CHAPTER ONE

Introduction
Generals

 There are many different materials

used in the building industry.
 Watch around and observe what you
see in the surrounding:
• Walls made of HCB
• Columns and beams made of steel
and concrete
• Paint
• Wooden door
• Metal windows
 Introduction
Generals

 Material found naturally are

called “Natural building
materials”
 Produced in the factories
are called “Artificial building
materials”.
 Should be well studied
 To produce safe and economical
construction
 Introduction
Definition Of Terms

 Construction Materials: any material used

in construction industry.
 Building Materials: Materials that are used
in the building industry
 Cementitious materials: -Portland cement
or another type of hydraulic cements
 Ceramic Materials: materials based on clay
(silicate mineral)
• crystalline and brittle,
• do not conduct electricity very well, and
• can withstand high temperatures.
 Introduction
Definition Of Terms

 Crystalline materials: atoms repeat pattern in

3D dimensions.
 Thermoplastic Materials: turn plastic (soft)
when subjected to heat.
 Ductile Materials: to be drawn out or
stretched to a considerable extent before
rupture.
 Measured as the percentage of elongation (increase in
length) or as the percentage of the reduction in the cross-
sectional area, when the material is subjected to tension.
 Examples :steel ,aluminum etc.
 Introduction
Definition Of Terms

Elastic Materials: deform under load without a

permanent set or deformation up on release
of the load.
 A perfectly elastic material – retains original
shape and dimensions when loads are removed.
 None of the materials remain perfectly elastic
throughout the range of stress leading up to
failure.
 But all exhibit elastic properties up to some
stress level.
 An elastic material behaves in elastically when
the stress exceeds the elastic limit, beyond
which changes in volume, shape are permanent.
 Introduction
Nature of Materials

• The nature of the material is so

scattered that no one can predict
without reliable knowledge as to how
the materials respond when they are
exposed to some actual working
conditions: such as;
• firing effects,
• damping effects, and
• loading conditions.
 Introduction
Choice of Construction Materials

• Modern structures often comprise vast

number of components.
• Pre-manufactured & assembled on site
• Manufactured at a construction site
• In each case satisfactory operation of
the building as a whole depends on
• Performance of the materials from which its
components are made
• How they interact with each other in the
structure.
 Introduction
Consideration in Choosing Construction Materials
• AVAILABILITY
• Is the material produced locally, or is it partially or entirely imported?
• Can the material and technology be used and understood by the local workers, or are
special skills and experience required?
• Are repairs and replacements possible with local means?
• ECONOMICAL
• Is it cheap, abundantly available, and/or easily renewable?
• Has it been produced in a factory far away (transportation costs!);
• Does it require special machines and equipment, or can it be produced at lower cost on
the building site?
• ENVIRONMENTAL
• Does its production and use require a high-energy input, and cause wastage and
pollution? Is there an acceptable alternative material which eliminates these problems?
• SAFETY
• Is the material and construction technique climatically acceptable?
• Does the material and construction technique provide sufficient safety against common
natural hazards (e.g. fire, biological agents, heavy rain, and earthquakes)?
• SOCIAL ACCEPTANCE
• Is the material socially acceptable? Is it considered low standard, or does it offend
religious belief? Does it match with the materials and constructions of nearby buildings?
 Introduction
Choice of Construction Materials

What is that you specifically need from the material?

• color,
• shape,
• texture,
• size,
• strength,
• Answering this question will directly lead you to the exact
requirements that you have to apply on the material.
 What defects make the material fail?
• overloading,
• extra heat,
• collision,
• age,
• abrasion,
• Answering this question will tell you how you can handle the
materials properly and make their use economical.
 Introduction
Requirements

An ideal construction material shall be tested for the

following requirements:
1.Strength: This refers to the materials resistance against
forces or loads.
 Compressive strength: The material’s resistance against
compressive loading.
 Tensile strength: The material’s resistance against tensile
loading.
 Flexural strength: The material’s resistance against
bending moment.
 Shear strength: The material’s resistance against shearing
effects.
 Torsion strength: The material’s resistance against twisting
loads.
 Introduction
Requirements

2.Durability: The longer a material stays giving service; the more it

looses its strength. A material is said to be ‘durable’ if it scores greater
ages under service without failure.
3.Fire Resistance: This does not mean an absolute fire proof.
However, a material can be made fire resistant that it does not burn just
by simple firing effects.
4.Water proofing: A material should be, in most cases, be water
proof as water /moisture/ will affect the molecular /particular/ bond with in
the materials. The requirement becomes more important when the
material is to be exposed for high moisture.
5.Others: These usually take human psychology in to consideration:
color, shape, texture, and size are some of the requirements.
 Among these color is identified as the highly influential on human
beings. Dark and heavy black colors have negative influence on
human beings, while White and bright colors create ease.
 Introduction
Requirements

Note: Though cost of a material is one factor

that is taken in to consideration when selecting a
material, it should not be as such a detrimental
factor as cheaper materials may result in weak
performance on work.
Questions