AASHTO T22M pdf free download
AASHTO T22M pdf free download.Compressive Strength of Cylindrical Concrete Specimens.
2.2. ASTM Standards:
• C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for
Construction Materials
• C873/C873M, Standard Test Method for Compressive Strength of Concrete Cylinders Cast in
Place in Cylindrical Molds
• CI 231/Cl 231 M, Standard Practice for Use of Unbonded Caps in Determination of
Compressive Strength of Hardened Cylindrical Concrete Specimens
• E4, Standard Practices for Force Verification of Testing Machines
• E74, Standard Practices for Calibration and Verification for Force-Measuring Instruments
• R0030, Manual ofAggregate and concrete Testing (not an ASTM standard; available as PDF
only)
3. SUMMARY OF TEST METHOD
3.1. This test method consists of applying a compressive axial load to molded cylinders or cores at a rate that is within a prescribed range until failure occurs. The compressive strength of the specimen is calculated by dividing the maximum load attained during the test by the cross- sectional area of the specimen.
4. SIGNIFICANCE AND USE
4.1. Care must be exercised in the interpretation of the significance of compressive strength determinations by this test method because strength is not a fundamental or intrinsic property of concrete made from given materials. Values obtained will depend on the size and shape of the specimen, batching, mixing procedures, the methods of sampling, molding, and fabrication, and the age, temperature, and moisture conditions during curing.
4.2. This test method may be used to determine compressive strength of cylindrical specimens prepared and cured in accordance with R 39, T 23, T 24M1f 24, T 231, and ASTM C873/C873M.
4.3. The results of this test method may be used as a basis for quality control of concrete proportioning, mixing, and placing operations; determination of compliance with specification; and control for evaluating effectiveness of admixtures and similar uses (R 18).
5. APPARATUS
5.1. Testing Machine—The testing machine shall be of a type having sufficient capacity and capable of providing the rates of loading prescribed in Section 7.5.
5.1.1. Verify calibration of the testing machines in accordance with ASTM E4, except that the verified loading range shall be as required in Section 5.3. Verification is required under the following conditions:
5.1.1.4. Whenever there is reason to suspect the accuracy of the indicated loads.
5.1.2. Design—The design of the machine must include the following features:
5.1.2.1. The machine must be power-operated and must apply the load continuously rather than intermittently, and without shock. If it has only one loading rate (meeting the requirements of Section 7.5), it must be provided with a supplemental means for loading at a rate suitable for verification. This supplemental means of loading may be power- or hand-operated.
5.1 .2.2. The space provided for test specimens shall be large enough to accommodate, in a readable position, an elastic calibration device that is of sufficient capacity to cover the potential loading range of the testing machine and that complies with the requirement of ASTM E74.
Note 2—The types of elastic calibration devices most generally available and most commonly used for this purpose are the circular proving rings or load cells.
5.1.3. Accuracy—The accuracy of the testing machine shall be in accordance with the following provisions:
5.1.3.1. The percentage of error for the loads within the proposed range of use of the testing machine shall not exceed ±1.0 percent of the indicated load.
5.1.3.2. The accuracy of the testing machine shall be verified by applying five test loads in four approximately equal increments in ascending order. The difference between any two successive test loads shall not exceed one third of the difference between the maximum and minimum test loads.AASHTO T22M pdf download.
