Full-Depth Reclamation with Hydraulic Road Binders

Abstract

According to a recent report, 16.4% of Canadian roads are in a poor or very poor condition. This means 146,255 km of the Canadian roads are either unfit for service or are approaching the end of their service life. The roads in these conditions require immediate action to restore their serviceability. One of the plausible techniques that could be applied to restore the serviceability of roads in poor or very poor conditions is full-depth reclamation (FDR). Full depth reclamation is a type of pavement cold in-place recycling in which the existing old and deteriorated pavement is pulverised, treated with appropriate stabilizer and compacted to form a strong base layer. In Canada, the stabilizers commonly used in the FDR process are asphalt emulsions, foamed asphalt, and Portland cement. Hydraulic road binders (HRB), however, are alternative cementitious stabilizers that can be used in full-depth reclamation process with some better attributes than Portland cement. The main objectives of this research are characterisation and impact assessment of fully reclaimed pavement materials treated with HRB. The study was conducted in the form of comparative assessment by using reclaimed materials treated with General Use (GU) cement as control mixes. Four types of reclaimed materials and four types of cementitious binders, including GU cement, were used to make sixteen different mixes. Characterisation and performance tests were conducted to understand the behaviour of the mixtures under static and dynamic loadings. Besides, life-cycle assessment was conducted to investigate the environmental impacts of the different cementitious binders. The findings of the study indicate that HRB, of the type used in the study, can be used in full-depth reclamation process without compromising the strength and durability of the mixtures. However, not all HRB substantially reduce the environmental impacts and energy requirements. Among the binders used in the study, the HRB with the lowest C/S ratio can significantly reduce the global warming potential.