Revamping corrosion damaged reinforced concrete balconies: Life cycle assessment and life cycle cost of life-extending repair methods

Facing the aging building stock, challenging times can be expected with a sharp increase of reinforced concrete buildings requiring maintenance, repair and/or replacement which induces an increase in construction and demolition waste and the use of new materials. To improve the sustainability of the renovation practice of existing concrete structures, a supporting analysis of the life cycle environmental and financial consequences has a high added value with regards to the selection of durable service life-extending repair strategy. As corrosion is the main contributor to the degradation of existing concrete structures, a residential building in a Belgian coastal environment with damaged reinforced concrete balconies is selected as case study in order to evaluate five different frequently used repair techniques by means of a life cycle assessment (LCA) and life cycle cost analysis (LCC): (i) patch repair, (ii) conventional repair, (iii) galvanic cathodic protection, (iv) impressed current cathodic protection and (v) total replacement of the element. For a short service lifetime extension (5y) of the balconies, a patch repair was revealed as the most preferable option as the existing situation is restored with a minimum of intervention. When a service life extension up to 40 years is requested, different options (conventional repair, cathodic protection) are found as competing performance options for both LCA and LCC. The total renewal of the balconies after demolition involves overall the highest LCA and LCC impact. •The amount of contaminated concrete has a decisive influence on the repair strategy.•Total replacement of the balconies has overall the highest LCA and LCC score and therefore is the less favourable repair option.•When a protecting coating is excluded, cathodic protection has a lower environmental and financial impact compared to a conventional repair.•The repair technique should be adjusted to the required service life extension.