Physical Properties of Concrete and Concrete Constituents




Introduction

Concrete is manufactured at the plant or on site from various

components: cement, water and different granular materials such as sand,

gravel and various mineral additions. It may also contain admixtures

intended to modify its properties from its fresh state (for example retarding

or accelerating admixtures, superplasticizer) or its properties in its hardened

state (for example air entraining agents). Properties introduced in this

material are varied. They concern both its fresh state through its ability to be

transported and poured in forms that are more or less fluid, as well as in its

hardened state. Properties include its performances, for example mechanical

resistance, resistance to aggressive environments, and acoustic or heat

insulation. The formulation of concrete consists of finding components and

their proportions to meet specific requirements, which may be very different.

All of this should be done keeping in mind that concrete is a widely used

material, its cost should be limited, and it is prepared and implemented on

site in variable environmental conditions.


Understanding the rheological properties of fresh concrete, the hydration

phenomenon of cement responsible for structuration, the relationship

between the characteristics of the porous solid obtained and its mechanical

performances or resistance to the aggressive penetration requires a complex

knowledge of the physicochemistry of reactive porous materials. The

development of simple formulation rules therefore requires the assimilation

of this knowledge and a good command of the properties of these materials.


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