1、CEN ENS678 93 m 3404589 005b499 Ob m I Central Secretariat: rue de Stassart 36, B-1050 Brussels EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 678 December 1993 UDC 666.973.6.035.55 : 620.1 : 531.75 Descriptors: Concrete, aerated concrete, tests, measurements, density, dry density English vers
2、ion Determination of the dry density of autoclaved aerated concrete Dtermination de la masse volumique sche du bton cellulaire autoclav Bestimmung der Trockenrohdichte von dampfgehrte tem Porenbeton This European Standard was approved by CEN on 1993-12-07. CEN members are bound to comply with the CE
3、NKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to
4、any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions.
5、 CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation
6、Europisches Komitee fr Normung O 1993 Copyright reserved to CEN members Ref. No. EN 678 : 1993 E CEN ENab78 93 m 3q04589 005b500 b28 = Page 2 EN678: 1993 Foreword This European Standard has been prepared by CENTC 177, Prefabricated reinforced components of autoclaved aerated concrete or lightweight
7、aggregate concrete with open structure. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 1994, and conflicting national standards shail be withdrawn at the latest by June 1994. The standard wa
8、s approved and in accordance with the CENKENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland an
9、d United Kingdom. Contents 1 2 3 4 5 5.1 5.2 5.3 5.4 6 6.1 6.2 7 8 Scope Normative references Principle Apparatus Test specimens Sample Shape and size of test specimens Number of test specimens Preparation of test specimens . Rsting procedure Determination of the volume of the test specimens Determi
10、nation of the dry mass of the test specimens Test results Test report Page 3 3 3 3 3 3 3 3 3 4 4 4 4 4 CEN EN*b78 93 m 3404589 0056503 564 m 1 Scope This European Standard specifies the procedure for the determination of the dry density of autoclaved aerated concrete. 2 Normative references This Eur
11、opean Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publicatio
12、ns apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 679 Determination of compressive strength of autoclaved aerated concrete 3 Principle Test specimens are taken from prefabrica
13、ted components. The dry density is determined as the ratio between the mass of the test specimens after drying to constant mass at (i05 f 5) OC and their volume. 4 Apparatus a) a saw, (for cylindrical test specimens also a core drill) for cutting test specimens; b) a straightedge, at least 200 mm lo
14、ng, and a O, 1 mm-feeler gauge; c) calipers, capable of reading the dimensions of the test specimens to an accuracy of 0,l mm; d) a ventilated dqiy oven, capable of maintaining a temperature of (105 f 5) OC; e) a balance, capable of determining the mass of the test specimens to an accuracy of O, 1 %
15、. Page 3 EN 678 : 1993 5 Test specimens 5.1 Sample The sample for the preparation of the test specimens shall be taken in such a manner that it is representative of the product to be investigated. NTE. The test specimens may be prepared from prefabricated reinforced components. Alternatively, they m
16、ay be taken from prefabricated unreinforced components of the same mould. 5.2 Shape and size of test specimens The test specimens shall be prisms, cubes, or cylinders with a minimum dimension of at least 50 mm and a volume of at least 0,5 x m3 each. It is recommended that the dry density be determin
17、ed on the test specimens used for the determination of the compressive strength according to EN 679. 5.3 Number of test specimens A test set shall consist of three test specimens. Whenever possible, one test specimen shail be prepared from the upper third of the component, one from the middle and on
18、e from the lower third, in the direction of rise of the mass during manufacture (see figure 1). The position of the test specimens in the material, relative to the rise of the mass, shall be shown by the numbering. Alternatively, one single test specimen is sufficient, if it extends over the full he
19、ight of the rise of the mass and if its volume is at least 1,5 x lop3 m3. The dry density determined on such a test specimen is equivalent to the mean value of three individual test specimens. 6.4 Preparation of test specimens The test specimens shall be cut by means of a saw (or a core drill in the
20、 case of cylindrical test specimens). Plane surfaces shall not deviate from planeness by more than O, 1 mm. Planeness shall be checked across the two diagonals of each surface, using a straightedge and a O, 1 mm-feeler gauge. Deviations shall be corrected by means of grinding, milling, or a similar
21、process. Nm. Preferably, the test specimens should not contain any reinforcement. If the inclusion of reinforcement cannot be avoided, the mass and the volume of the reinforcement including anticorrosion coating shall be considered in the calculation of the dry density. CEN EN*biB 93 m 3404589 O0565
22、02 qTO m Page 4 EN 678 : 1993 Direction of rise - Zone 1 Zone 2 Zone 3 A / A A W I - I - I - I W W I Width W I I- Figure l. Sampling scheme 6 Testing procedure 6.1 Determination of the volume of the test specimens The volume of the individual test specimens is calculated from their dimensions. For t
23、his purpose, the dimensions shall be measured at different places to an accuracy of O, 1 mm by means of calipers. The necessary number of individual measurements from which the mean dimensions are calculated depends on the shape, size, and regularity of the surfaces and shall enable determination of
24、 the volume Vof the test specimen with an error not exceeding 1 %. 6.2 Determination of the dry mass of the test specimens The test specimens are placed in a ventilated drying oven at (105 I 5) OC until constant mass is attained. Immediately after removal from the drying oven, the dry mass, md, of t
25、he individual test specimens shall be determined. The error in determining the mass shall not exceed 0,l % of the mass of the test specimen. The mass of the test specimen is considered constant if after 24 h of further drying it has not changed by more than 0,2 %. 7 Test results The dry density pi,
26、in kilograms per cubic metre, of each individual test specimen i is calculated as follows: where : mdi is the dry mass of the test specimen, determined according to 6.2, in kilograms; Vi is the volume of the test specimen, determined according to 6.1, in cubic metres. The dry density of each individ
27、ual test specimen, pi, shall be expressed to the nearest 5 kg/m3. The dry density of the product, p, in kilograms per cubic metre, is defined as the mean value of the dry densities pi of the three test specimens of the test set: 1 P = 31 + P2 + P3) The dry density of the product, p, shall be express
28、ed to the nearest 5 kg/m3. 8 Test report The test report shail include the following: a) identification of the product; b) date of manufacture or other code; c) place and date of testing, testing insitutue and person responsible for testing; d) number and date of issue of this European Standard; e) shape, size, and relative position of the test specimens; f) dry density of each individual test specimen and mean value; g) observations on the appearance of the test specimens.
