The work of fracture in the eco-mechanical performances of structural concrete

Abstract

To assess the ecological and mechanical performances of concrete structures, a new holistic approach is herein presented. The embodied energy and the carbon dioxide released by the production of a certain concrete, with preestablished strength and ductility, are both combined to define the so-called eco-mechanical index. Alternatively, the ecological and mechanical indexes can be reported within a non-dimensional diagram, especially when code rules or tender requirements are the benchmarks. In the two cases, a comparison among different structural concretes can be performed in order to select, or tailor, new eco-friendly and high performance cement-based composites. This approach is carried both for compression and for tension in order to investigate all possible situations occurring in concrete structures. As a result, the best concrete can be attained not only by applying ecological strategies for sustainability (e.g., the partial substitution of cement with mineral additives), but also by increasing the work of fracture both in tension and in compression (e.g., by means of steel fibers). Copyright © 2013 Japan Concrete Institute.