Quality control in concrete repair works essential to regain lost strength in concrete due to cracks or other damages. Concrete repairs are required when structural members get damaged or cracks. The reason for cracks or damages can be many. It can be due to over-stressing, poor construction practices, environmental exposures, chemical attacks or with age of concrete member etc.
The concrete repair involves replacing, restoring or renewing of old or damaged concrete from existing structural member. The need for repair can vary from time to time depending on structural requirement or type of damages in the structural member.
The concrete repair procedure involves following steps:
- Determining the cause of damage
- Evaluation of damage to identify need and method of concrete repair
- Preparation of damaged structural member
- Application of repair method selected
- Curing of repaired concrete member.
As listed above, the damages in concrete structures need to be carefully evaluated and repaired, each step involved need to be carefully performed. Inadequate workmanship, procedures or materials in concrete repairs may result in poor repair and may fail during occupancy involving significant cost.
Workmanship in Concrete Repairs:
Quality and durability of concrete repairs depends on the workmanship during repair process. The aim of repair is to provide strength and durability of structural member comparable to its original or designed strength.
For this, the workmen involved in repair process should have sufficient knowledge, skills and training to perform the concrete repair work. Work carried out should be done in a way that the repaired concrete is well bonded with existing concrete and durability requirement is met.
All the process should be carefully supervised by experienced personnel. Well trained, competent workmen are particularly essential when epoxy, polyurethane, or other resinous materials are used in repair of concrete.
Concrete Repair Procedures:
Selection of right procedures for concrete repair is essential to ensure repair quality control and techniques are carefully performed. Wrong or poor repair procedure and workmanship may lead to ineffective concrete repairs.
Repairs can be on old concrete surface or new concrete just after stripping of formwork. For new concrete surface, the repairs are easy and bond between repair concrete existing concrete surfaces will be same as the original construction work.
Materials for Concrete Repairs:
The selection of repair materials for concrete should be of high quality and as per the specifications requirements as per the need and type of repair method selected. Testing of repair materials should be done to ensure its quality and suitability for the given repair method.
Any materials procured from vendors should have its manufacturers test certificate and should be used only as per manufacturer’s specifications and approved methods. Suitability of materials for type of damage should be ensured as this may lead to high cost and failure of repair, if the materials used are unsuitable.
Care should be taken during mixing, proportioning, handling and placement of repair materials to ensure good concrete repair quality control.