Analysis on Chemical Composition of Different Brands of Cement in Nigeria with Their Corresponding Setting Time

The quality and standard of cement available in the open market has been a thing of question, which necessitated this research that assessed different Portland cements commonly used in Nigeria within the southern region, in view of understanding the relationship between their chemical compositions and their corresponding setting time. Five brands of cement labelled sample A, B, C, D and E representing Dangote 3x R, Bua, Dangote 3x N, Unicem and Elephant supaset cement respectively were investigated. Chemical composition test was carried out using the atomic absorption spectrophotometer while the vicat apparatus was used for the setting time test. The chemical composition test result showed that the oxides composition of samples A, B and E met the British standard while for samples C and D the CaO, C3S and C2S content did not meet standard. The result further revealed that sample D has the highest percentage of C3S (73.58%) while sample C has the highest percentage of C2S (40.67%). The percentage of C3A is highest in sample E (9.04%) and sample B has the highest percentage of C4AF (10.76%). The setting time result showed that both the initial and final setting time of the cement samples are within the limit values that initial setting should be greater than 60mins and final setting time should be less than 600mins. Sample D has the fastest initial setting time of 70mins which is as a result of the C3S content that indicates that it will develop more early strength while sample E has the fastest final setting time of 405mins as a result of the C3A content which shows that it will generate more heat than other samples during the early stage of hydration. Sample C has the slowest initial and final setting time value of 105mins and 510mins respectively which is as result of the C2S content that shows that it will develop more late strength than any other sample. The correlation between C3A and gypsum indicates that sufficient amount of gypsum was added to delay the hydration of C3A, it was also observed that there was high correlation coefficient value of 0.9802 between chemical composition and setting time showing that there is a relationship between both. This shows that variation in chemical composition will cause a corresponding variation in setting time.