Ключевые слова: massive reinforced concrete structures

Predicting the risk of early cracking in massive monolithic foundation slabs using artificial intelligence algorithms

https://doi.org/10.58224/2618-7183-2025-8-1-6
Аннотация
The article presents a study of the application of artificial intelligence algorithms in predicting the risk of early cracking in massive reinforced concrete structures using monolithic foundation slabs as an example. The current experience of using algorithms such as convolutional neural networks, deep learning tools (YOLOv5 model) for crack detection at various stages of the life cycle of massive reinforced concrete structures is analyzed. The causes of crack formation, physical and mechanical processes, including cement hydration are considered.
A model has been developed that predicts the magnitude of the tensile stress level in monolithic foundation slabs during construction, based on CatBoost using Python, allowing to predict the risks of early cracking with an accuracy of up to 98%.
The model was trained on synthetic data containing various design parameters and material properties, including the geometric dimensions of the slabs, the temperature on the upper surface, the heat transfer coefficient on the upper surface, the curing rate, the class of concrete and the characteristics of the soil base. Statistical analysis of the data was performed, a correlation matrix was constructed. Practical and predicted values of the model were visualized in the form of a scatter plot. The most significant parameters influencing the risk of early cracking in massive monolithic foundation slabs were obtained. The constructed model passed quality assessment according to three metrics: MAE=0.0011; MSE=4.038; MAPE=0.0014.
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Methodology for determining true temperature stresses during the construction of massive monolithic reinforced concrete structures

https://doi.org/10.58224/2618-7183-2024-7-3-5
Аннотация
The purpose of the article is to develop and test a simplified method for calculating temperature stresses during the construction of massive monolithic reinforced concrete structures. The essence of the method is to calculate the stress-strain state in standard FEM complexes (ANSYS, Abaqus , etc.) with constant physical and mechanical characteristics of concrete over time, followed by recalculation to true stresses, taking into account the dependence of the elastic modulus of concrete over time. The methodology is based on the hypothesis of equality of temperature deformations for structures with a constant and time-varying modulus of elasticity of concrete. The developed
methodology was tested on experimental data for a massive monolithic foundation slab. The calculation at a constant modulus of elasticity of concrete was carried out in the ANSYS software package. Conversion to true stresses was implemented by the authors in the MATLAB environment. A good agreement between the calculated stress values and the experimental values was obtained.
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Failure criterion for concrete under volumetric stress state conditions

https://doi.org/10.58224/2618-7183-2023-6-6-7
Аннотация
Based on the experiments conducted by the authors, a six-parameter failure criterion for concrete has been developed, which makes it possible to take into account the volumetric stress state in strength calculations of massive concrete and reinforced concrete structures. The developed strength criterion is adapted to a spatial eight-node finite element (solid type) and implemented in the PRINS software. To verify the developed criterion, the work provides a com-parison with both experimental data and calculation results that meet other strength criteria widely used for concrete. Thus, the compression and tension meridians of the developed fracture criterion were compared with experimental data, as well as with the Willam & Warnke criterion and the modified Drucker & Prager criterion with Mohr & Coulomb constants. A comparison of compression meridians shows that in the mode of low hydrostatic stresses , these criteria converge with each other and with experimental data. In the mode of average hydrostatic stresses , the criterion proposed by the authors and the Willam & Warnke criterion show similar results, while the modified Drucker & Prager criterion shows on 20% overestimation of the failure value.
In the mode of high hydrostatic stresses , the Willam & Warnke criterion in com-parison with the proposed criterion and experimental data, gives an underestimated value of concrete failure.
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