- Publications (Center for Transportation Research Online Library)
0-6636 - Photocatalytic NOx /HRVOC/O3 Removal in Transportation Applications
The focus of the proposed research is intensive and thorough testing of two commercial photocatalytic coatings applied to portland cement concrete to provide accurate data that are representative of highway applications. While published laboratory data suggest that TiO2-based materials can remove NOx and VOCs from air samples, the tests have not been designed to be representative of outdoor air conditions. Laboratory tests have been designed for this proposal to emulate roadway conditions. The results of these data will be used to model the effects of using photocatalytic materials in the Houston-Galveston and Dallas-Fort Worth areas, predict the impact on air pollutant concentrations, and provide a cost-per-ton of pollutant removal among other metrics. Long-term outdoor exposure tests have been designed to examine the performance of the materials in real near-roadway locations in three different locations with varying pollutant concentrations and environmental conditions.
0-6617 - Revamping Aggregate Property Requirements for Portland Cement Concrete
Current TxDOT specifications for aggregates in portland cement concrete have been in Item 421 for over 37 years. Two tests have been required to qualify aggregate for concrete are the magnesium sulfate soundness test which was developed to evaluate the effect of freezing and thawing of aggregates and is only an indirect test for durability. It has had very mixed results as a predictor of performance. The Los Angeles abrasion test has been used to evaluate aggregate strength and toughness. This test has also been shown not to be a good predictor of performance. This research will evaluate several tests including the micro-Deval, aggregate imaging system (AIMS), unconfined freeze-thaw, crushing strength (wet and dry), and absorption tests singly and in combination. Performance will be established from subjective ratings by TxDOT personnel based on many years of service. The performance will be correlated with the aggregate test results. From these correlations aggregate tests and test limits will be recommended.
FHWA-Transtec-Task Order 6
The objective of this research is to implement and evaluate field application and demonstration projects focusing on structures affected by alkali-silica reaction. The researchers will provide technical assistance to the State Departments of Transportation (through presentations, handouts, brochures and training), instrument the field application and demonstration projects selected under this research, evaluate and collect data from the field sites, and analyze collected data to determine the efficacy of the technologies.