PROPOSED QUALITY CONTROL FOR COLD IN-PLACE RECYCLING TECHNOLOGY USING FOAMED ASPHALT COMBINED WITH CEMENT FOR PAVEMENT STRUCTURES IN VIETNAM

Abstract

Cold in-place recycling (CIR) using foamed bitumen combined with cement is an advanced pavement rehabilitation technology that promotes reuse of existing materials while reducing natural resource consumption and greenhouse gas emissions. Although CIR has been increasingly studied and applied worldwide and has been preliminarily implemented in Vietnam, its wider application is constrained by the lack of technical guidelines and quality control procedures adapted to local conditions. This paper reviews the scientific basis of CIR technology, analyzes key factors affecting the performance of recycled layers, and proposes a feasible quality control framework for Vietnamese conditions. The results show that cold recycled layers can achieve a 7-day compressive strength of about 1.5-2.5 MPa and an elastic modulus of 1,500-3,000 MPa, meeting the requirements for base layers of low- and medium-class highways.