Abstract
Asphalt-treated base (ATB-25) is a widely used flexible base material. The composition and gradation of mineral aggregate are important factors affecting pavement performance of asphalt treated base. In this study, two new methods were proposed to address the problems of existing aggregate proportion calculation for asphalt mixtures: (1) the combination of generalized inverse solution of the normal equation and spreadsheet trial and (2) quadratic programming. Both methods can calculate mass ratios of various aggregates in a quick and accurate manner. The orthogonal test was used to design nine aggregate gradations within the range of asphalt treated base (ATB-25) stated in the industrial standard. The aggregate proportion was calculated by two new methods. The Marshall test, water weight test, rutting test, and water-soaked Marshall test were carried out on the asphalt mixture specimens. The pavement performance test results were fuzzified using the fuzzy mathematics method, and the weights of pavement performance evaluation indexes were determined through the analytic hierarchy process. Taking the fuzzy comprehensive evaluation values as the objective function, test results were analyzed and evaluated. Finally, the optimal aggregate gradation was determined considering factors of compactness, high-temperature rutting resistance, and water stability.
Highlights
Asphalt-treated base (ATB-25) is a widely used flexible base material, which has the characteristics of small stiffness, high shear strength, flexural tensile strength, fatigue resistance, and not easy to produce shrinkage cracking and water damage. e composition design of the asphalt mixture determines the optimal mixing ratio of the coarse aggregate, fine aggregate, mineral powder, and asphalt to be used in the mixture to meet the performance requirements of the road
Because the use of waste material can reduce the cost of construction and increase the strength, steel slag and coconut shell were used in the asphalt mixture [1,2,3]
It was concluded that aggregate gradation has a significant impact on volumetric indicators such as the voids in mineral aggregates (VMA) and voids filled with asphalt (VFA) of the asphalt mixture [7]
Summary
Asphalt-treated base (ATB-25) is a widely used flexible base material, which has the characteristics of small stiffness, high shear strength, flexural tensile strength, fatigue resistance, and not easy to produce shrinkage cracking and water damage. e composition design of the asphalt mixture determines the optimal mixing ratio of the coarse aggregate, fine aggregate, mineral powder, and asphalt to be used in the mixture to meet the performance requirements of the road. Based on the aforementioned gradation theory and design methods, the Chinese industrial standard [19] determines the ranges of aggregate gradations for different types of asphalt mixtures. The table-based trial method and the common equation method can be used for the calculation of the aggregate composition of the asphalt mixture; the former is time-consuming and labor-intensive, yet the latter does not consider the requirements for the range of the design gradation curve and cannot ensure that the calculation result is a nonnegative number. Erefore, it is necessary to optimize the aggregate gradation of the asphalt mixture and select the best gradation To address these issues, this paper proposes new methods for calculating the aggregate proportion. Taking the fuzzy comprehensive evaluation value as the objective function, the test results indicating the pavement performance of the asphalt mixtures of the nine gradations are evaluated comprehensively using the fuzzy matrix, and a new method for optimizing the gradation of asphalt mixtures is proposed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
