Preparation and characterization of foamed concrete using a foaming agent and local mineral resources from Burkina Faso

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Résumé

The paper describes lightweight-foamed concretes (LFC) that were formulated from cement, natural sand, and foam from a foaming agent with densities of 600 and 700 kg/m3. The identified mineral phases in the cement are alite, belite, Celite, ferrite, calcite, and gypsum. The obtained foamed concretes have a porosity varying from 29.17 to 37.14 vol%, a thermal conductivity below 0.2 W/m.K, and a mechanical strength greater than 2 MPa. At 28 days setting, the relative quantities of crystalline and amorphous phases were identified by XRD and DTA/TG. These techniques allowed to show the importance of the carbonation process and hydrated phases formation on the macroscopic strength increase. The microstructural characterization by image analyses evidences that when the density decreases, growth of both crystalline and amorphous phases in the bubble walls during setting is a mean of compensating the role of density in strength.

Mots-clés

Carbonation, Materials science, Foaming agent, Porosity, Gypsum, Alite, Belite, Cement, Composite material, Calcite, Characterization (materials science), Amorphous solid, Compressive strength, Mineralogy, Clinker (cement), Portland cement, Geology, Chemistry