Potentialities of a calcined kaolin as material of partial replacement of portland cement in mortars

Revista Brasileira de Engenharia Agrícola e Ambiental

Barbosa, Normando P.²  Oliveira, Marilia P. de¹ 

[1] Universidade Federal de Campina Grande, Campina Grande;UFPB, João Pessoa

关键词: pozzolana;    calcined clay;    pozolanic activity    INTRODUÇÃO A principal propriedade de uma pozolana é a sua capacidade de reagir e se combinar com o hidróxido de cálcio;    formando compostos estáveis de poder aglomerante;    tais como: silicatos e aluminatos de cálcio hidratados;    assim;    no cimento Portland o hidróxido de cálcio liberado pela hidratação dos silicatos;    reage com a pozolana;    utilizada como substituição parcial do cimento;    resultando em uma produção extra de silicatos de cálcio hidratados;    que são produtos mais estáveis do cimento hidratado;   

DOI  :  10.1590/S1415-43662006000200034

学科分类：农业科学（综合）

来源: Universidade Federal de Campina Grande * Centro de Ciencias e Tecnologia

【 摘 要 】

The use of burnt clays, in the metakaolin form, as pozzolanic material for mortars and concretes has received a remarkable attention in the last years. This paper aimed to evaluate the mechanical property of mortars, in which a calcined kaolin originating from the State of Paraiba, was used as partial cement replacement material. Two finess of the kaolin were used: ABNT 200 (0.074 mm) and 325 (0.044 mm) and burnt at temperatures of 700, 800 and 900 ºC for a period of 2 h. Both materials were characterized by chemical analysis, differential thermal analysis, X-ray diffraction, specific area tests. The pozolanic activity index was obtanied using lime and cement Portland. The amounts of replacement were 10, 20, 30 and 40%, besides the reference mortar. The binder: sand ratio was 1:1.5 and the water/binder ratio was constant and equal to 0.4. The effect of partial substitution of cement in mortar was evaluated through compressive strength at 7, 28 and 90 days. Mortars with kaolin presented superior strength comparing to reference mortar, up to the level of 30% of substitution.

【 授权许可】

CC BY-NC