Characterization of Algerian reservoir sludges for use as active additions in cement: New pozzolans for eco-cement manufacture

This paper analyzes the chemical, physical, morphological, mineralogical and pozzolanic characteristics of several reservoir sludges and assesses their potential for use as 20% additions in blended cement manufacture. The studied sludges exhibit good pozzolanic properties, especially sample 5 which has high SiO2, Al2O3 and Fe2O3 contents. Blended cements prepared with 20% sludge additions complied with the European standard on compressive strength of one of the standardized cements, above 32.5 MPa at 28 days of curing; except for sample 5, which showed similar compressive strength values to the reference cement and up to 2% higher values at long curing times.

► Algerian sludges were studied as pozzolans.
► All sludges analyzed show good pozzolanic properties.
► The incorporation of sludges to blended cement decreases strength, except for SLD5.
► These sludges can be used as active additions to elaborate blended cements.