干旱区生态环境知识资源中心

To develop environment and eco-friendly cold mix technology, field trials were conducted using bitumen emulsion on Jammu-Srinagar Highway NH-1A near Patnitop (J&K) Under snow bound area, Jowai-Badarpur Road NH-44 near Silchar (Assam) Under heavy rainfall and H-S Road near Hanumangarh (Rajasthan) under desert climate. Specifications adopted were 25 mm semi dense bituminous concrete (SDBC) and 20 mm premix carpet (PMC) for laying test sections with bitumen emulsion and control section with paving bitumen 80/100. Laboratory mix design for SDBC with bitumen emulsion was developed using Marshall method. Marshall specimens of cold mix were prepared, cured at 40 degrees C for 3 days and tested at 25 degrees C for stability and flow value. Post construction performance evaluation has been carried out at 6-month intervals for 5-6 years. SDBC and PMC with bitumen emulsion performed better or comparable with that of conventional paving grade bitumen. Due to low viscosity, bitumen emulsion penetrated into cracks and helped in sealing them during tack coating, which resulted into retardation of reflective cracks on overlays. Performance of SDBC with bitumen emulsion was also found comparable with that of paving grade bitumen.