Utilização de cinzas industriais e cascalho de perfuração de poço de petróleo na produção de blocos de concreto para pavimentação

Abstract

The disposal of solid waste generated by industries is among the most difficult problems to be resolved. Much of this waste does not receive treatment or adequate disposal, therefore it ends up polluting the environment and causing disruption to society. Drilling gravel, generated during offshore oil extraction, and eucalyptus ash and sugarcane bagasse generated in the ceramics and alcohol and sugar production industries, are examples of waste that require studies for their use. The civil construction sector, responsible for a high extraction of raw materials, has great potential to insert waste in the manufacture of its materials, developing new products that aim to contribute to the Sustainable Development Goals (SDGs) established by AGENDA 2030. As in production of concrete paving blocks, which can gain new properties with the introduction of drilling gravel and agro-industrial ash in their manufacture. Therefore, the objective of this research was to evaluate the physical-mechanical, microstructural properties and durability of concrete paving blocks produced with drilling gravel waste and eucalyptus ash and sugarcane bagasse, which are waste destined for landfills or disposed of in a inadequate and have potential for use in the production of construction materials. The gravel was characterized in terms of particle size, pozzolanicity, curing inhibition, chemical composition, oil, water, solids content and density, while the ash was characterized in terms of granulometry, pozzolanicity and curing inhibition. Blocks produced with drilling gravel in percentages of 25, 50, 75 and 100% were evaluated as a replacement for stone dust, in addition to a control treatment without the use of waste. Blocks produced with drilling gravel and eucalyptus ash and sugarcane bagasse were also evaluated, in two different percentages for each residue, with 10 and 20% being evaluated as a replacement for cement, in addition to the control treatment. The blocks were made in a vibropress, by vibrocompression, to acquire the desired size and shape and were characterized in terms of compressive strength, water absorption, apparent density, apparent porosity, microstructural characterization and durability. An increase in the density of the blocks was observed with the inclusion of drilling gravel due to its greater real density compared to stone dust and a greater absorption of water and formation of pores in floors with residue. Accelerated aging intensified the formation of pores and cracks, negatively affecting the physical properties of the concrete blocks. However, after aging, the compressive strength increased for the control treatment and was maintained for the blocks with drilling gravel. The replacement of cement with industrial waste (ash and drilling gravel) negatively affected the physical and mechanical properties of concrete blocks due to greater inhibition of hydration reactions and less coverage of particles, due to the fineness level presented by the waste. Accelerated aging generated loss of adhesion and formation of pores and cracks, however it provided continued