Properties of Concrete with Recycled Concrete Aggregate Containing Metallurgical Sludge Waste

Abstract

Sand has been considered to be something of an immeasurable quantity. There are many indications that this view is no longer valid and that the limiting of natural aggregates usage is doubly justified. Firstly, the extraction of natural aggregates is expensive and has a huge impact on the environment. The main issues in sand and gravel mining are the large areas that are affected, ground water level changes, illegal mining, unsuitability of desert and marine sand, and costs of transport. Secondly, metallurgical waste can be used as a substitute for natural aggregates. This is doubly beneficial—the waste is recycled and the use of natural aggregates is reduced. Waste is stored in landfills that take up large areas and there is also the possibility of ground and groundwater pollution by hazardous compounds. The research presented in this article focuses on the technological conditions of using metallurgical waste in its original form and as a component of recycled concrete aggregate (RCA). The use of metallurgical sludge waste or crushed or round RCA to produce concrete deteriorates the consistency and does not significantly affect the air content and density of the concrete mix. RCA lowers the density of hardened concrete. Metallurgical sludge waste or RCA usage adversely affect the absorbability and permeability of concrete. Concrete containing metallurgical sludge waste is of higher compressive strength after 7 and 28 days, with up to 60% of waste as a sand replacement. RCA concrete achieved higher compressive strength also.

Investigation of the Effect of Addition Nano-papyrus Cane on the Mechanical Properties of Concrete

“…So that the density may be increased because of the lower pore (void) amount in the concrete matrix than that in the control mix, or this is caused by a higher degree of structure tightness by introducing a very fine material which fills the pores and gives more dense structure compared with the concrete mixture without nanoparticles. These results are in agreement with those [25] and Mendes and Repette (2019) [26]. Mix 1:1:2 also showed higher density values compared to 1:1.5:3 and 1:2:4, respectively, due to the formation of more cement paste in mixes with a higher cement/aggregate ratio, which gives the dense concrete structure.…”

Circular Economy for Municipal Solid Waste Incineration Bottom Ash (MSWIBA) Management in Mortars with CSA and CEM I, MSWIBA Glassy Phase, and DTG

“…The production of CSA had less emissions, and the mortars using CSA had better mechanical properties. This translates into a reduction in the negative impact on the environment [32] in the production of a building mix with CSA and MSWIBA versus the usual building mix [33].…”

Creation of Backfill Materials Based on Industrial Waste

“…Reuse of industrial waste and efficient use of by-products are two main principles of sustainable industrial processes. Contemporary research is focused on concrete modifications [21,22], forming of the man-made ground embankments [23] and even evolutionary game theory study for construction and demolition waste recycling [24]. The main way to ensure the sustainable development of the mining region is to use mineral deposit development systems with a hardening backfill and to include man-made waste in a closed production cycle [25,26].…”