TITLE:
Investigation on the Use of Local Sand in Burkina Faso as Standard Sand for Testing Compressive Strength of Cement
AUTHORS:
Nafissatou Savadogo, Yasmine Binta Traore, Philbert Nshimiyimana, Mohamed Ouedraogo
KEYWORDS:
Cements, Standardized Sand, Strength Class, Particle Size Distribution, Water Absorption Coefficient
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.14 No.12,
December
17,
2024
ABSTRACT: The aim of this work is to identify a substitute for imported standardized sand for determining the strength class of cements using local sands. To this end, three (03) local sands (Manga, Kaya and Dori) were characterized and then used to formulate sand mixtures fitting into the granular spindle of standardized sand noted SM1, SM2 and SM3. SM1 is composed of 80% Manga sand plus 20% Dori sand. SM2 is a mixture of 80% of the refusal and 20% of the passing through the 0.25 mm sieve of the Manga sand. SM3 is composed of 77% Manga sand 0.25 mm sieve refusals plus 23% Kaya sand. These sands were used to characterize a CEM II/B-M (P-L) 42.5 R cement by comparing it with the results of a standardized sand noted SS. Characterization of the local sand showed them to be less dense and more absorbent than the standardized sand. Mortars made with SM1, SM2 and SM3 thus have lower workability and bulk densities in the fresh and hardened states than the SS-based mortar, with higher porosities accessible to water after 28 days of curing. Mechanical characterization of the cement gave lower compressive strength values with local sands at 2 and 28 days cure. At 2 days cure, local sands gave 17.42 MPa, 14.68 MPa and 17.13 MPa respectively for SM1, SM2 and SM3, compared with 21.12 MPa for standard sand. At 28 days, mortars based on SM1 and SM3 sands give higher strength values than the 42.5 MPa required by standard NF EN 197-1, with 44.21 MPa and 43.17 MPa respectively, compared with 49.84 MPa for standardized sand. On this basis, correction factors have been proposed for the use of local sands in cement characterization. They nevertheless require repeatability studies before validation.