Development of an autonomous setup for evaluating self healing capability of asphalt mixtures

Abstract

It is a well known fact that asphalt mixtures have self healing capabilities. Yet most of the self healing investigations are carried out using complex and time consuming fatigue tests. In order to investigate the self healing capability in a simple and efficient manner, a beam on elastic foundation test setup (BOEF) is proposed in this paper. With a notched asphalt concrete beam fully glued on a low modulus rubber foundation, the BOEF setup is able to control the self healing process autonomously including crack closure and healing at different rest periods and temperatures. A load-crack opening displacement (COD) curve was used for characterizing the self healing capability of the monotonic response with a loading-healing reloading procedure. In addition, small numbers of dynamic loads were also applied to the BOEF setup under different cracking and healing conditions. An apparent modulus of the BOEF asphalt beam was obtained based on the dynamic response of the COD. The results indicate that the self healing capability which is obtained in the monotonic tests is dependent on the healing time and healing temperature. The healing temperature has the largest effect of the two. Most of the apparent modulus of the BOEF asphalt beam recovers at the beginning of the self healing process. The influences of healing time and temperature are limited. As a result, the BOEF setup is proven to be a potential tool for the self healing investigation of asphalt mixtures.