Comparative assessment of cmsdbc and hmsdbc competency

Abstract

Over ninety percent of the total road network in India, including the airfield pavements, are flexible pavements with black-top surfaces. The construction of wearing and binder courses of a flexible pavement require high energy consumption during heating of bitumen and aggregate, with consequent giant emission of greenhouse gases during the preparation of hot-mixed bituminous mixtures. Earlier, in flexible pavements, the use of bitumen emulsion was restricted to only spray applications and as dust palliatives, but over the years, with the development of new types, grades, specifications, and availability of improved construction equipment and practices, emulsion-based cold mix technology offers a wide range of solutions. Judicial selection and appropriate use of these technologies can yield significant economic benefits, environmental benefits, and energy security as far as construction and maintenance of roads are concerned. Hence, this paper aimed to compare the strength, durability, and performance of a cold mix semi-dense bituminous concrete (CMSDBC) and hot mix semi-dense bituminous concrete (HMSDBC) pertaining to competency. Materials for the preparation of representative samples are coarse aggregate, fine aggregate, and cement as a filler, in suitable proportions mixed with bitumen or slow-setting cationic bitumen emulsion (where applicable). Tests like Marshall stability, Indirect tensile strength, moisture susceptibility, and rut depth using wheel tracker device were carried out according to standard guidelines. The results showed that CMSDBC yielded significant values, which are comparable with HMSDBC. It infers that CMSDBC is capable to be exercised in the practice for low traffic, low rainfall, moderate and cold climate regions.