Comparative Life Cycle Assessment of Geosynthetics versus Concrete Retaining Wall

Paper i proceeding, 2013

Geogrids made of geosynthetics can replace conventional building materials like concrete. In this article, goal and scope, basic data and the results of a comparative life cycle assessment of concrete reinforced retaining walls (CRRW) and geosynthetics reinforced retaining walls (GRRW) are described. One running meter of a three meters high retaining wall forms the basis for comparison. The two walls have the same technical performance and an equal life time of 100 years. The GRRW has a lower demand of steel and concrete compared to the CRRW. The product system includes the supply of the raw materials, the manufacture of the geotextiles and the concrete, the construction of the wall, its use and its end of life. The life cycle assessment reveals that the GRRW causes lower environmental impacts. The cumulative greenhouse gas emissions of 300 m CRRW are 400 t and 70 t in case of GRRW. The use of an environmentally friendlier lorry in a sensitivity analysis and monte carlo simulation confirm the lower environmental impacts caused by the construction of a GRRW compared to a CRRW. More than 70 % of the environmental impacts of the geogrids production are caused by the raw material provision (plastic granulate) and the electricity demand in manufacturing.