Publicação
Biotreated conventional concrete and CDW-concrete by use of microbial mixed cultures bioproducts
| Resumo: | Cracks form in all concrete constructions shortening the life of concrete elements, particularly in exposed concrete. They provide a path for transport of moisture, chlorides, and various other deleterious substances. The aim of this study was to assess the protection and consolidation effect of eco-friendly healing biotreatments on water absorption of conventional and recycled concrete, with 50% substitution of natural coarse aggregate by CDW aggregate. Concrete were treated with bioproducts obtained using waste biomass from a microbial mixed culture process for polyhydroxyalkanoates production. Results showed that the reference samples, with application of tap water, presented an increase in water drop permeability, being the absorption time shorter than in the control (untreated) samples. The biotreatment with the non-sonicated bioproduct increased significantly the water absorption time, more evident in conventional concrete samples than in recycled ones. In the case of the sonicated bioproducts, the behaviour was similar for both types of concrete specimens, but the healing effect was higher. When the biotreatment was performed with three applications, the healing effect was not so effective. This observation may be associated with the formation of a hydrophobic film of organic material from the bioproduct, which detached from the concrete surface after outdoors exposure. |
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| Autores principais: | Garcia-Gonzalez, Julia |
| Outros Autores: | Freches, André; Lemos, P. C.; Vaz, Pedro; Pereira, Alice S.; Juan-Valdes, Andres; Faria, Paulina |
| Assunto: | Biotreatment Bioproduct Water absorption Construction and demolition waste Recycled concrete |
| Ano: | 2018 |
| País: | Portugal |
| Tipo de documento: | documento de conferência |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | Cracks form in all concrete constructions shortening the life of concrete elements, particularly in exposed concrete. They provide a path for transport of moisture, chlorides, and various other deleterious substances. The aim of this study was to assess the protection and consolidation effect of eco-friendly healing biotreatments on water absorption of conventional and recycled concrete, with 50% substitution of natural coarse aggregate by CDW aggregate. Concrete were treated with bioproducts obtained using waste biomass from a microbial mixed culture process for polyhydroxyalkanoates production. Results showed that the reference samples, with application of tap water, presented an increase in water drop permeability, being the absorption time shorter than in the control (untreated) samples. The biotreatment with the non-sonicated bioproduct increased significantly the water absorption time, more evident in conventional concrete samples than in recycled ones. In the case of the sonicated bioproducts, the behaviour was similar for both types of concrete specimens, but the healing effect was higher. When the biotreatment was performed with three applications, the healing effect was not so effective. This observation may be associated with the formation of a hydrophobic film of organic material from the bioproduct, which detached from the concrete surface after outdoors exposure. |
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