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During the past decades, to minimize Greenhouse Gas (GHG) emissions and asphalt fumes during the asphalt mix production and construction process, various warm mix asphalt (WMA) additives have been developed and successfully applied. Currently, as production of WMA reaches close to that of Hot Mix Asphalt (HMA) in the US, the varied definition of WMA is questioned in this paper. Not only are the temperature reduction ranges from HMA defined by various studies too wide, but also the minimum threshold to be classified as WMA is often too small. In this paper, a new category of "Cool Mix Asphalt (CMA)" is proposed to distinguish it from the newly defined WMA based not on the reduction amount from HMA temperature but its actual production temperature. It is proposed that HMA should be defined as asphalt mixtures produced at temperatures between 140 and 160 °C (between 284 and 320 °F), WMA as production temperatures between 120 and 140 °C (between 248 and 284 °F), and CMA as production temperatures between 100 and 120 °C (212 to 248 °F). By defining their actual production temperatures rather than reduction temperatures from HMA, WMA and CMA will be clearly defined. This paper then presents a new Polymer Cool Mix Asphalt (PCMA) additive called "Zero-M", which was developed to lower the mixing temperature to around 110 °C (203 °F). Recently, test sections using Zero-M were successfully constructed in Korea, Italy and Vietnam, and their laboratory test results of field cores and production and construction experiences are described in this paper. The chemistry and compositions of Zero-M are discussed along with its mechanism to significantly lower the production temperature of PCMA. All test sections constructed in three countries met the in-place compaction density requirements of their respective countries, which were close to or higher than those of the control HMA test sections. [ABSTRACT FROM AUTHOR]

This research project aims to organize the archival information of traditional Korean performing arts in a semantic web environment. Key requirements, which the archival records manager should consider for publishing and distribution of gugak performing archival information in a semantic web environment, are presented in the perspective of linked data.

Cold in-place recycling (CIR) is one of the most effective methods to rehabilitate asphalt pavements. In fact, most CIR roads have performed well at low cost in Iowa since the first CIR road was constructed in 1986. However, some CIR roads have reached failures earlier than their expected design lives because there is no design standard for designing CIR roads with a limited amount of past performance information. Some of the most prominent problems seemed to have come from selecting CIR in areas where there are poor subgrades. Therefore, it is critical to collect CIR performance data along with falling weight deflectometer (FWD) data in order to develop performance models. The main purpose of this paper is to document that effort. The performance models were developed on the basis of historical data collected from CIR roads in Iowa. First, an inventory of CIR roads was created which includes construction information, subgrade and base characteristics, and traffic levels. In consideration of pavement age, level of traffic, and subgrade condition, 26 test sections were selected from the inventory of CIR roads and pavement surface distress surveys were conducted on these roads using an automated image collection system. Distress data were then compiled to compute pavement condition index (PCI) for each test section. FWD data were collected from each test section to determine its relative soil support condition. Finally, to determine their long-term performance, the PCI values were plotted against the pavement age for each group of pavements categorized by their soil support conditions and traffic levels. Overall, it can be concluded that the CIR roads in Iowa, all under traffic level of annual average daily traffic of 2,000, have performed very well and predicted to last up to 25 years before reaching the poor condition (PCI = 40) when the pavements are to be rehabilitated. The CIR roads with a good subgrade support, however, are predicted to last up to 35 years. DOI: 10.1061/(ASCE)CF.1943-5509.0000093 CE Database subject headings: Asphalt pavements; Recycling; Service life; Stress; Measurement; Iowa. Author keywords: Asphalt pavements; Recycling; Service life; Distress; Measurement.

With a limited maintenance budget and unprecedented construction cost increases, many owner/agencies in the United States are beginning to rehabilitate existing distressed pavements. Cold in-place recycling (CIR) provides an economical rehabilitation method and has been widely used in the past 20 years. However, recycled roads have experienced inconsistent performance and that has hindered the application of CIR. The objective of this paper is to study the cause and effect relationships between factors, such as traffic loading, support condition, and aged engineering properties of the CIR materials, and pavement performance. Twenty-four roads in Iowa were examined through field and lab tests. Statistical analyzes show that, within the range of data in this study, better performance was observed on CIR roads with lower CIR modulus value and/or higher air voids. DOI: 10.1061/(ASCE)CF.1943-5509.0000092 CE Database subject headings: Asphalts; Highways and roads; Pavements; Construction materials; Recycling; Rehabilitation. Author keywords: Asphalt; Roads; Performance; Materials; Recycling.

As part of the validation effort to evaluate the consistency of a new cold in-place recycling using foamed asphalt (CIR-foam) mix design process for the Iowa Department of Transportation, the dynamic modulus and repeated load tests were conducted to evaluate the performance characteristics of CIR-foam mixtures over a wide range of loading and temperature conditions. The main objective of this research is to study the impacts of the foamed asphalt contents and reclaimed asphalt pavement (RAP) material characteristics on dynamic modulus and flow number. Dynamic modulus and repeated load tests were conducted on CIR-foam mixtures with RAP materials collected from seven different CIR project sites located throughout Iowa. Dynamic modulus values of the RAP materials varied depending on the sources and foamed asphalt contents. Coarse RAP materials with a small amount of residual asphalt content exhibited a higher modulus value at 4.4[degrees]C but exhibited a lower dynamic modulus value at 37.8[degrees]C than fine RAP materials with a large amount of residual asphalt content. Flow numbers were varied significantly depending on their RAP sources and foamed asphalt contents. Fine RAP materials with a hard residual asphalt binder exhibited a higher flow number than coarse RAP materials with a soft residual binder. The relative rankings of RAP materials in terms of the flow number did not change when the foamed asphalt was increased from 1.0 to 3.0%, which supports the repeated load test being consistent in evaluating a rutting potential of RAP materials. CE Database subject headings: Recycling; Asphalt pavements; Mixtures; Foam.

The main objective of this study is to validate a new mix design procedure for cold in-place recycling using foamed asphalt (CIR-foam) developed for the Iowa Department of Transportation. First, reclaimed asphalt pavement (RAP) materials were collected from seven different CIR construction sites located across the state of Iowa. To determine the consistency of a new CIR-foam mix design procedure, the mix design was performed seven times using these RAP materials. The test specimens were prepared using gyratory compactor rather than Marshall hammer because it produced more consistent mixtures for various foamed asphalt contents and curing conditions. The indirect tensile strength test was performed on the vacuum-saturated specimens prepared using each of seven RAP material sources for five different foamed asphalt contents (1.0, 1.5, 2.0, 2.5, and 3.0%), given a fixed moisture content of 4.0%. As the foamed asphalt content increased from 1.0 to 3.0% at 0.5% increments, air voids in the CIR-foam mixtures decreased gradually. The indirect tensile strength of CIR-foam specimens cured for two days at 60[degrees]C was significantly higher than that of CIR-foam specimens cured for three days at 40[degrees]C. Based on the new mix design procedure, the optimum foamed asphalt contents were consistently found at values between 1.5 and 2.5% for all seven different RAP materials. The stiffer residual asphalt required more foamed asphalt, whereas the higher residual asphalt content did not require a smaller amount of foamed asphalt. The raveling test result was very sensitive to the curing time and the foamed asphalt content, such that RAP materials with a large amount of stiff residual asphalt would exhibit more potential for raveling. DOI: 10.1061/(ASCE)0899-1561(2007)19:11(1000) CE Database subject headings: Recycling; Asphalt pavements; Mixtures; Tensile strength.

The main objective of this study is to determine mix design parameters for cold in-place recycling with foamed asphalt. First, the foaming process of laboratory foaming equipment was validated by varying the water and asphalt content. 1.3% water content was adopted to create the optimum foaming characteristics in terms of the expansion ratio and the half-life at 170[degrees]C under air pressure of 400 kPa and water pressure of 500 kPa. The mix design was then performed using both the indirect tensile test and the Marshall test for 13 combinations of foamed asphalt content and water content for three different gradations. The water content did not appear to affect the test results significantly. Maximum stability (both wet and dry samples), maximum bulk density, and indirect tensile strength (both wet and dry samples) were all obtained around 2.5% foamed asphalt content. Overall, the highest Marshall stability and redirect tensile strength were obtained in the order of line, field, and coarse reclaimed asphalt pavement gradations. It is recommended that the indirect tensile strength based on wet samples be adopted for determining the optimum foamed asphalt content. DOI: 10.1061/(ASCE)0899-1561(2006)18:1(116) CE Database subject headings: Recycling; Asphalt mixes; Asphalt pavements; Tensile strength.

The objective of this research is to develop a microelectromechanical system (MEMS)-based intelligent hybrid Biaxial Strain Transducer (BiAST) sensor for predicting railroad fatigue life based on strain history. The developed BiAST prototype was deployed to collect real-time strain data from the full-scale test track at the Transportation Technology Center (TTCI), near Pueblo, Colorado. The collected strain data were analyzed using the 'Binner' fatigue analysis program for counting the load cycles and estimating the fatigue life of a rail structure. Field-testing results of the BiAST were used to evaluate the BiAST prototype with respect to its repeatability, accuracy, and hybridization. BiAST was effective in detecting the dynamic response of a particular wheel and spurious overload events. BiAST can be used to detect passing wheels, train speed, and track condition. CE Database subject headings: Transducers; Evaluation; Fatigue life.

The objective of this research project is to determine the service lives of three different types of joint sealants - polyvinylchloride (PVC)-coal tar, rubberized asphalt, and silicone - and to recommend maintenance strategies to improve the performance of concrete pavements in Utah. The silicone material has been performing well for over 10 years. The PVC-coal tar material had failed in the test sections that are an average of 15 years old, and the rubberized asphalt material has aged beyond its expected service life in the test sections over 20 years old. Survival curves of the three sealants were developed with respect to their ages, and their performance correlated well with their ages. The conical spalling at the bottom of the joints increased after 10 years of service. Based on the limited field data, it is recommended that Utah Department of Transportation (UDOT) should consider the use of a narrower joint width of 6 mm instead of the current 9-mm design, use silicone or rubberized asphalt material, and implement a maintenance plan with a 10-year cycle for recutting and resealing of the joints to 9 x 9 mm.

Cold In-place Recycling (CIR) has been widely used in the world since it is easy to apply it in the field at a low cost. However, it is not normally used as a surface layer as a result of its inconsistent quality due to an excessive amount of fine aggregates pulverized during the milling process. Hot In-place Recycling (HIR) can retain the original shape of the aggregates, but it often produces a large amount of Volatile Organic Compounds (VOCs). Therefore, a third in-place recycling technique is introduced in this paper: Warm In-place Recycling (WIR). The WIR technique overcomes the limitations of both CIR and HIR techniques by lowering a heating temperature while adding a Tetraethylenepentamine (TEPA)/Soybean/SBS additive. To identify the effect of the additive on the RTFO-aged binder, viscosity and dynamic modulus values were measured at different temperatures. Based on Hamburg Wheel Tracking (HWT) and Disc-Shaped Compact Tension (DCT) tests, the additive improved the moisture susceptibility and low temperature cracking resistance. The indirect infrared heating equipment reduced the emission by lowering the pavement surface heating temperature by 20 °C from 140 to 120 °C. Compared with the heating at 140 °C, the LPG usage for heating at 140 °C was lowered by 21%. The proposed WIR equipment with an additive would revolutionize the in-place recycling practices. [ABSTRACT FROM AUTHOR]