This paper presents a new approach to recognize a long-term strength of concrete. We introduce into the calculation a new concept of energy integrity of the specific energy of W-maximum resistance to the destruction. In the formation and aging process the concrete is considered to be a non-conservative system. Strength development implies the increasing of the demanded specific work for fracture. The results of the calculations show that for critical reinforced concrete constructions operate at a significant level of long-term loading. The coefficient of the working conditions should be given as differentiating, taking into account the predicted concrete creep

In this article, we consider a method of producing biostable innovative materials in order to improve the biological resistance and durability of buildings and structures based on them. We present the results of the research work focused on the study of the cement composites bioresistance. Powders of milled quartz sand and dolomite were the fillers for the composites. Mathematical methods of experiments design allowed us to derive the dependences describing how the bioresistance coefficient, the elastic modulus and the water demand depend on the granulometric composition after 3 and 9 months of aging in the environment of filamentous fungi. We have found that the multifractional compositions have a higher bioresistance coefficient. We determined that dolomite significantly enhances bioresistance of the samples and Portland cement composites, filled with quartz sand and dolomite, are fungal resist.

The dynamic shear modulus and the loss modulus of Betula alba, Ulmus parvifolia, Quercus robur, Acer platanoides, Tilia cordata, Fraxinus excelsior and Pinus sylvestris wood were measured using an inverted torsion pendulum within a wide temperature range. The glass transition temperature of the lignin–carbohydrate complex and the decomposition temperature of the wood cellulose were estimated. The temperature band from 170°C to 240°С shows the transition of the lignin–cellulose complex from the glassy to the rubbery state. Mechanical properties of different types of wood are affected by moisture and anatomical differences, but glass transition and decomposition temperatures are the same. More than 5% of moisture in the wood stored at normal conditions were found. After drying, the increase of dynamic shear modulus of wood over the entire region of the glassy state was observed. The intensity of maximum peak of dynamic loss modulus is also increased due to activation of the segmental motion of macromolecules of the ligno-carbon complex. The decomposition temperature of the cellulose crystallites was unchanged for specimens containing moisture and for dried specimens.

In this paper, we consider a method of increasing biological resistance and biological durability of buildings and constructions that are subject to destruction from the impact of microorganisms activity. This article presents the results of studies of innovative materials in the field of bioresistant building materials. Powders of milled quartz sand and limestone were the fillers for the composites. Limestone used for the experiments is from the Chechnya depostits. We have implemented optimization for the cement composites compositions using the methods of mathematical experiment design. We derived the dependences describing how the bioresistance coefficient, the elastic modulus and the water demand depend on the granulometric composition after 3 and 9 months of aging in the environment of filamentous fungi. We have found that the multifractional compositions have a higher bioresistance coefficient. We determined the fungal resist compositions.