Effects of Diatomite and SBS on Freeze-Thaw Resistance of Crumb Rubber Modified Asphalt Mixture

Haibin Wei,Ziqi Li,Yubo Jiao

doi:10.1155/2017/7802035

Haibin Wei, Ziqi Li + Show 1 more

Open Access

https://doi.org/10.1155/2017/7802035

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Abstract

Asphalt mixture is susceptible to moisture damage under the effect of freeze-thaw (F-T) cycles. In this paper, crumb rubber (CR) was used to modify stone mastic asphalt (SMA) and the effects of diatomite and styrene butadiene styrene (SBS) on antifreezing performances of crumb rubber modified SMA (CRSMA) were investigated. Regression analysis and modified grey model (MGM) were used to construct the prediction models for properties of modified mixtures. CRSMA, CR and diatomite modified SMA (CRDSMA), and CR and SBS modified SMA (CRSSMA) were prepared in laboratory, respectively. Process of F-T cycles was designed. Air void, indirect tensile strength (ITS), and indirect tensile stiffness modulus (ITSM) were measured to evaluate the antifreezing performances of CRSMA, CRDSMA, and CRSSMA. Results indicate that air voids increase with the increasing of F-T cycles. ITS and ITSM all decrease with the increasing of F-T cycles. The addition of diatomite and SBS can reduce the air void and improve the ITS and ITSM of CRSMA. CRSSMA presents the lowest air void, highest tensile strength, and largest stiffness modulus, which reveals that CRSSMA has the best F-T resistance among three different kinds of mixtures. Moreover, MGM (1, 2) models present more favorable accuracy in prediction of air void and ITS compared with regression ones.

Highlights

Reuse of waste materials can reduce the consumption of natural resources
Corresponding estimation of vertical error bar was determined for each case, which represents the standard deviation
Results of air voids (Mean ± standard deviation (SD)) and ΔVV for crumb rubber modified SMA (CRSMA), CR and diatomite modified SMA (CRDSMA), and CR and SBS modified SMA (CRSSMA) before and after F-T cycles are shown in Figures 4 and 5

Summary

Introduction

Reuse of waste materials can reduce the consumption of natural resources. it can alleviate the waste accumulation, which can cause serious environmental problem [1,2,3]. The results reveal that the addition of crumb rubber can increase viscosity of Advances in Materials Science and Engineering asphalt and improve rutting deformation resistance. It presents poor stability with the increasing of rubber particle size. The results reveal that diatomite is helpful for improving the high temperature stability and antiaging property of asphalt. SBS copolymer is the most widely used modifier for asphalt, which can absorb the oil fractions and swell them [23,24,25] It can improve both high and low temperature performances of mixture. Modified grey model MGM (1, 2) was applied for prediction of air void and ITS

Materials

Experimental and Analytical Methods

Results and Discussion

Conclusions