Concrete Repair London
Our London Office have close ties with the YMCA charity who own and maintain various buildings across the UK. Newman’s were asked to competitively tender for the concrete repair works to their building in Watford high street.
Concrete had been witnessed falling off of the building posing a very high risk to the general public as the spalling extended across the 15 storey high tower block.
Carbonation of the concrete had occurred due to the tower blocks location and low concrete cover. Our in house concrete repair team, all trained abseilers, carried out a survey to the tower block to determine the amount of repairs necessary and the depth of carbonation. Cover metre tests were also carried out and it was noted that cover of concrete to the reinforcing rods was as little as 10mm is some areas.
In order to repair the spalled concrete our team of repairers cut out the concrete to locate low cover steel reinforcing that had suffered from carbonation attack. Initially carbonation of concrete hardens the concrete and increases its compressive strength but as the carbon penetrates further into the concrete a chemical reaction occurs which damages the passivating layer which protects the reinforcing from moisture, as this breaks down it allows moisture absorbed naturally by the porous concrete to corrode the steel causing expansion and spalling of the concrete.
Carbonation is unstoppable especially in porous concrete and to steel reinforcing that has low concrete cover. The effect of carbonation can be devastating leading to total structural collapse if ignored for a long period of time.
It is essential that concrete is sealed to resist the threat of carbon attack. In order to repair the spalled areas the concrete was hacked out to expose the corroded steel and the steel cleaned to SA 2 ½ it was then treated with Flexcrete steel reinforcing protector, the area of repair was then repaired with Flexcrete monolite concrete repair mortar.
Newman’s are a specialist concrete repair contractor and have the capabilities to carry out concrete repairs to almost any structure suffering from concrete defects.
Newman’s can help to diagnose structural defects, cracking and movement by arranging a free Structural Survey, contact London and the south East’s leading structural repair specialists for Help, Advice and peace of mind Call 0333 210 1410 or Email firstname.lastname@example.org