BS-EN-993-5 pdf free download

BS-EN-993-5 pdf free download. Methods of test for dense shaped refractory products – Part 5: Determination of cold crushing strength.
3 Definitions For the purposes of this standard, the following definitions apply. 3.1 cold crushing strength maximum load per unit area, applied under specified conditions at room temperature, that a refractory product will withstand before failure occurs 3.2 dense shaped refractory product product having a true porosity of less than 45 % (VIV), when measured in accordance with EN 993-1 4 Principle A test piece of known dimensions is subjected under specified conditions to a steadily increasing compressive load until its failure, when it cannot support a further increase in load. The cold crushing strength is calculated from the maximum load indicated at failure and the mean cross-sectional area over which the load is applied.5 Apparatus 5.1 Mechanical or hi’draulic cotnpress ion testing machine, lined with a measuring device capable of measuring the load exerted on the test piece to within ±2 %. Ihe machine shall he capable of increasing the stress at the rate of 1,0 MPa/s + 0.1 MPaJs, until the test piece is unable to support the load. The platens of the machine shall a) have a Rockwell hardness value between 58 HRC and 62 HRC; b) be ground plane to a flatness tolerance of 0.03 mm over the area to be in contact with the test piece c) have a surface texture (mean roughness value Ra) between 0,8 pm and 3,2 tm. This can he checked visually or by feeling with a “mean-roughness” reference standard such as is used for flat grinding. The area of the upper platen shall not be greater than 100 cm2. The upper platen shall work on a seating that will compensate for small deviations from parallelism between the platen and test piece. A testing machine whose upper platen does not comply with the above requirements for size can he used in conjunction with an ancillary adaptor, such as shown in Figure 1, placed centrally between the platens of the machine. The platens of the adaptor shall comply with the machine platen requirements for hardness and flatness given in this clause. They shall have a thickness of at least 10mm. NOTE The platens should be replaceable to allow re-machining and should not be matted. 6.2 Test pieces shall be cut from the item(s) so that the load applied during testing is in the same direction as the forming pressure during manufacture of the item, where this is known. The original position of the test pieces in the item(s) shall be reported. Test pieces containing cracks or visible defects shall be discarded and this shall also be reported. Both ends of the test piece shall be made plane and parallel, grinding the surfaces where required. W ater sensitive material where hydration is expected during the time of test piece preparation and handling shall be machined dry or by using a non-reacting liquid. To ensure that the top and bottom ends of the test pieces are plane over their entire surface, each end shall in turn be pressured with a load of3 kN士1 kN on to a levelling plate which is lined with carbon or blue paper and hard filter paper (0,15 mm in thickness). Test pieces that do not show two complete, clearly visible coloured impressions shall be reground (see Figures 2 to 5 for examples of cylindrical test pieces). NOTE A steel straight edge can be used to assist in checking the surfaces. Mortar should not be used to plane the surfaces. 6.3 The parallelism of the test pieces shall be checked by four measurements of the height, at the extremities of two perpendicular diameters for a cylinder, or for a cube, along the four edges between the load-bearing faces. The difference between any two of these measurements of height shall not exceed 0,2 mm.BS-EN-993-5  pdf download.