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Outline

Recommendations for recycling, processing and reuse of concrete

2007, Conference Paper

https://doi.org/10.1115/IMECE2007-43401

Abstract

Some countries started to recycle concrete material in order to reuse it in structural or other issues. Some of them, like Germany, Australia and Canada have established their own recommendation guide for recycling concrete. This recycling consists of crushing old concrete into aggregates, and then processing it into new mixture using the recycled aggregates with specified sizes. The aim of this recycling is to save nature from deforestation and dryness, by reducing the need to gravel and so the quarries work, and also to economize the waste management. The present research work consists of an experimental study treating the impact of using recycled aggregates on the concrete behavior and on the country’s economy. We are especially interested in determining the best composition for the new mixture of concrete resulting from reusing different types of recycled aggregates. Different types of tests have been done depending on the aggregates sizes, their origin and their state (burned or safe). The analysis is based on the comparison between compressive strength, water-cement ratio, slump, porosity and durability. Otherwise, the impact on economy is analyzed, a priori, by studying the effect of reducing the price of the resulting concrete on construction spending. The resulted recommendations indicate the sizes of aggregates which may constitute the best composition for recycling and processing concrete, and the best use for each type of concrete depending on behavior and economy effect.

Key takeaways
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  1. Recycling concrete can reduce waste management costs and environmental impact by using up to 40% recycled aggregates.
  2. Optimal structural concrete composition includes 20% recycled aggregates, balancing strength and porosity.
  3. Testing indicates durability of recycled aggregates is generally lower than that of ordinary concrete.
  4. Using silica aggregates is recommended for fire-prone constructions; more research needed on this.
  5. The study emphasizes distinguishing between structural and non-structural concrete during recycling processes.

References (13)

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