Concrete made with alternative fine aggregates: the reuse of porcelain electrical insulators

The use of alternative materials as substitutes for ordinary aggregates, mainly in concrete and mortar, has been common in recent decades in Brazil. Due to its physical and chemical similarities to common aggregates, ceramic waste, when coupled with a granulometric control, is suitable for use as an aggregate in concrete. Brazil has been estimated to dispose of approximately 25,000 tons of porcelain insulators annually, which are insulators that are often discarded along with other debris and harm the environment. This study examined the grinding methodology for and subsequent use of porcelain to replace fine aggregates in concrete and verified the improvement this substitution provided by evaluating the mechanical properties and durability of the concrete under study and examining scanning electron microscope images91218519

Blocos de Concreto com Areia de Descarte de Fundição: Viabilidade Econômica, Propriedades Mecânicas e de Durabilidade

No Brasil o volume de areia de descarte de fundição (ADF) é elevado, o que justifica o desenvolvimento de uma metodologia de reciclagem que permita a sua utilização na construção civil – beneficiando toda a cadeia produtiva e diminuindo o seu descarte nos aterros sanitários, que onera o setor. O bloco de concreto é um produto amplamente utilizado na construção civil brasileira, e a ADF pode ser utilizada como um agregado, substituindo a areia comum. Portanto, foram elaborados blocos de concreto com teores de substituição, em massa, de 13%, 19% e 25% da areia comum por ADF, submetendo-os aos ensaios de resistência à compressão nas idades de 7, 14, 21 e 28 dias, comparando estes resultados a traços de blocos com agregados comuns. Além de obterem-se blocos de concreto com resistência que permite classificá-los como Classe B, o seu custo de produção com a incorporação de ADF foi inferior ao custo do bloco com agregados comuns. Pretende-se, com este artigo, demonstrar o valor da ADF como agregado na confeção de blocos de concreto, e ressaltar que até o momento presente não há uma metodologia difundida para o seu reaproveitamento em escala nacional. A incorporação da ADF na produção de blocos de concreto resulta em benefícios ambientais e econômicos para toda a cadeia produtiva envolvida.In Brazil there is a very large volume of waste foundry sand (ADF), which explains the development of a recycling methodology that allows it to be used in civil construction - benefiting the entire production chain and reducing its disposal in landfills, which puts a burden on the sector. Concrete blocks are a widely used product in Brazil's civil construction sector and the ADF can be used as an aggregate, taking the place of ordinary sand. Therefore, concrete blocks were developed with levels of substitution of the common sand by the ADF, in terms of mass, of 13%, 19% and 25%. These blocks were then subjected to compressive strength testing at the ages of 7, 14, 21 and 28 days and the results were compared to concrete blocks made from common aggregates. In addition to obtaining concrete blocks with resistance that allows them to be classified as Class B, the production cost of the blocks that included ADF was lower than that of concrete blocks made from common aggregates. The objective of this article is to show the value of ADF as an aggregate in the manufacture of concrete blocks, and to stress that so far there is no widespread methodology for its reutilization on a national scale. The inclusion of ADF in the production of concrete blocks generates environmental and economic benefits for the entire productive chain involved