[EN] The higher water absorption of recycled aggregates is the main drawback which hinders the reuse of this secondary material, limiting its acceptance in the construction market. This study proposes the microbially induced carbonate precipitation (by using Bacillus sphaericus) to improve the quality of mixed and ceramic recycled aggregates. This precipitation has contributed to a weight increase and has unleashed a waterproofing response, most effectively on the roughest particle surfaces. High ceramic content aggregates profited from a greater biodeposition, leading to a remaining amount of precipitates is more deeply fixed in cementitious materials. The pore-filling effect was detected by SEM, supporting the waterproofing result. The use of biotreated aggregates led to more fluid recycled concrete consistencies when the same amount of mixing water was used. Without water adjustments in the concrete mixture, the presence of calcium carbonate lessened long-term compressive strength, although strength development was accelerated, with higher early-age (7 days) values than observed for concrete bearing untreated recycled aggregate
