Effect of Superplasticizer and Wetting Agent on Volumetric and Mechanical Properties of Cold Recycled Mixture with Asphalt Emulsion

Wenting Yang,Jian Ouyang,Yan Meng,Taixiong Tang,Jijiang Chen,Baoguo Han

doi:10.1155/2020/6251653

Wenting Yang, Jian Ouyang + Show 4 more

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https://doi.org/10.1155/2020/6251653

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Abstract

Cold recycled mixture with asphalt emulsion (CRME) has gained more appreciation due to its environmental and economical advantages. Surfactant greatly affects the interaction between asphalt emulsion and cement, which can greatly affect the volumetric and mechanical properties of CRME. If the surfactant can greatly improve the volumetric and mechanical properties of CRME, that could be of great attraction. In this study, a polycarboxylate-based superplasticizer and wetting agent (DN500, polymers containing high-pigment groups) were employed to improve the volumetric and mechanical properties of CRME. Results indicate that the addition of superplasticizer and DN500 can reduce the void content of CRME and increase the indirect tensile strength (ITS) and stiffness modulus as well as critical strain energy density (CSED) of CRME. Besides, the failure strain of CRME is also increased by adding superplasticizer and DN500. This phenomenon is probably due to that superplasticizer can decrease the viscosity of cement asphalt emulsion paste (CAEP) and help to form a better asphalt film, and DN500 can moderately decrease the viscosity of CAEP and increase the wetting ability of asphalt emulsion as a wetting agent. CRME with superplasticizer has the best mechanical properties among all CRMEs. Compared to reference CRME, the ITS, stiffness modulus, and CSED of CRME with superplasticizer can increase by 33.7%, 8.0%, and 17.5% at the optimum water content, respectively. It is recommended to improve the volumetric and mechanical properties of CRME by adding superplasticizer.

Highlights

Asphalt pavement tends to deteriorate gradually during its service life due to traffic load and environment action [1]
Based on the above consideration, superplasticizer and wetting agent were added into cold recycled mixture with asphalt emulsion (CRME) to improve its mechanical and volumetric properties. e mechanical and volumetric properties of CRME with superplasticizer and wetting agent at different additional water contents are discussed in this paper
E void content of CRME can reduce by 5.59% and 10.55% by DN500 and superplasticizer, respectively. erefore, both addition of DN500 and superplasticizer can be beneficial to the compactibility of CRME

Summary

Introduction

Asphalt pavement tends to deteriorate gradually during its service life due to traffic load and environment action [1]. The RAP is first milled and mixed with asphalt emulsion, water, virgin aggregates, and active additives, such as cement and mineral powder. To the best of our knowledge, few studies were conducted to control the interaction between asphalt emulsion and cement for improving the physical and mechanical properties of CRME, controlling such interaction is believed to be very important. Erefore, it is possible to improve the mechanical and volumetric properties of CRME by adding the superplasticizer and wetting agent. Based on the above consideration, superplasticizer and wetting agent were added into CRME to improve its mechanical and volumetric properties. E mechanical and volumetric properties of CRME with superplasticizer and wetting agent at different additional water contents are discussed in this paper. To the best of our knowledge, it is a very meaningful work to improve the mechanical and volumetric properties of CRME

Experimental Program

Testing Program

Failure point

Results and Discussion