Standard Test Procedures Manual: 1. Scope 1.1. Description of Test
Standard Test Procedures Manual: 1. Scope 1.1. Description of Test
Standard Test Procedures Manual: 1. Scope 1.1. Description of Test
1. SCOPE
This method describes the procedure for making and curing compression test specimens
from fresh concrete and for determining the compressive strength of the specimens.
Tamping Rod - a round straight steel rod 16 mm in diameter and 600 mm in length. One
end shall be a hemisphere 16 mm in diameter.
Capping Device - a device for applying a capping compound to the cylinder and surfaces
in the form of plane surfaces at right angles to the axis of the cylinder.
Testing Machine - a machine of sufficient capacity which will apply a load continuously
without shock within a range of 0.140 to 0.350 MPa per second. The testing machine
shall be equipped with two steel bearing blocks with hardened faces. One bearing block
shall be spherically seated and the other rigidly mounted. The testing machine shall be
accurate within a tolerance of ± 1.0 percent of the compressive strength of the specimen.
3. PROCEDURE
Samples of concrete for tests will be obtained in accordance with STP 106.
Form the test sample by placing concrete in the mold in three layers of approximately
equal volume.
Move the scoop around the top edge of the mold to ensure a symmetrical distribution of
the concrete within the mold.
Rod each layer with 25 strokes of the tamping rod. For layers 2 and 3, the rod shall
penetrate about 25 mm into the underlying layer.
Close the voids left by the tamping rod by lightly tapping the sides of the mold.
After the top layer has been rodded, the surface will be struck off with a trowel and
covered with saran wrap to prevent evaporation.
Store the specimen undisturbed for 24 hours in such a way as to prevent moisture loss and
to maintain the specimen within a temperature range of 15oC to 27oC.
Remove the test specimen from the mold between 20 and 48 hours and transfer carefully
to the place of curing and testing. If molds are being shipped it is permissible to leave
specimen in cardboard mold during transit.
Place the specimen in the water bath and store for the curing period designated in the
contract.
After the specimen has been cured for the proper length of time in the water bath remove
and cap. The capping compound will be prepared and applied to form a plane uniform
surface at right angles to the axis of the cylinder.
Allow the sulphur capping compound to harden at least two hours before applying the
load. Specimens will be kept moist until time of test.
Place the specimen in the machine and slowly bring the blocks to bear on the specimen
without shock until failure occurs.
Operate the machine at a constant rate within the range of 0.140 to 0.350 MPa per second.
4.1. Calculations
5. ADDED INFORMATION
5.1. References
CAN3-A23.2-M77
5.2. General
Make on set of three compressive strength cylinders for about 40 m3 or five truck loads.
Cylinders should be left in their cardboard forms until delivered to a commercial testing
lab. The forms will help to prevent damage and will hold in the moisture. Cylinders
should be packed in wet sawdust in wooden boxes for transportation to lab from field site
as sudden impact may fracture the green concrete and affect the strength.
One cylinder is usually tested at seven days and the remaining two at 28 days. If report
forms are available, transfer pertinent data to the form and send it along with set of test
cylinders to the commercial lab.
Strengths indicative of the quality of concrete can be obtained only if this procedure is
closely followed.
APPROVAL SHEET
Review/Implementation Process:
Reviewed by the Materials Section of the Technical Standards and Policies
Branch.
Comments/Concerns/Implications (Budget/Environment/Stakeholders):
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