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This study explores the mechanical properties of porous-asphalt pavement, focusing on the influence of various polymers (elastomeric and reactive elastomeric terpolymers) and different aggregate compositions. Two aggregates were utilized: one is exclusively limestone-based and the other is a blend of limestone and basalt aggregates. The research findings unveiled that mixtures containing the conventional bitumen failed to meet the Cantabro loss-test criterion required for porous asphalt, necessitating a maximum threshold of 20%. In contrast, asphalt mixtures modified with polymers exhibited notably superior performance, particularly in terms of permeability, Cantabro loss and the ratio of indirect tensile strength. These results underscore the significant impact of polymer modification on enhancing the crucial mechanical properties of porous asphalt. Therefore, the study suggests the adoption of polymer-modified asphalt as a viable strategy to improve pavement longevity and overall performance, promoting its use for sustainable and durable infrastructure. [ABSTRACT FROM AUTHOR]

Shingle material can appear as an excess usage due to defective production problems or at the end of their service life. Especially the reuse of shingle materials in bitumen has brought a different approach in terms of sustainability. In this study, the utilization of production shingle waste material in asphalt pavement were investigated. Mechanical properties of hot mix and warm mix asphalt samples involving different amount of production shingle waste (1-6% by weight of the aggregate) were evaluated. Following the determination of optimum rate of shingle waste bitumen content is reduced to decrease both hazardous effects of bitumen and production cost. Marshall Mix Design criteria was employed on determination of maximum reduction on bitumen content and the amount of shingle utilization within the asphalt pavement. As a final analysis, indirect tensile tests were performed on the specimens prepared with determined bitumen content and shingle waste. As a result, it is concluded that, utilization of waste shingles within the asphalt mixture not only benefits the environment and cost but also improves Marshall stability and Marshall quotient of the mixtures. [ABSTRACT FROM AUTHOR]

In recent years, studies on porous asphalt have gained more importance and countries are conducting various studies in order to improve the engineering properties of this type of pavement. As a result of these studies, each country developed its own standard and therefore different optimum bitumen content (OBC) determination methods emerged. This paper investigates the determination of the optimum bitumen content of porous asphalt samples prepared by using different aggregate types and polymers by the methods implemented in Turkey and in other countries. The results have shown that the application of each method yielded different bitumen content. [ABSTRACT FROM AUTHOR]

The predicted performance and service life of the pavement depend largely on the properties of bitumen used in the mixtures. The most important feature of bitumen, which has profound effect on the performance of the road is durability. The durability of bitumen is expressed as the resistance to aging. In this study, the bituminous mixture aging was performed instead of bitumen aging in order to represent the aging in the field in the best possible way. The aim of this paper is to evaluate different proposed laboratory aging methods (NCHRP 09-52, NCHRP 09-54 and RILEM) in relation with the current Standard AASHTO R30 (Standard Practice For Mixture Conditioning of Hot Mix Asphalt standard) and to make comparison with the samples performance taken from the field in terms of Indirect Tensile Strength (ITS). The level of aging has also been compared with the samples taken from recently constructed pavement surface and from the five years old pavement surface. Results depicted that, laboratory aging methods revealed the field aging properties on the unaged bitumen. Based on the results, 2 hours forced draft oven aging at 135°C is recommended as short term aging condition because, 2 hours or 4 hours short term forced draft oven aging did not yield significant variation in terms of ITS values. Additionally, 120 hours (5 days) oven aging of compacted samples at 85°C can be recommended as long term aging condition. [ABSTRACT FROM AUTHOR]