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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Originally published as C 42 — 21 T. Parte 1 de 2 Designation: 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.
CObtaining and Testing Drilled Cores and Sawed Beams of Concrete
When the frre of contact is not straight or contains projections or depressions having heights or depths greater than 0. The values stated may not be exact equivalents, therefore each system must be used independently of the other.
BoxFarmington Hills, MI Core specimens with length-to-diameter ratios less than 1. Significance and Use 3. Therefore, results of two properly conducted tests on cores sampled from the same hardened concrete where a single test is defined as asm average of two observations coreseach made on separate adjacent drilled 4 in. Additionally, this method may be used to provide strength information on older structures.
A specimen taken ast 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.
Combining values of the two units may result astmm nonconformance. If necessary, saw the ends of the specimens until the following requirements are met: A number in parentheses indicates the year of last reapproval.
When capping is employed the caps shall be as thin as practicable and shall be formed of high-strength gypsum plaster. When grinding or capping of the bearing surfaces is. For strengths above psi [70 MPa], test data on cores show that the correction factors may be larger than the values listed above. 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 fgee in the mortar.
If the ratio of asstm length to the diameter of the core specimen exceeds 2.
v42 They are applicable to both dry and wet concrete for strengths between and psi [14 to 42 MPa]. Measure core diameters to the nearest 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.
The ends shall be sawed or ground to tolerance or capped in accordance with capping procedures for hardened concrete specimens of Practice C Ends are not to be capped. 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. Cores for Compressive Strength 7.
In-place test methods may be used to estimate the level of strength development prior to attempting removal of concrete samples. Length of Drilled Cores 6. NOTE satm factors depend on various conditions such as moisture condition, strength level, and elastic modulus. C 39 with the addition of the following information: Last previous edition C 42 — Current edition approved Feb.
Do not use specimens with projections or depressions greater than 0.
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Livro sobre Cimento Portland e Concreto. A superscript epsilon e indicates an editorial change since the last revision or reapproval.
Core diameters less than 3. SI units are shown in brackets.
ASTM C42-C42M – 04
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.
ACI provides core strength acceptance criteria for new construction. Average values are given in the table.