Durability and service life 9
In case repair actions are needed, it should be realized that a qualitative
and durable repair is based on a combination of the following important
elements:
• The repair materials should comply with some minimal performance
criteria, and preferably undergo some production and compliance
testing. Not only the individual materials have to be tested, but also
the entire repair system obtained by the consecutive application of
different materials in different layers, within so-called repair systems.
• The technicians applying the repair materials should be well-trained
and have sufficient knowledge of concrete in general and damage to
concrete more particularly.
• For important structures to be repaired, an independent control
should be performed, not only concerning the repair itself, but also
concerning the diagnosis to be performed before defining the adequate repair method.
1.4 Durable concrete
The best and most economical option to reach a target service life is to
carefully design the structure duly considering the effect of relevant aggressive actions. An important element within this approach of ‘good practice’
is to design a durable concrete composition. A durable concrete structure
starts with a durable concrete for the considered application. Some traditional parameters are generally considered to be important for the durability of concrete: the water/cement ratio, the cement content, and the cement
type. Concrete strength can give a good indication, but is certainly not a
satisfying condition with regard to durability. Often neglected is the influence of the maximum particle size on the required cement content within
a mix. The application of puzzolan and inert fillers, and the degree to
which these fillers can be considered as cement replacing materials, is an
important point of discussion in concrete practice. The issue of designing a
durable concrete mix is further treated in this section. It is also explained
that casting and curing operations are also important with respect to the
final durability properties of the completed structure. As a general point
of attention, it should be realized that the concrete cover is crucial to some
durability properties of concrete structures.
1.4.1 fundamental background of
concrete durability
A fundamental study of the durability of concrete has to start from the physical and chemical properties of the material and needs to consider the transport
In case repair actions are needed, it should be realized that a qualitative
and durable repair is based on a combination of the following important
elements:
• The repair materials should comply with some minimal performance
criteria, and preferably undergo some production and compliance
testing. Not only the individual materials have to be tested, but also
the entire repair system obtained by the consecutive application of
different materials in different layers, within so-called repair systems.
• The technicians applying the repair materials should be well-trained
and have sufficient knowledge of concrete in general and damage to
concrete more particularly.
• For important structures to be repaired, an independent control
should be performed, not only concerning the repair itself, but also
concerning the diagnosis to be performed before defining the adequate repair method.
1.4 Durable concrete
The best and most economical option to reach a target service life is to
carefully design the structure duly considering the effect of relevant aggressive actions. An important element within this approach of ‘good practice’
is to design a durable concrete composition. A durable concrete structure
starts with a durable concrete for the considered application. Some traditional parameters are generally considered to be important for the durability of concrete: the water/cement ratio, the cement content, and the cement
type. Concrete strength can give a good indication, but is certainly not a
satisfying condition with regard to durability. Often neglected is the influence of the maximum particle size on the required cement content within
a mix. The application of puzzolan and inert fillers, and the degree to
which these fillers can be considered as cement replacing materials, is an
important point of discussion in concrete practice. The issue of designing a
durable concrete mix is further treated in this section. It is also explained
that casting and curing operations are also important with respect to the
final durability properties of the completed structure. As a general point
of attention, it should be realized that the concrete cover is crucial to some
durability properties of concrete structures.
1.4.1 fundamental background of
concrete durability
A fundamental study of the durability of concrete has to start from the physical and chemical properties of the material and needs to consider the transport