The purpose of this book is to bring together a series of reviews on topics of current relevance to the durability of concrete and cement-based composites. One might reasonably ask why such a book is now believed to be needed as concrete and related materials have been used with outstanding success in major construction projects for well over two thousand years. Indeed numerous ancient concrete structures, such as the Pantheon in Rome, and masonry structures with mortar joints, such as the Pont du Gard Aqueduct near NõÃmes in southern France (see Fig. 1.1), have survived to the present day in excellent states of preserva- tion. These and other examples of Roman construction works incorporating hydraulic cements made from lime and volcanic earth (or similar vitrified alumino-silicates, known collectively as pozzolanas, after Pozzuoli near Naples where a natural source of such material exists) have shown remarkable dur- ability even where they have been exposed to damp, aggressive environments. An impressive illustration was provided by Davey (1974) whose photograph of part of a Roman breakwater that had been exposed to the sea near Naples for two millennia (reproduced in Fig. 1.2), demonstrates that the mortar joints had endured far more successfully than the now heavily eroded stone blocks which they had been connecting.
Consideration of the factors influencing freeze-thaw behaviour involves considerable attention to the pore structure of the hardened cementitious matrix. However, […]
Freeze-thaw in concrete Aggregate characteristics Read Post »
Two different methods exist for assembling and prestressing steel tendons:10 (i) pre-tensioning, where the prestressed tendons are surrounded directly by
Air-entrainment is an accepted method of ensuring durability of concrete in a cold environment, with regard to both internal distress
Factors affecting frost resistance of aggregates Read Post »
DEF is a fairly weakly expansive mechanism, and so is likely to be less severe in dense flaw-free pastes and
Serious examples of corrosion-related damage in prestressed concrete structures seldom occur. The following are examples of serious failures which are
It may be possible to avoid external restraint by the provision of movement joints, but in most structures it is
The expansive ettringite form of sulfate attack in concrete exposed to aggressive ground is probably the most familiar type that
External sulfate attack involving expansive ettringite formation Read Post »
Groundwaters and soils containing sulfate salts may be liable to cause expansive sulfate attack. Sulfuric acid can also occur naturally
Choosing fibre and matrix combinations that reduce or eliminate deleterious interactions or interact in a benign manner can enhance the durability
Enhancements in durability through fibre and matrix modification Read Post »