Unshaped Refractories test pieces

Sand Rammer. The standard rammer for making test-pieces allows a 14 lb (6.25 kg) weight to fall 50 mm on sand contained in a 50 mm diam. mould three blows from the rammer are used in making a standard test-piece. Its use in compaction and workability tests for unshaped refractories is specified in B.S. 1902 Pt. 7.2. 

Prism Test (Air Quench) (PRE/R5 Part 2), test pieces 114 x 64 x 64 mm are cycled between 950°C and a cold air blast for 5 min. followed by a bend test under a load of 0-3MN/m2. The cycle is repeated to rupture, or for 30 cycles. Small Prism Test (B.S. 1902 S.5.11 1986 Method 1902-511. The test pieces are 75 X 50 X 50 mm and subjected to 10 min. cycles between cold and 1000-1200 C, and subjected to an equal stress in each cycle. Testing is to rupture. Water-Quench Test (for unshaped refractories) B.S. 1902 Pt.7.6. The test is a water quench cycle from 1200 C to... 

The definition for an unshaped refractory is given in ISO 1927 (5) and EN 1402-1 It is a mixture, which consists of an aggregate and a bond or bonds, prepared ready for use either directly in the condition in which it is supplied or after the addition of a liquid that satisfies the requirements on refractoriness given in ISO R 836. They may contain metallic, organic, or ceramic fiber material. This mixture is either dense or insulating. An insulating mixture is one whose true porosity is not less than 45% when determined in accordance with EN 1094-4, using a test piece prefired to specified conditions. 

In addition to the above-mentioned standards, a number of specifications exist, unfortunately. These specifications come from the petrochemical industry and deviate from EN and ASTM standards especially in regard to the shape of the test pieces. Here, too, harmonization would be in the best interest of all parties involved. Figure 2 demonstrates how many test pieces a producer of unshaped refractories has to prepare. 

Figure 2 Collection of test pieces made of unshaped refractories. Description from left to right (Top) Two bricks for measuring thermal conductivity (230 x 114 x 76 mm) Shape A according to EN cup for slag tests (100 x 100 x 100 mm, hole 50 mm in diameter and depth). (Middle) Test piece for measuring abrasion resistance according to ASTM C 704 (114 x 114 x 40 mm) test piece according to special specifications for petrochemical industry (230 x 50 x 50 mm) drilled 50 mm cylinders out of a shape B (one with 12.5 mm hole for determination of Refractoriness Under Load or Creep Under Compression). (Bottom) Shape B according to EN 3 cubes for petrochemical specifications (50 x 50 x 50 mm) Shape C according to EN.

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