Proposed Compaction Procedure for Dry Process Crumb Rubber Modified Asphalt Mixtures Using Air Void Content and Expansion Ratio

    Volume 42, Issue 2 (March 2014)

    ISSN: 0090-3973

    CODEN: JTEOAD

    Published Online: 20 January 2014

    Page Count: 12


    Yu, Miao
    Candidate, National and Regional Engineering Lab for Transportation Construction Materials, School of Civil and Engineering and Architecture, Chongqing Jiaotong Univ., Chongqing,

    Wu, Guoxiong
    Dean, School of Civil and Engineering and Architecture, Chongqing Jiaotong Univ., Chongqing,

    Zhou, Jinchuan
    Research Fellow, China Merchants Chongqing Communications Research & Design Institute Co., Ltd, Chongqing,

    Easa, Said
    Adjunct Professor, School of Civil and Engineering and Architecture, Chongqing Jiaotong Univ., Chongqing,

    (Received 24 November 2012; accepted 5 August 2013)

    Abstract

    The dry process for crumb rubber modified (CRM) asphalt mixtures is characterized by a simple construction process that results in greater environmental benefits than the wet process does. However, the difficulties of compaction in the dry process often lead to unstable pavement performance; therefore, its application is highly restricted. This research aims to investigate the compaction procedure for dry process CRM asphalt mixtures using air void content and expansion ratio as the principal indices for evaluation. To evaluate the key factors affecting compaction, a series of CRM mixtures were prepared and compacted at four different crumb rubber contents by total aggregate volume of 3.0 %, 5.5 %, 8.0 %, and 10 %. First, with the air void ratio as the target indicator, the crumb rubber content, compaction temperature, and compaction method were evaluated to determine the appropriate compaction procedure. Second, the variations in height and expansion ratio of the CRM asphalt mixture specimens with different crumb rubber contents were analyzed in order to calculate the expansion ratio. The results indicated that generally the height and expansion ratio increase as the crumb rubber content of the CRM asphalt mixtures increases. Furthermore, it was found that when the crumb rubber addition was 5.5 % of the bulk volume of minerals, the volume stability of the mixture was improved, and this value is recommended for dry process CRM asphalt mixtures.


    Paper ID: JTE20120337

    DOI: 10.1520/JTE20120337

    ASTM International is a member of CrossRef.

    Author
    Title Proposed Compaction Procedure for Dry Process Crumb Rubber Modified Asphalt Mixtures Using Air Void Content and Expansion Ratio
    Symposium , 0000-00-00
    Committee D04