Fog Seal Performance on Asphalt Mixture Longitudinal Joints

Due to the nature of construction, it is common for longitudinal joints in asphalt pavements to have lower densities and higher permeabilities than the main portions of the pavement lanes. To address this concern, many states employ joint sealant techniques such as fog seals or void reducing asphalt membranes (VRAM). Qualitative evidence in Indiana appears to indicate that longitudinal joint lives have been improved by the use of joint sealers and adhesives, but the specific materials and application rates used to treat longitudinal joints has not been quantitatively investigated. This research aims to specifically investigate the fog seal materials and application rates specified for use on longitudinal joints in Indiana and to compare the performance of fog seal and VRAM treatments in order to provide guidelines for future joint sealant treatments. These objectives were accomplished by employing laboratory testing of both laboratory prepared specimens and field samples. The research performed on the laboratory specimens found the application of fog seals can improve the performance of the longitudinal joints with respect to permeability. While the permeability was affected by the presence of a fog seal treatment, the benefits were irrespective of the specific fog seal material. The results also indicate that the fog seal should be reapplied at 5-7 year intervals. The data from the field samples indicated that the VRAM samples had on average higher air void contents than did the SS-1h fog seal samples. Additionally, the VRAM samples had permeability coefficients that were statistically higher than the SS-1h fog seal samples. These differences may be attributable to the lack of VRAM migration up into the asphalt surface mixture. While the SS-1h fog seal treatment appears to have better performance than the VRAM, the effectiveness of the treatments over time is not known

Factors Affecting Pavement Surface and Evaluation Rating Accuracy and Variability

The collection of sufficient, accurate, and consistent pavement condition data is essential to an effective pavement management system. Condition data drive a variety of pavement management tasks such as: • Predicting future pavement performance• Identifying current and future maintenance and rehabilitation needs • Estimating budget needs and requirements • Reporting to decision makers • Selecting appropriate pavement management tools Pavement condition data are represented at either the distress level or overall condition level. Common indices representing overall pavement condition include: • Pavement Condition Index (PCI) • Present Serviceability Index (PSI) • International Roughness Index (IRI) • Pavement Surface and Evaluation Rating (PASER

Development of Volumetric Acceptance and Percent Within Limits (PWL) and Criteria for Stone Metrix Asphalt (SMA) Mixtures in Indiana

SMA is to be designed based on SMA volumetric properties in terms of air voids content (Va), voids in the mineral aggregate (VMA), and adequate stone-on-stone contact. For construction quality assurance (QA) purposes, INDOT currently accepts SMAs based on aggregate gradation and asphalt binder content. Thus, there is a discrepancy between SMA design criteria and construction acceptance. To better align design and construction, it is necessary to consider SMA volumetric properties in the use of QA. For HMA mixtures, INDOT has already transitioned from volumetric QA acceptance procedures to PWL. Today, SMA still uses adjustment points not based on robust statistics for QA acceptance. SMA QA samples and QA data sets were collected from projects constructed in 2019 and tested in the laboratory. The Hamburg Wheel Track Test (HWTT) was performed on the 2019 QA samples to evaluate SMA rutting performance. Additionally, the PWL for HMA was applied to the 2019 SMA QA data to see if the HMA PWL method would work for SMA. Possible SMA QA measurements were compared to past QA data and HMA QA measurements. In addition, Voids in the Coarse Aggregate (VCA) was evaluated as a possible SMA QA measurement. Finally, using the suitable QA measurements for SMA, a PWL parameter study was performed to find PWL that provides a Pay Factor (PF) equivalent to the current SMA Adjustment Point (AP) PF. The current SMA QA measurements (binder content, gradation, and density) are recommended for Indiana\u27s SMA PWL. Based on the results of applying PWL to SMA QA data for the last four years, SMA PWL specification limits are recommended. Also, the SMA PF equations are suggested to get the SMA PWL to have PF equivalent to the current AP PF

Performance of Warranted Asphalt Pavements: Smoothness and Performance of Indiana Warranted Asphalt Pavements

In the early 1990s the Indiana Department of Transportation (INDOT) developed a five-year warranty specification for asphalt pavements with the first project being built in 1996. In 2004, results indicated that the asphalt pavements built with the warranty specification had improved performance over the conventional asphalt pavements. Nineteen years have passed since the original asphalt pavement warranty project was placed in Indiana. It has been eleven years since the performance of the warranted asphalt pavements has been analyzed to determine the effectiveness of warranties. Therefore, it is prudent to reexamine the potential benefits of asphalt pavement warranties. Hence, the ultimate goal of the project is to advise the INDOT on whether the use of asphalt pavement warranties has potential benefit for lowering the cost of ownership for asphalt paved roadways. Overall, performance comparisons of Indiana’s warranted and non-warranted asphalt pavements indicate that warranted asphalt pavements tend to perform more effectively than do non-warranted asphalt pavements. On average, warranted asphalt pavement sections had lower IRI values and rut depths than did non-warranted sections. The variability in IRI values and rut depths was also found to be less for warranted pavement sections than for the non-warranted sections. In terms of service life based on changes in IRI and rut depth, analyses indicate that warranted asphalt pavements could last 10 to 14 years longer than non-warranted asphalt pavements. When both initial capital costs and maintenance expenditures are considered, warranted asphalt pavements appear to be 15 to 40% more cost effective over a 5-year (short-term) period and 47 to 61% more cost effective over a 15-year (long-term) period. These savings do not include potential benefits of reduced user costs nor reduced INDOT inspection costs

UV-C treatment of soymilk in coiled tube UV reactors for inactivation of Escherichia coli W1485 and Bacillus cereus endospores

Coiled tube UV reactors were used to investigate the influence of tube diameter (1.6 mmID, and 3.2 mmID) and Reynolds number (Re) to inactivate Escherichia coli W1485 and Bacillus cereus spores in raw soymilk (RSM). Four levels of Re (343, 686, 1029 and 1372) were tested in RSM inoculated separately with each bacterium and treated in the UV reactors at a constant residence time of 11.3 s with UV-C dose of 11.187 mJ/ cm2 at 253.7 nm. Inactivation efficiency of both microorganisms increased with Re. Maximumreductions of 5.6 log10 CFU/ml of E. coli and 3.29 log10 CFU/ml of B. cereus spores were achieved in the 1.6 mm ID UV reactor. Inactivation efficiency was higher in the 1.6 mm ID UV reactor than the 3.2 mm ID UV reactor for both the organisms. Effect of UV-C light on lipid oxidation of untreated RSM, measured as malondialdehyde and other reactive substances (MORS) content, was much higher (95 nmol/ml) than the UV-treated (58 nmol/ml) and thermally pasteurized (55 nmol/ml) RSM during the storage period of 7 days. The UV-C treatment can be effectively used for reducing E. coli cells and B. cereus spores in soymilk without compromising its quality

Quantifying Asphalt Emulsion-Based Chip Seal Curing Times Using Electrical Resistance Measurements

Chip sealing typically consists of covering a pavement surface with asphalt emulsion into which aggregate chips are embedded. The asphalt emulsion cures through the evaporation of water, thus providing mechanical strength to adhere to the pavement while keeping the aggregate chips in place. The curing time for the chip seal depends on many factors, such as the asphalt emulsion and aggregate types, aggregate moisture content, emulsion and aggregate application rates, and environmental conditions (e.g., temperature, wind speed, relative humidity, and solar radiation). Currently, no field technique is available to quantify when sufficient mechanical strength has developed in the binder to allow traffic on a newly sealed roadway or to remove the surplus aggregate from a fresh chip seal through brooming. Instead such decisions are made by empirical factors that rely on the experience of field personnel. This study investigated the use of electrical resistance measurements to develop a quantitative method for determining the optimum curing time for chip seals. First, full frequency, two-point, uniaxial electrical impedance spectroscopy was used to characterize the electrical properties of asphalt emulsions and various asphalt emulsion-aggregate combinations. The laboratory test results suggest a relationship between the changes in the electrical resistance of an asphalt emulsion and the amount of curing that has occurred in the system. Additionally, standardized mechanical strength tests and full-scale field trials were conducted using a variety of materials. The electrical properties of the fresh seals were quantified using a handheld electrical device with a two-point probe to measure resistance. The findings suggest that chip seal systems gain significant mechanical strength when the initial electrical resistance measurement increases by a factor of 10. Finally, the implementation of the methodology for five full-scale chip seal projects in Indiana indicates that curing times for the chip seals range from 3.5 to 4.0 hours

Impact of UV-C processing of raw cow milk treated in a continuous flow coiled tube ultraviolet reactor

Raw cow milk (RCM) was treated in a continuous flow coiled tube ultraviolet reactor at the Reynolds number (Re) of 713 for a residence time of 17 s with cumulative UV-C dose of 16.822 mJ/cm2.  SPC in RCM was reduced by 2.3logs at these conditions.  Sensory analysis of milk samples was conducted using triangle test.  UV-C treated RCM and untreated RCM was compared with the fresh RCM (control) using triangle test method of olfactory sensory analysis right after the UV treatment and during storage periods (1, 3, 7 d) at 4℃.  There were no significant differences among the odor of UV-light-treated, untreated, and control, right after the UV treatment.  Perceivable change in the odor of UV-treated and untreated RCM compared to the fresh RCM was observed on the 3rd and 7th days after treatment.  There was no significant difference between the malondialdehyde and other reactive substances (MORS) content in untreated and fresh milk right after the treatment and during storage.  Lipid oxidation products content of UV-treated RCM was significantly higher than that of the fresh or untreated RCM.Keywords: raw cow milk, ultraviolet processing, UV-C treatment, sensory test, lipid oxidation substance

A stress–temperature superposition approach to study the nonlinear resilient behavior of cold recycled mixtures (CRM) with active filler addition

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract:] The asphalt paving sector is currently embracing and enhancing cold mixture technologies to reduce carbon emissions and decarbonize its operations. Cold recycled mixtures (CRM) have proven to be a promising alternative in road construction and rehabilitation, becoming a primary research focus. This study evaluates the effects on compactability and volumetric properties of adding 1% Portland cement or 1% hydrated lime to CRM made with 100% reclaimed asphalt pavement and bitumen emulsion. Dynamic triaxial tests with different confinement pressures (ranging from 20 to 200 kPa) and temperatures (5, 15, 25, and 35 °C) were used to determine the influence of these active filler additions on the resilient modulus (Mr) of the mixtures. All the mixtures exhibited increased Mr values at lower temperatures and reduced stress–dependency. Cement addition had the most favorable effect on compactability, reducing the necessary compaction energy, while mixtures with hydrated lime had more substantial increases in Mr and reduced stress dependencies. Finally, the results were analyzed by plotting master curves using a proposed novel approach called Stress–Temperature Superposition Principle (STSP), which allows for simpler and more straightforward analyses.The authors would like to acknowledge funding for the project BIA2016-80317-R from the Spanish Ministry of Science and Innovation, with an associated pre-doctoral scholarship for the training of research workers (FPI) BES-2017-079633. This scholarship also funded the corresponding author for conducting a pre-doctoral stay in a foreign research center, making it possible to carry out this research study. An special acknowledgement to the Universidade da Coruña/ CISUG for funding part of the Elsevier’s open access charge. The authors also acknowledge Milestone Contractors for contributing to the investigation with the recycled materials used. Moreover, finally, the corresponding author would like to express special thanks to Ayesha Shah, Behnam Jahangiri, and Mohammad Ali Notani for their help and support during the laboratory work, and to the rest of the people in the Innovative Materials and Pavements Group, Oscar Moncada, Bongsuk Park, Maya Khajehvand, for their hospitality during the pre-doctoral stay.Ministerio de Economía, Industria y Competitividad; BIA2016-80317-