Presence of High Alumina Cement (HAC)
However it has since been found that a further mineralogical conversion in the hardened concrete can occur over time which causes a severe reduction in strength of the concrete element, leading to structural weakness or a vulnerability to chemical attack.
Details of how to determine the possible presence of High Alumina Cement are contained within document reference BRE IS 15/74. Samples of the suspect concrete are taken by ‘knocking off’ a small amount of concrete. Drilled samples are not considered acceptable as the heat produced may affect the result. The concrete is then subject to a relatively quick chemical test to determine the likely presence of HAC. If this proves positive then further confirmatory testing can be undertaken by XRF methods.
Nicholls Colton is *UKAS accredited for the rapid chemical test as detailed within BRE IS 15/74.