Valorization of Pozzolans as Partial Additive of Portland Cement: A Case of Pozzolans from the Localities of Foumbot, Penja and Tombel (Cameroon)

摘要

The objective of this study is to find alternative materials that can be used as an addition in cement in order to produce ecological and economical cement. Three pozzolans coming from different volcanic regions of Cameroon (Penja, Tombel and Foumbot) were sampling. Mechanical compressions on 40 × 40 × 160 mm~(3) mortar specimens were made with partial replacements of 2%, 4%, 6% and 8% of the pozzolans in Portland cement and physical analyzes on the mortar powders were carried out. The values of the activity indices of different pozzolans obtained are in the normative range. The compressive strength of motars decreases at all ages with the proportion of cement substitution. The compressive strength values up to 40 Mpa are obtained for a substitution of 6% for the pozzolans from Penja, Tombel and 8% for the pozzolan from Foumbot. Pozzolan from Foumbot which contains the highest percentage of SiO_(2) offers a maximum substitution rate and therefore optimally reduces the production costs of Portland cement. Physical tests show that specific surfaces increase with an additions of pozzolans from Tombel and Penja.