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The issue of forming a reliable and stable structure of a crumb-rubber-modified binder is an important scientific and technical task. The authors supplemented existing concepts of the mechanism of effective interaction with rubber crumb by introducing a preliminary first stage: controlled partial physical destruction of rubber crumb—producing rubber reclaim. Proposed physical methods of rubber crumb destruction include high shear force (roll mills), high temperature, and a plasticizing medium. The controllability and degree of devulcanization of rubber were determined by acetone-chloroform extraction in different time intervals. The degree of devulcanization of rubber in the rubber reclaim was found to be 22 ± 0.24%, with stability over 14 days. It was found that the size of the particles of the rubber reclaim in the bitumen is less than 2 µm. The properties of the structure of the binder modified with rubber reclaim, characterizing the stability and sustainability, have been studied and established. The developed modified binders are stable in storage. Rheological parameters of the structure characterizing intermolecular interaction, such as shear stability for original and RTFOT-aged, modified bitumen, meet requirements of the state standard at test temperature 64 °C. The elastic structural component of the crumb-rubber-modified binder, as indicated by the relative irreversible deformation parameter J3,2, does not exceed 2.6 kPa (<4.5 kPa) at 64 °C. Additionally, it was determined that the rheological structural parameter for fatigue resistance, which characterizes the durability of road pavement under intensive operational conditions, does not exceed 4699 kPa (<5000 kPa) at 16 °C. The use of 10% rubber reclaim combined with waste frying oil provided the opportunity to obtain a modified binder with a stable and sustainable structure without the introduction of additional stabilizers and agents. Test results showed that the overall performance characteristics of the modified binder meet the 64(S)-40 grade standards. [ABSTRACT FROM AUTHOR]

This work aims to characterize the rheological properties of lignin-modified bitumen. Various contents (0, 10, 20 and 30% by total mass of the modified bitumen) of Kraft lignin, which is derived from softwood and were used with two soft and unmodified bitumen adapted for cold climates and standard traffic level (PG 58S-28 and PG 52S-34). Storage stability test and microscope observations were performed to check the stability and homogeneity of the modified bitumen. Brookfield rotational viscometer (BRV), dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR) and bending beam rheometer (BBR) tests were carried out to evaluate the thermomechanical behaviour and to determine the performance grade (PG Hn-L) of lignin-modified bitumens. Results indicate that the modified bitumen is homogeneous and no stability issues were observed. Also, results show that using Kraft lignin, as a bio-substitute to the bitumen, increased the viscosity (η), the stiffness (S) and the performance at high temperatures, but it made the bitumen more brittle and less performant at low temperatures. Notably, there is no significant change in the thermal range of use of bitumen (H–L), just a shift in performance grade (PG Hn-L) to higher temperatures. In addition, Kraft lignin has almost the same effects on both bitumen. To this end, the test results show that it is possible to use Kraft lignin to partially replace the bitumen. [ABSTRACT FROM AUTHOR]

The work discussed in this interim report is part of a larger study, funded by the California Department of Transportation. The study objective focuses on developing and recommending testing procedures and criteria for performance-based specifications of asphalt rubber binders used in gap-graded and open-graded mixes using current Superpave performance grade (PG) equipment. Work in this phase covered the testing of 19 plant-produced binders and the base binders used to produce them. Plant-produced gap-graded rubberized hot mix asphalt mixes from five of the projects were also tested. The following important observations from the binder rheology tests were made:--Although the low-temperature performance grades appeared to be reasonable, the high-temperature grades appeared to be unrealistically high, while the intermediate-temperature grades appeared to be potentially lower than anticipated, when comparedto the base binders. Fourteen of the binders tested with concentric cylinder geometry and 13 tested with parallel plate geometry had PGs higher than the maximum grade of 82°C listed in the AASHTO M 320 standard. Grades higher than 82 are considered to be unrealistically high and probably not a true indication of likely high-temperature performance (i.e., rut resistance under heavy loads on hot days).--A comparison of the concentric cylinder and parallel plate (3 mm gap) geometries indicated that the results between the two geometries are different and are likely to be higher than the precision and bias of the individual procedures. Precision and bias statements for these procedures had not been developed at the time of preparing this report. These results indicate that the two geometries cannot be used interchangeably.--No consistent trends in results were observed between any of the parameters tested.--Observations from previous testing and during this phase of the study indicated that incompletely digested rubber particles—which have different sensitivities to temperature, aging, and applied stress and strain than the base asphalt binder—appeared to have a dominant influence on results and caused variability between results, regardless of the testing geometry used. Considering these incompletely digested particles as part of a homogenous binder may therefore not be appropriate when determining performance grades. Work is continuing in Phase 3 of this study to adjust testing procedures to account for the influence that these incompletely digested particles have on results.The proposed modifications to short- and long-term aging procedures (i.e., rolling thin-film oven and pressure aging vessel) and to the bending beam rheometer specimen preparation procedures developed in Phase 2 are considered to be more aligned with the original intent of the tests and will likely reduce the variability between replicate specimens during testing.Preliminary test results indicate that Fourier transformed infrared spectroscopy is a potentially valid method for quantifying rubber content in rubber-modified binders.

The work discussed in this interim report is part of a larger study, funded by the California Department of Transportation, with the objective of developing and recommending testing procedures and criteria for performance-based specifications of asphalt rubber binders used in gap-graded and open-graded mixes using current Superpave performance grade (PG) equipment. Work covered the testing of five plant-produced binders, the base binders used to produce them, and the gap-graded rubberized hot mix asphalt mixes produced with them. The following important observations from the binder rheology tests were made:Although the low-temperature performance grades appeared to be reasonable, the high-temperature grades appeared to be unrealistically high, while the intermediate-temperature grades appeared to be potentially lower than anticipated when compared to the base binders. A comparison of the concentric cylinder and parallel plate (3 mm gap) geometries indicated that the results between the two geometries are different and are likely to be higher than the precision and bias of the individual procedures. Precision and bias statements for these procedures had not been developed at the time of preparing this report. Consistent trends in results were observed between high-temperature PG/true grade, Delta TC, and non-recoverable creep compliance at 3.2 kPa. Observations from previous testing and during this phase of the study indicated that incompletely digested rubber particles—which have different sensitivities to temperature, aging, and applied stress and strain than the base asphalt binder—appeared to have a dominant influence on results and caused variability between results, regardless of the testing geometry used. Considering these incompletely digested particles as part of a homogenous binder may therefore not be appropriate when determining performance grades. Work is continuing in Phase 3 of this study to adjust testing procedures to account for the influence that these incompletely digested particles have on results.The proposed modifications to short- and long-term aging procedures (i.e., rolling thin film oven and pressure aging vessel) and to the bending beam rheometerspecimen preparation procedures developed in Phase 2 are considered to be more aligned with the original intent of the tests and will likely reduce the variability between replicate specimens during testing.Preliminary test results indicate that Fourier transformed infrared spectroscopy is a potentially valid method for quantifying rubber content in rubber-modified binders.

The use of polymer-modified binders in asphalt concrete makes it possible to increase the efficiency and durability of highways. However, at present, there is an important and unresolved problem in this area, making it impossible to fully exploit the potential of modified binders. This is a tendency of aging processes that leads to the premature destruction of the pavement. In many literary sources, it is reported that reasons are related to the peculiarity of the chemical composition and occur at the submicron level. Therefore, the influence of single-walled carbon nanotubes has been studied for a better understanding of aging processes. The aging processes of the RTFOT (rolling thin film oven test) and PAV (pressure aging vessel) modified with SBS (styrene–butadiene–styrene) polymer, single-walled carbon nanotubes, and waste industrial oil were simulated in a laboratory furnace. Microstructural features were studied using the method of infrared spectral analysis. The dependences of viscoelastic properties on the component composition of binders were investigated. The optimal content of single-walled carbon nanotubes (0.001%), SBS (styrene–butadiene–styrene) polymer (3.5%), and waste industrial oil (4%) in the binder composition was established, which synergistically improved the performance of the modified binder from PG (52-22) (performance grade) to PG (64-34). It was established that single-walled carbon nanotubes provide improvement in the durability parameter ∆Tc binder by 150%, improved relaxation properties at low temperatures, and resistance to fatigue damage. [ABSTRACT FROM AUTHOR]

Natural conditions tend to affect the performance of the asphalt pavement. Climatic factors must be taken into account in the structural design of the asphalt pavement. Thus it is important to classify asphalt scientifically and reasonably based on the local climatic conditions. Based on 56-year meteorological data from 747 representative meteorological stations in China, temperature and precipitation were divided into eight meteorological indices. Three spatial interpolation methods are used for interpolation, namely Inverse Distance Weight, Ordinary Kriging and Collaborative Kriging considering Digital Elevation Model (DEM). After the comparison, the Collaborative Kriging considering DEM interpolation results of temperature and the Inverse Distance Weight interpolation results of precipitation were used to establish the standard climate zoning system in China. The classification of asphalt pavement is introduced on the basis of performance grading. According to the pavement high and low temperature design formula obtained by comparison, climatic suitability zoning of road asphalt is performed, and the classification table with performance grading of road asphalt in China is presented. The research results provide a theoretical basis for the selection of road asphalt and provide guidance for scientific and reasonable design of asphalt pavement. [ABSTRACT FROM AUTHOR]

Accurate identification of factors that primarily affect the number of low-temperature cracks is crucial for selection of road materials and planning of pavement maintenance. Field investigations of low-temperature cracks were performed in the years 2014 and 2020 on the same 68 road sections being in service in typical traffic conditions. The collected data were statistically analysed using the ordered logistic regression model. Comparison of the odds ratios which were calculated on the basis of the model enabled ordering of the selected factors from those having the greatest effect on low-temperature cracking of pavements to those with the least influence: (1) pavement age, (2) type of asphalt concrete, (3) modification of bitumen, (4) climatic zone (on the basis of low performance grade temperature). The odds of a section belonging to the group of cracked sections decreased by half when a polymer-modified bitumen was used in its binder course and asphalt base. Regardless of the considered factors, the odds of a pavement section being classified into the group of heavily cracked sections are comparable. It means that some external factors, including quality of paving works and bitumen chemistry, may prove the most crucial. [ABSTRACT FROM AUTHOR]

The impact of climate change on asphalt pavement infrastructure has become increasingly apparent. This paper investigated how climate change impacts the selection of asphalt binder for freeway pavement in China. The climate data predicted by the Global Climate Model were employed to select the appropriate performance grade for asphalt binder. The predicted air temperature converted pavement temperature, and performance grade distribution of the country was analysed. It is suggested that the performance grade of asphalt binder for freeways' pavement should be determined based on ten years' predicted climate data. This study concluded the following four major findings. Firstly, the selection of the appropriate asphalt binder performance grade needs to take into account the effects of future climate change. Secondly, the change in the standard deviation of temperature has a greater impact on the change in asphalt performance grade, as compared to the change in average air temperature. Thirdly, climate change affects the low-temperature performance grade more than the high-temperature performance grade in China. Finally, by 2050s, 15.2% of freeway asphalt pavement needs to upgrade high-temperature performance grade limit, and 17.3% of freeway asphalt pavement needs to upgrade to low-temperature performance grade limit. [ABSTRACT FROM AUTHOR]

A técnica de utilização de agentes rejuvenescedores (AR) na recuperação das propriedades de ligantes envelhecidos ainda tem muito a ser desenvolvida, considerando que a quantidade de AR afeta diretamente o desempenho dos ligantes à fadiga e deformação permanente, principais fatores de degradação do pavimento. Esta pesquisa avaliou os métodos de dosagem de AR Sylvaroad RP1000 em ligante envelhecido, com base em parâmetros reológicos. O ligante foi extraído de mistura asfáltica fresada (RAP), por meio de centrifugação e rotoevaporação. Foram produzidas amostras com 0, 3, 5, 7 e 10% de AR e submetidas a ensaios na Estufa de Película Delgada Rotacional (RTFOT) e Reômetro de Cisalhamento Dinâmico (DSR). A dosagem ideal foi avaliada com base no Performance Grade de alta temperatura (PGH) do ligante virgem. Os parâmetros de suscetibilidade à deformação permanente e à fadiga também foram obtidos pelos ensaios de Fluência e Recuperação sob Tensão Múltipla (MSCR) e Varredura de Amplitude Linear (LAS). Os resultados mostraram a eficácia do AR, cujo teor capaz de recuperar o PGH do ligante virgem foi de 10,6% da massa do ligante envelhecido. Este teor apresentou resultados satisfatórios de compliância não recuperável, taxa de recuperação e resistência à fadiga, inclusive superiores aos do ligante virgem.

This study investigated the applicability of olive pomace (OP) waste, a biomass waste, in bitumen modification. The OP modification was compared with styrene butadiene styrene (SBS) modified bitumen, which is widely used in asphalt modification, in terms of performance and cost. The OP and SBS binders were tested with conventional and rheological experiments. For this, modified asphalt binders were obtained by adding OP (wt. 4, 8, 15, 19, 25, 30%) and SBS (wt. 4, 4.5%) to pure B 50/70 penetration bitumen. The conventional test results of OP and SBS modified bitumen are close to each other, both modified bitumen decreased the penetration and temperature sensitivity of pure bitumen and increased the softening point. According to rheological test results, it was seen that the critical OP ratio was obtained from the 19% OP addition, and the critical SBS ratio was obtained from the 4% SBS addition and they exhibited the same performance grade. Then, for the hot mix asphalt (HMA) design, the optimum bitumen content was determined according to the Marshall method by using aggregate and B 50/70 pure bitumen, 19% OP, and 4% SBS modified bitumen. The effects of OP and SBS-modified bitumen on the mechanical properties of HMA mixtures were evaluated using Marshall stability tests. It could be said that OP-modified bitumen behaves like a more elastic solid at high temperatures, due to its lower penetration and higher softening point than pure bitumen. It has been observed that 19% OP additive provides an improvement, especially in rutting resistance, fatigue, and thermal crack resistance and 19% OP modified binder can be considered as an alternative to 4% SBS modified binder in general in terms of performance and cost. As a result, it is evaluated that OP can be used as a remedial additive in asphalt modification and contribute to the increase of pavement performance, and also that the damage of this waste material to the environment can be eliminated.

In Korea, large-scale apartment projects often give rise to disputes among residents, which have prompted implementation of the "Apartment Performance Rating System" by the Ministry of Land, Infrastructure, and Transport. In addition, disputes related to leakage defects in apartment structures are increasing, especially in underground spaces of joint residential complexes. This study aims to identify waterproofing materials and methods for specific underground structure components through experimental evaluations and to assign waterproofing performance ratings similar to existing apartment house grades. These performance ratings will serve as foundational data to prevent leakage in joint residential complexes. This study proposes composite and self-adhesive sheet waterproofing as effective methods, emphasizing the significance of sheet waterproofing materials for excellent performance. The need for improved waterproofing materials to address long-term permeability issues is also highlighted. This research provides essential data for future waterproofing performance ratings; therefore, contributing to construction quality and safety in joint residential complexes. [ABSTRACT FROM AUTHOR]

As asphalt binder is a temperature-dependent viscoelastic material, the asphalt pavement performance is affected by the temperature during its service life. Traditionally, selecting the asphalt binder performance grade (PG) is based on long-term meteorological data analysis, but this study used MODIS and ASTER remotely-sensed (RS), reanalysis ERA5-Land, and in-situ meteorological datasets to select the PG. The multiple linear regression (MLR), genetic algorithm (GA), and deep-learning (DL) techniques were used to create models to estimate the maximum air and road pavement surface temperatures, considering the Superpave specifications. Model parameters involved the land surface temperature, vegetation index, elevation, ERA5-Land air temperature, soil moisture, wind speed, thermal radiation, evapotranspiration, latitude, and climate type. Comparative analyses revealed that the DL model yielded the most reliable PG results and the proposed RS-based method was more accurate than conventional approaches and could determine the PG accurately with 1 km resolution independent of distance to meteorological stations. [ABSTRACT FROM AUTHOR]

Copyright of Tikrit Journal of Engineering Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study evaluates waterproofing methods for underground structures in multi-unit residential buildings. The objective is to select effective methods and establish performance ratings. Experimental assessments are conducted and scores are assigned for ranking. In this regard, waterproofing methods used in the upper slab of the top floor of multi-unit residential building underground structures were investigated, and they were categorized as composite waterproofing, sheet waterproofing, and membrane waterproofing methods. For performance evaluation purposes, experiments were conducted on qualified materials and scores were assigned to each test specimen, with a total score of 100 points. Based on the test results, scores for disqualified materials were deducted and, ultimately, the rankings of waterproofing materials and methods for the upper slab of the top floor of underground structures were determined based on the total aggregated scores. Subsequently, through proximity performance evaluation, the applied waterproofing methods were experimentally verified for defect issues based on the presence or absence of a proximity layer. This led to the ranking and performance grading of a total of 12 materials. The results confirmed the necessity of a proximity layer-dependent waterproofing method and highlighted the superiority of the composite waterproofing method with a proximity layer. Additionally, differences in installation methods and material properties between sheet and membrane waterproofing methods were identified, resulting in variations in performance grading. [ABSTRACT FROM AUTHOR]

Solutions for safer, more durable infrastructure are required in light of increasing traffic and severe weather in Iraq. The most significant road conservation and maintenance challenges are the pavement's low resistance to dynamic loads and short service life. As a result, vast sums of money are spent annually to enhance the road service capacities in Iraq. Thermoplastic electrometric polymers for bitumen modification create long-lasting, cost-effective roadways. This study aims to determine how the mechanical properties of neat asphalt binder change when styrene butadiene styrene (SBS) is added as a modifier. The current research investigates adding three percentages of SBS (3, 5, and 7% of the weight of bitumen). Both neat and polymer-modified bitumen (PMB) were subjected to a series of physical laboratory and Superpave tests, including a dynamic shear rheometer tester (DSR) and a storage stability test. In addition, a chemical analysis test was conducted to identify any change in the neat binder chemical composition due to the addition of SBS polymer. The results indicated that 5% of SBS polymer was the optimum addition percentage to the local asphalt in Iraq. Additionally, it reduced the susceptibility of bitumen to temperature changes and enhanced its characteristics in all laboratory tests. The obtained PMB significantly improved rutting and fatigue factors compared to the neat asphalt binder. Based on the DSR tester and the storage stability test, the ratio of 5% SBS met the requirements of class PG76-10, used in the central and southern governorates of Iraq. Using SBS polymer on the surface course in Iraq reduces road damage due to the scorching summer sun, reduces the likelihood of rutting and fatigue cracking, and works well in hot regions, resulting in roads that last longer, provide comfortable riding, and require less maintenance.

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Asphalt binder is a temperature-sensitive material with a performance that is greatly affected by changing climates. Improper selection of asphalt will cause a lot of damage and affect the durability of the road. The establishment of asphalt pavement performance zoning in Xinjiang, a vast area with great temperature differences, will provide a reference for the selection of asphalt suitability, the refinement of pavement design, and the sustainable development of road engineering. In this study, 11 years of temperature data in the Xinjiang region have been collected and analyzed, and 98% reliability of pavement design temperature has been used to draw a performance grading map of asphalt pavement in the Xinjiang region based on the ArcGIS platform. Finally, the Xinjiang region is divided into nine performance zones. At the same time, the performance grades (PG) of five kinds of asphalt binders in Karamay are explored. The result shows that there is little difference in continuous PG span between different matrix asphalt binders; the lower the penetration grade, the better the high-temperature performance, and the worse the low-temperature performance. After adding the SBS modifier, the continuous PG span can be about 20 °C higher than the matrix asphalt. The indoor test of asphalt mixture also shows that SBS-modified asphalt has better durability. All these provide the basis for a reasonable selection of asphalt binders in different areas of Xinjiang. [ABSTRACT FROM AUTHOR]

High content SBS polymer modified asphalt (HCPMA) can serve as pavements under heavy traffic and a wide range of temperatures. However, the applicability and validity of standard rheological evaluation methods to characterize HCPMA are still unclear. In this study, the influence of SBS content on the conventional properties and rheological behavior of HCPMA was analyzed. A higher content of SBS can improve the performance grade of the asphalt binder to PG100-34. The slope of the Jnr-σ linear curves from the MSCR under various stress levels decreases when the SBS content increases. The slope of the Jnr-σ linear curves can replace Jnrdiff as an indicator of stress sensitivity. A higher content of SBS can also decrease the flexural creep stiffness and increase the creep rate of the binders. The binder fatigue resistance parameter increases and the binder yields at higher strain, with increasing SBS content. These results show that a higher content of SBS can further improve the resistance to rutting, thermal cracking, and fatigue. Current standard rheological methods should be modified when evaluating HCPMA. The results also show that conventional tests are not valid for evaluating the performance of HCPMA. [ABSTRACT FROM AUTHOR]

The objective of this paper is to assess whether existing pavement temperature prediction algorithms can be used to reliably determine Performance Grade (PG) design temperatures for Australian asphalt pavements. The results show good agreement between internationally and locally developed pavement temperature algorithms for the prediction of high pavement design temperature. There is more variability between models in the prediction of low pavement design temperature. The paper also provides a set of PG grading results for a range of Australian asphalt binders. The findings indicate that for a given design situation harder bitumen, ormore highly modified binder would be specified in Australia than in jurisdictions using the PG system. [ABSTRACT FROM AUTHOR]

This study investigated the impact of using modified bitumen binders and additives to enhance the physical characteristics of asphalt mixtures at high, medium, and low temperatures. Both basic and rheological characteristics of the bituminous binders were tested by adding Styrene-Butadiene-Styrene, a type of thermoplastic elastomer, as a chemical additive to asphalt mixtures at various fractions (3.5%, 4%, and 4.5%), and two kinds of modified Bitumen: Kraton styrene block copolymers and Europrene (SOL T 6302). The following methods were used to test the properties of the binders: needle penetration, ductility, softening point, resistance to hardening when exposed to heat and air, Pressure Aging Vessel test dynamic (PAV), Shear Rheometer (DSR), Bending Beam Rheometer (BBR), direct tension test, and storage stability. The results showed that the best properties of the asphalt concentration were observed when using 4% of additives, while the penetration of Bitumen was reduced to 27.2% and 30.3% when adding Kraton and Europrene SOL T6302, respectively. The influence of adding 4.0% additives decreased the bulk specific gravity to 2.395. Laboratory tests showed how the mentioned chemical additives directly affect the properties of the mixture and the binder by increasing their viscosity. [ABSTRACT FROM AUTHOR]

The use of polymer-modified binders in asphalt concrete makes it possible to increase the efficiency and durability of highways. However, at present, there is an important and unresolved problem in this area, making it impossible to fully exploit the potential of modified binders. This is a tendency of aging processes that leads to the premature destruction of the pavement. In many literary sources, it is reported that reasons are related to the peculiarity of the chemical composition and occur at the submicron level. Therefore, the influence of single-walled carbon nanotubes has been studied for a better understanding of aging processes. The aging processes of the RTFOT (rolling thin film oven test) and PAV (pressure aging vessel) modified with SBS (styrene–butadiene–styrene) polymer, single-walled carbon nanotubes, and waste industrial oil were simulated in a laboratory furnace. Microstructural features were studied using the method of infrared spectral analysis. The dependences of viscoelastic properties on the component composition of binders were investigated. The optimal content of single-walled carbon nanotubes (0.001%), SBS (styrene–butadiene–styrene) polymer (3.5%), and waste industrial oil (4%) in the binder composition was established, which synergistically improved the performance of the modified binder from PG (52-22) (performance grade) to PG (64-34). It was established that single-walled carbon nanotubes provide improvement in the durability parameter ∆Tc binder by 150%, improved relaxation properties at low temperatures, and resistance to fatigue damage.

The present paper investigates the effects of simultaneous mechanical foaming using water and fluxing with a bio-derived agent on the properties of three distinct asphalt binders: 50/70 paving-grade bitumen, 45/80–55 polymer-modified bitumen, and 45/80–80 highly modified asphalt binder. The testing involved classical tests for assessing binder consistency (penetration at 25 °C, ring and ball softening point, Fraass breaking point, and dynamic viscosity) as well as performance tests (high and low Superpave critical temperatures and multiple stress creep recovery). The tests included assessment directly after asphalt binder foaming and were repeated after a 14-day period. It was shown that bitumen foaming had only short-term effects on the asphalt binders, which did not persist in the repeated tests after 14 days. The fluxing agent that was utilized caused significant changes in the consistency of all asphalt binders. The changes in the performance characteristics of the 50/70 and 45/80–55 binders were severe and amounted to a significant decrease in high-temperature performance of these binders. On the other hand, an improvement in all performance characteristics in the case of the 45/80–80 asphalt binder was observed as a result of the applied processes, particularly when measured 14 days after foaming. This study shows that the simultaneous use of foaming and the fluxing additive decreased the dynamic viscosity of the 45/80–80 binder, while improving its properties relating the pavement performance. [ABSTRACT FROM AUTHOR]

The efficacy of polymers on the various performance parameters of modified bitumen was investigated. For PG 64-22, three distinct kinds of polymers with distinct ratios--3.5 %, 8 %, and 1.5 % by weight of base bitumen, respectively--were manufactured, each of which was deemed to have a high effectiveness on properties by local experts. These polymers' ratios were as follows: The four samples, three of which had their physical qualities and storage stabilities examined using traditional methods, were changed using Butonal NS, PR Plast, and Titan Polymers. In addition, experiments for both short-term and long-term aging processes were carried out using a rolling thin film oven as well as a pressure aging vessel. In order to evaluate the bitumens' rheological characteristics, a rotating viscosity and bending beam rheometer was used. Following the rheological analysis, the essential kind of road asphalt mix was developed so that it could be tested for rutting. According to the findings, all three varieties of polymer-modified bitumen give an improvement in the rheological and physical characteristics of bitumen, as well as a strong resistance against rutting. Furthermore, it was discovered that they are very compatible with base bitumen. The viscosity and stiffness of the bitumen were greatly improved by the addition of polymers. [ABSTRACT FROM AUTHOR]

Asphalt pavements are highly susceptible to temperature-induced stresses, which can lead to significant deterioration such as rutting at high temperatures and cracking at low temperatures. These challenges are exacerbated by global warming, which raises pavement temperatures and potentially accelerates material degradation. Addressing these issues, this study utilizes two base asphalt binders, PG 64–22 and PG 76–22, and the use of phase change materials (PCMs) like styrene-butadiene-styrene, lignin, and ground tire rubber to enhance the resilience of asphalt binders. Through an extensive experimental investigation, which includes aging processes such as rolling thin film oven and pressure aging vessel, alongside a series of both traditional and advanced tests (including dynamic shear rheometer, rotational viscometer, Fourier transform infrared spectroscopy, among others), a comprehensive set of 51 samples were analysed. By incorporating these binders and PCMs into asphalt, the experimental work demonstrated a significant improvement in the thermal and mechanical properties, effectively increasing resistance to high-temperature rutting and fatigue cracking. Complementing the experimental approach, machine learning models were employed to predict complex asphalt binder properties, such as combustion value and failure temperature, based on the experimental data. This dual approach fills a significant gap in the literature by offering a more efficient method and prediction model for optimizing pavement materials amidst climate change, while also promising to significantly advance pavement technology by enhancing material design and performance. • Two base asphalt binders were modified with phase change materials. • Styrene-butadiene-styrene, lignin, and ground tire rubber were used as PCM. • Rolling thin film oven and pressure aging vessel aging processes were considered. • Viscosity, rheology, combustion heat, and chemical changes were evaluated. • Explainable ML models are used for developing the prediction model. [ABSTRACT FROM AUTHOR]

In Korea, large-scale apartment projects often give rise to disputes among residents, which have prompted implementation of the “Apartment Performance Rating System” by the Ministry of Land, Infrastructure, and Transport. In addition, disputes related to leakage defects in apartment structures are increasing, especially in underground spaces of joint residential complexes. This study aims to identify waterproofing materials and methods for specific underground structure components through experimental evaluations and to assign waterproofing performance ratings similar to existing apartment house grades. These performance ratings will serve as foundational data to prevent leakage in joint residential complexes. This study proposes composite and self-adhesive sheet waterproofing as effective methods, emphasizing the significance of sheet waterproofing materials for excellent performance. The need for improved waterproofing materials to address long-term permeability issues is also highlighted. This research provides essential data for future waterproofing performance ratings; therefore, contributing to construction quality and safety in joint residential complexes.

Increased heavy-vehicle traffic, higher traffic volumes, and temperature changes lead to distresses such as stripping, rutting, fatigue cracks in asphalt pavements, increasing the cost of road maintenance. Therefore, it is inevitable that the properties of bitumen and asphalt mixtures must be improved. Polymer modification is one of the methods to improve bitumen properties. In the present paper, styrene butadiene styrene (SBS), styrene-butadiene rubber (SBR), and low-density polyethylene (LDPE), along with Sasobit wax, were used to modify the bitumen. For that purpose, we used tests, including conventional bitumen tests and linear amplitude sweep (LAS) tests. The results of the present study showed that the polymer mentioned above improves the rutting index of the base bitumen. Based on the bending beam test results, polymer additives and Sasobit have no positive effect on the low-temperature performance of the base bitumen. The LAS test results were used to compare PMBs' fatigue performance, and it was evident that SBR had the most significant effect on increasing the fatigue life of the base bitumen. In the meantime, Sasobit increases the fatigue life of PMBs at high strain levels. [ABSTRACT FROM AUTHOR]

This study evaluates waterproofing methods for underground structures in multi-unit residential buildings. The objective is to select effective methods and establish performance ratings. Experimental assessments are conducted and scores are assigned for ranking. In this regard, waterproofing methods used in the upper slab of the top floor of multi-unit residential building underground structures were investigated, and they were categorized as composite waterproofing, sheet waterproofing, and membrane waterproofing methods. For performance evaluation purposes, experiments were conducted on qualified materials and scores were assigned to each test specimen, with a total score of 100 points. Based on the test results, scores for disqualified materials were deducted and, ultimately, the rankings of waterproofing materials and methods for the upper slab of the top floor of underground structures were determined based on the total aggregated scores. Subsequently, through proximity performance evaluation, the applied waterproofing methods were experimentally verified for defect issues based on the presence or absence of a proximity layer. This led to the ranking and performance grading of a total of 12 materials. The results confirmed the necessity of a proximity layer-dependent waterproofing method and highlighted the superiority of the composite waterproofing method with a proximity layer. Additionally, differences in installation methods and material properties between sheet and membrane waterproofing methods were identified, resulting in variations in performance grading.

High content SBS polymer modified asphalt (HCPMA) can serve as pavements under heavy traffic and a wide range of temperatures. However, the applicability and validity of standard rheological evaluation methods to characterize HCPMA are still unclear. In this study, the influence of SBS content on the conventional properties and rheological behavior of HCPMA was analyzed. A higher content of SBS can improve the performance grade of the asphalt binder to PG100-34. The slope of the Jnr-σ linear curves from the MSCR under various stress levels decreases when the SBS content increases. The slope of the Jnr-σ linear curves can replace Jnrdiff as an indicator of stress sensitivity. A higher content of SBS can also decrease the flexural creep stiffness and increase the creep rate of the binders. The binder fatigue resistance parameter increases and the binder yields at higher strain, with increasing SBS content. These results show that a higher content of SBS can further improve the resistance to rutting, thermal cracking, and fatigue. Current standard rheological methods should be modified when evaluating HCPMA. The results also show that conventional tests are not valid for evaluating the performance of HCPMA.

ObjectiveThe aim of this study is to explore the influence of fine management combined with the plan-do-check-action (PDCA) cycle method on the management of ophthalmic precision instruments.MethodsThe ophthalmic precision instruments centralized in the disinfection supply room of our hospital were selected as the research objects and divided into groups A and B. Traditional instrument management method was adopted in group A, and fine management combined with the PDCA cycle method based on the group A was adopted in group B. The instrument management risk scores, the qualified rate of disinfection, instrument performance grade, and incidence of toxic anterior segment syndrome (TASS) of the two groups were compared.ResultsThe risk scores of instrument management and incidence of TASS in group B were lower than those in group A (p < 0.05). The qualified rate of disinfection and instrument performance grades in group B were higher than those in group A (p < 0.05).ConclusionFine management combined with the PDCA cycle method can improve the qualified rate of disinfection of ophthalmic precision instruments, optimize the performance of instruments, reduce the risk of instrument management, and reduce the incidence of TASS.

In order to improve the comprehensive performance of asphalt and its mixture, SBR/PP thermoplastic elastomer particles were prepared by mixing SBR powder with waste polypropylene particles, the influence of SBR/PP thermoplastic elastomer with different rubber plastic ratio and content on the rheological properties of modified asphalt at high and low temperatures, and the high temperature deformation resistance, low temperature cracking resistance, water stability of the mixture were studied. The results show that compared with SBR modified asphalt, SBR/PP thermoplastic elastomer can significantly improve the high-temperature rutting resistance and high-temperature stability of the modified asphalt, and when the rubber plastic ratio is 5∶5,and the low-temperature performance of modified asphalt mixture with different contents is improved, and the water damage resistance ability is significantly improved. [ABSTRACT FROM AUTHOR]

The present paper investigates the effects of simultaneous mechanical foaming using water and fluxing with a bio-derived agent on the properties of three distinct asphalt binders: 50/70 paving-grade bitumen, 45/80–55 polymer-modified bitumen, and 45/80–80 highly modified asphalt binder. The testing involved classical tests for assessing binder consistency (penetration at 25 °C, ring and ball softening point, Fraass breaking point, and dynamic viscosity) as well as performance tests (high and low Superpave critical temperatures and multiple stress creep recovery). The tests included assessment directly after asphalt binder foaming and were repeated after a 14-day period. It was shown that bitumen foaming had only short-term effects on the asphalt binders, which did not persist in the repeated tests after 14 days. The fluxing agent that was utilized caused significant changes in the consistency of all asphalt binders. The changes in the performance characteristics of the 50/70 and 45/80–55 binders were severe and amounted to a significant decrease in high-temperature performance of these binders. On the other hand, an improvement in all performance characteristics in the case of the 45/80–80 asphalt binder was observed as a result of the applied processes, particularly when measured 14 days after foaming. This study shows that the simultaneous use of foaming and the fluxing additive decreased the dynamic viscosity of the 45/80–80 binder, while improving its properties relating the pavement performance.

Reclaimed asphalt pavement (RAP) has been widely implemented in asphalt pavement construction due to its cost benefits along with its reasonable engineering performance. With the trend of higher RAP applications, it is more critical to consider the complicated interactions between RAP and virgin binders. An unreasonable assumption of the full blending of RAP material could lead to many issues, such as insufficient virgin binder content and poor pavement durability. This paper focuses on the determination of virgin binder grades and content during the design of a high RAP content mixture by considering RAP blending effectiveness. By integrating the blending ratio parameter, a modified blending chart is proposed to determine the PG grade of the virgin binder, and a partial blending method is used to estimate the optimum virgin binder content. It is found that when an 83% blending ratio is considered in the 40%-content RAP mixture design, the differences of the determined virgin binder grade from the traditional blending chart and modified one is within 6° (one PG grade). If the blending ratio is 56% or less for a 40%-content RAP mixture, the required base binder needs to drop one PG grade (6°). Moreover, the partial blending method typically demands 0.5%–1% more virgin binder than the Superpave volumetric method, which could result in significantly improved cracking performance without jeopardizing its rutting resistance. [ABSTRACT FROM AUTHOR]

The use of recyclable materials in road construction, protect the environment, is an influential factor in the decision-making process for road projects. As one of the most important elements in nature and an original basis for the formation of life on earth, Carbon has been used in many different industries for its high surface area and porosity. Because of asphalt binder rheology characteristics, asphalt layers tend to return to their initial conditions after traffic flow but some of these deformations return in elastic form and some not return in plastic form. In this research, the Dynamic Shear Rheometer (DSR) test was used to analyze asphalt Binder performance Grade. Carbon Black particles processed from agricultural waste recycling (walnut skin) with specific weight percentages of 3, 5, 7 and 10, were used for asphalt binder rehabilitation. According to the results, the use of Carbon Black particles derived from the recycling of agricultural waste improved asphalt binder performance Grade from PG64 to PG74 for modified asphalt binder with 7% carbon black and rheological parameters like complex modulus increased 1.7 times and phase angle decreased approximately 0.85 times.

This study is to determine asphalt binder performance grades (PGs) of North Korea (N.K.) so that the asphalt pavement can be designed to resist distresses of rutting and cracking that occurred due to seasonal temperature changes. The first step of determining the PG is to establish high and low temperatures for a location because the asphalt binder is a temperature sensitive viscoelastic material. The temperature zoning for developing the PG map were performed by obtaining last 26 year temperature data of 27 cities in N.K. from world meteorological organization. A trend and statistical reliability of the temperature data were analyzed to secure asphalt binder performance. Three air-pavement temperature prediction models of Superpave, South Korea, and Japan were utilized to predict the pavement temperatures. Finally, the reliability levels of 98% and 50% were used to determine the local PGs. Since the Superpave equation includes the dependent variable of latitude that can more reflect geographic locations of North areas rather than the other models, this study finally adopted the SHRP Superpave model to determine the binder PGs. Based on the Superpave models with the reliability analyses, PG maps were drawn. It was found out that the most common grades used for low volume roads are PG 58-22 and 58-28, covering 79% and 93% of the N.K. area. [ABSTRACT FROM AUTHOR]

Highlights • AESO can be used as an additive in asphalt modification. • AESO decreases viscosity of the neat asphalt binder. • AESO lowers the mixing and compaction temperatures. • AESO reduces the compaction effort of HMA. • LabAESO at high dosages improves resistance against fatigue and thermal cracking. Abstract This investigation examines the modification effect of using two types of acrylated epoxidized soybean oil (AESO) in asphalt binder at various concentration levels. The effects of AESO on rheological performance of neat asphalt binder were evaluated by employing rotational viscosity (RV), dynamic shear rheometer (DSR), and bending beam rheometer (BBR) tests. The results indicate that AESO has positive softening effects on decreasing the stiffness of asphalt binder, thereby reduces viscosity and lowers mixing and compaction temperatures. Moreover, laboratory produced AESO (LabAESO) performs superior to commercial available AESO (ComAESO) in terms of low temperature properties and fatigue life at the same concentration level and shows no separation. These findings suggest that a sufficiently high level of LabAESO is necessary in asphalt modification to dramatically affect rheological properties, and therefore enhance the neat asphalt binder’s resistance to fatigue damage at intermediate temperatures and thermal cracking for cold regions pavement applications. Overall, LabAESO shows the potential to be used in asphalt modification with desirable performance improvement, and economic and environmental benefits. [ABSTRACT FROM AUTHOR]

This study aims to investigate the function and impact of the reactive terpolymer (Elvaloy® RET) in improving the performance properties of modified bitumens. To this end, four different percentages of Elvaloy® RET (0%, 0.5%, 0.75%, 1.0% by weight of bitumen) were mixed with B-100/150 grade bitumen. The physical properties of these binder samples were investigated using conventional tests such as penetration, softening point and ductility while their rheological properties were investigated using Superpave binder tests such as rotational viscosity, dynamic shear rheometer and bending beam rheometer test. The determination of high and low temperature performance grades of binder samples were supplied with the Superpave specification. The findings indicate that Elvaloy® RET-modified bitumens were less sensitive to temperature changes. Elvaloy® RET significantly improved the stiffness of bitumen. It also improved the resistance of bitumen against rutting and fatigue cracking, without causing a serious decrease in the resistance of bitumen against thermal cracking. [ABSTRACT FROM AUTHOR]

This study is mainly focused on the evaluation of the effect of Warm Mix Asphalt (WMA) additives on the performance grade of straight and polymer modified asphalt binder and the performance of asphalt mixtures. In order to analyze these effects, the Performance Grade (PG) of asphalt binder and the degree of compaction of WMA mixtures with various additives were examined initially. Moreover, the degree of compaction was evaluated in field test sections. Lastly, the effect on WMA performance were evaluated using wheel tracking test and indirect tensile (IDT) strength test for the rutting resistance, moisture susceptibility and crack resistance, respectively. Based on the laboratory and field test results, it can be concluded that WMA additives can affect the PG grades of conventional but not for polymer modified asphalt binder while viscosity related to mixing and compaction results in conversely. From the field test, the rutting and crack resistances of WMA pavements are higher than HMA pavements in most cases. [ABSTRACT FROM AUTHOR]