Improvement of the Durability of Recycled Masonry Aggregate Concrete

The use of recycled masonry aggregate for concrete is mostly limited by the worse properties in comparison with natural aggregate. For these reasons it is necessary to find ways to improve the quality of recycled masonry aggregate concrete and make it more durable. One possibility is utilization of crystalline admixture which was verified in this study by laboratory measurements of key material properties and durability. The positive influence of mineral admixture was proved for freeze-thaw resistance. The positive impact to carbonation resistance was not unambiguous. In conclusion, the laboratory evaluation shows how to improve the durability of recycled masonry aggregate concrete, however, it is necessary to investigate more about this topic.

The Utilization of Recycled Masonry Aggregate and Recycled EPS for Concrete Blocks for Mortarless Masonry

The main aim of this paper is to carry out the environmentally based enhancement of a concrete mixture containing recycled materials whilst considering natural resource consumption as well as mechanical and thermal property levels. The developed concrete is intended to be used in mortarless masonry wall structures. Ten concrete mixtures with different types and replacement rates of recycled masonry aggregate and recycled expanded polystyrene were prepared, and their mechanical and thermal properties were experimentally investigated. It was found that the use of recycled masonry aggregate led to better thermal properties while maintaining sufficient mechanical properties. On the contrary, the addition of recycled expanded polystyrene did not significantly affect the thermal properties of concrete, but the mechanical properties considerably declined. For this reason, the recycled masonry aggregate is suitable to use as an aggregate for concrete masonry blocks for wall structures.

CONSTRUCTION POTENTIAL OF RECYCLED MASONRY FOR LIGHTWEIGHT CONCRETE

A sustainable and developing building industry requires large quantities of raw materials such as aggregates and crushed rocks. However, sourcing natural aggregates is becoming more problematic due to environmental impacts. Hence, the use of secondary materials, such as recycled aggregate can reduce the amount of natural aggregates required. Lightweight concrete is frequently used by the building industry, and it is commonly produced with natural lightweight aggregates such as scoria, which results in high production costs. Preliminary tests on recycled aggregates showed that recycled masonry has a similar specific gravity as scoria and relatively good strength. Hence, crushed masonry can be used to replace natural lightweight aggregates. This paper discusses the use of partial or total replacement of normal-weight aggregates with recycled lightweight aggregates, and its effects on the strength and elastic properties of concrete. It is shown that concrete mixes with recycled aggregates generate comparable results to mixes with scoria, but at lower production costs.