Моделирование свойств и прочностных характерис.тик бетонов для конструкций, эксплуатируемых в сложных условиях

Abstract

RU: Рассматриваются вопросы, связанные с моделированием бетона для конструкций и сооружений железных дорог. Приводится деформационная модель расчета бетона. Показана целесообразность использования информационных технологий для оценки прочностных характерис.тик бетона.

EN: Concrete production is a complex process, which consists of several important tasks. Design of concrete — the first and most demanding task in this list. Successful solving of this task determines the efficiency, reliability and safety of constructions.

The paper is devoted to the use of mathematical and computer modeling for solving the problem of concrete designing for constructions of railways.

A great amount of literature, which focuses on questions of concrete mix designing, is an indicator of the importance and relevance of the chosen direction.

Methodology of concrete mix design, which has been developed in the Ukrainian Academy of Railways, provides a high mechanical and physical properties of concrete and selected as the basis.

The methodology supplemented possibility of account of influence of plasticizers and additives hardening accelerators.

Expediency and relevance of the use of information technology to solve the problem of designing the concrete composition confirmed by the existence of software for solving such problems (of both domestic and foreign developers), its active development and improvement, and positive experience of the authors in the development of such projects.

The goal of research — the improvement of models, methods and algorithms designing of concrete for construction of railways.

The model represents the mechanical state of the equation in the form of analytical dependence, which approximates the stress–strain diagram of core concrete elements. This model is considered as a parametric curve, the points of which are the result of the experimental curves. The basis of this model is the experimental dependence in the form of diagrams «s–e« (stress — strain). In experimental studies, different stress–strain diagram for the same concrete under different load conditions that exceed the limits of its long–term strength.

Modeling of the deformation diagram of concrete and as a result, the definition of the strength characteristics of concrete made with the involvement of both experimental studies and with the involvement of existing methods of forecasting the strength of concrete

The authors have proposed and experimentally verified a new dependency for the evaluation of concrete strength in time with the use of various types of cements and additives hardening accelerators. The basis of dependence — acceleration factor, which is determined experimentally.

Developed dependency introduced into the algorithm of software «PSB UkrSAR», which allows the design of concrete with the achievement of the desired strength in the specified period of hardening, as well as present the results of the application of dependence in the as a diagram strength development concrete.

Mathematical and computer modeling allows us to solve the problem of designing concrete compositions with desired properties, to carry out numerical simulation and analysis of the results, make recommendations regarding the application and use of concrete for railway designs and constructions.