Concrete is one of the most important structural materials in modern construction. But its strength can be changed with the accumulation of damage during operation. In addition, the durability of buildings depends on the mechanical properties of the cement stone, the strength of the aggregates and the types of additives. The methods that are currently used in accordance with current building codes do not allow tracking the process of damage accumulation and controlling the remaining lifetime of structures.
The deformation and destruction of concrete under the action of "fatigue" from repeated loads has not been sufficiently studied yet. In order to predict the processes occurring in concrete structures, scientists have proposed the use of structural simulation modeling. With its help, one can create a technique that will allow to take into account the influence of the various components properties of concrete on its durability. Researchers have developed mathematical models that demonstrate the failure of concrete under repeated loads. The technique will allow to determine the mechanisms of damage accumulation in the structure.
Scientists were able to determine the modulus of elasticity and ultimate strength of cement stone in bending and compression, taking into account the uneven accumulation of damage. To do this,there was carried out the number of experiments using a testing machine and a hydraulic press. At the same time, the team of scientists was motivating by the recommendations of modern standards in the field of construction.
The researchers tested the samples on a universal electromechanical system using equipment for digital analysis of strain fields and registration of acoustic emission signals. To do this, there were used the unique scientific facilities of the Center for Experimental Mechanics of the Perm Polytech called "Complex of testing and diagnostic equipment for studying the properties of structural and functional materials under complex thermo mechanical loading."
The development will allow predicting the durability of concrete, that will avoid premature destruction of reinforced concrete buildings and structures.