Predicting the deformability of mineral wool slabs under constant compressive stress

The results of investigating the creep strain mineral wool slabs used for thermal insulation of flat roofs, cast-in-place floors and external walls of basements subjected to long-term compressive stress σ c = 0.35 σ 10 % are presented. Slabs under short-term compressive stress are tested and regressive equations for calculating the stress σ 10 % , ultimate stress σcr, which slabs can endure without changing their structure, and the respective relative ultimate strain εcr, as well as the initial modulus of elasticity E, are offered. For the approximation of the creep curves an exponential equation is used according to EN 1606. It has been shown that the prediction of the creep strains for the lead time of 10 years may be made based on the data obtained in the direct experiment with the duration shorter than 122 days as specified in EN13162. A possibility of estimating the expected creep strains of mineral wool slabs for the lead time of 10 years, based on the stress σ c = 0.35 σ 10 % and relative ultimate strain εcr of slabs under short-term compressive stress, has been considered.