GRC systems of improved durability

This section deals with various systems of improved durability, and discusses their performance in view of these mechanisms. A review of this topic covering developments until 1985 was presented by Bijen [94], 

Artificial carbonation to reduce the alkalinity of the matrix and thus improve the durability of E glass composite was studied by Bentur [96], Although a marked improvement could be obtained, the performance achieved was still no better than that of AR-GRC composites with a conventional Portland cement matrix. Also, to achieve complete carbonation, an elaborate vacuum drying process was involved, which is difficult to apply in practice. An alternative method of supercritical carbonation of GRC was studied by Purnell eta/. [97,98], using AR fibres. This study evaluated only the properties of unaged composites. 

The use of a polymer modified cement matrix reinforced with E glass fibres was developed by Bjjen and Jacobs [99-104], using a special acrylic polymer (Forton) which was developed for that purpose. In the production of this composite, the tiny polymer latex particles ( 0.1 p.m in diameter) infiltrate and fill the spaces between the filaments in the strand and eventually coalesce into a film. Thus they can provide a protective effect, both to reduce the chemical attack, and to reduce the extent of the microstructural mechanism, by eliminating the growth of dense and rigid hydration products around the filaments. The coalescence of 

There has also been a growing interest in AR glass compositions produced by the sol-gel method. Here, the glass is made through hydrolysis and gelling rather than by conventional melting techniques. This is potentially advantageous 

The modification of the matrix can have a profound effect on the durability of AR-GRC composites, as demonstrated in the data compiled by Majumdar [17] in 

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