This standard is issued under the fixed designation C42/C42M; the number . of core test results.2 and that is free of is the individual responsible for analysis or. ASTM C42/C42M () Standard Test Method for Obtaining and Testing Drilled ASTM International, West Conshohocken. Free SCIRP Newsletters>> . ASTM C Potential Resistance to Degradation. In-situ Tests . Determine time from start until no free water is on ASTM C42, Coring, 3 cores/5, sf.
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Combining values of the two units may result in nonconformance. If necessary, saw the ends of the specimens until the following requirements are met: If the ratio of the length to the diameter of the core specimen exceeds 2.
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When the line of contact is not straight or contains projections or depressions having heights or depths greater than 0. When grinding or capping of the bearing frer is. This standard has been approved for use by agencies of the Department of Defense. Do not use specimens with projections or depressions greater than 0.
Last previous edition C 42 — If this is not practical, removal of concrete can proceed if the cut surfaces do not display erosion of the mortar and the exposed coarse aggregate particles are embedded firmly in the mortar. The relationship is affected by many factors such as the strength free of the concrete, the in-place temperature and moisture history, and the strength gain characteristics of the concrete. The preferred length of the capped specimen is between 1.
Cores for Compressive Strength 7. BoxFarmington Hills, MI It is the responsibility of the user of this vree to establish appropriate safety asstm health practices and determine the applicability of regulatory limitations prior to use. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
Additionally, this method may be used to provide strength information on older structures.
CObtaining and Testing Drilled Cores and Sawed Beams of Concrete
Current edition approved Feb. In-place test methods may be used to estimate the level of strength free prior to attempting removal of concrete samples. Measure the lengths of such cores in accordance with Test Method C Core diameters less than 3. The saw shall have a diamond or silicon-carbide cutting edge and shall be capable of cutting specimens which conform to the prescribed dimensions, without excessive heating or shock.
Measure core diameters to the nearest 0. NOTE 3—Correction factors depend on various conditions such as moisture condition, strength level, and elastic modulus.
Originally published as C 42 — 21 T. If time permits, the concrete should not be removed before it is 14 days old.
C42-Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
Core specimens with length-to-diameter ratios less than 1. Sampling and sample preparation requirements are given to ensure that dimensional requirements are met and that the specimens are comprised of intact sound concrete as free of flaws as the particular structure will allow.
The values stated may not be exact equivalents, therefore each system must be used independently of the other. C 39 with the addition of the following information: Length of Drilled Cores 6. Parte 1 de 2 Designation: NOTE 1—It is not possible to specify a minimum age when concrete is strong enough to withstand damage during removal, because the strength at any age depends on the curing history and strength grade of the concrete.
Thus, these factors should be applied to high-strength concrete with caution. SI units are shown in brackets.
The ends shall be sawed or ground to tolerance or capped in accordance with capping procedures for hardened concrete specimens of Practice C A specimen taken perpendicular to a vertical surface, or perpendicular to a surface with a batter, shall be taken from near the middle of a unit of deposit when possible and not near formed joints or obvious edges of a unit of deposit.
Determine the average diameter by averaging two measurements taken at right angles to each other about the midheight of the specimen. The acceptance criteria for core strength is to be established by the specifying authority.
When capping is employed the caps shall be as thin as practicable and shall be formed of high-strength gypsum plaster.
Livro sobre Cimento Portland e Concreto. Cap or grind the cores, and test them within 48 h of receipt. Significance and Use 3. Average values are given in the table.
A number in parentheses indicates the year of last reapproval. Therefore, results of two properly conducted tests on cores sampled from the same hardened concrete where a single test is defined as the average of two observations coreseach made astn separate adjacent drilled 4 in. When preparing strength test specimens from samples of hardened concrete, samples that show defects or samples that have been damaged in the process of removal shall not be used.
Ends are not to be capped.