BS-EN-15304-2007.pdf

BRITISH STANDARD BS EN 15304:2007 Determination of the freeze-thaw resistance of autoclaved aerated concrete The European Standard EN 15304:2007 has the status of a British Standard ICS 91.100.30 ? Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS EN 15304:2007 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2007 © BSI 2007 ISBN 978 0 580 54454 5 National foreword This British Standard was published by BSI. It is the UK implementation of EN 15304:2007. The UK participation in its preparation was entrusted to Technical Committee B/523, Prefabricated components of reinforced autoclaved aerated concrete and lightweight aggregate concrete with open structure. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 15304 June 2007 ICS 91.100.30 English Version Determination of the freeze-thaw resistance of autoclaved aerated concrete Détermination de la résistance au gel/dégel du béton cellulaire autoclavé Bestimmung des Frost-Tau-Widerstandes von dampfgehärtetem Porenbeton This European Standard was approved by CEN on 10 May 2007. CEN members are bound to comply with the CEN/CENELEC 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 CEN Management Centre or to 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 CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2007 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15304:2007: E Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 15304:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references4 3 Principle4 4 Apparatus .4 5 Test specimens5 6 Testing procedure6 7 Test results.8 8 Test report9 Annex A (informative) Determination of the loss in mass and compressive strength 10 Annex B (informative) Flow chart of freeze-thaw test13 Bibliography15 Figures Figure 1 Cutting scheme.6 Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 15304:2007 (E) 3 Foreword This document (EN 15304:2007) has been prepared by Technical Committee CEN/TC 177 “Prefabricated reinforced components of autoclaved aerated concrete or light-weight aggregate concrete with open structure”, the secretariat of which is held by DIN. 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 December 2007, and conflicting national standards shall be withdrawn at the latest by December 2007. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 15304:2007 (E) 4 1 Scope This document specifies a method of determining the freeze-thaw resistance of autoclaved aerated concrete manufactured according to prEN 12602 or EN 771-4. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 678, Determination of the dry density of autoclaved aerated concrete EN 679:2005, Determination of the compressive strength of autoclaved aerated concrete EN 1353, Determination of the moisture content of autoclaved aerated concrete EN 12390-4, Testing hardened concrete Part 4: Compressive strength Specification for testing machines 3 Principle Cubic test specimens (two equal groups consisting of main test specimens and reference test specimens) are cut from products sampled from normal production, saturated in water for 48 h, removed and then placed in polythene bags or similar protecting against drying for 24 h to equilibrate. The main test specimens are subjected to repeated freezing at 15 °C for at least 8 h followed by thawing in an environment of 95 % relative humidity and 20 °C for at least 8 h. The reference test specimens are stored in a climatic chamber at 20 °C in conditions that prevent drying of the AAC during storage. After the specified number of freeze-thaw cycles (not less than 15), the mass loss of the main test specimens is determined. The dry density and moisture content is also determined on the reference test specimens. If the loss in compressive strength is also required to be determined, then Annex A should be followed. NOTE Depending on the conditions at the place of use, the number of freeze-thaw cycles can be specified by national provisions. 4 Apparatus a) saw with rotating carborundum or diamond blade or similar equipment for cutting test specimens; b) balance, capable of determining the mass of the test specimens to an accuracy of 0,1 %; c) callipers, capable of reading the dimensions of the test specimens to an accuracy of 0,1 mm; d) container, to store the test specimens under water at (20 ± 2) °C; e) feeler gauge, capable of measuring 0,1 mm, (if required) 0,5 mm and 1 mm; f) conditioned room or cabinet for thawing of the main test specimens able to maintain a relative humidity 95 % at (20 ± 2) °C; g) storage room for reference test specimens able to maintain a relative humidity 95 % at (20 ± 5) °C; Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 15304:2007 (E) 5 h) freezing chamber with internal air circulation capable of maintaining a uniformly distributed temperature of (15 ± 2) °C; i) ventilated drying oven, capable of maintaining a temperature of (105 ± 5) °C; j) straight edge, at least 200 mm long and a square; k) compression testing machine, preferably hydraulically operated, which meets the requirements of EN 12390-4. NOTE The room according to f) needs not necessarily be humidity-controlled. Alternatively it is possible to substitute moisture losses by 2 h prior to the end of the thawing period placing the main test specimens in underwater storage for 1 h at (20 ± 5) °C and subsequently leaving the test specimens to equilibrate in air for 1 h at (20 ± 5) °C before freezing. This procedure is especially appropriate in combination with automatic systems. It should be ensured that the starting moisture content is not exceeded. 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, and the test specimens shall be cut from the sample as illustrated in Figure 1. 5.2 Shape and size of the test specimens The test specimens shall be cubes with an edge length of (100 ± 2) mm. 5.3 Number of test specimens A test set shall consist of 12 test specimens: 6 main test specimens and 6 reference test specimens. The main test specimens are exposed to a specified number of freeze-thaw cycles in accordance with 6.1, and their loss in mass (see 7.3) and, if required, their loss in compressive strength due to this exposure is determined (see A.3 and A.4). The reference test specimens are used for determination of the moisture content of the AAC prior to the freeze-thaw test and of the dry density and, if required, for the determination of the (control) compressive strength. 5.4 Preparation of test specimens The test specimens shall be cut by means of a rotating diamond or carborundum blade or similar equipment. Their surfaces shall not deviate from planeness by more than 0,5 mm. Planeness shall be checked across the two diagonals using a straight edge and, if necessary, a 0,5 mm feeler gauge. Where test specimens are used for the determination of the compressive strength, their loadbearing surfaces shall not deviate from planeness by more than 0,1 mm and the angle between the load bearing surfaces and adjacent surfaces shall not deviate from a right angle by more than 1 mm/100 mm. If necessary, the latter shall be checked along both orthogonal middle axes of the load bearing surfaces by means of a square and a 1 mm feeler gauge or similar instrument. NOTE If the load-bearing surfaces of the main test specimens determined for the compression test are pitted after completion of freeze-thaw cycles, they should be ground to a flatness of 0,1 mm. The position of the test specimens in the material relative to the rise of the mass shall be shown by the numbering, and the direction of rise shall be marked on the test specimens. Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 15304:2007 (E) 6 Equal numbers of test specimens shall be prepared from the upper third of the sample, from the middle and from the lower third in the direction of rise of the mass during manufacture (see Figure 1). The test specimens shall be cut in pairs (main test specimens and reference test specimens) from adjacent areas of the sample to ensure a good comparison. Test specimens shall be suitably referenced and indicated either as main (m) or reference (r). In addition, the position of the test specimens in the unit and the number of the unit shall be marked. Key 1 Direction of rise m Main test specimen r Reference test specimen Figure 1 Cutting scheme 5.5 Measurement of test specimens and determination of their volume The dimensions of the test specimens shall be measured to an accuracy of 0,1 mm, using callipers. Length, height and width shall be measured in mid height at two opposite sides, and the volume V of the test specimens shall be calculated by multiplying the mean values. 5.6 Conditioning of test specimens After their preparation, the main test specimens and the reference test specimens shall be saturated in water for 48 h at (20 ± 2) °C. For this purpose they shall be stored for 24 h with half of their thickness (50 mm) in water and for 24 h totally under water. Then they shall be removed from the water and placed in a polythene bag or similar protecting against drying for 24 h to allow the specimens to equilibrate. 6 Testing procedure 6.1 Freeze-thaw test The main test specimens shall be frozen in air at a temperature of (15 ± 2) °C, preferably placed on wooden bearers or on mesh shelves. The distance between the main test specimens among each other as well as to the lateral chamber walls and to the upper shelves shall be at least 50 mm. The temperature at the centre of the test specimens shall fall to 0 °C within (3 ± 1) h and shall be checked on a control specimen prior to commencing the test. The total duration of the freezing period shall be at least 8 h, until freezing temperature (-15 ± 2) °C is reached in the centre of the test specimens. x 2 Licensed Copy: London South Bank University, London South Bank University, Mon Jul 16 04:20:12 GMT+00:00 2007, Uncontrolled Copy, (c) BSI EN 15304:2007 (E) 7 NOTE 1 The air temperature in the freezing chamber can be (15 ± 2) °C from the very beginning of the freezing period or decreased gradually from (20 ± 2) °C to that temperature for automatic systems. Thawing of the main test specimens after the freezing cycle can take place either in the same freezing chamber, for automatic systems, or in a separate thawing chamber. The main test specimens should be positioned preferably on wooden bearers, and the distance between each other as well as to the lateral container walls and to the upper shelves shall be at least 50 mm. During the thawing period a relative humidity of above 95 % shall be maintained to prevent moisture loss. The final air temperature shall be maintained at (20 ± 2) °C. The temperature at the centre of the test specimens shall rise to 0 °C within (1 to 5) h and shall be checked on a control specimen prior to commencing the test. The test specimens shall be left to thaw for a total of at least 8 h, until a temperature of (20 ± 2) °C is reached in the centre of the test specimens. NOTE 2 At the initial stage of thawing a lower humidity is permitted for a short period. NOTE 3 The required rate of temperature rise or fall in the centre of the main test specimens can be obtained by variation in the volume loading and air circulation of the chamber or by an automatic control system. This completes one freeze-thaw cycle. In case of a forced interruption of testing, the main test specimens shall be kept in the thawed condition, in a storage room at a temperature of (20 ± 5) ºC and a relative humidity of 95 %, so that drying is excluded. The reference test specimens shall be kept during the period of freeze-thaw-cycles of the main test specimens in a storage room at a temperature of (20 ± 5) ºC and a relative humidity of 95 % or alternatively sealed in polythene bags at the same temperature so that they do not lose moisture. NOTE 4 If not automatised, the freeze-thaw cycles are best programmed such that the placing of the main test specimens in the