Concrete Repair

Concrete repair from the concrete repairs specialists

Before looking at the concrete repair solutions available from Structuralwise let us first look at some of the reasons that concrete deteriorates.

Carbonation

Concrete is a porous material which will allow carbon dioxide in the air to penetrate into the concrete via the pores. Calcium Hydroxide and soluable alkalis give concrete a pH of around 12.5/ Carbonation will occur when carbon dioxide reacts with the calcium hydroxide which in turn lowers the pH of the concrete leaving it more vulnerable to deterioration. The carbonation process starts off at the surface and slowly penetrates into the concrete through the air filled pores. However, If the concrete is fully submerged below water, carbonation will not occur.

Once the carbonation process begins the protective environment which once existed for the steel bar is reduced leaving it susceptible to corrosion if any moisture is present.

Chlorides

Chlorides are introduced into concrete via natural aggregates, water, and salt.  Where chlorides are present accelerated corrosion of the steel reinforcing bars can occur.

Freeze & Thaw

Water expands when it freezes and enters pores and defects. Freezing causes outward pressure on the surrounding material.

Sulphate Attack

Chemical reaction caused by the properties in the aggregates and cement, subsequently break down concrete.

Surveying and testing concrete

The method for testing concrete prior to a concrete repair is simple:

• A visual inspection
• Tapping the surface with a metal hammer. Good concrete gives a relatively
  high-pitched sound and sub-surface deterioration a lower-pitched, “hollow”
  sound.
• Corrosion can produce low-level voltage similar to a battery. Half-cell
  testing to the reinforcing steel, the electrical potential (voltage) is then
  measured indicating corrosion.
• Core sample testing, compressive strength, depth of carbonation and
  chloride content.

The Structuralwise concrete repair system

The base coat is a one component, polymer modified mortar, which is light weight and offers excellent bonding properties. No bonding coat or corrosion protection is required with this product. The finish is a one component light-weight fine finishing mortar.

The benefits of the Structuralwise concrete repair system:

• Easy and reliable application.
• Two products – no risk of mix-up / confusion.
• No bonding or protection coat.
• Protects concrete against carbonation.
• A “complete” concrete protection system.
• Tested approved.
• Time saving.
• Short scaffolding times

For more information on concrete repairs or to arrange a concrete repair survey from Structuralwise call 0800 0199 213 or email structuralwise@timberwise.co.uk