Permeabilidade de sistemas compostos de resíduos de construção e demolição reciclados (RCD-R) e geotêxteis não tecidos

• Autor(a) principal: Britto, Alexandre Faria Seixo de
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/0013000009ck0
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10476
• topic: Resíduos de construção e demolição; Reciclagem; Permeabilidade; Geotêxtil não tecido; Tensões normais; Construction and demolition waste; Recycling; Permeability; Nonwoven geotextile; Normal stress; ENGENHARIA CIVIL::GEOTECNICA

Recycling can help reduce environmental impacts, provides high quality construction materials and lower the cost of geotechnical works. Recently, studies have shown the feasibility of using these materials as backfill material in geosynthetic reinforced soil (GRS) structures. In this scenario, most of these studies focused on investigating the physical, mechanical and chemical properties of recycled construction and demolition waste (RCDW). However, the hydraulic properties of these recycled materials are also relevant information for the design of GRS structures, given that the filling material must be able to allow the drainage of the reinforced soil. In this context, the main objective of this work was to investigate the hydraulic properties of RCDW simulating field conditions (different levels of normal stress), as well as their association with non-woven geotextiles (GTNW). Bearing in mind the geotechnical approach, RCDW (gray sand and rubble dust) were tested following the standard procedures usually performed on soils. Samples of RCDW (gray sand and rubble dust) were collected in a recycling plant and a natural sand was used as a reference material. Constant head permeability tests were carried out on RCDW and natural sand, associated or not with GTNW polyester (PET) with different masses per unit area (200 and 300 g / m²), and under different normal stress levels (0, 50, 100 and 200 kPa) applied to the specimen top. Granulometric analysis was carried out on material exhumed from the specimens in order to investigate any changes. Scanning electron microscopy (SEM) images were also obtained in the exhumed GTNW to assess the occurrence of clogging. The geotechnical characterization showed that RCDW presents characteristics similar to those of granular soils and with low variability. It was observed that the application of normal stress to the specimens top reduced the permeability of the RCDW and natural sand, when associated or not with the GTNW, once the applied stress altered the voids of the materials and so hindered the flow of water. The permeability of RCDW and natural sand also reduced when just associated with GTNW without the application of normal stress. Laser granulometric analysis revealed different granulometry alterations in different points along the specimen height and among the researched materials. The images by SEM did not show evidence of the GTNW clogging. The results showed that RCDW presented physical, mechanical and hydraulic properties similar to those of granular materials, which allow the application of these recycled materials in several types of geotechnical works, with the advantage of being environmentally friendly filling materials.