Defects in concrete structures can result in potentially catastrophic failure of the structure under certain conditions. It is important for engineers and construction teams to be on the lookout for these defects, such as cracking, crazing, blistering, scaling, efflorescence, curling and dusting, to ensure that the structure being built out of the concrete is capable of lasting for years into the future.
Here are just a few examples of some of the causes of defects in concrete structures in Idaho:
- Structural deficiency caused by design errors, errors in loading criteria or unexpected overloading
- Structural deficiency caused by defects that occurred in the construction process, not the actual design of the structure or application
- Damage caused by natural conditions such as fires, earthquakes, floods, hurricanes and storms
- Damages caused by flooding and marine environments
- Damage caused by abrasion of granular materials
- Damage caused by chemicals
- Damage caused by movement of the concrete as a result of physical characteristics of the structure
Preventing some of the most common types of concrete defects
So what can be done to prevent some of the most common types of concrete defects from forming? Here are some tips for some of the specific types of defects:
- Cracking: If deep cracks form in the concrete, that concrete structure will be unsafe to use. The most common reasons for cracking tend to be improper curing or mix design, failure to implement contraction and expansion joints, use of high-slump concrete mix and an unsuitable sub-grade. The best method of preventing cracking is to use a low water-cement ratio and to maximize the amount of coarse aggregate in the mix while avoiding admixtures that contain calcium chloride. In addition, you should do everything you can to protect the surface against rapid evaporation of the moisture content. Only apply loads to the surface after the concrete has cured to its maximum strength.
- Blistering: Blistering is characterized by the appearance of hollow bumps of varying sizes on the surface of the concrete as a result of air that got trapped under the surface before it was finished. Prevent blistering from occurring by using the proper proportion of ingredients in the concrete mixture and by covering up the top surface to reduce evaporation in the final stages of curing.
- Dusting: Also commonly referred to as “chalking,” this is the formation of a loose powdered concrete substance on top of the hardened concrete, caused by disintegration of the material. This happens because of an excess amount of water in the concrete, so it is critical to maintain a proper water-cement ratio to avoid the problem.
- Curling: Sometimes the concrete might distort itself into a curved shape as a result of upward or downward movement along the edges or corners of the slab. This usually happens when there are differences in moisture content or temperature between the top and bottom of the slab. Implement control joints and use low-shrink concrete mix while offering heavy reinforcement along the edges to avoid this problem.
For more information about defects in concrete structures in Idaho and how to avoid them, contact the team at Mason & Associates today.