We received an urgent call to carry out a Safety Survey to a High Rise residential development in Birmingham.
Reports of falling masonry had been received which needed immediate attention.
We deployed our Rope Access Team to carry out the survey to the large residential site and carried out a dynamic risk assessment before undertaking the Safety Survey
On completion of the survey, we removed approx 10 kg of loose concrete. Our report has recommended that safety surveys take place every quarter and to monitor further spalling from the buildings.
Why does concrete spall or fall off buildings?
When steel is cast into concrete, the naturally high alkalinity helps to protect the embedded steel from corrosion. However, the protection afforded by high alkalinity can be compromised by the ingress of acidic atmospheric gases, a process normally referred to as carbonation, or by the presence of salts in the concrete, typically from marine environments or from the use of de-icing salts. Combine these contaminants with oxygen and water and we have the key ingredients for corrosion. The reason some concrete structures exhibit widespread spalling whilst other appear to be in a sound condition is down to a combination of age, maintenance, concrete quality, the depth of concrete cover and local environmental conditions.
What will happen if my concrete is spalling?
Firstly, spalling is not attractive and makes a structure look uncared for. More seriously, if the structure is in an area accessed by the public, or by workers, then spalling can be hazardous in terms of falling debris or trip hazards.
If left unchecked then spalling will tend to accelerate and spread so that, eventually, the structure could become unstable. Diligent maintenance is therefore of great importance and legislation places a duty of care on owners to ensure that structures are not hazardous to users.
There are also serious commercial considerations. If a structure is left to deteriorate then the value of the asset will diminish and, furthermore, maintenance costs will tend to increase as corrosion and spalling becomes more widespread. For some structures, such as car parks, customers will stay away if the environment is unattractive and potentially hazardous.