Sustainability aspects of using geotextiles

Sustainability of materials and processes are commonly assessed by calculating the carbon emissions (CO2) generated. This is a simplification but the ease of calculation encourages comparisons of solutions, makes outputs of assessments accessible, transparent and repeatable, and CO2 savings can readily be counted towards industry, national and international targets. This chapter describes a framework for calculating embodied carbon of construction solutions that incorporate geotextiles. It outlines carbon footprinting techniques and common definitions, presents examples of embodied carbon for geotextile materials, defines life cycle boundaries and presents example calculations for common construction case studies: Protection, working platform and landfill capping. All three examples demonstrate the significant CO2 savings that can result from employing geotextiles. These savings are realised through reducing the amount of imported fill material used and this minimises the transport related carbon emissions. The approach introduced can be used to undertake site specific calculations that inform decisions on selection of construction approaches that contribute to sustainable practice

Obtaining reliable embodied carbon values for geosynthetics

Changing climate and the damaging effects of carbon dioxide (CO2) on the environment, has led to awareness throughout the construction industry of the need to deliver more sustainable solutions. Robust and rigorous carbon footprinting procedures for assessing solutions and projects can help to identify where action can be taken to reduce CO2 emissions. It also promotes the marketing of those solutions and methods that produce lower CO2 emissions. Geosynthetics often provide a cost-efficient alternative to more ‘traditional’ construction techniques. Recently, work by the Waste and Resources Action Programme in the UK has shown that geosynthetic solutions can also produce much lower CO2 emissions. However, there are still questions as to the reliability of such calculations. Although the methodologies employed are relatively consistent worldwide, the accuracy of the embodied carbon data available for use in calculations remains uncertain. Geosynthetic products are not specifically included in the embodied carbon construction materials databases most commonly employed in Europe, and often generic values for polypropylene and polyethylene are used. This paper presents a study in which the embodied carbon data for geosynthetic products was calculated using first-hand manufacturing process data. The values calculated for two categories of geosynthetics were considerably lower than commonly employed database values. Nonwoven geotextiles had an average embodied carbon value of 2.35 tCO2e/t, with values for example geogrids of 2.97 tCO2e/t for extruded and 2.36 tCO2e/t woven

Constraints and barriers to the application of geosynthetics

This paper outlines the current state of practice in the UK with regard to the use of geosynthetics in construction projects. It examines the awareness that geotechnical engineers possess about the technical and sustainability (i.e. reduced CO2) advantages that geosynthetics can provide over traditional construction techniques, and the barriers to their increased use. A survey of UK International Geosynthetic Society (IGS) Corporate Sponsors was carried out to understand the perceived constraints and barriers to increased early stage inclusion of geosynthetic based design solutions, and to obtain views on the current awareness of the UK construction industry of the sustainability benefits. The findings from the survey highlight a lack of clarity in the guidance on fill material provided in the literature. The survey results also showed that main barriers to the use of geosynthetics were education and the conservative approach of consultants