The coupling of concrete with fiberglass reinforcement at different values of its diameter and depth of sealing is investigated. The difference in the distribution of tangent stresses over the depth of reinforcement bars‘ sealing is determined due to their diameters, which is reflected in the nature of the destruction of fiberglass reinforcement when it is pulled out of concrete. The values of correction coefficients that take into account the dependence of the fullness of the tangent stress plot in the sealing area on the diameter of the reinforcing bar are determined. Recommendations for calculating the base length of the fiberglass reinforcement anchorage in concrete are given.

Prefabricated reinforced concrete structures are widely used to speed up the erection of structures in construction practice; they are connected during installation by means of embedded core elements, subsequently monolithic with concrete. Under the influence of external loads, axial tensile and transverse shear forces arise in such nodal joints, which are often neglected in the static analysis of structures. In turn, this can lead to the development of ultimate deformations in the assembly, to a change in the conditions for fixing the structure, and, as a consequence, to their premature collapse. This article discusses the effect of the axial pulling force in the reinforcing bar on the stress-strain condition (VAT) of the concrete mass surrounding it. To solve this problem, a numerical experiment is carried out in the ANSYS 19.0 Workbench package, in which the adhesion of fiberglass and metal reinforcement to concrete is simulated. It allows establishing the nature of the stress distribution in the core embedment area.

Reinforced concrete is one of the most common materials in construction. Constructions made of this material have a high bearing capacity; well perceived dynamic and static loads. This is ensured by the adhesion between the reinforcing bar and concrete. The amount of adhesion is made from a number of different factors formed in the region of the conventional surface of interaction of reinforcement with concrete. It is implied that even if any reinforcement is used, materials come into contact over the surface, which can collapse depending on the load. Violation of the clutch causes significant deformation of the structure, which subsequently leads to a loss of the bearing capacity of the element. Therefore, there is a need to study the magnitude of the adhesion between concrete and reinforcement under various influences. This article describes the results of a numerical experiment on pulling out fiberglass reinforcement of a periodic profile from concrete. A mathematical model is constructed, which allows to study the accumulation of defects and the destruction of reinforcement in the area of concrete fixing. The results of numerical studies are considered.

In areas rich in large-sized wood in low-rise buildings, are composite wooden structures. Compliance in calculations of such structures is taken into account by factors. Compliance factors are determined experimentally with a large spread of values, which leads to a significant overstatement of the material intensity of the structures. Issues of error of calculation of bearing capacity of composite wooden elements at variation of their layering are considered in the work.

Аннотация. Предложено использовать в качестве наполнителя цементно-песчаных бетонов асбоцементные отходы из строительных изделий и конструкций. Асбоцементные отходы в качестве наполнителей бетонов используются ограничено. При этом основная их часть утилизируется в отвалы, что приводит к загрязнению окружающей среды. Отходы боя шифера и асбоцементных труб разделялись по фракциям 0…5, 10…20 и 20…40 мм. Изучалось влияние асбоцементных отходов на основные физико-механические свойства и долговечность цементно-песчаных бетонов. Установлены оптимальные концентрации и размер зерен наполнителей. Определены значения прочности, предельного водопоглощения и долговечности при заданных параметрах эксплуатации цементно-песчаных бетонов. Изучалось влияние жидких активных добавок на долговечность и морозостойкость бетонов. В качестве активных добавок использовались поливинилацетатный клей (ПВА) и силикат натрия. Разработаны составы бетонов с наиболее высокими эксплуатационными характеристиками. Проведены длительные механические испытания этих составов с позиций термофлуктуационной (кинетической) концепции разрушения. Получены значения термофлуктуационных констант, отражающих физическую и химическую структуру материалов. Дана трактовка механизма разрушения бетонных образцов в широком диапазоне нагрузок и температур. Предложен способ расчета и прогнозирования механической долговечности в реальных условиях эксплуатации. Приведены примеры расчета долговечности для бетонных облицовочных панелей на металлическом каркасе. Ключевые слова: цементно-песчаный бетон, асбоцементные отходы, оптимальная концентрация, жидкие активные добавки, водопоглощение, морозостойкость, долговечность. Информация об авторах Ярцев Виктор Петрович, доктор технических наук, профессор кафедры конструкций зданий и сооружений.