When it comes to building construction, concrete is one of the primary terms you will come across. It’s one of the most sought and used building material due to its famous durability features. When construction experts use concrete the correct way, it can serve you for years even without the need for repairs. However, sometimes due to negligence and other environmental factors, it can crack causing an unpleasant sight. How can you avoid this during your next construction project? Proper planning can help you minimize their occurrence
Reasons Behind Concrete Cracks
To prevent/avoid cracks, you have to learn why they occur in the first place.
Plastic Shrinkage. This occurs due to the fast loss of water from the sight of a freshly done concrete. In this case, the top-most part of the concrete gets to dry way faster than the inner part making them fall apart.
Poor Settlement. This is as a result of the instability of the ground underneath the concrete. It could be because of poor soil compact, tree roots, and even water erosion. So as it moves causing a crack.
Increased Drying Shrinkage. Water is the main component of any concrete mixture. When the concrete begins to dry, the excess water has to evaporate. However sometimes the process is so intense such that leading to rapid shrinkage, thus the appearance of cracks.
How Can I prevent Cracking Concrete?
Whichever prevention measures you incorporate should be related to the cause of the damage. The same way you cannot treat a disease with medications meant for another is the same way to address this issue.
- For plastic shrinkage, you have to ensure the surface meant to support the concrete is well moisturized. Due to unavoidable environmental factors such as wind, high temperatures, and evaporation, you can ensure this by covering it up. Use a plastic or polythene covering to shield it from direct environmental interference. You, however, have to leave enough time for the concrete to settle-in before proceeding with this precautionary measure. Avoid unnecessary disturbances as much as possible and remember to mist your concrete frequently for at least three consecutive days to minimize the effects of evaporation.
- When it comes to poor ground settlement, ensure you take your time to examine the surroundings of the place you intend to work on before embarking on the process. If you notice that the soil is a bit poorly compacted, ensure to gently dig it out and reinforce the surface with some crushed stones. This will enhance the stability before you pour the concrete. For an area with sidewalk water retention, use gravel to properly backfill it before work. You should also ensure the area stays clear of trees as the strong roots are likely to cause cracks in the concrete sidewalks. It might not seem so at the moment, but trust us, you won’t say the same in the next few years or probably months.
- Increased shrinkage can be equally prevented by ensuring proper placement of the control joints between the slabs. If you don’t know what that means; these are typically the weak joints that help to guide the formation of straight cracks in any concrete surface. They also ensure the cracks happen at the right places without disrupting the final look of your work. They include;
- Expansion Joints; they are normally made with a cork-like material and are placed at the exact separation point on the floor and the fresh concrete. This allows flexibility in movements hence preventing any form of damage.
- The construction joints; these ones come in handy whenever the concrete work takes more than a day to complete. In this case, you can place the slab at the end of your day’s work to enable a smooth transition into the next day’s work. Be careful, however, not to overdo it as the prolonged interruptions can lead to the formation of a cold joint. Therefore, your construction joint should always be in place no matter your final joint formation plans, to avoid cracking concrete at all costs.
- The Contraction Joints; as their name suggests, these ones offer concrete cracking solutions by enhancing the formation of straight lines in the various concrete points of weakness. This ensures all possible cracks occur in a straight predetermined manner. The recommended slab thickness for this stands at 1/4 with the spacing of not more than 36 times that of the slab thickness. You can easily create these joints with the help of a groover that’s deep enough to meet such needs.
- The Saw Joints; they are quite similar to control joints only that they’re sawed-in. Their appearance is that of clear straight lines that adhere to the 1/4-inch slab thickness rule. For best results, ensure you conduct this procedure as soon as you feel the concrete is strong enough to reduce the impact of the saw blade. If done wrong, this procedure can lead to more damage than good such as resistance in tearing or forceful saw blade implications.
- Additionally, ensure you use adequate and proper material mixing in your construction tasks. There are some mix materials that are known for their durability features and this includes but not limited to cement and admixtures. You should however if possible, stay clear from the use of clay and some other forms of dirt as they are not only harmful to your health but also have a bad service record.
- Once your concrete is in place and you have applied all the necessary concrete-cracking prevention measures, you shouldn’t forget one final step; the curing process. Yes, you might feel that you have already done enough but it won’t cost you much to take one more extra caution to enhance the durability of your concrete. Here begin by applying a moist curing compound of your choice. Remember, the more concrete you have to cure, the longer the process should take and the more curative measures you will require.
From the above points, it’s important to understand that you cannot entirely prevent cracks in concrete no matter how much you try. But, there are various measures you can take to prevent their impact and redirect their occurrence. If you use properly designed joints, the appearance of cracks will be minimal and the outcome will be a beautiful sight. After all, most beautiful designs are as a result of corrected imperfections.