Construction and Monitoring of Post-tensioned Masonry Sound Walls

Construction and Monitoring of Post-tensioned Masonry Sound Walls
Author: David B. Woodham
Publisher:
Total Pages: 52
Release: 2002
Genre: Noise barriers
ISBN:

The purpose of this project was to document the installation of a post-tensioned concrete masonry sound wall constructed as part of a widening and sound wall project along US 36 near Denver, Colorado. In addition, the wall was instrumented at the time of construction to monitor the loss in prestress in the steel tendons over time due to concrete masonry creep and shrinkage and steel relaxation. Tendon tension was monitored for one year to obtain values for the accumulated losses. Accurate losses in post-tensioned concrete masonry are important for economical design. Currently, there are limited data to support an accurate prediction of prestress loss in concrete masonry.

Performance Evaluation of Various Corrosion Protection Systems of Bridges in Colorado

Performance Evaluation of Various Corrosion Protection Systems of Bridges in Colorado
Author: Yunping Xi
Publisher:
Total Pages: 166
Release: 2004
Genre: Concrete bridges
ISBN:

Corrosion of reinforced concrete structures has been a significant problem for many state and transportation agencies since the application of deicing salts was introduced. Much research has been conducted to develop corrosion protection systems that can prolong the life span of reinforced concrete structures. The Colorado Department of Transportation (CDOT) has several routine and experimental measures to prevent corrosion of the rebar including epoxy-coated rebar, calcium nitrite admixture, organic corrosion inhibitors, a thick cover of quality concrete, and a waterproofing membrane covered by an asphalt overlay. An extensive literature review was performed to collect information on various corrosion protection systems that have been used in the U.S. and around the world. Current CDOT practices in terms of corrosion protection measures were reviewed. A draft inspection plan for Colorado's bridge structures was proposed.

Structural Masonry Designers' Manual

Structural Masonry Designers' Manual
Author: W. G. Curtin
Publisher: John Wiley & Sons
Total Pages: 357
Release: 2006-07-12
Genre: Technology & Engineering
ISBN: 0632056126

This major handbook covers the structural use of brick and blockwork. A major feature is a series of step-by-step design examples of typical elements and buildings. The book has been revised to include updates to the code of practice BS 5628:2000-2 and the 2004 version of Part A of the Building Regulations. New information on sustainability issues, innovation in masonry, health and safety issues and technical developments has been added.

Sampling Location Impact on Measured Asphalt Content of Hot Mix Asphalt

Sampling Location Impact on Measured Asphalt Content of Hot Mix Asphalt
Author: Mohammad Abu-Hassan
Publisher:
Total Pages: 80
Release: 2002
Genre: Pavements, Asphalt
ISBN:

In May 2000, the Colorado Department of Transportation (CDOT) requested a forensic study of a project located on I-24 north of Denver. The request was made because, within a year of the 1997 overlay, longitudinal cracking appeared in the surface. Transverse cracks were attributed to reflective cracking. However, the longitudinal cracks appeared to be surface initiated. In October 2000, a forensic team reviewed the project and established a sampling and testing plan to take cores from the roadway. Based on data analysis of the cores, the higher than expected in-place air voids, the low effective asphalt, and segregation within the mat, all contributed to the early cracking.

Extent of Top-down Cracking in Colorado

Extent of Top-down Cracking in Colorado
Author: Donna S. Harmelink
Publisher:
Total Pages: 64
Release: 2003
Genre: Pavements, Asphalt concrete
ISBN:

In 2000, a forensic evaluation was conducted on a project that was exhibiting early longitudinal cracking near the wheel paths. A team of national asphalt experts conducted this forensic evaluation. The forensic team concluded that the cracking on the project was surface initiated cracking and was caused by a number of contributing factors. One of the contributing factors to the early distress that was identified by the experts were the pockets of segregation that were observed at the bottom of the surface lift but were not apparent on the surface. The object of this study was to determine the extent of "top-down cracking" in Colorado, what causes it, how can it be prevented, if it occurs how is the distress treated, and how quickly does the distress need to be treated.

Development of Site-specific ESAL

Development of Site-specific ESAL
Author: Sirous H. Alavi
Publisher:
Total Pages: 204
Release: 2002
Genre: Pavements
ISBN:

This study was approved by the CDOT's Research Implementation Committee as a high priority research with the goal of improving the accuracy of the existing and forecasted traffic loads of CDOT's highway network. The overall scope of this project involved examination of those resources directly related to the current statewide ESAL classification system and the generation of this final report discussing the research and analysis conducted and recommendation of procedures required for CDOT to develop and implement a more site-specific ESAL classification system. In this study Nichols Consulting Engineers (NCE) analyzed all available CDOT permanent and portable weigh-in-motion (WIM) data.

Corrosion Effects of Magnesium Chloride and Sodium Chloride on Automobile Components

Corrosion Effects of Magnesium Chloride and Sodium Chloride on Automobile Components
Author: Yunping Xi
Publisher:
Total Pages: 110
Release: 2002
Genre: Automobiles
ISBN:

The project consisted of two phases. In the Phase I study, the relative corrosiveness of the two salts [magnesium chloride (MgCl2) and sodium chloride (NaCl)] were examined by SAE J2334 test and ASTM B117 test. In the Phase II study, SAE J2334 test and NACE TM-01-69 test (as modified by the Pacific North States) were applied. Representative metals examined in the project included stainless steel 410 and 304L, aluminum 2024 and 5086, coated automobile body sheets, copper wires, and mild steels.