Analysis of mechanical parameters of concrete and mortar containing pozzolans from brick power

This study investigates the use of brick powder, a construction and demolition waste derived from red ceramic masonry, as a supplementary cementitious material in mortars and concretes. Portland cement, while essential for construction, is associated with high CO2 emissions, which motivates the search for sustainable alternatives. To assess the potential of brick powder as a partial cement replacement, mixtures were produced with 10% (B10) and 20% (B20) substitution levels, selected based on literature and the limitations of the pozzolanic reaction. Mortars were prepared at 1:3:0.54 (cement:sand:water) ratio and concrete at 1:1.45:2.35:0.52 (cement:sand:crushed stone:water). Specimens were cured in saturated lime solution and tested at 7 and 28 days for workability and compressive strength. Mortars with brick powder exhibited higher compressive strength, supported by pozzolanic activity confirmed through X-ray diffraction and calorimetry. In contrast, concrete showed a marked reduction in workability (from 180 mm for B0 to 110 mm for B10 and 95 mm for B20), which led to decreased mechanical performance (compressive strength decreasing from 34.36 MPa for B0 to 32.14 MPa for B10 and 29.63 MPa for B20). Despite this drawback, beams containing brick powder achieved ultimate loads consistent with theoretical predictions according to NBR 6118, demonstrating their structural feasibility. Overall, the findings indicate that brick powder can be applied as a sustainable supplementary cementitious material, reducing environmental impact while maintaining adequate performance in structural applications, although the observed loss of workability highlights the need for further optimisation to expand its practical use.