Durable Structural Concrete Produced with Coarse and Fine Recycled Aggregates Using Different Cement Types

Abstract

The durability properties of structural recycled aggregate concrete (RAC) produced with 50% coarse recycled concrete aggregates and up to 20% fine recycled concrete aggregates were analysed and compared to those of conventional concrete (NAC). Both the RAC and NAC mixtures achieved the same compressive strength when using an effective water–cement ratio of 0.47 and 0.51, respectively. All the concretes were produced using three types of cement: CEM II A/L 42.5 R, CEM II A/S 42.5 N/SRC and CEM III/B 42.5 N-LH/SR. The properties of drying shrinkage, chloride permeability, and accelerated carbonation coefficient of the concretes were determined experimentally, and the obtained results were compared with the values estimated by specific standards of exposure to XC1–XC4 (corrosion induced by carbonation can happen due to the presence of humidity) and XS1 (corrosion caused by chlorides from seawater) environments. The results showed that all the concretes achieved maximum drying shrinkage for use in structural concrete. Any concretes produced with CEM IIIB, including the RAC-C50-F20 concrete, achieved very low chloride ion penetrability, ranging between 500 to 740 Coulombs. In addition, all concretes manufactured with CEM IIAL and CEM IIAS, including RAC-C50-F20, were suitable for use in XC3 and XC4 exposure environments, both with 50- and 100-year lifespans.

Development of Sustainable Cement-Based Materials with Ultra-High Content of Waste Concrete Powder: Properties and Improvement

“…Therefore, effective utilization of construction waste [3,4] can not only alleviate natural resource shortages but also contribute to environmental protection, optimizing resource allocation and promoting sustainable economic and social development. Researchers have proposed using recycled aggregates (RAs) or recycled powder (RP) as replacements for natural aggregates and ordinary Portland cement (OPC), which can have a positive impact on reducing the environmental impact of cement [5][6][7]. After screening and crushing, concrete generates approximately 10-20% of construction waste powder, which can be used as a substitute for OPC in the binding process.…”