A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Trinidad porcellanite as a pozzolan
Abstract “Fuel consumer” countries could save fuel and also make better use of their own resources by using pozzolans to replace part of their Portland cement requirements. A recent BRE study of porcellanite from Trinidad provides an example of the type of work needed to assess such materials. Porcellanite is a naturally fired clay and the extensive Trinidadian deposits show marked lateral and vertical variations in both pozzolanic activity and sulphate content. Sulphate is present as the mineral alunite,K Al 3 (OH) 6(SO 4)2. In most of the localities sampled, pozzolanic activity is relatively low, but one area has been identified where the porcellanite has good pozzolanic properties. This area may contain sufficient reserves by itself for exploitation in the production of a Portland-pozzolan cement for use where relatively high early strength is required. Several other localities could provide porcellanite for use in Portland-pozzolan cements where requirements for early strength are not demanding. TheSO 3 content of the porcellanite varies between localities but no difficulty is envisaged in blending the material to comply with the ASTM specifications for pozzolans and Portland-pozzolan cements. Although volume stability tests on concrete made from a porcellanite containing 7.0%SO 3 have given satisfactory results up to 6 1/2 years it is recommended thatSO 3 levels should be kept within the appropriate ASTM limits in practice. Heat, treatment of the porcellanite to improve the pozzolanic activity could provide a further, if more costly, path towards utilisation.
Trinidad porcellanite as a pozzolan
Abstract “Fuel consumer” countries could save fuel and also make better use of their own resources by using pozzolans to replace part of their Portland cement requirements. A recent BRE study of porcellanite from Trinidad provides an example of the type of work needed to assess such materials. Porcellanite is a naturally fired clay and the extensive Trinidadian deposits show marked lateral and vertical variations in both pozzolanic activity and sulphate content. Sulphate is present as the mineral alunite,K Al 3 (OH) 6(SO 4)2. In most of the localities sampled, pozzolanic activity is relatively low, but one area has been identified where the porcellanite has good pozzolanic properties. This area may contain sufficient reserves by itself for exploitation in the production of a Portland-pozzolan cement for use where relatively high early strength is required. Several other localities could provide porcellanite for use in Portland-pozzolan cements where requirements for early strength are not demanding. TheSO 3 content of the porcellanite varies between localities but no difficulty is envisaged in blending the material to comply with the ASTM specifications for pozzolans and Portland-pozzolan cements. Although volume stability tests on concrete made from a porcellanite containing 7.0%SO 3 have given satisfactory results up to 6 1/2 years it is recommended thatSO 3 levels should be kept within the appropriate ASTM limits in practice. Heat, treatment of the porcellanite to improve the pozzolanic activity could provide a further, if more costly, path towards utilisation.
Trinidad porcellanite as a pozzolan
Gutt, W. (author) / Gaze, M. E. (author)
Matériaux et Construction ; 8 ; 439-450
1975-11-01
12 pages
Article (Journal)
Electronic Resource
English