Title: Carbonation Degree as Durability Criteria for Autoclaved Aerated Concrete
Author(s): F. Matsushita and S. Shibata
Publication: Symposium Paper
Appears on pages(s): 1123-1134
Keywords: atuoclaved products; carbonation; cracking; durability; surface finish; waterproofing
Durability and service life of Autoclaved Aerated Concrete (AAC) panels become subjects of renewed study and close examination because they have been produced for several decades in many countries. This paper deals with the durability and its criteria for AAC panels. Cracking, panel bending properties, compressive strength, drying shrinkage and carbonation degree were investigated for field AAC panels aged 4 to 33 years. When the carbonation degree was more than 50%, the AAC panels showed cracking and degradation in span-deflection ratio, compressive strength and drying shrinkage. Therefore, we propose the durability criteria for AAC as follows; 'When the degree of carbonation of an AAC panel exceeds 50% as defined in this paper, it may be considered as deteriorated'. With this criteria, acrylic resin-finished AAC panels were 1.5 times more durable than non-finished ones. And also, water-repellent AAC panels had twice the durability as normal ones.