Concrete is easily one of the strongest and most reliable construction materials. From temperature changes and structural errors to tree roots and reinforcing mesh Brisbane, many things lead to cracks in concrete. Unlike the common perception, not all concrete cracks are the same. In fact, identifying the correct type can actually help you in properly correcting the cracks.
Let’s take a look at the six most common types of concrete cracks you might encounter:
1. Plastic Shrinkage Crack
Before the concrete hardens, it is considered plastic and contains a significant amount of water. Sometimes puddles of water, upon drying, leave behind voids within the slab. Such voids make the structure of the slab prone to cracks when subject to pressure. Unless prominently visible, plastic shrinkage cracks pose no threat to the structure of the slabs.
2. Expansion Crack
When subject to heat, concrete slabs tend to expand outwards. Lack of space to expand causes slabs to develop cracks. However, expansion cracks are mostly dealt with during the planning and concrete delivery Brisbane stage of the structure. Expansion joints are inserted between slabs that can absorb pressure from expansion and thus pre-empt and avoid cracks.
3. Heaving Crack
Another crack that occurs due to temperature are heaving cracks. Heaving cracks develop due to being exposed to extreme cold weather, which causes the slab to condense. When the temperature returns to normal, the slab also expands back to its normal shape. However, this change in shape often leads to the development of heaving cracks.
4. Settling Cracks
The structural weakness of the underlying ground can lead to settling cracks. For instance, when a large tree is removed, its roots decay and leave large voids behind which soften the ground. A weak ground gives poor support to the concrete slab above and the steel bar Brisbane surrounding it, causing settling cracks.
5. Cracks due to overloading
Premix concrete Brisbane comes with their own strength (measured in PSI or pounds per square inch), which indicates the maximum pressure they can take before being crushed. However, overloading of slabs occurs quite often in residential areas – this is not what actually causes the cracks. In cases where the underlying ground has become soft (like after heavy rain), it might enable a section of the slab to be pushed downwards. Heavy vehicle parking spots are most likely to see such cracks.
6. Premature Drying
When a concrete slab (or its top layer, to be specific) loses moisture quickly, it can lead to cracks. Crazing cracks appear when the top layer of the slab quickly loses moisture naturally, resembling a spider-web. Crusting cracks appear during the stamping process when the top layer is dried for embedding patterns. Both these types might look unappealing, but they are largely harmless for the structural strength of the slab.
As you saw, different causes lead to different types of concrete cracks. Understanding the specific types allows us to identify the root cause behind these cracks and take appropriate steps.