Repairing and Restoring Concrete

Concrete Problems: Understanding the Cause

It takes time and effort to preserve and extend the life of concrete structures. Many factors can impact the expected service life of concrete structures, including freeze-thaw resistance, alkali-silica reactivity, carbonation, poor original construction, or unsuitable design. Successful concrete repairs begin with a condition evaluation to determine the underlying cause of the problem, with special attention paid to repair design and implementation.

If concrete damage is caused by reinforcing steel corrosion, the concrete repair method should include Type 1 discrete anodes or concrete cathodic protection. If the concrete damage was caused by a chemical attack, the concrete repair method should include removing all contaminated concrete and replacing it with acid resistant concrete or Portland cement concrete with chemical resistant coatings and linings.

Process of Concrete Preservation

It takes some work to preserve and prolong the service life of concrete structures. Many aspects must be addressed in order to achieve long-term service life extension.

Removal of Bulk Concrete

Concrete removal and surface preparation procedures are also essential elements in the repair process and can have a strong impact on the lifespan of concrete repairs. Lightweight electric or pneumatic chipping hammers weighing 15 pounds are used to remove aged concrete without damaging the sound concrete that will be left in situ.

Another efficient method for removing bulk concrete is hydro demolition, which utilizes high-pressure water blasting. If larger jackhammers or other methods such as concrete scarifiers or rotomilling are applied, caution should be taken to remove any microcracked concrete substrate as well as concrete surrounding the reinforcing bars.

Unless a cathodic protection system or electrochemical treatment is utilised, concrete removal should continue until the exposed steel no longer exhibits any significant corrosion, even if some sound concrete should be removed.

Simple Concrete Repairs

The shape of concrete patches is also a significant factor. In order to reduce the formation of dying shrinkage cracks in the repair material, which might damage bond or long-term durability, the repairs should be basic in geometry – rectangular, square, or any mix of both shapes. 1/2 inch to 1 saw cuts are utilised along the repair boundary to define the patch edges and prevent the possibility of thin repairs at the ends, also known as featheredges.

Materials for Concrete Repair

For structural repairs where the repair material will be placed in-service, the chosen concrete repair material should have qualities equivalent to the parent concrete, such as compressive strength and modulus of elasticity.

Constructability Is Another Important Factor in The Selection of Concrete Repair Material

Constructability is a comprehensive concept that includes handling aspects, rheology, and cure durations. Pumpability, slump, flow, and hang / stickiness of concrete repair materials vary, and they can be designed for a specific installation procedure such as form-and-pour repairs, form-and-pump repairs, pre-placed aggregate repairs, tremie concrete repairs, dry pack repairs, trowel-applied vertical and overhead concrete repairs, low velocity wet sprayed repairs, and dry sprayed shotcrete repairs.

When there is a requirement for an early return to service, such as bridge deck or parking deck repairs, or to allow coatings and membranes to be changed sooner, a concrete repair material with a short set time might be useful.

Ready-mix concrete from a close concrete factory is a popular material for concrete repair and major parking deck repairs. Ready-mix concrete can have a variety of material features, such as self-consolidating concrete, which provides a well-consolidated mix with an outstanding formed surface finish. Repair materials can also be site batched concrete from a mobile mixer, and many companies provide a wide selection of formulated pre-blended bagged repair mortars and concrete.

After installation, the repair material should be kept from severe temperatures. While in the plastic condition, repair materials should be shielded from wind, dryness, and freezing temperatures. Curing concrete repair material properly is essential in preventing moisture loss, drying shrinkage, cracking, and curling. Wet curing and curing chemicals, like new construction, will increase the durability of the repair material.

Implementing a quality control procedure guarantees that concrete repairs are done appropriately.

Some basic procedures include documenting the repairs with before and after photos, confirming that the surface preparation is acceptable by observing the cleanliness and surface amplitude or direct tension testing, material testing by a qualified testing agency, sounding the finished repair to detect voids or lack of bonding, and direct tensile bond testing of the cured repair material.

Summary

Because concrete repair differs from new construction, it is essential to engage with expert concrete repair contractors to guarantee the structural integrity of your facility is preserved. A certified concrete repair contractor will have proven experience in the project environment as well as a good safety record.

Repairs of industrial plants, cooling towers, parking structures, concrete silos, railroad and DOT bridges, concrete dams, wind turbine foundation repairs, building façade repairs, and the repair and preservation of historic buildings can all have specific access and safety needs.

Most of the work required to preserve and prolong the service life of structures is self-performed by specialty concrete repair companies. Concrete repair contractors can be general contractors as well as specialty subcontractors such as post-tensioned concrete repair contractors, structural strengthening specialists employing carbon and glass fibre composites, waterproofing contractors, and cathodic protection contractors.

AJ is a passionate writer who aimed to provide valuable information through writing. AJ is interested in search engine optimization, he show his true skills while cooperate with local SEO company in Malaysia