Surface coating, cement mortar: Anti-carbonation effect (NT BUILD 372)

Abstract

SCOPE

This Nordtest Method specifies a procedure for the determination of the anti-carbonation effect of a surface coating system on concrete (cement mortar). The anti-carbonation effect is determined by accelerated comparative testing of coated and uncoated specimens.

FIELD OF APPLICATION

The method is suitable for comparing the performance levels of surface coating systems on concrete (cement mortar). Coating systems may include complete surface coating systems or parts of coating systems including brittle materials and non-film forming materials. The uncoated reference is usually untreated concrete (cement mortar); if relevant another reference, e.g. smoothed/levelled concrete (cement mortar), can be included. Concretes (cement mortars), water-cement ratio 0.6 and 1.0, are generally used as substrates; cement mortar 1.0 represents a porous and relatively fast carbonating material and cement mortar 0.6 represents a relatively slower carbonating concrete which is of greater practical relevance. Determination of the carbon dioxide diffusion resistance of paint coatings on a paper substrate can be carried out according to NT Build 300. Other properties relevant to surface coatings for the protection of concrete are: water vapour diffusion (e.g. ASTM E 96-80, procedure b) and water absorption/ desorption (e.g. NT Build 342).