Volume stability and cracking
Many of the long-term performance problems of fibre-reinforced cement com- posites are not the result of changes in the composites’ […]
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.
Many of the long-term performance problems of fibre-reinforced cement com- posites are not the result of changes in the composites’ […]
Modern concretes are extremely varied in their characteristics relevant to the concerns of this chapter. To begin with, concretes designed
Variations among concretes and -archetypical concrete- Read Post »
Supplementary cementing materials (SCMs) are materials that contribute to the properties of concrete through either pozzolanic reaction (e.g., low-calcium fly
Although the use of aggregates that are not susceptible to ASR would be the most obvious option for avoiding the
Use of non-reactive aggregate (or exploitation of the ‘pessimum’ effect) Read Post »
The ability of lithium-based compounds to suppress deleterious expansion due to alkali-silica reaction (ASR) in mortar and concrete was first
Figure 3.18 lists the main types of crack that can occur in concrete both before hardening and after hardening. Included
Requirements and properties Prestressing steels10 are used in prestressed concrete elements which are under tensile stresses due to their dead
Types and metallurgical characteristics of prestressing steel Read Post »
Figure 9.4 shows the decrease in bending strength (expressed as a fraction of the 28-day strength, i.e. the initial strength
The causes of the time-dependence of properties fall into two broad categories, regardless of the type of fibre involved. First