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Cement composite long-term property assessment usually is limited to the compression strain state due to the difficulty of performing long-term tests in tension and 3-point bending. This paper shows the difference in long-term properties in compression, tension, and 3-point bending for plain ordinary Portland cement mortar (OPC). The obtained results were compared to reinforced specimen results to determine whether the PVA refibres improve the long-term properties of OPC mortar in various stress-strain conditions. Cylinders, compact tension specimens (CT), and beams – plates were prepared to evaluate material properties and the role of fibre reinforcement in these different stress states. Additionally, to conventional surface-attached strain gauges, 2D-DIC was employed to observe the creep strain of specimens in tension. This paper aim to determine long-term property differences in compression, tension and 3-point bending and, also, to see if low amount PVA fibre incorporation improve long-term properties in previously stated stress-strain states. It was determined that the usage of 1 % of PVA fibres increases creep strains in compression on average by 15 % and reduced by 7 % in tension. It reduces shrinkage strain by 18 % in compression and 8 % in tension. The long-term deflection for the PVA fibre-reinforced specimens are, on average by 55 % higher than for plain OPC mortar specimens in 3-point bending.

The article provides selection and approbation of the model and the model-based method for the analytical determination of thermal expansion and rock fracturing (decompression) and concrete mineral aggregates according to the data about thermal deformations of minerals based on information of the mineral composition, the average grain fineness of minerals and the elasticity modulus of rock. To accomplish the research, the author has used two models available in scientific publications: 1. Balashov and Zaraisky Model for calculating the thermal expansion and decompression of rock based on thermal deformations of minerals. The model does not take into account the structure and mechanical properties of rock. 2. The model of Denisov (one of the authors of this work) and Dubrovskiy was developed and evaluated earlier for the analytical determination of radiation expansion and rock fracturing when neutrons are irradiated by nuclear reactors on the basis of radiation deformation of minerals. The model takes into account the grain fineness and elasticity modulus of rock. The model is accepted for research on the basis of the analogy between the processes of thermal and radiation changes of rock at the level of interaction in mineral crystals. The approbation was done on the basis of both the information available in the scientific publications and experimental data obtained in this work which have shown thermal expansion of 22 in magmatic and sedimentary rock in the range from 20 to 700 °C. It has been determined that the model of Denisov and Dubrovskiy especially with correction introduction associated with the increase in the rock plasticity when heated is adequate and better than the Balashov and Zaraisky Model which describes the process of thermal expansion and rock fracturing. This model can be used for the analytical determination of thermal expansion and isotropic rock fracturing and concrete mineral aggregates at temperatures up to 700 °C (the most reliable – up to 500 °C) at normal pressure and humidity with the absence of included minerals that provide water and gases emission when heated.

The article presents results of the experimental and theoretical research of bearing capacity determination for fixings, used for bearing and supporting brackets in facade systems with the base from sandwich panel. The experiment included the consideration of several types of brackets fixing: using self-tapping screws and threaded rods, taking into account the variation in the thickness of the bearing steel plates. The required values of the research were critical longitudinal force for the pull-out from the base, deformations of the base, which lead to the disruption of sandwich-panel structural integrity. In addition, full-sized samples of the bearing bracket (the most loaded element of the facade system), installed on sandwich panel, were tested for the longitudinal (wind) and shearing (self-weight of cladding and system) load with different types of fixing. As a result, the article gives recommendations for the joints design of facade system brackets fixing to the base from sandwich panel, developed on the results of tests and theoretical studies.