Experimental Research on Compression Properties of Cement Asphalt Mortar due to Drying and Wetting Cycle

Ping Wang,Jingmang Xu,Rong Chen,Hao Xu,Xiaohui Zeng

doi:10.1155/2014/769248

Ping Wang, Jingmang Xu + Show 3 more

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https://doi.org/10.1155/2014/769248

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Abstract

Uniaxial compression test of cement asphalt (CA) mortar specimens, due to drying and wetting cycle of 0, 2, 4 and 8 times, is carried out by using the electronic universal test machine, with the strain rate ranging from 1 × 10−5 s−1to 1 × 10−2 s−1. The effects of strain rate and drying and wetting cycle time on the compressive strength, elasticity modulus, and stress-strain full curve are investigated. Experimental results show that the strain-stress full curve of CA mortar is affected obviously by strain rate and drying and wetting cycle time. The compressive strength and elasticity modulus increase with the strain rate under the same drying and wetting cycle time. The compressive strength and elasticity modulus decrease with the increase of drying and wetting cycle time in the same strain rate. The lower the strain rate is, the greater the compressive strength and elasticity modulus of CA mortar decrease. When the strain rate is 1 × 10−5 s−1and drying and wetting cycle time is 8, the largest reduction of average compressive strength of CA mortar is 40.48%, and the largest reduction of elasticity modulus of CA mortar is 35.51%, and the influence of drying and wetting cycle on the compressive strength of CA mortar is greater than its influence on the elasticity modulus.

Highlights

Slab ballastless track is a track structure, which is widely used in high speed railway (HSR)
The stress-strain relationship of cement asphalt (CA) mortar under different strain rates and drying and wetting cycle times has been got through the uniaxial compression experiment, and the change rule of related mechanics index has been analyzed
(2) Because the stress generated by dry shrinkage and wet expansion deformation of CA mortar will damage the CA mortar, the compressive strength and elasticity modulus decrease with the increase of drying and wetting cycle times in the same strain rate

Summary

Introduction

Slab ballastless track is a track structure, which is widely used in high speed railway (HSR). As the buffer, damping structure layer of slab ballastless track, CA mortar is mainly under the vertical load and in dynamic loading process [8, 9], so the influence of loading rate on the mechanical properties of CA mortar was researched in paper [10,11,12,13]. Wang et al [10] explored the variation in compressive strength of CA mortar under different loading rates. Kong et al [11] tested the compressive stress-strain of two CAMs at different displacement rates ranging from 0.3 mm/min to 30 mm/min. Yongliang et al [12] tested two typical CAMs at varied deformation rates over a range of

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