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Working With Damaged Concrete – Repair or Replace?

By January 28, 2015No Comments

Concrete structures can be damaged or degraded by several factors, including but not limited to constant exposure to natural elements, heavy loads, salt and other corrosive substances, moisture content and poor installation. The type and extent of the damage determine the treatment plan, which most often revolves around repair or replacement. Replacing damaged concrete could prove a laborious and costly process, but fortunately is not mandatory unless the surface is beyond repair. There are several points to be considered before deciding the course of action.

Points to Consider

What is the type and extent of damage?
Is structural integrity compromised?
If subbase is intact, will repair cost more?
How long will the space be off limits?
Will a concrete resurfacer suffice to restore form and function?
Should a DIY be attempted?

Let’s not forget the fact that it takes an expert eye to gauge the damage accurately and remedy it in an apt manner. That said, it is equally easy to rectify surface cracks and pits with readily available adhesives and fillers. However, it is not advisable to attempt a DIY repair without consulting a professional, for the process may not be worth the effort.

Damage Beyond Repair

While all cracks may look quite the same, those that are widespread and run all the way down to the subbase or subgrade are beyond cosmetic repair. Such networked, deep cracks on horizontal concrete surfaces are attributable to erosion or poor preparation of the underlying terrain.

Concrete also develops cracks over time when subjected to heavy loads and heavy vehicles, and the damaged sections will need to be replaced.

Concrete is also susceptible to temperature changes as it expands when exposed to heat. Installations that do not allow for spaced expansion joints tend to develop cracks, which are vantage points for water seepage. Freezing and thawing of this water within concrete structures further weakens its integrity. Replacing affected areas is a must in these cases.

Poor installation, poor quality of the subgrade, excess weight or even subsidence may cause concrete surfaces to sink. While existing concrete slabs can be removed and reused – the underlying terrain must be prepared and compacted well before the concrete is re-laid.

Spalling or external lumps are often caused by corrosion or installation problems and need also need to be replaced.

Damages that Can Be Repaired

The degree or extent of the damage determines the solution. Hairline cracks, delamination, pitting and mild spalling on horizontal and vertical concrete surfaces can be repaired using appropriate acrylic, polyurethane or epoxy-based fillers. You could also try self-levelling resurfacing mixtures on floors with cosmetic damage to achieve a new look at relatively low costs.

One prerequisite though is to thoroughly clean the affected area before attempting a repair. It is also important to use the right material for the patch, as silicone and latex-based sealers and fillers are known to shrink over time. Again, going with professional advice will help avoid errors that could make the repair more costly in the future.

In short, damage caused by poor installation or repairs that need over a couple of inches of filling are best addressed by replacing the concrete, with the help of professional contractors.

For aesthetic issues, repairing the damage with suitable adhesives, binders, fillers and surface coats will prove both cost-effective and efficient without any compromises on structural integrity.

For any more information or advice, simply contact the expert team at EKA concrete.