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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From time to time during lapping, and when changing to a finer abrasive and when lapping is complete, clean all surfaces of the specimen gently and thoroughly to remove the grinding compound. Combining values from the two systems may result in non-conformance with the standard. The flash point of the lubricant may be found by use of Test Method D The test method can also be used as an adjunct to the development of products or procedures intended to enhance the resistance of concrete to cyclic freezing and thawing 1.

Astn most common examples are concrete with large coarse aggregate and samples astk the finished xstm region, for both of which the examined sample consists of a disproportionately large amount of the mortar fraction. 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.

Includes both point count and linear traverse data. C39M – 16 – Compressive Strength of Cylindrical Juliano atsm Enviado por: Print and complete the following order form. A superscript epsilon indicates an editorial change since the last revision or reapproval. They are most common beneath horizontal reinforcing bars, pieces of coarse aggregate and as channelways along their sides. These points may be in one or more planes intersecting the asrm.


Any such distinction is arbitrary, because the various types of voids intergrade in size, shape, and other characteristics.

Juliano row Enviado por: Friable particles of aggregate can also cause difficulty. 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.

However, significant differences may be observed if the sample of fresh concrete is consolidated to a different degree than the sample later examined microscopically. 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.

Reports that do make such a distinction typically define entrapped air voids as being larger than 1 m in at least one dimension being irregular in shape, or both. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. For concrete with a relatively high air content usually over 7.

A Modified Point Count: The usual cause is a weak cement-paste matrix. Warning—If the specimen was sawn with a lubricant other than water, heating must be done so as to avoid inhaling the fumes and to preclude fire or explosion.

Air Void Testing for Concrete, ASTM C

An increase in the water-cement ratio or the paste content must be accompanied f457 an increase in the air content, if the spacing factor. Thus, this method can be used to evaluate the potential for damage due to cyclic freezing and thawing of the concrete.


The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.

Appraisal, John Wiley and Sons, Inc. Use of ultrasonic cleaners may be harmful to the surface. Consequently, utmost care must be taken in conducting either microscopical method to observe asm record.

ASTM C457.C457M – 12 – Microscopical Determination of Parameters of the Air-Void…

Hence, this test method can be used to develop data to estimate the likelihood of damage due to cyclic freezing and thawing or to explain why it has occurred. Privacy Policy Sensors Sitemap. Parte 1 de 4 Designation: Current edition approved Dec. For voids per in.: An appropriate series of abrasives would include nominal 75, 35, NOTE 1—The air-void content determined in accordance with this test. 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.

Three procedures are described: The ratio of the volume of atm 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.

If you need more info or have any questions, please note the Lab ID number 56 and contact us at: A surface that is satisfactory for microscopical examination will show an excellent reflection of a distant light source when viewed at a low incident angle and there shall be no noticeable relief between the paste and the aggregate surfaces.

For specific hazard statements see Note 9 and C57