No abstract

The food processing industry generates large amounts of eggshell waste worldwide. The eggshell waste is rich in calcium carbonate (CaCO3), and is considered to be a solid waste material of very complex and difficult final disposal. This work investigates the reuse of eggshell waste as an alternative raw material into a soil–cement brick body, replacing cement by up to 30 wt%. Soil–cement bricks are uniaxially pressed and cured for 28 days. The technological properties of the cured bricks (e.g. apparent density, water absorption and compressive strength) are then determined. The results show that eggshell waste can be used in soil–cement bricks with excellent technical properties, in the range up to 30 wt%, as a partial replacement for Portland cement. Hence, application in civil engineering could be one of the best management practices for eggshell waste as a low-cost, alternative raw material.

The reuse of pollutant solid wastes produced in distinct industrial activities (avian eggshell waste and welding flux slag waste) as a source of alternative raw material for producing soil-cement bricks for civil construction was investigated. Soil-cement bricks containing up to 30 wt% of industrial solid waste were uniaxially pressed and cured for 28 days. Special emphasis is given on the influence of solid waste addition on the technical properties (as such volumetric shrinkage, water absorption, bulk density, durability, and compressive strength), microstructure and mineral phases of soil-cement bricks. Microstructural evolution was evaluated via confocal microscopy. The experimental results showed that the solid wastes behave as charge material and influenced both technical properties and microstructure of the soil-cement bricks. It was found that up to 15 wt% of welding flux slag waste and up to 30 wt% of avian eggshell waste could be added into the soil-cement bricks for use as building material.

In the cellulose industry the Kraft process is widely used to produce cellulose. This process generates huge volumes of inorganic solid wastes, including the grits waste. In Brazil, the final disposal of this solid waste is of high economical and environmental interest. The present work assesses the influence of the addition of grits waste on the densification behavior of soil-cement bricks. The raw materials used were soil, Portland cement, and grits waste. Soil-cement bricks containing up to 30 wt.% grits waste in partial replacement of Portland cement were prepared by uniaxial pressing and cured for 28 days. The following technological properties were determined: water absorption, compressive strength, and durability. The microstructure was evaluated by scanning electron microscopy and X-ray diffraction. The experimental results indicated that the addition of grits waste influenced positively the densification behavior of the soil-cement bricks. Moreover, the grits waste could be incorporated into the soil-cement brick composition up to 20 wt.% as a partial replacement of Portland cement. Keywords:grits waste, soil-cement brick, densification, microstructure. Resumo

No abstract