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Application Guide and Specifications for Geotextiles in Roadway Applications

Wed, 23 May 2012 19:20:52 UTC

Geotextiles, one among the different geosynthetic products, can be used for a number of functions or applications in pavement design. The benefits of using geotextiles in pavements and other transportation applications have triggered a proliferation of products. While this abundance of new products has led to reduction in costs, it has also made it difficult for TxDOT personnel to choose appropriate products based on their engineering properties. Consequently, this report provides the basis for (i) guidelines for proper use and selection of geotextiles in pavements, (ii) material specifications for geotextiles in pavement applications, and (iii) draft construction specifications.

Evaluation of Corrosion Resistance of Improved Post-tensioning Materials after Long-term Exposure Testing

Wed, 23 May 2012 21:10:16 UTC

Ten full-scale post-tensioned beam specimens were subject to 4 years of aggressive cyclic ponded saltwater exposure. Three of those specimens were additionally exposed to saltwater spray once per month on one anchorage face. Non-destructive monitoring was conducted during the exposure period. This consisted of half-cell potential measurements, AC impedance measurements (for specimens with fully encapsulated tendons), and regular visual inspections. Chloride samples were extracted from the specimens at the end of exposure. After 4 years, the specimens were autopsied, and all reinforcing elements from the middle of each specimen were examined for corrosion and damage. Anchorage regions were also autopsied and examined for corrosion. Duct systems included galvanized metal ducts, plastic ducts, and encapsulated duct systems. Strand types included conventional strand, hot dipped galvanized strand, copper clad strand, and stainless steel strand. Complete observations are presented.

Texas Energy Sector: Past and Future

Wed, 23 May 2012 19:29:47 UTC

The objectives of this research study were to (a) illustrate and quantify the impacts imposed by the energy sector on Texas’s transportation system and (b) identify key energy demand indicators by energy source that TxDOT can track in an effort to anticipate the associated future transportation impacts on Texas’s transportation system. This report describes how Texas’s energy sector uses the transportation system and quantifies the impact imposed by the energy sector on Texas’s road infrastructure. It is, however, also important to understand what the future holds—which industries within the energy sector are expected to grow, which industries are expected to decline, and how Texas’s transportation system could be impacted in the future. The focus of this report is the development of four energy scenarios that reflect different assumptions and outcomes for Texas’s future energy sector over a 20- to 30-year period. Analyses of several factors, referred to as "drivers," that may impact the energy sector are presented within.

Training Manual

Wed, 23 May 2012 17:32:25 UTC

"The purpose of this product is to summarize the activities that the research team has accomplished on Project 6590: Material Selection for Concrete Overlays – Task 6: Development of a Training Manual. This manual is intended to educate TxDOT personnel for training design engineers, construction personnel, and inspectors. All the information provided can be referenced to the 0-6590 project report." --p.1