Concrete containing recycled aggregates: Estimated lifetime using chloride migration test
•Estimated service life through the chloride migration test.•Concretes with 0%, 50%, and 100% of recycled coarse aggregate.•The use of w/c minimum ratios and pre-wetting are proposed to the application the material for structural purposes.•A strong correlation between time lag and chloride ion flux....
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| Published in: | Construction & building materials Vol. 222; pp. 108 - 118 |
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| Main Authors: | , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Elsevier Ltd
20-10-2019
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | •Estimated service life through the chloride migration test.•Concretes with 0%, 50%, and 100% of recycled coarse aggregate.•The use of w/c minimum ratios and pre-wetting are proposed to the application the material for structural purposes.•A strong correlation between time lag and chloride ion flux.•In terms of durability, concretes with lower w/c ratios presented lower performance losses.•Adaptation to ASTM C 1202 is suggested.
This paper presents a study regarding the durability of concrete containing Recycled Coarse Aggregate (RCA) from the largest civil construction waste plant in Latin America, CTR Grajau, located in São Paulo, Brazil. Conventional reference concretes were produced with natural aggregates and water/cement ratios of 0.35, 0.45, and 0.55. The recycled concretes were produced by replacing the Natural Coarse Aggregate (NCA) of the reference concretes with RCA in percentages of 50% and 100% by volume. Specimens were submitted to tests to determine the apparent porosity, capillary absorption coefficient andcompressivestrength. To verify durability aspects, the diffusion coefficients of chlorides (obtained by a procedure adapted from ASTM C 1202:2017) and electricalresistivity (obtained using a Wenner probe)were determined. Results demonstrated that NCA substitution with RCA increased porosity, with a consequent increase in the capillary absorption coefficient and a reduction in compressive strength. Total replacement of NCA with RCA reduces the concrete service life, calculated using Fick’s Second Law of Diffusion, by at least 40% for concretes with water/cement (w/c) ratio equal to 0.35, while a partial replacement (50%) reduces the service life by approximately 22%, considering a marine environment and 40 mm of cover thickness. The use of w/c minimum ratios, detailed RCA characterization and pre-wetting are some of the methods proposed for the application of the material for structural purposes. The lifetimes of the different concretes were determined. |
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| ISSN: | 0950-0618 1879-0526 |
| DOI: | 10.1016/j.conbuildmat.2019.06.136 |