Numerical study of aggregate effects on the strength of light concrete

The article represents the results of lightweight concrete’s composition designing by numerical methods. The study is aimed at finding rational aggregate particles packing that provides the highest mechanical characteristics of the composite material. Numerical simulation uses the finite element method. To simplify a calculation scheme, the study was carried out in a flat format. Models with regular aggregate particles of spherical and cylindrical shape have been investigated. The advantage of a two-component model built on the fractal principle of a triangle and containing up to 70% of aggregate particles has been proven. The model of aggregate distribution according to the type of an equilateral triangle provides minimal stresses and deformations inside the composite material. To ensure the mechanical resistance of the composite material, the rounded shape of granules is preferable compared to quasi-cylindrical particles. Under a regular multi-row distribution of rounded granules, the model containing particles with diameter from 6 to 8 mm is characterized by a minimum concentration of normal and shear stresses. The results of numerical simulation are consistent with experimental studies of lightweight alkaline silicate concrete based on porous granular aggregate.