Engineering Commons^™

A Novel Concrete-Based Sensor For Detection Of Ice And Water On Roads And Bridges, Habib Tabatabai, Mohammed Aljuboori

Civil and Environmental Engineering Faculty Articles

Hundreds of people are killed or injured annually in the United States in accidents related to ice formation on roadways and bridge decks. In this paper, a novel embedded sensor system is proposed for the detection of black ice as well as wet, dry and frozen pavement conditions on roads, runways, and bridges. The proposed sensor works by detecting changes in electrical resistance between two sets of stainless steel poles embedded in the concrete sensor to assess surface and near-surface conditions. A preliminary decision algorithm is developed that utilizes sensor outputs indicating resistance changes and surface temperature. The sensor consists …

Testing And Modeling Of The Thixotropic Behavior Of Cementitious Materials., Bashir Hasanzadeh

Electronic Theses and Dissertations

During construction, concrete goes under various operations. It is normally transported to the job site, be placed and consolidated in the formwork, etc. The easiness and quality of these operations are very much related to the intrinsic rheological properties of concrete. Therefore, a good understanding of rheological behavior of concrete under various conditions are needed. Thixotropy is an important part of rheology. The thixotropic behaviors of concrete can be good representatives of its flow behaviors on the job site. For example, the breakdown aspect of thixotropy can help to explain how its flow behavior can impact concrete pumping and its …

Reducing The Porosity And Sealing Cracks By Using Crystalline Admixture In Conventional Concrete, Visar Krelani, Liberato Ferrara

UBT International Conference

There is a continuous increase of quality on civil engineering materials in developed countries and parallel increase of need for new constructions in developing countries. Professional community should propose solutions for the durability that can resist in different severe environments. The most important factor that can affect concrete durability is represented by the pore distribution. Transport properties can take place through the porous network inside the cementitious composites and the aggregates interface, permitting the ingress of aggressive agents damaging concrete function intrinsically as a material and the wellfunctioning of the entire structure. The use of a crystalline admixture during the …

Using Of Proper Pavement Material For The Intersections With Slow-Moving Traffic, Bekim Selimi

UBT International Conference

Use of proper pavement material for some of intersections need special attention by road designers. At Camp Bondsteel-Kosovo on 2002 were built four road intersections using the concrete as pavement material. Heavy and slow-moving trucks that are turning or accelerating exposed these intersections to some of the highest stress level. After some years this intresections start deteriorating on their surface due to friction. The concrete pavements did not survive this period of usage and after eight years were removed and replaced with asphalt pavements. After more than seven years, the asphalt has shown minor distress but is still in good …

Development Of High Early-Strength Concrete For Accelerated Bridge Construction Closure Pour Connections, Stephanie Castine

Masters Theses

Accelerated bridge construction (ABC) has become a popular alternative to using traditional construction techniques in new bridge construction and existing bridge deck replacement because of the reduction of time spent in field activities. A key feature of bridges built using ABC techniques is the extensive use of prefabricated components. Prefabricated components are joined in the field using small volume closure pours involving high performance materials (steel and concrete) to ensure adequate transfer of forces between components. To date, the materials developed for closure pours have been based on proprietary components, so a need has arisen for development of mixes that …

Shrinkage Cracking In Concrete Tilt-Up Construction, Stewart Hooks, Jack Robinson

Architectural Engineering

The purpose of this project is to investigate a particular, undesirable cracking pattern in concrete tilt-up panels that, until now, did not have a known definite cause. The cause of this cracking pattern is hypothesized to be due to shrinkage restraint of the concrete panels. The cracking under investigation occurs at the bottom corners of the Tilt-Up panels, suggesting that the base of the panel is restrained from shrinkage. This project models various components of Tilt-Up Construction that have potential for restraining the panels from shrinking. This project consists of the following main components.

The first aspect of this project …

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 …

Assessments Of Concrete Internal Damage Caused By Freeze-Thaw Cycles And Mechanical Loading, Zeqian Li

Theses and Dissertations

Concrete in bridge decks in Northern States, such as Wisconsin, is subjected to both freeze-thaw cycles and mechanical stresses. Standard testing methods are available to evaluate the deterioration of concrete, including ASTM C215 (Dynamic Modulus test), ASTM C1202 (Rapid Chloride Ion Penetrability test), and ASTM WK37880 (ESR test) are available. In addition, ASTM C642 (water absorption test) helps quantification of permeable voids in concrete. These tests have been used to evaluate undamaged concrete or concrete samples after freeze-thaw cycles.

The concrete samples in this study have been subjected to compressive stresses (0.4f_c^') and freeze-thaw cycles (100 to 300 cycles) to …

The Confinement Effects On The Fiber Pullout Response Of Ultra-High Performance Concrete (Uhpc, Arden Mcswain

Honors College

Fiber pullout tests were conducted on more than ninety 10 mm by 10 mm cylindrical concrete specimens with a single, straight steel fiber embedded 10 mm in the center of the concrete specimen. Each specimen was subjected to one of three levels (90 N, 2000 N, 4000 N) of confining force applied by a steel fixture and a servo-hydraulic Instron test frame was used to conduct fiber pullout tests. A previously published fiber pullout model was used to determine the approximate bond strength and frictional stress experienced by the fiber-concrete matrix for each of the three confinement levels. Results show …

Development Of A Lightweight Hurricane-Resistant Roof System, Ehssan Amir Sayyafi

FIU Electronic Theses and Dissertations

Roofs are the most vulnerable part of the building envelope that often get damaged when subjected to hurricane winds. Damage to the roofs has a devastating impact on the entire structure, including interior losses and service interruptions. This study aimed at the development of a novel light-weight composite flat roof system for industrial, commercial and multi-story residential buildings to withstand Category 5 hurricane wind effects based on the Florida Building Code requirements for hurricane-prone regions, the strictest wind design code in the United States.

The proposed roof system is designed as a combination of two advanced materials: ultra-high performance concrete …

Electrochemical Methods To Characterize Drilled Shaft Deficiencies, Sarah Jo Mobley

USF Tampa Graduate Theses and Dissertations

In recent years drilled shafts have become the preferred foundation method for marine bridges. Typically, the drilled shaft is selected over traditional driven piles due to soil strata encountered, construction economy, increased lateral stiffness requirements, and/or vibration control considerations. The most critical component in drilled shaft construction is borehole stabilization. Wall sloughing or groundwater inclusion can have devastating effects on the strength of the finished shaft however recent research has shown that the materials, more specifically the slurry, used to accomplish stabilization may be having a negative impact on the durability of the finished product. This thesis investigates the durability …

Compressive Strength Relative To Sustainable Materials In Concrete, Brad Harvey

Williams Honors College, Honors Research Projects

The objective of this study is to determine how integrating abundant waste materials into concrete affects its compressive strength. This research will be used to benefit the construction industry by replacing a portion of a conventional concrete mix (cement, stone, sand, and water) with more sustainable materials. In order to create a more sustainable concrete mixture, the following mix design and methodology was followed.

The initial step was to create an updatable MS Excel spreadsheet to aid in the mix development (the spreadsheet is shown in Appendix A). These sheets allowed for easy transitions from one mix to another by …

Chemical Modification Of Crumb Rubber To Increase Its Bonding With Concrete, Mary T. Mccannon, Kendall J. Sweitzer

Williams Honors College, Honors Research Projects

The hydrophilicity of crumb rubber was increased with wet chemical modification and added to concrete to increase its adhesion with concrete, consequently the compressive strength relative to that of concrete with untreated rubber. Other modification methods were tested on crumb rubber and rubber sheets to yield an increase in hydrophilicity. Certain tests were less reliable for powder testing or tedious and time consuming and concrete materials and rubber may not be homogeneous.

For wet chemical modification, several approaches were attempted. First, crumb rubber was soaked in 5% sodium hydroxide, 5% potassium permanganate and saturated sodium bisulfite, tested for hydrophilicity using …