Unit 11 Module: Testing the Tensile Strength of Steel Bars

Question 1

the most suitable building material among metallic materials. This is due to a wide range
and combination of physical and mechanical properties that this has.

Answer 1

Steel

Question 2

also known as low carbon or soft steel.

Answer 2

Mild Steel

Question 3

also known as hard steel. It is tougher and more elastic than mild steel. It can be
forged and welded with difficulty.

Answer 3

High carbon Steel

Question 4

It is used for reinforcing cement concrete and pre-stressed concrete
members. It can take shocks and vibrations and is used for making tools and machine parts. Its specific
gravity is 7.90.

Answer 4

High carbon Steel

Question 5

also known as high strength steel and is essentially a medium carbon steel. It is
used in pre-stressed concrete construction.

Answer 5

High Tensile Steel a

Question 6

ASTM Code for Testing of Steel for Tensile Strength

Answer 6

ASTM A 615/ A 615M 04a

Question 7

What is the yield strength of grade 40 steel

Answer 7

280 mpa

Question 8

What is the yield strength of grade 60 steel

Answer 8

420

Question 9

What is the yield strength of grade 75 steel

Answer 9

520

Question 10

1. Test Specimens

Answer 10

a. All mechanical tests for the specimens shall be conducted in accordance with test methods and
definitions.
b. Specimens for tension tests shall be the full section of the bar rolled and the unit stress
determination shall be based on the nominal bar area.

Question 11

2. Number of Tests

Answer 11

a. One test for bar sizes number 10 - 35, if from one batch differs by three or more designation
numbers; one test shall be made from both lowest and highest designation number.
b. One test for bar sizes number 45 and 55 of each size from each batch.

Question 12

3. Tensile Requirements

Answer 12

a. The test specimen shall conform to the requirements for tensile as prescribed.
b. The yield point or yield strength shall be determined by one of the following methods:
* The yield point shall be determined by drop of the beam or halt in the gage of the testing
machine.
* If the specimen tested does not have a well-defined yield point, the yield point shall be
determined by reading the stress corresponding to the prescribed strain using an autograph
diagram method or an extensometer. The strain shall be 0.5% of gage length for Grade 40 and
Grade 60; and shall be 0.35% of gage length for Grade 75%.
c. The percentage of elongation shall conform to the tensile requirements.