Investigation of Mechanical Properties and Hydration Behavior in Cement Mortars Partially Substituted with Water Treatment Sludges

This study delves into the mechanical behavior and hydration characteristics of cement mortars incorporating varying percentages (5-25%) of water treatment sludges. The research explores the evolution of compressive strength over curing periods, revealing a notable increase in mechanical strength for all sludge content levels. This phenomenon affirms the pozzolanic activity of the partially replaced cement mortars with sludges from water treatment units. Notably, mortars with 5% sludge exhibit compressive strength values comparable to reference mortars. Conversely, an investigation into the influence of sludge addition indicates a proportionate reduction in mechanical strength, with a significant impact observed at higher sludge percentages (15-25%). The study further identifies a deceleration in hydration rates due to the presence of organic matter in the sludges, hindering cement hydration and extending the mortar setting time. Overall, this research sheds light on the nuanced effects of water treatment sludge incorporation in cement mortars, offering valuable insights for sustainable and effective waste utilization in construction materials.