Performance Grade Research Articles (Page 1)

Asphalt is a viscous-elastic material, where structural capacity can vary due to temperature variations and is influenced by the climatic environment. Asphalt pavement with good durability, one of which is determined by the Performance Grade (PG) of asphalt. Several models have been developed to estimate asphalt PG, including the SUPERPAVE model. This study aims to develop a maximum and minimum asphalt pavement temperature model to determine PG asphalt in tropical climates. Observations of air temperature (T Amb), humidity (RH), and asphalt pavement temperature at several depths were carried out on 4 national roads on the Bali Islands using thermocouple sensors with a data logger and SAGA Technology program application, continuously for 7 x 24 hours with recording at 30-minute intervals. There are 960 T Amb, RH, minimum surface temperature (T00 Min), and maximum pavement temperature at a depth of 20 mm (T20 Max) data, and linear regression models have been T00 Min = 17.357 + 0.577 T Amb -0.078 RH and T20 Max = 34.163 + 0.650 T Amb – 0.177 RH. The developed model has adequate accuracy, with the MAPE values less than 10%. If the model is compared to the SUPERPAVE model, it has better accuracy. It is hoped that the developed model will be useful as a reference for determining the maximum and minimum temperatures for road pavement in tropical climates.

Accurate modelling of asphalt pavement temperature is crucial for ageing evaluation, performance prediction, and structural design of asphalt pavements. Pavement temperature modelling requires complex model inputs, including the thermal properties of materials and pavement surface characteristics. To reduce the input complexity, this study introduced and calibrated a seasonal variable for asphalt pavement sections located in 27 states across the United States. The calibrated model in this study performed equivalently or better than existing models. This study also ran a 44-year simulation from 1980 to 2023 for calibrated pavement sections. The high and low pavement temperature data from modelling correlated well with the performance grade results from the LTPPBind Online tool. Based on the developed model, this study also assessed asphalt thermal ageing rates in the projected years under both low- and high-emission scenarios. The results indicated that at the end of this century and under the high-emission scenario, the fast and constant asphalt ageing reaction rates may experience an average of 82% and 48% increases, respectively, compared with the ageing reaction rates in 2025. The effect of climate change on asphalt thermal ageing rates has more profound impacts on pavements in cold regions than on those in warm regions.

Abstract Despite extensive evidence on the importance of non-cognitive skills for labor market outcomes, to what extent training can affect specific skills in adulthood remains an open question. We conducted a randomized controlled trial with low-skilled employed workers in Senegal where workers were randomly assigned to receive a training intervention designed to affect conscientiousness-related skills. We found that treated workers were significantly more likely to stay in their job, had higher earnings and better performance grades post intervention. Our findings suggest that non-cognitive skills can be affected later in the life cycle and targeted training can have substantial labor market returns.

The inherent characteristics of asphalt binder can pose challenges to achieving a flexible pavement with the desired properties. However, these challenges can be addressed through asphalt modification. While numerous additives are available, selecting the most suitable one is crucial due to issues such as cost, storage stability, and homogeneity. This study focused on evaluating the physical and rheological properties of an asphalt binder modified with a hydrocarbon-based thermoplastic resin. The investigation included conventional binder tests and rotational viscometer (RV) analysis, along with an in-depth rheological evaluation of the modified binders using a dynamic shear rheometer (DSR). Additionally, the thermal properties of the additive were analyzed through thermogravimetric analysis (TGA). The findings revealed that the modified binders exhibited reduced penetration, elevated softening points, and increased viscosity, all achieved without compromising workability or pumpability. Furthermore, the modification enhanced rutting resistance. Laboratory tests identified 5% as the optimal additive content, which improved the performance grade of the pure binder. Activation energy results derived from the complex viscosity master curves indicated that while the energy required for flow increased with the addition of 5% resin, the elevated viscosity mitigated the temperature sensitivity issue observed in the pure binder.

Objective: To develop and standardize valid and reliable tests for measuring the long passing Accruracy of handball goalkeepers in the Kurdistan Regional Premier League, and to establish corresponding performance grades and standard levels. Methodology: The study employed a descriptive survey method with a population of 67 goalkeepers from the 2023-2024 season. Two novel tests measuring the speed and accuracy of long passes were designed and validated by experts. Scientific procedures for validity (face, content, discriminant), reliability (test-retest), and objectivity were conducted on a construction sample (n=30) and a pilot sample (n=3). The final validated tests were then administered to an application sample (n=32). Performance was scored using a formula combining accuracy points and time (Raw Skill Score = Accuracy/Time). Results: The overall performance of the goalkeepers in the two tests was average. However, success rates were very high compared to failure rates. The established standard levels indicated that the performance of most goalkeepers was classified as "acceptable" or "very good." Statistical analysis confirmed that the test data approached a normal distribution. Conclusions: The two tests developed by the researchers are effective, valid, and reliable instruments for measuring the long passing accuracy of handball goalkeepers. These tools provide coaches in the Kurdistan Region of Iraq with an objective method for performance evaluation, training monitoring, and talent development.

Higher education refers to that phase of education that starts after schooling. Universities offer graduate courses in multiple disciplines, and students select courses that interest them. Both the government and private sectors run universities in India. These institutions certify the students based on their performance in the academic sessions. These universities compete with each other in providing quality education that opens new avenues for further studies or employment globally. Due to the intense competition in the education and employment sectors, designing a robust assessment system for students' performance has become imperative. Given the vast majority of the student population and their potential in various domains, there is a need for a computer-aided algorithm that can analyse their performance with the highest possible degree of accuracy. The existing methods that used machine learning algorithms to assess student performance gave less accuracy and could not handle massive datasets. This paper presents a deep learning methodology capable of managing diverse datasets, ranging from minimal to extensive, incorporating a Deep Artificial Neural Network (DANN), a Convolutional Neural Network (CNN), and Bidirectional Long Short-Term Memory (BiLSTM) algorithms, along with hybrid deep learning architectures, including DANN-BiLSTM and CNN-BiLSTM. This approach aims to assess student performance, known as the student performance grading system. The research shows that the proposed Students Performance Grading system gave accurate results on various factors of training and testing compared to the existing ones. The results show that the MSE of CNN is 0.0227, the MSE of Deep ANN is 0.0219, and the MSE of Bi-LSTM is 0.0233. Additionally, the MSEs are 0.0211 for DANN-Bi-LSTM and 0.0215 for CNN-BiLSTM. The accuracies are 96.74% for DANN, 96.42% for CNN, and 95.80% for Bi-LSTM. and DANN-Bi-LSTM attained an accuracy of 99.31%, while CNN-Bi-LSTM achieved an accuracy of 97.30%. This research identified that DANN-Bi-LSTM is the most effective algorithm for forecasting student success.

This research looks into the effects of AI-assisted grading systems on feedback in higher education in Pakistan. Using a mixed methods approach, data were collected over an academic semester from 80 faculty members and 800 undergraduate students across 12 public universities in four provinces. The sample included six universities who implemented AI grading systems and six that continued with conventional grading without the AI grading systems. Data were collected from surveys of faculty and students, classroom observations, and interviews regarding feedback quality, time efficiencies, faculty satisfaction, student performance, and engagement, and faculty assessment marking and grading. The primary findings showed that the AI grading systems improved the timeliness, consistency, and personalization of student feedback significantly at the universities using them, per the SPSS data. Faculty reported that the automated grading systems improved their teaching efficiency, reduced grading time, and improved student engagement, but they faced some technological issues and advised caution regarding purely automated grading to grade, for example, a 'subjective assignment'. The qualitative data also noted challenges in using AI grading comparison to rubric criteria. In sum, the findings indicate that there is potential for AI grading to help improve feedback and assessment practices in higher education in Pakistan, although challenges remain.

Anti-stripping agents (ASAs) have become a mandatory inclusion in bituminous mixtures containing hydrophilic aggregates and in regions experiencing extreme rainfall. Even with superior binders such as polymer-modified bitumen (PMB), ASAs are added to enhance moisture resistance in high-stress locations such as airfields, where significant pavement stresses and a strict zero-failure policy are critical for safety. This study deeply probes the rheological change in the behavior of PMB because of the addition of liquid ASAs: amine and silane. The performance of ASAs is analyzed from the perspective of cohesion, rutting, fatigue, and aggregate-bonding properties. Artificial aging of binders was performed to imitate short-term and long-term aging conditions using a rolling thin film oven and then a pressure aging vessel, respectively. A series of tests were conducted, which included FTIR (Fourier transform infrared spectroscopy), high performance grade temperature, Bitumen-Typisierungs-Schnell-Verfahren, rotational viscosity, force ductility, MSCR (multiple stress creep recovery), the BYET (binder yield energy test), and binder bond strength. FTIR tests evinced chemical rearrangement and polymer degradation because of the addition of ASAs in the PMB. MSCR analysis at multiple stress levels indicated a drop in rutting resistance with the presence of ASAs at high stresses and temperature, stipulating a loss of recovery property. The novel BYET measured the fatigue resistance of long-term aged binders and demonstrated that ASAs cause early yielding of binders. The addition of ASAs improved the bond strength of PMB with limestone, basalt, and quartzite aggregates. Comprehensively, this study concludes that ASAs have an impact on the rheology of PMB; however, there is a compromising of certain binder properties to attain the benefits of moisture resistance.

Performance grade similarity-based generalized zero-shot operating performance assessment of industrial processes with insufficient samples

Abstract: Every year, thousands of tires made of crumb rubber are consumed as scrap. Burning this material means that more landfill space is needed, which creates a crumb rubber in PG76 performance grade and 80–100 penetration grade asphalt binder mix. Using a wet method, the asphalt binders were combined with waste crumb rubber to create a powder form 40 mesh (0.425 micron). health risk and environmental problems. The study concentrated on using crumb rubber to replace 15, 20, and 25% of the modified asphalt binder mix's total weight. The Malaysian JKR/SPJ/2008-S4 standard and the American Society for Testing and Materials (ASTM) served as the foundation for the laboratory work. Numerous tests were carried out, including pressure aging vessel, rolling thin film oven, penetration, softening point, and viscosity testing on modified asphalt binder. The outcome demonstrates a beneficial effect, with penetration decreasing as 80–100% and PG76 blend asphalt binder are partially substituted with crumb rubber. In contrast to 80–100 asphalt binder, the PG76 asphalt binder result exhibits reduced penetration in terms of stiffness throughout both short- and long-term aging. The softening point test results indicate that replacing a portion of the asphalt binder with crumb rubber raises the temperature of the PG76 and 80-100 asphalt binder mix. This is especially true after the PG76 short-term aging test (RTFOT) at 20% replacement when the temperature reached 85°C, and after the long-term aging test (PAV), when the temperature dropped to 75°C. However, resistance to increased temperature susceptibility is indicated by the partial replacement of asphalt binder by crumb rubber. According to the results of the viscosity test, the PG76 asphalt binder is more viscous than the original PG76, and the 80-100 asphalt binder replacement is made of a crumb rubber mix. For the short-term aging (RTFOT) test, the PG76 asphalt binder suggests that a crumb rubber replacement of 20% is ideal. When compared to the RTFOT test, the viscosity decreased in the long-term aging (PAV) test.

The Superpave binder grading system ensures that appropriate binder grades are selected to meet the climatic and traffic conditions of a project site. Liberia still selects asphalt binders based on a penetration grading system, despite its significant limitations. Premature asphalt pavement failures are common, and there is a need to improve asphalt mixture performance. To facilitate the adoption of the Superpave binder performance grade (PG) system in Liberia, a selection guide was developed in this study. Temperature data spanning 1979 to 2014 were gathered from 29 weather stations in Liberia and incorporated in the Long-Term Pavement Performance Program (LTPP) and the Strategic Highway Research Program (SHRP)- based models to determine PG binder grades at 50 %, 85% and 98 % reliability levels. While the SHRP model produced higher binder grades at 50 % reliability compared to the LTPP model, at 85% and 98% reliability levels, the LTPP model produced higher binder grades. However, the highest variance in the PG produced by the two models was one standard grade (6 °C) at all reliability levels. At 98 % reliability, recommended for high traffic volume roads, the LTPP model produced high standard grades of PG 64-YY and PG 70-YY, compared with PG 58-YY and PG 64-YY, for the SHRP model. The study resulted in the development of a PG binder grade selection guide for Liberia to facilitate asphalt mixture design, construction and research. The study recommends field performance monitoring to improve effectiveness of the recommended binder grades, and further research to develop local pavement temperature prediction models.

Effective station–city integration is crucial for sustainable development around high-speed rail stations. However, research assessing public preferences regarding the aspects of this integration remains limited. We constructed a performance evaluation model for station–city integration in high-speed rail station areas. By considering the high-speed rail station area in the Yangtze River Delta region as a research object, which is located in the metropolitan cities centered on Shanghai, China, we dissected the five dimensions of population, industry, land use, function, and environment into 15 indicators that flow into the three value objectives of attraction–retention–integration (NPI). Subsequently, we systematically analyzed the performance differentiation characteristics of station–city integration in the Yangtze River Delta region’s high-speed rail station areas by employing a multiple regression model to delve into the influence mechanisms affecting the performance differentiation patterns of station–city integration. Our findings indicate the following. (1) Regarding station–city integration performance grade differentiation, a few high-speed rail station areas in the Yangtze River Delta region exhibit a high-efficiency integration level, whereas more areas fall within the higher and general integration levels. (2) Spatially, the station–city integration performance in high-speed rail station areas within the Yangtze River Delta region exhibits a distinct distribution characterized by “high-grade point-block dependence and low-grade concentrated contiguous patches.” (3) The spatial distribution of the five dimensions of station–city integration performance exhibits significant disparities. (4) Regarding the development types of station–city integration performance advantages, efficient integration of stations and cities represents a multidimensional advantageous development type and higher integration falls into the same category. (5) Station–city integration performance results from the comprehensive effects of four factors: government policy inducement, station energy level attraction, station–city relationship adhesion, and urban energy level promotion. This study advances a systematic framework—encompassing performance measurement, mechanistic inquiry, and strategy formulation—for examining station–city integration in HSR station areas. By integrating the perspective of cyclical cumulative development into the node–place model from urban planning and geographical viewpoints, we articulate a new performance model that clarifies critical influencing factors and mechanisms, thus broadening the theoretical scope of HSR station area research. We believe that the NPI evaluation model can provide valuable insights for guiding the integrated development of high-speed rail station areas and enhancing the quality of urban development.

This study modified a neat asphalt binder of PG 58-28 grade using in situ grown iron oxide particles. Particle contents of 0.25, 0.5, and 1.0 wt% improved the performance grades to PG 64-28, PG 70-28, and PG 82-28, respectively. The particles enhanced high-temperature properties while maintaining low-temperature performance. At 70 °C, the rutting parameter of the unaged binder increased from 0.33 kPa to 4.29 kPa with 1.0 wt% iron oxide. Multiple Stress Creep Recovery at 58 °C and 3.2 kPa stress showed recovery rising from 0.3% to 65.2% for the 1.0 wt% binder. Recovered particles exhibited polycrystalline γ-iron oxide structure with average size 2–9 μm, depending on content. Unlike ex situ mixing based modification, no particle aggregation was observed. Overall, in situ grown iron oxide particles substantially improved binder performance and outperformed most additives reported in the literature, including nanoparticles..

Asphalt pavements are highly sensitive to climatic conditions, and their performance and longevity are significantly affected by temperature fluctuations, precipitation, and extreme weather events. With increasing climate variability, the development of refined and adaptive climate zoning systems for pavement engineering has become essential. This study reviews the evolution, methodologies, and applications of asphalt pavement climate zoning in China. First, it delineates the historical progression of climate zoning into three stages, from general natural zoning to the specialized three-indicator model and performance grade (PG) system, and finally to refined spatial processing based on meteorological data. Notably, 48% of provinces have conducted localized zoning studies, with South and Northeast China as key focus areas. Second, this study classifies existing zoning models into three major categories: the traditional three-indicator model (based on high temperature, low temperature, and precipitation), the hydrothermal coefficient model tailored to hot, humid climates, and clustering models incorporating spatial interpolation and multivariate analysis. While the three-indicator model remains the most widely applied due to its simplicity, it may result in coarse divisions in climatically diverse regions. The hydrothermal model offers general guidance but limited accuracy, whereas clustering methods provide high-resolution, adaptive zoning results at the cost of increased computational complexity. Third, the application of climate zoning results to the PG system for asphalt binder classification is analyzed. Although SHRP, LTPP, and C-SHRP formulas are commonly used, C-SHRP tends to overestimate pavement temperatures by 6.0–8.6 °C in China. Approximately 68.8% of studies rely on existing formulas, while 31.2% propose localized conversions to improve PG grading accuracy. Overall, this review identifies both the methodological diversity and key challenges in China’s climate zoning practices and provides a scientific foundation for more performance-oriented, climate-resilient pavement design strategies.

Asphalt binder performance grading (PG) is key for selecting suitable pavement materials. Currently, standard test methods to determine the high and low-temperature PG values of asphalt binder are the dynamic shear rheometer (DSR) test and the Bending Beam Rheometer (BBR) test. However, in China, BBR is rarely used due to high costs and complexity, hindering widespread PG adoption. Instead, penetration, softening point and ductility prevail, but their test temperatures misalign with in-service low conditions, failing to accurately reflect true low-temperature performance. This study developed a method to predict low-temperature PG of typical Chinese asphalt binders via DSR: using the 8-mm parallel geometry for low and intermediate temperature data, fitting with the 2S2P1D model, converting frequency to the time domain and calibrating creep stiffness at selected key time points to determine BBR parameters and low-temperature PG. It can effectively address BBR limitations, aiding binder selection and quality assurance in China.

A fluorine-free waterproof and antifouling finishing agent for acrylate was prepared using a simple emulsion polymerization method to optimize the addition amount and ratio of oxidant and reductant in the redox system. The finishing agent is copolymerized by Tris(trimethylsiloxy)silylpropyl methacrylate (M3T), stearic methacrylate (SMA) and glycidyl methacrylate (GMA). The polymer emulsion has an average surface tension of 19.8 mN/m and has good dilution, acid and alkali stability, and thermal stability and can withstand a use temperature below 170 °C. The experimental results show that the finishing agent can form a uniform polymer film on the cotton fabric's surface. The finished cotton fabric has excellent waterproof performance: a water contact angle of 147°, a spray test grade of 4.5, and a resist water-borne pollution performance grade of 4-5. It is worth noting that the water contact angle is still more than 140° after 20 washing cycles, indicating that the cotton fabric has good washing resistance. At the same time, following the green sustainable development, although the finishing agent does not contain fluoride that endangers the human body and the environment, it can repel the pollution of some ordinary vegetable oils, and the antifouling grade can reach 4.

ABSTRACT This study investigates the relationship between academic recognition, student attendance, and academic performance among 422 final-year Business and Management students in UK higher education. Building on existing literature emphasising the importance of consistent participation in learning, the research highlights active learning as crucial for fostering deeper student engagement beyond traditional lecture methods. Using a positivist deductive approach, data on attendance, quiz performance, and final grades were collected and analysed with SPSS. The results show a significant positive correlation between attendance, continuous quiz performance, and final grades, with correlation coefficients for attendance and final grades (0.482), quiz scores and final grades (0.403), and attendance and quiz scores (0.544). These findings underscore the value of continuous engagement, suggesting that integrating recognition-based formative assessments, such as quizzes, into the curriculum could enhance student performance. The study concludes that academic recognition and active participation are key to improving educational outcomes.

This study is centered on assessing the influence of nano-modifiers on healing and the fatigue properties of asphalt binders. Nano-modified binders were prepared by incorporating three nanomaterials (i.e., nanoclay, nanosilica, and nanoalumina) into performance grade (PG) 58-22 and PG 76-22 binders at 1%, 3%, and 4% dosages by binder weight. The binders’ fatigue life was evaluated using the conventional linear amplitude sweep test by obtaining the number of cycles to failure corresponding to 2.5% strain. The self-healing capability of nano-modified asphalt binders was assessed by employing different rest periods (10, 20, and 30 min) and damage levels (25%, 37.5%, and 50%) in a linear amplitude sweep healing test. It was observed that nanoclay was the best performing modifier, followed by nanosilica and nanoalumina. Also, the healing capability of the binders was found to improve with the addition of rest periods that is, 10 and 20 min, beyond which it again starts decreasing. Moreover, the damage level of 25% was found to be most effective for introducing rest periods, which can be considered as the micro damage zone. Finally, the nanoclay at higher dosages (4%), 20 min rest duration, and 25% damage level was recommended as the ideal combination for self-healing in the asphalt binders based on the outcomes of this study.

The use of reclaimed asphalt pavement (RAP) has been increasing, making better use of resources and reducing the environmental impact of the asphalt industry. Standard asphalt plants have limitations on the RAP content they can accommodate. Additionally, volumetric design methods can limit the content of RAP used to meet specifications. This paper presents a field demonstration of a newly developed asphalt plant using microwave technology. The new design directly heats RAP to warm-mix temperatures, eliminating concerns of degrading materials that arise with high RAP mixtures in a conventional plant. The process reduces plant site emissions while increasing RAP content up to 100%. Balanced mix design was used to select the asphalt binder grade and content, and additives required for a 100% RAP mix design to meet Wisconsin mixture performance requirements. The study demonstrated that the microwave heating process is feasible, and the asphalt mixture meets or exceeds the performance of comparable traditional asphalt mixtures. Results showed that the plant emissions were significantly reduced and below levels permitted in Wisconsin. Also, virgin material inputs were eliminated, except for 0.6% asphalt binder containing additives. Performance testing confirmed that the 100% RAP mixture met specifications for rutting, moisture sensitivity, and cracking resistance. Test sections were surveyed after two years. No visible distress was observed, and field densities were similar for all sections. Recovered binder was subjected to extended aging and was characterized based on performance grade and durability parameters. Results demonstrated that the 100% RAP mixture had equivalent or improved binder aging properties to the control mixtures.

This paper examines the impact of several psychological and educational factors on the behavior of entrepreneurs and job seeking and employability of the graduate students especially in regard to being job ready as well as the career opportunities. Based on a convenience sampling of 400 graduate students, the research establishes student grade as the independent variable with self-efficacy, attitude toward entrepreneurship and entrepreneurial intention taking the role of mediators. The dependent variable is entrepreneurial behavior, which is used as a proxy of improved outcomes of employability. The study examines the role of entrepreneurial education, which is signified by the academic performance (grade), into providing students with essential learning attributes like problem solving, innovation and adaptability. This ability is also determined by self-efficacy and entrepreneurial attitudes, and this has a bearing in entrepreneurial intentions and behavior. The paper also shows how family support contributes to the development of confidence and resilience, and how social connections can be used to widen the opportunities and professional networks of the person. One of the most essential elements of the study is exactly the entrepreneurial approach that will be staged as the moderator that will boost the correlation between the educational accomplishment and the psychological mediators and employability. This attitude-identified as being proactive, risk-taking, and opportunity-seeking intends to increase direct and even indirect impact, empowering the overall process of academic performance to career preparation. The results will be likely to favor a broader model wherein all the direct as well as indirect hypotheses are confirmed and helpful ideas can be extracted about the way that entrepreneurial competencies and contextual support assist in creating better career performances. The study emphasizes the importance of the entrepreneurial behavior not only as a by-product of education and psychosocial processes but as the way to overcome the disparity between the education and the labor market that is positively changing.