LectureTESTING - personal.stevens.edu

Dr. Sophia Hassiotis
Strength Testing
Compressive Testing
Tensile Testing
 Beam
 Split Cylinder
Durability Testing
Chemical Attack
Concrete is most often known for its compressive strength
Flexural strength is of importance when used in rigid
Most often, 28-day strength is specified although other strengths
such as 1-day, 7-day, 56-day and 90-day strength can be used as
Concrete continues to gain strength over time
Curing methods can pay a major
role in Concrete strength gain and
a standard curing method has to be
observed for repeatable test results.
Compressive Strength of
Cylindrical Concrete
Specimens (ASTM C39)
Apparatus: Forney
Hydraulic Universal
Testing Machine
200,000 lbs Tension,
400,000 lbs Compression
Accuracy is approximately
10% of the maximum load.
Maintain the specimen in a water storage
tanks and controlled temperature of 73.5 +3.5 °F [23.0 +- 2.0 °C] up to the time of
compression testing.
Carefully align the axis of the specimen with the
center of thrust of the spherically seated upper
Bring the upper platen to
bear on the specimen, adjusting
the load to obtain uniform
seating of the specimen, no more
than 50% of the ultimate load.
Center the specimen on the
lower platen of the testing machine.
Apply the load at a loading rate of 35 psi/s (within a
range of 28 to 42 psi/s). Maintain this loading rate at
least for the last half of the anticipated loading phase.
Make no adjustment in the rate of movement till the
end of the test
Apply the compressive load until the load indicator
shows that the load is decreasing steadily and the
specimen displays a well-defined cracking pattern.
Record the maximum load (lb)
Concrete is not nearly as strong in tension as
it is in compression.
Concrete flexural strength is important in
some applications. For example, flexural
strength is typically used as a Concrete
performance measure for pavements because
it best simulates flexural stresses at the
bottom of the Concrete surface course as it is
subjected to loading.
The standard flexural strength test is:
 AASHTO T 97 and ASTM C 78: Flexural
Strength of Concrete (Using Simple Beam
with Third-Point Loading)
 AASHTO T 177 and ASTM C 293: Flexural
Strength of Concrete (Using Simple Beam
with Center-Point Loading)
The standard split tension test is:
AASHTO T 198 and ASTM C 496: Splitting Tensile Strength of
Cylindrical Concrete Specimens
In absence of flexural or tensile testing,
the ACI Concrete Code gives some rough rules-of-thumb
for converting compressive strength:
Durability is a measure of how Concrete
performs over time.
Two major factors that affect Concrete
durability are freeze-thaw cycles and
chemical attack.
Some standard tests for chemical attack are:
 AASHTO T 259: Resistance of Concrete to
Chloride Ion Penetration
 AASHTO T 277 and ASTM C 1202: Electrical
Indication of Concrete's Ability to Resist
Chloride Ion Penetration
 AASHTO T 303 and ASTM C 227: Accelerated
Detection of Potentially Deleterious
Expansion of Mortar Bars Due to Alkali-Silica
Standard freeze-thaw tests are:
 AASHTO T 161 and ASTM C 666: Resistance
of Concrete to Rapid Freezing and Thawing
 AASHTO T 121: Mass Per Cubic Meter (Cubic
Foot), Yield, and Air Content (Gravimetric) of
 ASTM C 671: Critical Dilation of Concrete
Specimens Subjected to Freezing
Each one of you will write and submit his/her own lab report (no group reports)
Your lab report should be typed and all figures should be professional
looking. A big percentage of your grade will be dedicated to the degree
of professionalism of your report.
DUE: One week after cylinder breaking
Report the following information:
Cover page with Name, Lab group, Group members, Date
Calculations for concrete mixing,
Procedure for mixing concrete in the lab. ASTM test number
Procedure for Slump Testing, ASTM test number
Procedure for setting cylinders, size of cylinders, ASTM test number
When do you remove the cylinders, how do you cure and for how long
Compression testing. Record testing machine and procedure for
compression testing
Record Compressive strength ,type of fracture, Defects in specimen
Age of specimen.

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