Page 8 - Masonry and Concrete

Source: Masonry and Concrete

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CHAPTER

Understanding Concrete

esidential construction today nearly always includes concrete in
Rsome form and to some extent. Concrete is used in footings, foun-
dation walls, floor slabs, retaining walls, sidewalks, driveways, and
patios. Concrete is a strong, durable, and economical material whose
appearance can be altered in many ways to make it decorative as well
as functional. Concrete is a controlled mixture of cement, aggregates,
and water. Because it is a fluid mix, concrete can be formed into
almost any shape and finished with a variety of textures.
Concrete strength and durability are easier to achieve with an
understanding of how concrete is mixed and cured, how strength
develops, and how variations in materials and mix design can accom-
modate different seasonal weather conditions and project require-
ments. An understanding of concrete properties and ingredients will
produce better projects with greater efficiency and economy, higher
profits, and fewer callbacks. This chapter discusses the essential prop-
erties of fresh and hardened concrete, the characteristics of different
cements and aggregates, the role of admixtures, the processes of hydra-
tion and curing, basic concrete mix designs, and the critical impor-
tance of water-cement ratio. Some discussion is also given to the cause
of common problems and how to avoid them.

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