Civil and Environmental Engineering Commons^™

The Development Of A Novel Experiment On Confined, Flattened Brazilian Disks To Correlate Damage And Permeability In Brittle Geo-Materials, Samuel H. Boyce

Civil Engineering ETDs

This research develops a novel experiment using flattened Brazilian disks under confining pressure with concurrent permeability measurements and acoustic emission monitoring. The purpose of this work is to correlate damage and permeability in brittle geo-materials. Two series of tests are performed on concrete and one series on tuff, under a range of confining stresses between 2.76 and 13.79 MPa. Tests were continued beyond peak stress conditions, capturing data in the post-peak region. The acoustic emission data (cumulative energy and counts) are used to identify damage thresholds and track the progression of microscopic damage. This quantified damage is then correlated to …

Effects Of Coefficient Of Thermal Expansion On Unbonded Concrete Overlay Design And Performance, Gauhar Sabih

Civil Engineering ETDs

With the deterioration of highway pavements across the country, more emphasis is being laid on the rehabilitation of existing pavements. Unbonded concrete overlay (UBCO) is a cost-effective technique used to rehabilitate damaged concrete pavements. The design and performance of UBCO rely on various properties of concrete, of which coefficient of thermal expansion (CTE) is an important one. Concrete CTE has a direct impact on the design and performance of rigid pavements and overlays. CTE regulates the magnitude of curling and related stresses that impact the performance of overlays with regards to cracking, faulting and pavement roughness. Previous research revealed that …

Performance Of Concrete Tunnel Systems Subject To Fault Displacement, Michael Morano

Masters Theses

A Finite Element Analysis (FEA) investigation of concrete tunnel systems traversing seismic faults is carried out to determine how to effectively mitigate the stresses induced in the liner when subject to fault displacement. A parametric study of various fault parameters, both in the damage zone and competent rock, is carried out to determine the site conditions which induce the most stress on the tunnel liner system. Results indicate that friction angle, cohesion, and elastic modulus of fault zones have varying effects on the stresses induced on the liner. The width of damage zone and expected displacements are also investigated and …

Coir Fiber Reinforced Concrete, Jose De La Serna, Moses Karakouzian

AANAPISI Poster Presentations

This poster exhibits the testing and research done on general Portland Cement Concrete with the addition of coir (coconut) fibers as reinforcement. Using the fundamental constituents of cement (water, cement, fine and coarse aggregate) and processed coir fiber, concrete specimens were batched to test for compressive and flexural strengths (per appropriate ASTM standards). Cylindrical and rectangular beam specimens were subjected to loadings until failure occurred. The capacity and modes of failures of the specimens were observed. It was determined that:

• The addition of processed coir fibers decreases the overall strength of general Portland Cement Concrete. • The tested concrete’s …

Modeling And Simulation Of Damage In The Brazilian Indirect Tension Test Using The Finite-Discrete Element Method, Jeremiah C. Leyba

Civil Engineering ETDs

The Brazilian indirect tension test is used to investigate possible correlations between progressive damage and associated permeability changes. The test offers ease of replicability with a damage behavior known to lead to fracture openings as a tool for interpreting the indirect tensile strength of concrete and rocks. This behavior can lend insight into the nature of tensile damage and fracture progression in association with changes in permeability. The nature of these brittle materials is known to exhibit rapid failures in the Brazilian indirect tension test and require a method to retard the progression of damage for the possibility of acquiring …

Understanding Asphalt Concrete Aging Using Nanoindentation, Hasan M. Faisal

Civil Engineering ETDs

Asphalt concrete (AC) is created by mixing liquid asphalt binder with solid aggregates. When asphalt binder is mixed with aggregates, it creates a thin film (about 7-16 microns thick) around the aggregate surface. Fine aggregate (smaller than 0.075 mm size) get entrapped within the binder film or mixed with the binder, and create a phase called mastic. Both asphalt film and mastic play significant roles in aging of asphalt pavement. To this day, tests were performed mainly on the bulk liquid asphalt, but not on the film or mastic. In this study, for the first time, nanoindentation tests were done …

Integration Of A Prototype Wireless Communication System With Micro-Electromechanical Temperature And Humidity Sensor For Concrete Pavement Health Monitoring, Shuo Yang, Keyan Shen, Halil Ceylan, Sunghwan Kim, Daji Qiao, Kasthurirangan Gopalakrishnan

Daji Qiao

In recent years, structural health monitoring and management (SHMM) has become a popular approach and is considered essential for achieving well-performing, long-lasting, sustainable transportation infrastructure systems. Key requirements in ideal SHMM of road infrastructure include long-term, continuous, and real-time monitoring of pavement response and performance under various pavement geometry-materials-loading configurations and environmental conditions. With advancements in wireless technologies, integration of wireless communications into sensing device is considered an alternate and superior solution to existing time- and labor-intensive wired sensing systems in meeting the requirements of an ideal SHMM. This study explored the development and integration of a wireless communications sub-system …

Fluid Isolator, Purdue Ect Team

ECT Fact Sheets

The reliability of concrete infrastructure is vital to ensuring daily life, as well as commerce, can progress without interruption. From the pavement of interstate highways to the driveways and sidewalks in a local neighborhood, concrete is expensive to install and often even more expensive, and intrusive, when it needs to be replaced. Unfortunately, to maintain functionality in winter climates concrete is heavily exposed to deicing salts. This not only affects the roads, driveways, and sidewalks where salt is applied directly, but many other areas such as parking and residential garages where vehicles (and people) will track salt along with water …

Use Of Recycled Crushed Concrete (Rcc) Fines For Potential Soil Stabilization, Lindeman Mark, Varilek Brandon, Lieska Halsey, Rick Gloe, Maria Olomi

Nebraska Department of Transportation: Research Reports

This study evaluated the use of Recycled Crushed Concrete (RCC) Fines for potential soil stabilization. Soil stabilization is the enhancement of subgrade stability to improve the constructability of successive pavement layers. Use of RCC fines may not only provide less costly alternatives for subgrade stabilization, but their use may also alleviate landfill disposal challenges.