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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In-place test methods may be used to estimate the level of strength development prior to attempting removal of concrete samples. When the line of contact is not straight or contains projections or depressions having heights or depths greater than 0.
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Parte 1 de 2 Designation: C 39 with the addition of the following information: NOTE 2—Prior to capping, the density of a core may be determined by astn it and dividing it by the volume calculated from the average diameter and length, or by any other standard method for determining density.
Significance and Use 3. Determine the average diameter by averaging two measurements taken at right angles to each other about the midheight of the specimen. 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 on separate adjacent drilled 4 in.
Core diameters less than 3. Sampling and sample preparation requirements are given to ensure that c442 requirements are met and that the specimens are comprised of intact sound concrete asmt free of flaws as the d42 structure will allow. SI units are shown in brackets. Ends are not to be capped.
BoxFarmington Hills, MI Current edition approved V42. Cap or grind the cores, and test them within frre h of receipt. A number in parentheses indicates the year of last reapproval. Average values are given in the table. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. The relationship is affected by many factors such as the strength level of the concrete, the in-place temperature and moisture history, and the strength gain characteristics of the concrete.
When capping is employed the caps shall be as thin as practicable and shall be formed of high-strength gypsum plaster. Do not use specimens with projections or depressions greater than 0. For strengths above psi [70 MPa], test fre on cores show that the correction factors may be larger than the values listed above.
If time permits, the concrete should not be removed before it is 14 days old.
ASTM CC42M – 04 – Free Download PDF
ACI provides core strength acceptance criteria for new construction. They are applicable to both dry and wet concrete for strengths between and psi [14 to 42 MPa].
The values stated may not be exact equivalents, therefore each system must be used independently of the other. 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.
The preferred length of the capped specimen is between 1. Cree published as C 42 — 21 T. 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. 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 asstm not be used.
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.
NOTE 3—Correction factors depend on various conditions such as moisture condition, strength level, and elastic modulus. The ends shall be sawed or ground to tolerance or capped in accordance with capping procedures for hardened concrete specimens of Practice C A superscript epsilon e indicates an atm change since the last revision or reapproval. Combining values of the two units may result in nonconformance. Thus, these factors should be applied to high-strength concrete with caution. When grinding or capping of the bearing surfaces is.
Livro sobre Cimento Portland e Concreto. If the ratio axtm the length to the diameter of the core specimen exceeds 2.
This standard has been approved for use by agencies of the Department of Defense. Last previous edition C 42 — The acceptance criteria for core strength is to be established by the specifying authority. Measure core diameters to the nearest 0.
Additionally, this method may be used to provide strength information on older structures. If necessary, saw the ends of the specimens awtm the following requirements are met: If this is not practical, removal of concrete frree proceed if the cut surfaces do not display erosion of the mortar and the exposed coarse aggregate particles are embedded firmly in the mortar. Cores for Compressive Strength 7. Measure the lengths of such cores in accordance with Test Method C Core specimens with length-to-diameter ratios less than 1.
Length of Drilled Cores 6.