Analysis on Three-Dimensional Strength Influencing Factors and Control Measures of Asphalt Mixtures.

Tuo Huang,Mi Li,Mou-Ying Huang,Hong-Fu Liu,Yao Tang,Hao-Hao Jiang

doi:10.3390/ma13112541

Abstract

Strength is an important parameter for the design of asphalt pavement materials and structures. To study the influence of various factors on the three-dimensional strength of asphalt mixtures, three aggregate gradations (dense-graded bituminous mixture AC-13, stone mastic asphalt SMA-13 and bituminous stabilization aggregate paving mixture OGFC-13) and two binders (SBS modified bitumen and 70# base bitumen) were used to prepare the asphalt mixture specimens. Among them, SBS+SMA-13 asphalt mixture has the best performance. On this basis, the uniaxial compressive test, uniaxial tensile test and confining triaxial test were conducted on the SBS+SMA-13 asphalt mixture under six oil-stone ratios conditions (5.5%, 5.7%, 5.9%, 6.1%, 6.3%, and 6.5%), six temperatures conditions (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, and 30 °C), and five loading rates conditions (1 mm/min, 2 mm/min, 3 mm/min, 4 mm/min, and 5 mm/min). In addition, a unified three-dimensional strength calculation model considering the influence of temperature, loading rate, and oil-stone ratio was proposed, and the change law of the three-dimensional strength with these above factors was revealed. Furthermore, two sets of three-factor three-level orthogonal tests were carried out on the SMA-13 asphalt mixture. The sensitivity analysis and strength regulation research between three-dimensional strength and each factor were carried out. The results show that the type of asphalt has the greatest influence on the strength of the mixture, the temperature has the second most influence, the loading rate has less influence, and the oil-stone ratio has the least influence. The strength regulations proposed to improve the strength of the asphalt mixture include the use of modified asphalt, high-temperature stability high-quality asphalt, and the lower oil-stone ratio than the Marshall optimal oil-stone ratio. The strength control measures proposed from the perspective of the three-dimensional stress state, the joint failure of each stress components and real stress states are taken into consideration.

Highlights

Asphalt pavement is currently the most widely used high-grade pavement structure form around the world [1], for its performance, convenience in construction and maintenance, evenness, and comfort when driving
To analyze the effect of gradation on the strength of asphalt mixture, three type of asphalt were tested under optimal oil-stone ratio respectively, the test temperature was 20 ◦ C and the loading mixtures were tested under optimal oil-stone ratio respectively, the test temperature was 20 °C and rate was 2 mm/min
Among the three mixture prepared by the 70# base bitumen, the compressive strength of SMA-13 asphalt mixture is gradations of asphalt mixture prepared by the 70# base bitumen, the compressive strength of SMAhigher than AC-13 asphalt mixture and OGFC-13 asphalt mixture, and the increase corresponding to 13 asphalt mixture is higher than AC-13 asphalt mixture and OGFC-13 asphalt mixture, and the AC-13 asphalt mixture and OGFC-13 asphalt mixture were 7.4% and 19.4%, respectively

Summary

Introduction

Asphalt pavement is currently the most widely used high-grade pavement structure form around the world [1], for its performance, convenience in construction and maintenance, evenness, and comfort when driving. As the main road material, the mechanical properties of asphalt mixtures, especially direct tensile, uniaxial compression, and confining triaxial strength characteristics are quite important parameters for the design of mixture composition and the combined design of asphalt pavement structures [2]. Put forward corresponding control measures to ensure the quality and durability of asphalt. The research on the strength characteristics of asphalt mixtures mostly focuses on the traditional experiments of tension, bending, shear, and mixtures torsion [8,9,10]. A typical the research on the compression, strength characteristics of asphalt mostlyAsfocuses on visco-elastoplastic material, of thetension, difference of its mechanical properties is directly to the stress the traditional experiments compression, bending, shear, and torsion related [8,9,10]. As a typical state and test conditions [12], Lee and Pszczola [14] carried outrelated the strength visco-elastoplastic material,[11]

Methods

Results

Conclusion