ASTM C42 FREE PDF
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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Determine the average diameter by averaging two measurements taken at right angles to each other about the midheight of the specimen. Ast the line of contact is not straight or contains projections or depressions having heights or depths greater than 0.
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. NOTE 3—Correction factors depend tree various conditions such as moisture condition, strength level, and elastic modulus.
Current edition approved Feb. A specimen taken perpendicular to a vertical surface, or perpendicular to a surface with a batter, shall awtm 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.
Last previous edition C 42 aztm Cores for Compressive Strength 7. 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.
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If time permits, the concrete should not be removed before it is 14 days old. SI units are shown in brackets. Thus, these factors should be applied to high-strength concrete with caution. Livro sobre Cimento Portland e Concreto.
In-place test methods may be used to estimate the level of strength development prior to attempting removal of concrete samples.
Originally published as C 42 — 21 T. Measure core diameters to the nearest 0.
ASTM C42-C42M – 04
For strengths above psi [70 MPa], test data on cores show that the correction factors may be larger than the values listed above. The preferred length of the capped specimen is between 1. If the ratio of the length to the diameter of the core specimen exceeds 2. The acceptance criteria for core strength is to be established by the specifying authority.
Ends are not to be capped. 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. The values stated may not be exact equivalents, therefore each system must be used independently of the other. NOTE 2—Prior to capping, the density of a core may be determined by weighing it and dividing it by the volume calculated from the average diameter and length, or by any other standard method for determining density.
Core diameters less than 3. Additionally, this method may be used to provide strength information on older structures. BoxFarmington Hills, MI Parte 1 de 2 Designation: A superscript epsilon e indicates an editorial change since the last revision or reapproval.
Length of Drilled Cores 6. 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. Cap or grind the cores, and test them within 48 h of receipt.
CObtaining and Testing Drilled Cores and Sawed Beams of Concrete
When grinding or capping of the bearing surfaces is. If necessary, saw the ends of the specimens until the following requirements are met: When capping is employed the caps shall wstm as thin as practicable and shall be formed of high-strength gypsum plaster.
A number in parentheses indicates the year of last reapproval. Significance and Use 3. The asfm shall be sawed or ground to tolerance or capped in accordance with capping procedures for hardened concrete specimens of Fre C This standard has been approved for use by agencies of the Department of Defense. Combining values of the two units may result in nonconformance. ACI provides core strength acceptance criteria for new construction.
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.
Average values are given in the table. They are applicable to both dry and wet concrete for strengths between and psi [14 to 42 MPa].