Determination of the optimal replacement content of Portland cement by stone powder using particle packing methods and analysis of the influence of the excess water on the consistency of pastes

  • Heloisa Fuganti Campos Universidade Federal do Paraná
  • Thaisa Mariana Santiago Rocha Universidade Federal do Paraná
  • Giovana Costa Reus Universidade Federal do Paraná
  • Nayara S. Klein Universidade Federal do Paraná
  • José Marques Filho Universidade Federal do Paraná

Abstract

Cement is considered the basic component with the highest environmental impact in construction, in terms of CO2 emissions. As for the aggregates, the process of comminution of rocks, in addition to artificial sand, generates stone powder that ends up being stored outdoors, generating environmental damages. Thus, the replacement of cement by stone powder appears as an attractive alternative towards the sustainable concretes. In this context, the objective of this papres is to determine the maximum packing density in Portland cement, silica fume and stone dust pastes, to determine the optimal cement substitution content for the stone powder. In addition, it is intended to verify the influence of excess water on the consistency of the mixtures produced. The substitution was done in contents equal to 0%, 7%, 14% and 21% by volume and, for each content, the packing density was determined analytically by CPM model and combinations were reproduced experimentally. Excess water was checked by the mini Kantro cone test. The results showed that the higher cement substitution content of the stone powder obtained the higher packing density, experimental and analytical, and the higher workability, allowing economic and environmental advantages. Analyzing each material, the stone powder resulted in the highest packing density and silica fume is the lowest one. Therefore, finer particles resulted in lower packaging densities, due to the greater specific surface area, which demands more water. The agglomeration resulted in more empty gaps between the grains. In addition, mixtures flowability increased with the increase of the stone powder content. As the excess water is responsible for  mixture lubrication, a higher packing density for a given volume of water improves the flowability.

Author Biography

Heloisa Fuganti Campos, Universidade Federal do Paraná
Doutoranda do Programa de Pós-Graduação em Engenharia de Construção Civil da Universidade Federal do Paraná, na área de concentração Materiais e Estruturas. Mestre em Engenharia de Construção Civil pelo Programa de Pós-Graduação em Engenharia de Construção Civil da Universidade Federal do Paraná. Especialista em Sistemas Estruturais de Concreto, pelo Instituto de Educação Tecnológica De Luca Daher e Engenheira Civil graduada pela Universidade Federal do Paraná. Professora do Departamento de Construção Civil da Universidade Federal do Paraná nas áreas de Gerenciamento de Projetos, Construção Civil e Materiais de Construção Civil. Atua na área de materiais de construção civil com foco em novas tecnologias do concreto e sustentabilidade e na execução de projetos estruturais.
Published
2019-01-21
Section
Artigos