Eco-trench: a novel trench solution based on reusing excavated material and a finishing layer of expansive concrete
journal contributionposted on 20.03.2018, 16:59 by Ana Blanco-Alvarez, Pablo Pujadas, C. Fernandez, Sergio Pialarissi-Cavalaro, Antonio Aguado
Installing utility pipelines generates a significant amount of trench arisings, which are usually transported to landfills instead of being reused as backfill material. This practice generates CO 2 emissions and wastes raw materials. This paper presents a more sustainable solution, an eco-trench, which is based on re-using trench arisings as backfill and adding a top layer of expansive concrete to improve the eco-trench's structural performance. The technical feasibility of the eco-trench was evaluated through a finite element model, which identified the degree of expansion in concrete required to avoid failure or subside the stresses caused by traffic. The potential expansion of concrete was measured under confined conditions in the laboratory by means of a novel test developed for this purpose. The results showed that adding calcium oxide generates the required internal stress. The results were then confirmed in a pilot experience.
The authors would like to acknowledge Gas Natural SDG, S.A. for their collaboration and support of this project. The authors thank the support provided by the Spanish Ministry of Economy and Competitiveness in the scope of the project with reference number IPT-2012-0313-370000. The second and third author acknowledge the PDJ and FI grants provided by the Departament d’Universitats, Recerca i Societat de la Informacio of the Generalitat de Catalunya.
- Architecture, Building and Civil Engineering