Hot recycling of road surfacing has become necessary for urban areas of India where the road levels are increasing to cater for high traffic loading. The first job of hot recycling was undertaken in a major city where it is extremely hot in summer and cold in winter. The study includes details of the laboratory studies carried out to arrive at a suitable job mix formulae in an attempt to utilize the maximum possible usage of the existing surface material. The detailed laboratory studies included the analysis of core samples, determination of aggregate gradation and recovery of binder to control the penetration of the binder and the mix gradation as close as possible within the specified grading as per the specifications. Based on frequent changes in the job mix formulae, the correct grading combinations were obtained during construction of the trial sections. The experiences gathered during construction have been discussed including the problems related to improvement of binder properties and prevention of hardening of asphalt during hot recycling, the performance of the recycled surface both before and after laying. The paper will apprise users of hot recycling in tropical countries regarding the precautions to be taken during construction. (a) For the covering entry of this conference, please see ITRD abstract no. E127099.
Samenvatting