محتوای سیمان و آسفالت امولسیون شده
Abstract
1. Introduction and literature review
2. Materials and test methods
3. Test results of mechanical properties
4. Test results of road performances
5. Scanning electron microscopy (SEM) and computed tomography (CT) results
6. Conclusions
Declaration of Competing Interest
Acknowledgements
References
Abstract
The effects of cement and emulsified asphalt contents on the performance of cement-emulsified asphalt mixture were systematically evaluated, including the indirect tensile strength, compressive strength, modulus of resilience, tensile strength ratio, dynamic stability, maximum bending strain, and Cantabro loss. In addition, the mesoscopic images and void characteristics of cement-emulsified asphalt mixtures with different material compositions were obtained, using scanning electron microscopy (SEM) and computed tomography (CT). The results indicated that at a constant cement content of 3%, when the emulsified asphalt content increased from 6% to 9%, the indirect tensile strength, compressive strength, and modulus of resilience first increased and then decreased. At a constant emulsified asphalt content of 8%, when the cement content increased from 0% to 4%, the indirect tensile strength first increased and then decreased, and the compressive strength and modulus of resilience each reached its maximum at a cement content of 3%. The addition of cement significantly improved the high-temperature stability and moisture stability of the asphalt mixture but was not conducive to its low-temperature performance. In addition, a minimum Cantabro loss was observed at a cement content between 2% and 3%. The mesoscopic void structures formed in different cement and emulsified asphalt contents also significantly affected the mechanical properties and mixture performances.
Introduction and literature review
A cement-emulsified asphalt mixture contains cement, emulsified asphalt, and aggregates, and is mixed at a normal temperature. In the mixture, the emulsified asphalt aggregates and demulsifies, and the cement hydrates, crystallizes and solidifies, forming a new engineering material [1,2]. Emulsified asphalt is liquid at normal temperature, and the process of mixing, paving and compacting with aggregate and cement would cause emulsion asphalt to demulsification [3,4]. Part of the moisture produced by the demulsification was consumed by the hydration reaction of the cement, and the other part was lost by evaporation. The asphalt and aggregate heating process were avoided throughout the construction process, thus avoiding the emission of asphalt smoke from heating, thereby greatly reduced energy consumption and carbon emissions during construction [5,6]. Therefore, it has been applied more and more in civil engineering, especially in pavement engineering. Because a cement-emulsified asphalt mixture contains both cement and emulsified asphalt, which have different engineering properties, the properties of the mixture are thus between those of cement and emulsified asphalt [7–9].