Search Results (5)

This paper proposes two chemical activators that are used to prepare mixtures for pothole repairs based on reclaimed asphalt. Repair mixtures, especially those used as “cold” mixes, must be characterized by special properties because they are primarily used in the winter period, i.e., at low temperatures and high humidity. The proposed additives W1 and W2 affect the functional and rheological properties of asphalts. Therefore, their influence on the behavior of asphalt 35/50 in three states, i.e., non-aged, after technological aging, and after service aging, was examined. At the same time, the issue of determining the optimal mass content of additives in relation to the aged binder was undertaken using the original methodology applying the MSCR test. In the latter part of the paper, the influence of additives W1 and W2 on asphalt recovered from reclaimed asphalt (aged in real conditions) was also analyzed and asphalt mixtures for pothole repairs were made. For these mixtures, the average contact stresses and tensile strength were determined as a function of time and conditioning temperature, giving positive results in terms of practical application of the proposed solution. The obtained mixtures were successfully used to fill potholes in winter weather conditions. Full article

Cold mix asphalt (CMA) pothole repair is extensively utilized in time-sensitive highway maintenance due to its rapid deployment and all-weather applicability. However, premature failures caused by suboptimal construction practices under operational constraints (e.g., emergency repairs and adverse weather) necessitate frequent reworks, inadvertently escalating material consumption and associated environmental burdens. To address this challenge, this study proposes a quality-driven optimization framework integrating enhanced Analytic Hierarchy Process (AHP) and Grey Relational Analysis (GRA). The methodology systematically evaluates 18 technical parameters across six critical construction phases—grooving/molding, cleaning/drying, bonding layer application, material paving, compaction, and edge trimming—to identify dominant quality determinants. The analysis highlights material placement and compaction as the most significant phases in the repair process, with specific technical parameters such as compaction standardization, paving uniformity, compactor dimension selection, and material application emerging as key quality drivers. To assess the feasibility of the optimized process, a grey relational analysis was adopted to compare the proposed protocol with the cold-patch practices currently adopted by two municipal maintenance agencies in Shanghai, demonstrating superior alignment with an ideal repair benchmark. The developed model empowers highway agencies to achieve dual operational–environmental gains: maintaining urgent repair efficiency while mitigating secondary resource depletion through reduced repetitive interventions. Full article

In order to reduce the amount of diluent in a diluted asphalt mixture, this study developed a cold patch asphalt (CPA) for repairing pavement potholes by using a mixture of treated biodiesel and diesel as the diluent. The effects of biodiesel on the performance of the cold patch asphalt mixture (CPAM) during the construction process were investigated through Brookfield rotational viscosity tests, adhesion tests, and FTIR (Fourier transform infrared spectroscopy) analyses. At the same time, the effect of biodiesel on the performance of the CPAM was analyzed by combining the strength growth test, rutting test, and water-soaked Marshall test of CPAMs. The test results show that the construction performance of the CPAM can be significantly improved by adding pretreated biodiesel. Under the same amount of diluent, the strength and high-temperature performance of the asphalt mixture diluted with biodiesel were significantly improved compared to that with diesel as the diluent. The optimal high-temperature performance reached 9027 (times/mm), representing an approximate increase of 94.7% compared to 4636 (times/mm) when only diesel was used as the diluent. When the biodiesel content increased from 10% to 40%, the residue stability improved from 85.9% to 91.3%. The corresponding 0.5 h Marshall stability increased from 5.59 kN to 8.1 kN, while the 48 h Marshall stability rose from 4.8 kN to 7.39 kN. All tests met the requirements for hot mix asphalt. Full article

The purpose of this research was to promote the recycling of pellet asphalt with Crumb Rubber Modifier (CRM) and Graphite Nanoplatelet (GNP) in pothole restoration. In this study, several laboratory tests were carried out on mixes containing CRM content ratios of 5%, 10%, and 20% and GNP content of 3% and 6% in order to identify the ideal mixing ratio of pellet-type asphalt paving materials. The Marshall stability test, the Hamburg wheel tracking test, and the dynamic modulus test were all performed to compare the effectiveness of the proposed method and heated asphalt combinations. Afterward, the full-scale testbed was conducted to verify the practical application between the proposed method and popular pothole-repairing materials. Both laboratory and field test findings confirmed that the asphalt pavement using 5% CRM and 6% GNP improved the resistance to plastic deformation and anti-stripping compared to the generally heated asphalt paving material, thereby extending road life. However, the resistance to fatigue cracking can be slightly reduced by incorporating these additives. Overall, the CRM and GNP asphalt pellet approach is a feasible solution for sustainable pavement maintenance and rehabilitation, particularly in small-scale damage areas such as potholes. Full article

The maintenance of potholes is a long-standing problem. Previous studies focused on pothole patching materials and methods but not on bonding at the interface joint. In this study, the influence of the patching shape and depth on the bonding at the interface joint using two patching materials: hot mix asphalt (HMA) and hot mix asphalt containing 5% (by volume) steel fiber (HMA+) was investigated. Slabs with circular and square potholes in the middle with different depths (35, 50 and 70 mm) were prepared. The two shapes of potholes were patched with two patching materials: HMA and HMA+, at different depths. The slabs were tested after patching using a rigid steel frame. The experimental results were compared with those obtained from finite element analysis using the ABAQUS software, applying the same model of slabs with the same dimensions and properties of the materials used. The results indicated that the bonding at joint interface for circular-patched potholes slightly improved using HMA+ and this was independent of patching depth. As for the square-patched potholes, the bonding at the interface joint was better than for the circular-patched ones; the bonding increased with increasing depth. Using HMA+ for patching the square-patched potholes, the bonding at the interface joint slightly increased, only for the 3.5 cm depth. Full article