Development of a new aggregate-binder adhesion test method

Abstract

Adhesion in asphalt mixtures can be defined as energy required to fracture the adhesive bond between binder and aggregate causing isolation from each other. The main objective of this study was to develop a simple, practical and reliable laboratory adhesion test method enabling direct measurement of the adhesive bond strength of binder-aggregate systems. The adhesion results were subjected to comparative analysis to determine the effect of various variables and parameters. Four binders: two conventional and the other two are their polymer modified varieties, and two types of aggregate, were used to arrive at standardised testing conditions. When the binder thickness increased, the failure transitioned from adhesive to cohesive accompanied by a decrease in the maximum tensile load at failure. Practical work of adhesion decreased with increased testing temperature but the largest decrease was due to moisture conditioning, which increased with increase in loading rate.

Development of compression pull-off test (CPOT) to assess bond strength of bitumen

“…This is attributed to different nature of two tests for quantification of tensile strength (pull-off strength) and shear strength respectively. In addition to this, different studies have used trimming of specimen in pull off testing (Sultana 2014;Al-Haddad and Al-Khalid 2015;Apeagyei, Grenfell, and Airey 2015;Abd, Al-Khalid, and Akhtar 2018). This study suggests effect of trimming on the results of pull-off strength.…”

“…The control of film thickness in specimens have been another concern, different approaches and gap assemblies have been used (Jakarni 2012) . The use of Dynamic Shear Rheometer for control of bitumen film at submicron level has also been reported (Zhang et al 2017;Al-Haddad and Al-Khalid 2015).…”

“…In these studies, it has been demonstrated that that the peel test is a suitable method to determine the adhesive fracture energy. In addition to this, there are numerous studies which emphasis the importance of thin film binder to evaluate its response to pull-off loading (Kanitpong and Bahia 2005;Jakarni 2012; A Copeland et al 2006;Audrey Copeland, Youtcheff, and Shenoy 2007;Poulikakos and Parti 2011;Alvarez, Ovalles, and Caro 2012;Harvey and Cebon 2003;Apeagyei, Grenfell, and Airey 2014;Sultana 2014;Al-Haddad and Al-Khalid 2015;Rahim 2017;Abd, Al-Khalid, and Akhtar 2018;Chaturabong andBahia 2018)(Audrey Copeland, Youtcheff, andShenoy 2007).…”

Meso-Scale Study on Shear Creep Behavior and Characteristic of Asphalt-Aggregate Interface

“…After polished, aggregate columns and asphalt were heated to 160℃ and glue together using a servo hydraulic frame. More detailed for sample preparation can be found elsewhere (Al-Haddad and Al-Khalid 2015). Then, sandwich-like specimens were confined in oblique shear device, see Fig.3 (left).…”