spalling concrete repair singapore
Spalling concrete a most generally having issue on any buildings. The major reason of spalling concrete is due to carbonation, a natural deterioration process. This causes the building concrete's steel bars embedded in the ceiling slab to damage them, which in turn causes your building's strongest concrete cover to start crack and deformations.
A spall is defined as flakes of material that are broken off of a larger solid body. Concrete spalling typically begins when the steel reinforcing embedded within the concrete member rusts. Contrary to popular belief, concrete is porous. Rusting of the embedded steel reinforcing occurs when that reinforcing bar is exposed to water and air; without both of these elements, the steel bar does not rust.
When exposed to both of those elements, a chemical reaction takes place wherein iron oxide (rust) is produced. The production of iron oxide includes a volumetric expansion of the bar by up to 6 times the original volume, and that increase in volume imposes significant expansive forces upon the surrounding concrete. These expansive forces can cause the concrete to delaminate or to crack, spall, and break off.
How to prevent spalling concrete Spalling concrete is a surface maintenance problem that occurs in reinforced concrete structured buildings. If you could realize as soon as possible with help of Spalling concrete repair contractor singapore immediately, your building’s structural integrity will be analysed properly to rectify the dangerous consequences.
Here’s how spalling concrete can be prevented:
Do periodic painting on your ceilings : Paint protects the ceiling and helps to prevent any carbonation. Ideally, you should paint your ceiling regularly as mentioned.
If you seen any cracks/ holes, seal them immediately and properly Check your ceiling regularly for any holes or cracks. These should be sealed immediately to prevent moisture and carbon dioxide from entering the concrete. Similarly, seal up any holes drilled into the ceiling that are no longer in use (e.g. holes left after a ceiling fixture is removed).
Ensure sufficient ventilation A humid environment will speed up carbonation. To reduce the humidity in moisture-prone areas such as the kitchen, toilet, and bathroom, open the windows, vents, or doors when the areas are not in use.
Repairing spalling concrete With regular maintenance, spalling concrete within HDB flats will usually be minor and can be easy repaired. However, if the spalling concrete is left unattended over a long period, it will spread to a bigger area and weaken the building structure.
The steps below briefly show how spalling concrete is repaired. For more details, please watch this video.
- Step 1: Remove the concrete at the spalled areas to expose the corroded steel bars
- Step 2: Clean and paint the corroded steel bars. Scrape and clean the exposed steel bars and use a wire brush to remove any rust. Apply 2 coats of anti-rust paint to the steel bars
- Step 3: Patch the hacked area. Apply a bonding agent to the affected surface to ensure proper adhesion. Patch the hacked area using polymer modified cement mortar
- Step 4: Paint all the areas properly. Paint over the patched area to match the rest of your ceiling.
While waiting for the repairs, do remove any loose spalling concrete to prevent injury to your family members.
You should wear a pair of protective gloves, and prepare a hammer and chisel to remove the loose concrete. You can replace the chisel with a long flat point screw driver. Cover the floor and protect the surroundings with thick cardboard Secure the ladder and climb up to remove the loosen concrete. Hold the affected portion of concrete and bring it down carefully