Waterworks purify water to make it fit for drinking. Their large concrete structures are subject to wear and tear; however, awareness of the importance of concrete maintenance is spreading.
“We want to get away from the cycle of makeshift repairs. In many cases, implementing thorough repairs and renovations can extend the working life considerably,” says Mikael Jacobsson, concrete specialist at RISE.
In 2016, the Swedish Water & Wastewater Association published the RISE report "Betongskador i vattenverk" (Concrete damage in waterworks).
In many ways, this report proved to be an eye opener.
“There is a widespread perception that concrete lasts forever. To some extent, this is true – one need only look at the Pantheon in Rome, which is still standing today. In many cases today however, it is rebar and remesh that cause problems. Although rebar allows us to construct vast buildings with less concrete, it is also prone to rusting, which in turn leads to structural damage to the building,” says Mikael Jacobsson.
The processes that damage concrete are slow moving. A small patch of crumbling concrete that we pass every day will not necessary alert us to slowly developing damage. This makes it especially important to gain knowledge of how concrete damage develops at waterworks; because, once rust sets in, it can progress rapidly.
“Another issues is the large numbers of cosmetic repairs carried out at waterworks. For example, there is a natural desire to ensure that walls appear to be in good condition during study visits and the like. This leads to add hoc repairs to surfaces that simply cover up underlying damage or, in the worstcase scenario, even make matters worse.”
The majority of Swedish waterworks were built between 1950 and 1970. The working life of these structures is currently estimated at around 50 years; leaving the owners of many Swedish waterworks facing a decision as to whether to repair, refurbish or construct new facilities. Nobody wants to be left with structures at risk of cracking. This makes it important that they are able to base their decisions on facts.
“Subsequent to the report, we have continued to work on compiling and documenting knowledge on the interaction between water and concrete. In my opinion, when we have completed this material, it will be a bit of an eye opener,” says Mikael Jacobsson.
The main focus of waterworks is to ensure that water quality remains high. It is therefore hardly surprising that concrete maintenance is sometimes neglected.
“In comparison, the Swedish Transport Administration – another stakeholder with many vital concrete structures, such as bridges and tunnels – draws up detailed maintenance plans and conducts regular inspections of their infrastructure. If it were possible to introduce similar working methods into the waterworks sector, it would be an easy matter to increase the working life of many waterworks.”
Currently, more often than not, concrete specialists at RISE are contacted when it’s too late; however, increased knowledge of the maintenance of concrete structures may lead to help being called in earlier, or even being available locally.
“We are currently making efforts to be of help as early as when large concrete structures are being built. We are then in a position to quickly be of great benefit. In cases where many problems have been fixed in stages, we are often faced with some detective work regarding what measures have, and haven’t, been implemented. While this is admittedly very exciting, it takes an unnecessary amount of time and therefore costs the client more money,” concludes Mikael Jacobsson.