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.
Three exposure classes (XA1, XA2 and XA3) are described in BS EN 206-1 (2000) according to the aggressiveness of attack on […]
Sources of guidance for attack on concrete by acid and other aggressive chemicals Read Post »
Silica, SiO2, is a component of many rocks; however, not all forms of silica react significantly with the pore solution
Pores, especially the larger pores visible in backscatter SEM, are not distributed entirely uniformly within cement paste in concrete. One
Spatial distribution of pores in concretes: the ITZ Read Post »
The present writer has recently attempted to call attention to a feature observed in the microstructure of many concretes that
Spatial distribution of pores in concretes: local porous patches Read Post »
Further information on the subject matter of this chapter may be found in various books that deal specifically with corrosion
Shrinkage of concrete is caused by loss of water by evaporation or by hydration of cement, and also by carbonation.
Metallic corrosion processes in general, and the rusting of steel in particular, are by nature electrochemical. They therefore require an
The remedial treatment of corrosion problems in reinforced concrete has become a field of major activity in recent years and
Remedial treatment of corrosion in reinforced concrete Read Post »
A variety of different fibres are used to reinforce concrete and the nature of their distribution throughout the concrete ±