The Importance of Test Piece Preparation of Unshaped Refractory Products for the Characterisation of Physical Properties According to EN ISO Standards
Calderys France SA, 51121 Sézanne Cedex/France
Revision
Volume 7, Issue 2, Pages 73 - 82
Abstract
At present, most standards published for the determination of physical, chemical and technological properties of refractory materials disclose little or no data on the precision of the determined values for those properties, which are nevertheless typically communicated between refractory producers and users. A mismatch of results provided by different laboratories can lead to discussion and claims against the refractory producers. In order to define testing standards with higher precision, a multinational consortium of testing laboratories is currently engaged in the elaboration of improvements for several physical and technological testing methods of refractory materials. This paper highlights the importance of the preparation methods of unshaped refractory samples dedicated to the characterization of their physical properties by EN ISO standard methods. During the test piece preparation step, EN ISO 1927-5 the parameters which have a significant impact on unshaped test piece final properties are mixing time, vibration, water addition and the choice of equipment used. The water content is the most crucial parameter to control. An excess of water leads to the reduction of mechanical strength, density and an increase in porosity. It is essential to follow the indications given by the manufacturer and use well defined detailed EN ISO procedures on test piece preparation and standardized equipment for the testing standards. The samples of the medium cement castable (MCC B) were part of a homogeneous lot of material prepared for the ReStaR project [1, 2]. Complete and detailed tests were made to ensure homogeneity of the lot used in the project.
Keywords
monolithics, consistency, water content, testing standard, preparation, repeatability, reproducibility
References
[1] Website: www.restar.eu [2] Dannert, C.: ReStaR – Collaborative R&I in the European refractory sector to review and improve testing standard. refractories WORLDFORUM 5 (2013) [4] 41–42 [3] Hloben, P.: Refractory materials, major industrial applications. Rexxon, 2000 [4] Plibrico Japan company: Technology of monolithic refractories. Plibrico Japan company limited, 1984
Copyright
Göller Verlag GmbH
