CORPUZ, BHRYLLE HUMBERT L. GROUP NO.
2
CE152P-5 E01 July 08, 2024
Experiment No. 10
TENSION TEST
I – Introduction
Understanding the behavior of materials under various forces is a cornerstone of
engineering and construction. One of the most fundamental tests to assess this is the tension test,
where a material specimen is subjected to a pulling force until it fractures. This process provides
valuable insights into the material's strength and flexibility, aiding engineers in determining its
suitability for specific applications.
In this lab report, the researchers explore the outcomes of a tension test performed on a
plain steel bar. Steel is widely utilized across many industries due to its remarkable strength and
versatility. However, a thorough understanding of its behavior under tensile stress is essential for
its effective application.
The primary objective of this experiment is to observe and measure the response of the
steel bar to increasing tension. Key properties, such as the material's capacity to stretch before
breaking and its ultimate tensile strength, will be examined. These characteristics are crucial for
ensuring that steel components used in structures like buildings, bridges, and machinery can
endure the forces they will encounter in practical scenarios.
The subsequent sections of this report detail the methodology employed by the
researchers in conducting the tension test, from the preparation of the steel sample to the
execution of the testing procedure. The findings are then presented and discussed, highlighting
their significance in real-world engineering contexts. Through this comprehensive analysis, the
researchers aim to elucidate the performance and reliability of plain steel in various applications.
II – Materials and Equipment
UNIVERSAL TESTING MACHINE (UTM) and Plain Steel Bar
III – Experimental Procedure
1. The researchers obtained a plain steel bar from the laboratory.
2. Dimensions of the bar were measured, Weight (W) = 0.63 kg, Length (L) = 0.5 m.
3. The bar was put on the Universal Testing Machine (UTM), for the tension strength
testing.
4. After testing, significant data were then obtained.
5. Compute for yield strength, tensile strength, % elongation, grade classification,
elongation requirement.
Formulas used:
W
Unit weight=
L
2
πd
Area=
4
P yp
Yield strength=
A
P max
Tensile strength=
A
FL−GL
% Elongation= x 100 %
GL
Nominal diameter = (interpolation used)
15.88−x ( 15.88−19.05 )
=
1.552−1.26 ( 1.552−1.26 )
x = 14.22 mm
IV – Discussion and Interpretation
BAR TYPE LOAD PLAIN
Weight (kg) Yield point (N)0.63 kg 49943.7 N
Length (m) Maximum point (N) 0.5 m 61856.3 N
Unit weight (kg/m) STRENGTH1.26 kg/m
2
Nominal DiameterYield Strength (N/mm
14.22) mm 390 N/mm2
(mm) Gage length (mm) 200 mm
Area mm Final length (mm)
2
158.81 mm2 265 mm
% Elongation 32.5%
Grade classification 230
Elongation requirement (%) 24.63%
If suitable as concrete reinforcement (YES/NO) YES
The results of the tension test on the plain steel bar provide valuable insights into its
mechanical properties, which are essential for assessing its suitability for engineering
applications, especially as concrete reinforcement.
Load and Strength Analysis
Yield Point and Maximum Load: The steel bar's yield point was recorded at 49,943.7 N,
and it could withstand a maximum load of 61,856.3 N before breaking. These numbers tell us
that the bar can endure significant tensile forces, highlighting its strength.
Yield Strength: With a yield strength of 390 N/mm², the bar can handle considerable stress
before it starts to deform permanently. This is a key property for materials used in structural
applications where maintaining shape under load is crucial.
Elongation and Ductility
Gage Length and Final Length: The initial gage length was 200 mm, and after the maximum
load was applied, the bar stretched to 265 mm. This elongation shows that the steel is quite
ductile, meaning it can stretch significantly before breaking.
Percentage Elongation: The bar exhibited a 32.5% elongation, much higher than the required
24.63% for grade 230 steel. This indicates that the steel has excellent flexibility, allowing it to
handle significant deformation without failing.
Grade Classification and Suitability
Grade Classification: The steel bar is classified as grade 230, a common type for
construction steel known for its balance of strength and ductility.
Suitability for Concrete Reinforcement: The test results show that the steel bar is suitable
for concrete reinforcement. Its high yield strength and significant elongation mean it can
effectively absorb and distribute tensile stresses in reinforced concrete structures, ensuring safety
and durability.
V – Conclusion
The tension test on the plain steel bar has provided comprehensive insights into its
mechanical properties, highlighting its suitability for engineering applications, particularly as
concrete reinforcement. The test results indicate that the steel bar exhibits a high yield strength of
390 N/mm² and can withstand substantial tensile forces, with a yield point of 49,943.7 N and a
maximum load of 61,856.3 N. These properties underscore the material's ability to endure
significant stress without permanent deformation, a crucial attribute for structural components.
Moreover, the steel bar demonstrated excellent ductility, with a notable elongation of
32.5%, far exceeding the required 24.63% for grade 230 steel. This high degree of elongation
indicates that the bar can absorb and dissipate energy efficiently, reducing the likelihood of
sudden failure under load. The steel's classification as grade 230, coupled with its compliance
with elongation requirements, further affirms its reliability and robustness.
In summary, the plain steel bar tested in this experiment has proven to possess the
necessary strength and flexibility for use in concrete reinforcement. Its performance in the
tension test confirms that it can effectively contribute to the safety and durability of reinforced
concrete structures, making it a dependable choice for various construction and engineering
projects.
VI – Recommendations
Monitoring and Maintenance:
Implement regular monitoring and maintenance programs for structures using this steel to
ensure long-term performance. Periodic inspections and maintenance can help detect and
address any issues early, thereby extending the lifespan of the structures.
Design Considerations:
When designing reinforced concrete structures, consider the high elongation percentage
of this steel bar. This property can be leveraged to design more flexible and durable
structures that can better withstand dynamic loads and stresses
Further Research:
Conduct additional tests, such as fatigue and impact tests, to gain a more comprehensive
understanding of the steel's behavior under different loading conditions. This will help in
optimizing material selection for specific engineering applications.
VII – References
Carbonell, R. (2022, July 18). Understanding tensile strength in steel bars. Pinoy Builders.
https://pinoybuilders.ph/tensile-strength-in-steel-bars/
Corporation, C. S. (n.d.). Quality. Cebu Steel Corporation. http://cebusteel.ph/steel/deformed-
bars/
Prasad. (2021, March 5). Tensile strength of Rebar. Structural Guide.
https://www.structuralguide.com/tensile-strength-of-rebar/
Ogunbiyi, Moses & Olawale, Simon & Tudjegbe, Oke & Akinola, Samson. (2015). Comparative
Analysis Of The Tensile Strength Of Bamboo And Reinforcement Steel Bars As Structural
Member In Building Construction. International Journal of Scientific & Technology Research. 4.
47-52.
