Evaluation the influence of chemical composition, finances and addition technique of local metakaolins as supplementary cementing materials
Volume Title: ICASGE2025
Paper ID : 1003-ICASGE-FULL
Authors
Abstract
Worldwide several investigations have been conducted to minimize the harmful environmental impact of cement through a range of strategies, including the partial substitution of Portland cement by supplementary cementing materials (SCMs). Most of SCMs are composed of silicate-based materials, most of which are industrial wastes. Some of the SCMs are aluminosilicates such as activated clays, metakaolins. Metakaolin (MK) is obtained from the thermal treatment of raw kaolin. Our country Egypt has very large reserves of raw kaolin. However, local kaolin has not been used for reactive MK manufacturing as pozzolanic mineral concrete admixture.
So, the paper objective is to study the impact of chemical composition, finances and addition technique of local metakaolins at various substation levels on performance of concretes. Three types of produced local metakaolins (MK24, MK33 and NMK) while, commercially fly ash (FA) was also examined as a reference admixture for comparison. The behavior of concrete mixtures that containing different types of MKs was investigated through a serios of testes, setting time and slump as fresh properties, compressive strength at age 7, 28 and 150 days of curing, water absorption, electrical resistivity and ultra-sonic pulse velocity after 28 days as hardened properties. It was found that, concretes incorporating local metakaolins MK24 & MK33 resulted in almost the same strength and durability performance when compared with that of the control concrete. Therefore, it can be concluded that there is no noteworthy beneficial effect of the presence of the high alumina content that the metakaolin type MK33 was characterized.
So, the paper objective is to study the impact of chemical composition, finances and addition technique of local metakaolins at various substation levels on performance of concretes. Three types of produced local metakaolins (MK24, MK33 and NMK) while, commercially fly ash (FA) was also examined as a reference admixture for comparison. The behavior of concrete mixtures that containing different types of MKs was investigated through a serios of testes, setting time and slump as fresh properties, compressive strength at age 7, 28 and 150 days of curing, water absorption, electrical resistivity and ultra-sonic pulse velocity after 28 days as hardened properties. It was found that, concretes incorporating local metakaolins MK24 & MK33 resulted in almost the same strength and durability performance when compared with that of the control concrete. Therefore, it can be concluded that there is no noteworthy beneficial effect of the presence of the high alumina content that the metakaolin type MK33 was characterized.
Keywords
Supplementary cementing materials; local metakaolins; Fly ash; hardened concrete properties fresh properties
Subjects