Assessing a Reclaimed Concrete Up-Cycling Scheme through Life-Cycle Analysis
Abstract
The present study evaluates the environmental impacts of a recycling scheme for gravels from building concretes wastes, in which the liberated aggregates are reused in structural concretes while the residual mortar fines are sent to the raw mill of a clinker kiln. The evaluation follows a life-cycle analysis approach performed according to the ISO standard 14040, and whose scope encompasses the production of clinker through a dry kiln technology, the mining processes of the raw materials needed in the kiln, the extraction of round and crushed natural aggregates, and the crushing of concrete wastes using usual jaw crushers or pulsed-power electrical fragmentation. Insofar as possible, the inventory data are collected at the national scale of France and are recovered from the supplier of the fragmentation device, from local quarries and from an estimated mean-technology of clinker production. The choice of the impact assessment indicators is restricted to midpoints according to a problem-oriented methodology, and primarily focuses on a potential reduction in the natural resources depletion and in the CO2 emissions. The study specifically addresses the influence of (i) the amount of recovered cement paste added to the kiln raw mill, and (ii) the distance of transportation modalities of concrete wastes to the crushing processes and of the recycled aggregates to construction sites. The results establish links between significant environmental gains and the various distances of transportations that intervene in the alternative processing of concrete wastes. These links will be probed more deeply in a future work.
Domains
Chemical engineering
Origin : Files produced by the author(s)
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