Behavior of a Clayey Soil Mixture with Fine Crushed Polyethylene Terephthalate.

Nathalia dos Santos Lopes Louzada¹; Michéle Dal Toé Casagrande¹

¹ PUC-RIO

Baixar PDF doi:10.20906/CPS/CB-01-0127

Resumo

Every year millions of bottles of polyethylene terephthalate (PET) are discarded into the environment. In order to reduce the disposal of this polymer in nature, this study aims to evaluate the mechanical behavior of a clayey soil mixed with fine crushed PET. The potential use of this waste material in geotechnical applications may ultimately reduce the problem of improper disposal and to improve the strength and deformation characteristics of the soil. This paper presents an experimental study to evaluate the mechanical behavior of pure soil and mixtures with different contents of PET waste by triaxial tests, in order to obtain the strength parameters of the Soil-PET mixtures. The clayey soil used in this research came from the Experimental Field II located in PUC-Rio campus, which is a residual tropical. It has a micro-granular texture, constituted by quartz, altered garnet, clay minerals (mainly kaolinite) and iron and aluminum oxides. The soil was mixed with 10 and 20% of fine crushed PET (resulted of a specific method of crushing, and the PET comes out with a particle size up to 50 mesh.) by dry weight. Characterization tests such as grain size, Atterberg limits and compaction test were performed on the clayey material. Triaxial tests at confining stresses of 50, 150 and 300 kPa were done on the soil and mixtures. The results show that the soil strength parameters are influenced by the addition of the fine crushed PET, thus improving characteristics such as friction angle and cohesion of the Soil-PET mixtures. This improvement also depends upon the confining level which the samples were submitted. It is observed that in both mixtures, when material is submitted to a low confining stress the insertion of fine crushed PET does not improve the strength parameters of the soil. However, at higher confining stresses the improvements of the strength parameters are evident. The fine crushed PET works as a grain size improvement, and in higher confining stress, when the consolidation step is applied, the fine crushed

Palavras-chave: triaxial tests; Fine Crushed PET; waste; reinforced soil