Page 4 - Masonry and Concrete

Introduction to Concrete and Masonry
INTRODUCTION TO CONCRETE AND MASONRY 3

ago destroyed hundreds of homes. It showed a neighborhood comp-
letely devastated by the fires—except for one house. An engineer who
had spent his childhood in Vietnam during the war and learned firsthand
the danger of spreading fire had designed his home of structural concrete
and masonry. While nothing remained of his neighbors homes except the
concrete slabs and masonry fireplaces, his home was intact and undam-
aged. Although most homes in the United States are built of wood frame
rather than structural concrete, the use of noncombustible masonry
veneers as a protective outer layer is recognized as an impediment to
spreading fire and reduces the risk of property loss and the associated
insurance premiums.

Durability: Concrete and masonry are durable against wear and
abrasion and weather well for many years with little or no mainte-
nance. Wood is highly susceptible to moisture damage and requires
protective coatings to prolong service life. Properly designed and con-
structed concrete and masonry will provide many years of service to
the homeowner without any additional investment of time or money.

Energy Efficiency: For centuries the thermal performance characteris-
tics of masonry have been effectively used in buildings. Large masonry
fireplaces used during the day for heating and cooking were centrally
located within a structure. At night, the heat stored in the masonry radi-
ated warmth until dawn. In the desert Southwest of the United States,
thick adobe masonry walls provided thermal stability. Buildings
remained cool during the hot summer days, and heat stored in the walls
was later radiated outward to the cooler night air. Until recently, how-
ever, there was no simple way of calculating this behavior.
We now know that heat transfer through solid materials is not
instantaneous. There is a time delay in which the material itself
absorbs heat. Before heat transfer from one space to another can be
achieved, the wall which separates the two spaces must absorb heat
and undergo a temperature increase. As temperatures rise on one side
of the wall, heat begins to migrate toward the cooler side. The speed
with which the wall will heat up or cool down is dependent on its
thickness, density, and conductivity, and the amount of thermal
energy necessary to produce an increase in temperature is directly pro-
portional to the weight of the wall. Although most building materials

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