Baixe grátis o arquivo ASTM CCM – 12 _ Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete (2).pdf enviado por. This standard is issued under the fixed designation C ; the number concrete. 1 This practice is under the jurisdiction of ASTM Committee C-9 on Concrete. Humboldt’s Linear Traverse Machine for concrete air void testing facilitates the counting of microscopic voids in concrete. Meets or exceeds ASTM C
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Parte 4 de 4 ASTM C, petrographic examination of concrete. NOTE 1—The air-void content determined in accordance with this test.
Because Procedure C requires darkening the paste and aggregate, its use must occur after other tests if the analyst is also gathering petrographic data in addition to the measurements described in this test method. The data gathered are the linear distance between stops along the traverse Ithe total number of stops Stthe number of stops in air voids Sathe number of stops in paste Spand the number of air voids N intersected by the line of traverse over which the component data is gathered.
Use The test is a quantitative method that measures the air-void content and other air-void system parameters in hardened concrete.
Unless other precautions are taken, the temperature must not be allowed to approach the flash point. C39M – 16 – Compressive Strength of Cylindrical Provide at least the minimum area of finished surface given in Table 1 in each sample. Instructions A 3 to 4- inch diameter core, about 4 to 6 inches long is typically needed to process a sufficient test area in accordance with the test method, depending on the top size of the aggregate.
ASTM CCM – 12 – Microscopical Determination of Parameters of the Air-Void
Link to Active This link will always route to the current Active version of the standard. The suggested sizes will usually be appropriate, but others may 4c57 selected according to the experience of the user.
Hence, this test method can be used to develop data to estimate the likelihood astn damage due to cyclic freezing and thawing or to explain why it has occurred. They are most common beneath horizontal reinforcing bars, pieces of coarse aggregate and as satm along their sides. The ratio of the volume of aggregate to the volume of paste in the original mix must be accurately known or estimated to permit the calculation of the air-void systems parameters from the microscopically determined paste-air ratio.
From time to time during lapping, and when d457 to a finer abrasive and when lapping is complete, clean all surfaces of the specimen gently and thoroughly to remove the grinding compound.
The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Print and complete the following order form. For specific hazard statements see Note 9 and Note For specific hazard statements see 8. If scaling and suspected freeze-thaw distress is the issue, or if delamination is the suspected problem, the samples need to contain the finished top surface. Hence, substantial differences in spacing factor may be caused solely by sampling and between laboratory variation.
These points may be in one or more planes intersecting the sample. The CTLGroup contacts can assist with questions about sample size and number of samples. Consequently, utmost care must be taken in conducting either microscopical method to observe and record. The data gathered are the total length traversed Ttthe length traversed through air voids Tathe length traversed through paste Tpand the number of air voids intersected by the traverse line N.
Prepared sections of such concrete should include a maximum of the mortar fraction, so as to increase the number of counts on air voids or traverse across them. 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.
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. Any such distinction asrm arbitrary, because the various types of voids intergrade in size, shape, and other characteristics. The following aatm provides useful information on air-void system parameters of known freeze-thaw durable concrete and explains guidelines and specifications from other respected specifying agencies.
The selection of which one of the three methods to be used shall be subject to agreement of the user and provider of the determination Note 1: To convert to units of percent air content, divide by n and multiply by to get percent. They are most common beneath horizontal reinforcing bars, pieces of coarse aggregate and as channelways along their sides.
When assessing strength problems it is helpful to comparatively analyze acceptable and low strength samples. Such compressive strength must be at least 28 MPa [ psi].
Any such distinction is arbitrary, because the various types of voids intergrade in size, shape, and other characteristics.
ASTM C457.C457M – 12 – Microscopical Determination of Parameters of the Air-Void…
Current edition approved Dec. Results Produced Numerical values for percent total air, spacing factor, specific surface, number of voids per inch, paste-air ratio, and percent paste are reported. If only the air content is desired, only Sa and St need be determined. They occur also immediately below surfaces that were compacted by finishing operations before the completion of bleeding.
These data are used to calculate the air content and various parameters of the air-void system. A Includes all data—all labs and all operators. This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised, either reapproved or withdrawn.
C39M – 16 – Compressive Strength of Cylindrical They occur also immediately below surfaces that were compacted by finishing operations before the completion of bleeding. Additionally, this test method can be used for concrete product and mixture development requiring resistance of the concrete against freezing and thawing damage.
BoxFarmington Hills, MIhttp: The ratio of the volume of aggregate to the volume of paste in the original mix must be accurately known or estimated to permit the calculation of the air-void systems parameters from the microscopically determined paste-air ratio. Three procedures are described:.