This standard is issued under the fixed designation C138/C138M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the U.S. Department of Defense. 1. Scope* 1.1 This test method covers determination of the density (see Note 1) of freshly mixed concrete and gives formulas for calculating the yield, cement content, and air content of the concrete. Yield is defined as the volume of concrete produced from a mixture of known quantities of the component materials. 1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. NOTE 1-Unit weight was the previous terminology used to describe the property determined by this test method, which is mass per unit volume. 1 This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.60 on Testing Fresh Concrete.
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Dry concrete, also known as no-slump concrete and earth-moist concrete, is used to manufacture paving units and demands vibrocompressers to be molded. The features on the fresh state have influence on the production process, whereas the mix that are easily compacted demands less strength of the equipment and also will result on paving units that are more dense, with higher mechanical resistance and lower water absorption. However, there aren’t any test methods for the fresh state, and normally it is used empirical methods. Hence, on this paper it was develop a testing method to analyze the features of the no-slump concrete on its fresh state. The method also provides a specimen that allows testing the hardened state features. With this method is possible to obtain data on strength x time x displacement, as well as swelling, allowing to analyze which mix design is easily compacted and has less elastic recovery. To verify the method it was conducted tests using the mix design of a ref.
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The properties of the aggregates affect both the fresh and hardened properties of concrete. It is crucial to know the properties of the aggregates to be used in the making of concrete in order to obtain the desired quality in a concrete. Therefore, the tests performed on aggregates are very important. Definitions (EN 12320) aggregate-granular material used in construction. Aggregate may be natural, manufactured or recycled. natural aggregate-aggregate from mineral sources which has been subjected to nothing more than mechanical processing. manufactured aggregate-aggregate of mineral origin resulting from an industrial process involving thermal or other modification. recycled aggregate-aggregate resulting from the processing of inorganic material previously used in construction. aggregate size-designation of aggregate in terms of lower (d) and upper (D) sieve sizes expressed as d/D fine aggregate-designation given to the smaller aggregate sizes with D less than or equal to 4 mm coarse aggregate-designation given to the larger aggregate sizes with D greater than or equal to 4 mm and d greater than or equal to 2 mm. all-in aggregate-aggregate consisting of a mixture of fine and coarse aggregates. fines-particle size fraction of an aggregate which passes the 0,063 mm sieve. grading-particle size distribution expressed as the percentages by mass passing a specified set of sieves. SAMPLING Before conducting any test on aggregates, the first thing to do is sampling. A sample is a representative small portion from a larger whole or group of materials. There are two methods of reducing the size of an aggregate sample: Splitting and quartering. 1. Determination of Particle Size Distribution – Sieving Method (EN 933-1) In a sieve analysis, a sample of dry aggregate of known weight is separated through a series of sieves with progressively smaller openings. Once separated, the weight of particles retained on each sieve is measured and compared to the total sample weight. Particle size distribution is then expressed as a percent retained by weight on each sieve size. Results are usually expressed in tabular or graphical format. The test consists of dividing up and separating, by means of series of sieves, a material into several particle size classification of decreasing sizes. The aperture sizes and the number of sieves are selected in accordance with the nature of the sample and the accuracy required. The mass of the particles retained on the various sieves is related to the initial mass of the material. The cumulative percentages passing each sieve are reported in numerical form or in graphical form.
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Aggregates comprise a significant proportion of all materials used in the many different construction processes, so it is important to determine the properties of different types of aggregates through effective testing and measurement. The required properties will vary from project to project, for example, resistance to polishing will be unimportant in a pavement base course but will be crucial in a wearing course. However, the key criteria throughout are accurate and repeatable test procedures, and our range of aggregate testing equipment has therefore been designed to help determine a wide range of factors. These include: particle size, shape and texture; relative, bulk and compacted densities; soundness and resistance to chemical attack; and mechanical properties.
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