In this PhD study on Combined urea hydrolysis and nitrate reduction driven bio-deposition for self-healing concrete, the potential of combining urea hydrolysis and nitrate reduction driven MICP by using single bacteria strain was firstly investigated with the purpose to improve the total bacterial CaCO3 yield. Secondly, non-axenic production of hybrid CaCO3 producing microbial communities (CPBs) by using a SBR reactor have been demonstrated. Finally, the self-healing performance as well as the effect of CPBs on durability have been investigated on mortar scale.  The public defence of Xuejiao Zhu will take place on 13th December 2021 at 13:00 in Vergaderzaal A0.1 Azalea, Coupure Links 653, 9000 Ghent (Please confirm before December 3th), and via Livestream through MS Teams (Click to join: Deelnemen aan gesprek (microsoft.com)).