Concrete Testing – Carbonation
Carbonation depth is generally assessed on site using a solution of phenolphthalein indicator that appears pink in contact with alkaline concrete with pH values in excess of 9 and colourless at lower levels of pH. The test is covered by BS EN 14630: Products and systems for the protection and repair of concrete structures and Test Methods:
Determination of carbonation depth in hardened concrete by the phenolphthalein method.
Phenolphthalein indicator can also be used in the laboratory to determine carbonation of concrete in removed core samples; however Petrographic examination will provide a more accurate measure of cement binder carbonation.
Cement paste has a pH of about 13 which provides a protective layer (passive coating) to the steel and protects reinforcement against corrosion. Loss of passivity occurs at about pH 11. Carbonation of the concrete, caused by carbon dioxide in the atmosphere, has the effect of reducing the pH.
Concrete Testing – Core Samples
Concrete coring utilises a diamond cutting drill to cut a perfect round hole in any concrete structure – in a floor, wall, or ceiling. The process is low-noise, dust-free and non-percussive, meaning it is the most popular choice for cutting.
Concrete coring uses a drilling tool made with a diamond cutting end attached to a steel tube to pierce concrete. Holes can be drilled at any angle – whether vertical or horizontal. We can use electric or hydraulic rigs for drilling in High Rise Buildings or Confined Spaces.
As the rig drills, the cutter is water cooled to reduce friction. When the cutting process is complete, the concrete core is removed for laboratory analysis for compressive or petrographic testing. The results from this can ascertain whether further works are required at the site.
Our Specialist Teams can be deployed to carry out sampling to High Rise Buildings & Structures or inside Confined Spaces such as Culverts or Undercrofts
Cladding Inspection and Testing
In today’s day & age it is imperative that the construction details of All Cladding to High Rise Buildings are known to the management of properties they represent.
Our Rope Access Team regularly undertakes sampling & inspection to determine type of firewall, size of cavity and actual sampling of the cladding to be tested to BS EN 13501-1