Innovative, multifunctional repair technique to extend the service life of concrete structure


  • Mohammadali Yazdi 
  • Kim Van Tittelboom (supervisor)
  • Geert De Schutter (supervisor)
  • Nele De Belie (supervisor)


Refurbishment and repair of existing structures takes about 50% of Europe’s annual construction budget and this figure is expected to increase as the major population of concrete structures built in the 1960s and 1970s, which form a key part of Europe’s infrastructure, start to require further repair and refurbishment. Moreover, the durability of repaired concrete structures continues to be a major global concern as after 5 years, 20% of the repairs seem to be unsatisfactory. After 10 years this percentage increases to 55% and after 25 years 90% of the repair works fail. For patch repair, which is applied in 60% of the case studies, 30% of failures were due to cracking, 25% due to debonding, 25% due to continued corrosion and 20% due to other failure modes. In addition, it is worth mentioning that many failures are attributed to too aggressive removal of the contaminated concrete and incorrect use of repair materials. The aim of this research project is to develop an innovative, multifunctional repair technique for concrete structures with improved properties in the short and the long term and being resistant to harsh weather conditions by: (I) healing cracks in the concrete substrate, caused by aggressive pretreatment, through bacterial CaCO3 precipitation and/or nano-materials to decrease the permeability; (II) improving the concrete’s surface properties for an improved bond with the repair material by a bacterial CaCO3 layer and/or nano-material treatment; (III) limiting the formation of shrinkage cracks in the cement-based repair mortar through the use of hydrogel-based micro-containers (HBMCs); (IV) limiting the ingress of chloride solutions through the blocking and entrapment effect of the containers. This will finally lead to more durable and sustainable concrete repair as failure due to bond loss, continued corrosion, cracking,… will be tackled.

Ali Project.PNG