Engineering Science and Materials Commons^™

Simplified Approach For Structural Evaluation Of Flexible Pavements At The Network Level, Mena Souliman, Stefan Romanoschi, Samer Dessouky

Publications

Currently, there are few available simple procedures to identify structurally weak pavement sections utilizing Falling Weight Deflectometer (FWD) data at the network level (e.g., city, state or province). A simple method is required to determine the structural condition of pavement sections that can be directly implemented and automated in current pavement databases. The objective of this research study is to develop a simple analysis method to determine the structural condition of pavement sections utilizing the currently available non-destructive testing (NDT) deflection measurement devices at the network level that can be directly implemented and automated in the database of a typical …

Modeling Sulfate Attack In Modern Concrete For Building Sustainable And Resilient Infrastructure, Zachary Grasley

Publications

External sulfate attack is a complex phenomenon and is manifested in the form of large expansion, cracking, and spalling depending on the exposure solution and material constituent properties. Several models were developed in the past to demonstrate sulfate attack mechanisms that account for the diffusion of sulfate ions into the porous concrete and the successive deformation triggered by the chemical reaction and precipitation of expansive agents. However, none of these models accounts for the effect of the migration of solvent water from the low solute concentration solution to high solute concentration solution driven by the osmotic pressure. Osmotic pressure is …

Development Of Self-Healing Mechanisms For Asphalt Pavements, Max Abelardo Aguirre Deras

LSU Doctoral Dissertations

Self-healing mechanisms, such as microcapsules or hollow-fibers, filled with an asphalt rejuvenator present an emerging technology that would enhance an asphalt mixture’s resistance to cracking damage caused by vehicular and environmental loading. The objectives of this study were to: (a) Evaluate the effects of asphalt rejuvenators on hot-mix asphalt mixtures in order to test its effects on the fundamental engineering properties of the mixtures at high and intermediate temperatures; (b) Develop a synthesis procedure for production of microcapsules and hollow-fibers containing an asphalt rejuvenator; (c) Evaluate the self-healing efficiency of double-walled microcapsules and hollow-fibers filled with an asphalt rejuvenator, through …

A Coupled Thermo-Mechanical Theory Of Strain Gradient Plasticity For Small And Finite Deformations, Yooseob Song

LSU Doctoral Dissertations

In this work, a thermodynamically consistent coupled thermo-mechanical gradient enhanced continuum plasticity theory is developed for small and finite deformations. The proposed model is conceptually based on the dislocations interaction mechanisms and thermal activation energy. The thermodynamic conjugate microstresses are decomposed into energetic and dissipative components. This work incorporates the thermal and mechanical responses of microsystems. It addresses phenomena such as size and boundary effects and in particular microscale heat transfer in fast-transient processes. Not only the partial heat dissipation caused by the fast transient time, but also the distribution of temperature caused by the transition from the plastic work …

Preliminary Investigation Of Tensile Strength And Impact Characterization Of Cementitious Composite Incorporating Carbon Nanotubes, Robabeh Jazaei

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cement has been largely used in the construction industry, specifically as a matrix for concrete. Recently, a new generation of cement-based composite that greatly increases mechanical properties is replacing conventional concrete. With periodic advances in the field, researchers considered particles with high-aspect ratios such as Carbon Nanotubes (CNTs) to reinforce cement matrices. Although there is not much literature to draw upon in research, some research on improving the tensile strength of cementitious composite incorporating with CNTs does exist. However, there had been no evidence of investigation into impact strength until this study.

Most papers presented examined the effect of multi-walled …

Spot-R By Triax, Purdue Ect Team

ECT Fact Sheets

Triax’s Spot-r system was developed to tackle the construction industry’s unique safety and productivity challenges, stemming from a demonstrated lack of total jobsite visibility and automatically collected, easily accessible field data. Spot-r by Triax combines a proprietary mesh network with sensor technology to record and transmit previously unattainable workforce and equipment location, activity and safety data within a defined area – all in real-time.

The Spot-r network is installed around the site and operates in a 900 MHz network, with a subset using a cellular connection to forward Spot-r sensor data to Triax’s custom, cloud dashboard. In the hazardous construction …

Mdp (Machine Drive Power) Intelligent Compaction Technology, Purdue Ect Team

ECT Fact Sheets

Caterpillar developed MDP (Machine Drive Power) technology to fill this gap. Rather than an accelerometer and vibratory drum, it uses the principle of rolling resistance to provide indications of soil stiffness. This allows it to perform more reliably on cohesive and granular soils with less variability than accelerometer systems. It also means that the technology can be used on both vibratory and static drum compactors, which are often used on larger sites. While the technology is quite useful on its own, it is even better as a complementary technology to the existing accelerometer-based systems. Contractors who use vibratory soil compactors …

Purdue’S Biowall, Purdue Ect Team

ECT Fact Sheets

Mechanical ventilation, energy recovery ventilation, and infiltration (air that leaks into a building) are commonly used to introduce fresh air. These are all valid approaches, but a living plant-based filter is an innovative complement to these traditional technologies. A Biowall has the potential to improve indoor air quality while reducing the quantity of air needed for ventilation, creating the potential for energy savings. Figure 1 shows a Biowall prototype being evaluated in the ReNEWW House, a research home located near the Purdue University campus (http://www.renewwhouse.com/).