Redistribution of solute concentration
The capillary pore water contains solutes, in particular alkalis and salts. The ice crystals that grow as the temperature drops […]
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.
The capillary pore water contains solutes, in particular alkalis and salts. The ice crystals that grow as the temperature drops […]
These materials are quite different from polymer-modified mortars in that they do not contain any hydraulic cement. They consist of
Since there is a very wide range of systems available, it is very important that the right one is chosen
Reactive polymer matrix composite materials generally have a high resistance to water transmission, although the extent depends very much on
Reactive polymer matrix composites Water absorption Read Post »
Premature failure of prestressing steel in prestressed concrete structures is usually induced by corrosion. The most obvious type of failure
These materials are visco-elastic in nature and thus, over time, may undergo creep and stress relaxation even at ambient temperatures.
In general the coefficients of thermal expansion for unfilled (lower modulus) and filled (higher modulus) products are ~40-100 and 20-40
The yield strength (0.2% proof stress) of prestressing steels should be high to make their use effective and economical. Depending
Production, dimensions and types of delivery of prestressing steel Read Post »
Production methods for frc fall into three main categories: pre-mix, spray-up and automated processes. Pre-mix simply uses normal concrete mixing