Name: Hazem Emam Ali
Section: 2
I.D: 13P1082
Building Engineering Materials
Assignment (1)
Q.1. What do you know about the following?
- Standard specifications: Specify whether the material, design, product, or service
for any project satisfy the specifications itself.
- Code of practice: represents the basic fundamentals for design and construction
of a project to ensure its overall safety
Q.2. What are the organizations those are responsible to issue the
standard specifications?
Types of organizations that develop specification include:
1- Corporation
2- Consortium (a small group of corporations)
3- Trade association (an industry-wide group of corporations)
4- National government (including its military, regulatory agencies, and national
laboratories and institutes)
5- purpose-made standards organization such as ISO and Egyptian organization
for standardization and quality (EOS)
Q.3. Explain briefly why and how the standard specifications can be update
Why? Specifications may be updated due to development in technologies and
materials or because the old specification is no longer suitable for exceptional
new cases.
How? It is updated every several years by specialist organizations according to
development in materials science. (E.g. ECP 203-2001 ECP 203-2007(current))
Q.4. Define the following.
1- Physical properties: describe shape, general condition.
Examples: Density, Unit weight, Void ratio, Frost action.
2- Chemical properties: reactivity to other materials
Examples: Durability, flammability, reactivity to acid.
3- Mechanical Properties: usually describe strength
Examples: Stiffness, Young’s modulus
Q.5. Define the “durability” of building materials?
It is the capability of maintaining the serviceability of a product,
component, assembly or construction over a specified time. Or in
other words the “Strength with time” relation.
It is usually measured by doing several tests (Water absorption,
Permeability test, Chloride permeability test for concrete)
Q.6. Draw the load-time relationships for static, dynamic, repeated loading.
P P P
Tension
Compression
1 cycle
Δt(Large) t Δt(Small) t
Static Load Dynamic Load Repeated Load
The most dangerous case is the dynamic load because it causes cracks that spread
widely and quickly.
Q.7. Define the safety factor, explain the different factors affect its value.
It is defined as :
And is “Dimensionless”
It depends on :-
Accuracy of calculations
1- Loads Nature of loading
2- Variability of material properties
3- Importance of each part of the structure
Q.8. Ten concrete cubic specimens (10X10X10 cm) were tested in
compression, the failure loads were (13.5 – 15.0 – 14.0 - 16.5 – 14.3 –
15.1 - 13.1 - 14.3 - 16.5 – 17.1)tons.
a.
1- Average compressive strength:
∑
t
2- Standard deviation:
√∑( )
√
3- Coefficient of variation:
b. “Good”
Q.9. Five cubic specimens were taken from lime stone (7X7X7 cm) and
were tested in compression, the failure loads were (12.5 – 18.0 – 19.0 -
10.5 – 14.3) tons.
a.
1- Average compressive strength:
∑ 𝑥𝑖 8
𝑥 8 𝑡
𝑛
2- Standard deviation:
∑ 𝑥𝑖 𝑥 8 8 8 8
√ √
𝑛
3- Coefficient of variation:
b. “Poor”
Q.10. Five Lime stone cubic specimens were tested in compression,
dimensions and the failure loads were:
Cube Dimensions (cm) 7x7x7 10x10x10 15x15x15 15x15x15 20x20x20
Failure Load (ton) 14.7 30.0 67.5 69.0 118.0
Cube Dimensions (cm) 15×15×15 15x15x15 15x15x15 15x15x15 15x15x15
Failure Load (ton) 67.5 67.5 67.5 69.0 66.375
a.
1-Average compressive strength:
2- Standard deviation:
∑
√ √
3- Coefficient of variation:
b. “Excellent”
