The research focuses on the properties of foam glass, popular insulation material used in various industries and applications, including construction, chemistry and defence, after several years of use under varying load, thermal and humidity conditions. The material used as an insulating sub-base underneath industrial steel tank, which had failed with a threat of leakage of the stored high-temperature medium (200°C), was tested. After macroscopic and material evaluation of the foam glass samples, their compressive strength, water absorption, and behaviour under complex conditions including loading, high temperature, and moisture were examined experimentally. Absorption of water considerably affects reducing the foam glass performance. Investigations show that the foam glass generally does not reach the declared compressive strength. If this surface is additionally heated to high temperature, the foam glass undergoes destruction by chipping or crushing just at stresses several times lower than the limits for this material, and even with no applied load. The test results show that foam glass exposed to simultaneous action of water and high temperature undergoes progressive deterioration, resulting in a decrease in declared parameters and losing its usability. Therefore, effective and durable protection from water is of critical importance to ensure reliability of foam glass exposed to high temperatures.

Ballast layer has weighty share in the lifecycle costs of railway track. The strict standards and maintenance rules of ballast grading significantly contribute to the ballast costs. One ways to the costs reduction is differential demands to ballast grading for the secondary and low loaded railway lines. Additional one is the different ballast grading over the ballast height. This study presents a full scale laboratory investigation of technical efficiency of such railway ballast under the long-term cyclic loading in comparison with the standard ballast layer. The double layer is presented with standard grading ballast upper layer and bottom sub ballast layer consists of ballast mixture. Pressure distribution under the ballast layer and permanent settlements of the layers are measured during the loading cycles. The reference measurements with standard grading ballast material are carried out. The study shows that initial settlement accumulation of the double layer railway ballast are lower to that of the standard ballast layer. However, the settlements accumulation intensity of the ballast is higher. The analysis of the pressure distribution measurements under the ballast layer and the settlements inside the ballast layer explain the causes of the different settlement accumulation.