrier-Overhang Connection In Concrete Bridge Superstructures Using Aashto Lrfd Method, Byungik Chang, Kamal Mirtalaei, Seungyeol Lee, Kenneth Leitch

Civil Engineering Faculty Publications

The U.S. Departments of Transportation adopted the AASHTO LRFD Bridge Design Specifications during the year 2007, which is mandated by AASHTO and FHWA. The application of LRFD specification initiated numerous research works in this field. This investigation addresses the LRFD and Standard design methodologies of concrete deck slab, deck overhang, barrier and combined barrier-bridge overhang. The purpose of this study is to propose a simplified manual design approach for the barrier-deck overhang in concrete bridges. For concrete deck slab overhang and barrier, application of National Cooperative Highway Research Program crash test is reviewed. The failure mechanism, design philosophy and load …

Optimization Of Post-Tensioned Box Girder Bridges With Special Reference To Use Of High-Strength Concrete Using Aashto Lrfd Method, Byungik Chang, Kamal Mirtalaei, Seungyeol Lee, Kenneth Leitch

Civil Engineering Faculty Publications

With the Federal Highway Administration-mandated implementation of the LRFD specifications, many state departments of transportation (DOTs) have already started implementing LRFD specifications as developed by the AASHTO. Many aspects of the LRFD specifications are being investigated by DOTs and researchers in order for seamless implementation for design and analysis purposes. This paper presents the investigation on several design aspects of post-tensioned box girder bridges designed by LRFD Specifications using conventional or High-Strength Concrete (HSC). A computer spreadsheet application was specifically developed for this investigation. It is capable of analysis, design, and cost evaluation of the superstructure for a cast-in-place post-tensioned …

Service Life Prediction Of Residential Interior Finishes For Life Cycle Assessment, Can B. Aktas Ph.D.

Civil Engineering Faculty Publications

Service life of building products has an important influence on life cycle assessment (LCA) results of buildings. The goal of this study was to propose a systematic approach to estimate service life of building products by including both technical and social factors. A hybrid service life prediction method, combining the statistical approach described in American Society for Testing and Materials (ASTM) standard G166, with the Factor Method adopted by International Organization for Standardization (ISO) standard 15686 was proposed. In their current forms, the two methods are not suitable to provide accurate lifetime estimates for the wide variety of products that …

Computational Benchmarks In Simulation Of Cyclic Performance Of Steel Connections Using Three Dimensional Nonlinear Finite Element Method, Ali Abolmaali, Mohammad Razavi, Roozbeh Kiamanesh

Civil Engineering Faculty Publications

The presented manuscript is intended to introduce accurate computational benchmarks to predict the hysteresis behavior of beam-column steel connections by means of a 3D non-linear finite element analysis. In this study, element type, inelastic material behavior, bolts pre-tensioning, and contact properties between different components of connections are discussed. Incremental nonlinear analysis takes into account all three types of nonlinearities including material, geometry, and contact properties in predicting moment-rotation hysteresis loops. A series of full-scale structural tests are performed to validate the results obtained from the finite element analyses. This study shows that cost efficient numerical analysis simulation is capable of …