Reduction of carbon footprint of roads construction thanks to the Pavement Optimisation with hexagonal geogrids

Abstract

There is a growing demand on reduction of greenhouse gases emission from all branches of industry. Roads construction is responsible for a substantial part of building industry carbon footprint. One of the ways to reduce its carbon footprint is the use of Pavement Optimisation (PO) with hexagonal geogrids technology. This technology utilizes the phenomenon of aggregate stabilisation by interlock within apertures of geogrid. When aggregate is placed and compacted on a layer of geogrid, a geogrid/aggregate composite – called Mechanically Stabilised Layer (MSL) - is created. Stiff geogrid ribs resist particle movement reducing layer deformation, which increases its stiffness. Increased stiffness of aggregate can be utilized in design, and has a substantial influence on pavement life. This provides the possibility to reduce the thickness of a pavement, including thickness of asphalt. Thinner pavement will require less materials, workforce, time and energy. It will be cheaper, and its construction will result in lesser emission of CO2. This paper presents the overview of Pavement Optimisation technology and results of full scale accelerated pavement tests confirming the influence of hexagonal geogrids. Case studies of projects with optimised pavements and calculations of carbon footprint savings achieved thanks to the use of PO are presented.