POCTI ECM/36027/99-00 (2000-2003)
Summary: This project intended to contribute for the understanding of the influence of granite and calcareous aggregates (mostly used in concrete production inPortugal) on the durability of concrete. Extensive experimental studies to evaluate the influence of physical and geometrical properties of granite and limestone aggregates on the durability of a C20/25 strength class concrete were carried out. Different granite and limestone aggregates were collected from seven quarries. Physical, geometrical and mechanical properties of aggregates as well as the rock weathering state were quantify by several tests such as, abrasion, surface hardness, uniaxial compressive strength, ultrasonic pulse velocity, water absorption by capillarity, vacuum water absorption and oxygen permeability.
Using aggregates from each quarry, several C20/25 strength class concrete mixes have been produced, with the same workability and volume proportions. Concrete specimens have been cured under water for 90 days; after that time concrete durability parameters were obtained through tests such as, vacuum water absorption, capillarity water absorption, water permeability and oxygen permeability.
The relevance of coarse aggregates of different geological sources in the permeability of structural concrete was also evaluated. Good quality granite, basalt, calcareous and marble coarse aggregates, obtained from different quarries, were used to produce structural concrete of strength class C30/37. Concretes were produced with constant volume proportions, workability, mixing and curing conditions using different sizes of each aggregate type. Aggregates were mixed in concrete in both dry and water saturated states. In this type of concretes the thickness of the interfacial transition zone was determined to evaluate its influence on the concrete mechanical and physical properties. This study was carried out analysis in backscattered electron microscopy (BSE) associated with energy dispersive spectrometry (EDS).
Results outline:
Relevant statistical correlations have been obtained between absorption and permeability test of rock material and rock deterioration state (weathering). Valid statistic correlation was also obtained between durability parameters as well as among aggregates geometrical properties and concrete durability parameters.
Concrete durability parameters, such as capillary water absorption and oxygen permeability, measured at 28 days, were found to be significantly affected by coarse aggregate size and its water content rather than aggregate mineralogy.
Concrete mixtures produced with granite and basaltic aggregates presented smaller interfacial transition zone thickness. Thus, concrete produced with aggregates having better physical and mechanics properties posses’ smaller interfacial transition zone thickness.
International journal papers:
F. Pacheco Torgal, Castro-Gomes, J.P. (2006), Influence of Physical and Geometrical properties of granite and limestone aggregates on the durability of C20/25 strength class concrete, Construction and Building Materials 20, 1079-1088.
Gonilho Pereira, C.N., Castro-Gomes, J.P., Pereira de Oliveira, L.A. (2007), Influence of coarse aggregate size, mineralogy and water content on the permeability of structural concrete, Construction and Building Materials. (submited for publication)
National journal papers:
Torgal, F.M.A.S.P., Castro Gomes, J.P., Lopes, S.R.M., (2003), Durabilidade do Betão: Influência de Agregados Graníticos e Calcários em Betão da Classe C20/25, Revista Betão, Ano V, Nº 10, Maio.
Articles in international conferences:
Torgal, F.M.A.S.P., Castro Gomes, J.P., Lopes, S.R.M., (2002), Experimental Study of Concrete Durability Parameters Produced with different Types of Aggregates, XXX IAHS World Congress on Housing, 9-13 September, Coimbra-Potugal.Housing Construction, Coimbra.
Castro Gomes, J.P., Pereira de Oliveira, L.A., Gonilho Pereira, C.N., Torgal, F.M.A.S.P., (2002), Discussion of Aggregate and Concrete Water Absorption and Permeability Testing Methodology, XXX IAHS World Congress on Housing, 9-13 September, Coimbra-Potugal.Housing Construction, Coimbra.
Articles in national conferences:
Gonilho Pereira, C., Castro Gomes, J.P. e Pereira de Oliveira, L., (2003), Influência de Tipos de Agregados e Condições de Mistura na Durabilidade de Betão Estrutural, Engenharias 2003. Inovação e Desenvolvimento, Universidade da Beira Interior, Covilhã, 6 a 8 Novembro.
Torgal, F.M.A.S.P. e Castro Gomes, J.P., (2003), Definição de Novos Índices Físicos e Geométricos de Agregados e a Durabilidade de Betões Correntes, Engenharias 2003. Inovação e Desenvolvimento, Universidade da Beira Interior, Covilhã, 6 a 8 Novembro.
Castro Gomes, J.P., Rodrigues Carvalho, J.A., Pissarra Cavaleiro, V.M., (2002), Water Absorption and Oxygen Permeability of Covilhã Granite, PortugueseGeotechnical Congress, LNEC, Lisboa, April.
Castro Gomes, J.P., Pereira de Oliveira, L.A., Gonilho Pereira, C.N., Torgal, F.M.A.S.P., (2002), Absorption and Permeability Tests of Aggregates, PortugueseGeotechnical Congress, LNEC, Lisboa, April.
Castro Gomes, J.P., Pereira de Oliveira, L.A., Gonilho Pereira, C.N., Torgal, F.M.A.S.P., (2001), Absorção e Permeabilidade de Inertes como Parâmetro de Avaliação da Durabilidade do Betão, Engenharias 2001, Universidade da Beira Interior, Covilhã, Novembro, pp. 315-321.
Master thesis:
Cristiana Nadir Gonilho Pereira, Estudo da Influência de Diferentes tipos de Agregados no Betão Estrutural: Durabilidade e Zona de Interface, Mestrado em Engenharia Civil – Construção (2ª Edição), UBI. (2005).
Fernando M. Alves S.P. Torgal, Influência das Propriedades Físicas dos Inertes na Durabilidade do Betão, Mestrado em Ciências da Construção, FCTUC. (2002)
Curricular and Professional Reports:
Avaliação da Qualidade de Agregados para o Fabrico do Betão, Cristiana Nadir Gonilho Pereira (UBI),Estágio Ordem dos Engenheiros. Concluído em 2004.
Caracterização de Inertes Explorados na Pedreira Joaquim Bartolomeu e sua Aplicabilidade em Construção Civil, José Silveirinha Damião Carrasco (UBI), Estágio Ordem dos Engenheiros. Concluído em Setembro de 2001.
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