Predicting the deformability of mineral wool slabs under constant compressive stress

Prediction of creep strain in mineral wool slabs under compression

“…Its essence -is as follows: predicted values obtained from power law (2) and an exponential equation (3) weighted average result determination. The less reliable the individual score, the lower is its weighted contribution to the combined prediction which should be much more reliable than its components (Gnip et al 2008(Gnip et al , 2009Vaitkus 2007).…”

“…It should be also noted that the extrapolation method is rather crude operation and is based on a series of assumptions, consequently, it is assumed that the confidence probability is (70-95)% (Gnip et al 2009). Since differences of predicted creep deformation values are set by going very far from a direct experimental time range, it suggests that prediction results (T power = 10), and (T exponential = 10) is not in conflict with each other, they are compatible.…”

“…However, such data practically cannot be found in literature, because these experiments are complex and long-term, it is important to carry out short-term tests and extrapolate obtained results for a longer time (Žiliukas 2004;Gnip et al2007Gnip et al , 2009. Moreover, if in the case of expanded polystyrene products their mechanical properties with the confidence level of 90-95% may be related with their density (Gnip et al2005(Gnip et al , 2007(Gnip et al , 2012bVaitkus 2007;Mihlaynlar et al 2008), in the case of stone wool products such data cannot be easily systemized due to anisotropic structure, especially when it is crimped (Bergonnier et al 2005;Karamanos 2007; Gnip et al 2009) because compressive and other loads are received by unevenly distributed inter fibre contacts (Gnip et al 2012b). Mechanical behaviour of stone wool products under long-term loads is significantly different from the behaviour of the material under short-term loads (Merkel 2002).…”

Stability of Strength and Deformation Characteristics of Expanded Polystyrene (EPS) within the Time of Long-Term Investigation of Creep Strain under Permanent Compressive Loading

“…As the criterion of evaluation of deformability of boards at constant compressive stress expanded polystyrene creep deformation of specimens in the form of a cube with an edge of 50 mm was used, which was measured using special stands [5,12] ensuring constancy of applied stress for 2034 days. Each experiment (altogether 15 lots were tested) included results of testing of three specimens of equal density.…”

Analysis of Structure and Deformation Mechanisms of Mineral Wool Slabs under Compression

“…The properties of mineral wool and other fibrous materials are dependent on filament orientation, since the direction of fibers exerts an influence on value of physical and mechanical indices [6].The control of fibrous structure by regulating the direction of filament orientation in the bed of fiber at stage of technological process of production allows to make products of mineral wool with desired heat insulating, strength and deformation properties [7,8].…”