R-curve behavior and crack propagation properties of asphalt concrete at low temperatures

    Sepehr Ghafari Info
    Fereidoon Moghadas Nejad Info
DOI: https://doi.org/10.3846/13923730.2014.890653

Abstract

Fracture properties and crack propagation characteristics of asphalt concrete mixtures were studied by obtaining fracture resistance curves using three point single edge SE(B) notched beam specimens. Elastic-plastic approach is used in the calculation of the J-integral since the fracture process zone size is large enough to not use a linear elastic approach. Crack length measurements were obtained directly from high resolution images taken during the tests. A rising R-curve was observed in all the specimens which indicates ductility and a toughening mechanism in the ductile to quasi-brittle fracture of the mixture. Mixtures developed by limestone and siliceous aggregates with 4%, 4.5% and 5% binder contents were tested at temperatures ranging from +5ºC to –20ºC. Mixtures with 5% binder content showed greater crack resistant behavior at each temperature. Crack lengths at which crack propagation instability occurred were decreased by the reduction of temperature. A significant drop of this critical crack length is observed in temperatures below –15ºC. As well, the elastic-plastic fracture toughness is increased by the reduction of temperature up to –15ºC and starts to diminish thereafter.

Keywords:

resistance curves, unloading compliance, fracture toughness, stable crack growth

How to Cite

Ghafari, S., & Moghadas Nejad, F. (2015). R-curve behavior and crack propagation properties of asphalt concrete at low temperatures. Journal of Civil Engineering and Management, 21(5), 559-570. https://doi.org/10.3846/13923730.2014.890653

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May 6, 2015
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2015-05-06

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How to Cite

Ghafari, S., & Moghadas Nejad, F. (2015). R-curve behavior and crack propagation properties of asphalt concrete at low temperatures. Journal of Civil Engineering and Management, 21(5), 559-570. https://doi.org/10.3846/13923730.2014.890653

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