Production of granilite concrete plates with recycled aggregates and ornamental rock processing sludge

Abstract

The ornamental rock industry generates millions of tons of waste in different stages of rock processing. These wastes are stored or disposed of inadequately, which causes environmental degradation. The objective of this study was to evaluate the concomitant use of ornamental rock processing sludge as partial replacement of Portland cement in contents of 0%, 5%, 10% and 20% and of recycled stone aggregate as total replacement of coarse natural aggregates in the production and performance of granilite concrete plates. Four concrete formulations were produced with different replacement contents and their characteristics were determined through tests of axial compression strength, flexural tensile strength, water absorption, impact strength and strength to stains. Mechanical results were inversely proportional: the higher the sludge replacement content, the higher the axial compression strength and the lower the flexural tensile strength. Water absorption tests showed a gradual decrease with an increase in sludge replacement, impact tests showed that the plates performed better at resisting shocks best up to a height of 50 cm and, in terms of stain resistance, multi-use products and butoxyethanol-based stain remover were more efficient on waterproofed granilite concretes and natural rock pieces, respectively. It was possible to conclude that it was viable to use up to 20% replacement of the aforementioned wastes in conventional concrete, with additional minimization of environmental impact associated with the extraction and processing of ornamental stones.

Pineapple fibre as an additive to self-compacting concrete

“…When the economics, strength, and durability necessary for unique constructions are considered, the use of Self Compacting Concrete with much increased compressive strength of concrete is becoming increasingly common in the construction sector, and it is recognised as an optimised option [5,6]. Because of so many benefits, SCC is utilised in large structural buildings in various parts of the world [7][8][9][10]. As a result, some SCC proportioning guidelines were developed, such as lowering the water/powder ratio, rising paste quantity, managing the overall amount of coarse aggregate and its maximum particle density, and utilizing a powerful super plasticizer in combination with a great number of powders and/or viscosity-modifying admixtures (VMA) to smooth the stability between visco-elastic properties and consistency [11][12][13].…”

Experimental investigation on soil stabilization technique by adding nano-aluminium oxide additive in clay soil

“…Aside from these problems, the cement stabilisation process is affected by the ratio of water to cement, the temperature at which the mixture cures, and the specific surface area of the mixture, the presence of contaminants or foreign substances and the presence of additives [1] Other than this traditional method, the following materials are used for chemical stabilization: GGBS, volcanic ash [11,12], fly ash, biomass bottom ash, Phosphogypsum, steel slag, concrete slurry waste [13], fibre and pith of coir, rubber waste, glass, polypropylene fibre, straw of barley fibre,sisalfibre [14], carpet waste, geogrid, geotextile, geocomposite, Chemical soil stabilisation involves modifying the physical-synthetic properties of clay particles so that less water is needed to maintain the static imbalance [15]. Apart from these materials recycled aggregate waste [16], plastics, red mud, kaolin waste etc are also nowadays used in civil works like concrete batch preparation and making building materials [17].…”