## 4 Materials and Methods
Quadrants A-D of manufactured basic full-size annular cross-section specimens (in plan): on the left, for the study of integral characteristics (1--four cubes with an edge of 150 mm in axial compression \(R_{b,cub}\), 1-4 levels of quadrant A in height; 2--one prism of 150 \(\times\) 150 \(\times\) 600 mm\({}^{3}\) for the study of tension in bending \(R_{btb}\), 5 th level of quadrant A in height; 3--two prisms of 150 \(\times\) 150 \(\times\) 600 mm\({}^{3}\) for axial compression \(R_{b}\), 1-2 levels of quadrant B in height; 4--two prisms of 150 \(\times\) 150 \(\times\) 600 mm\({}^{3}\) for the study of axial tension \(R_{bt}\), 1-2 levels of quadrant C in height); on the right, for the study of differential characteristics (1--nine cubes with an edge of 50 mm in axial compression \(R_{b,cub}\), 1 st level of quadrant D in height; 2--nine prisms of 50 \(\times\) 50 \(\times\) 200 mm\({}^{3}\) for the study of tension in bending \(R_{btb,i}\), 2 nd level of quadrant D in height; 3--nine prisms of 50 \(\times\) 50 \(\times\) 200 mm\({}^{3}\) for axial compression \(R_{b,i}\), 3 rd level of quadrant D in height; 4--nine prisms of 50 \(\times\) 50 \(\times\) 200 mm\({}^{3}\) for axial tension \(R_{bt,i}\), 4 th level of quadrant D in height). As a binder, Portland cement was used with a normal density of 25.5%, a specific surface area of 365 m\({}^{2}\)/kg, an activity of 5.9 MPa (in bending) and 51.5 MPa (in compression), and setting times as follows: start at 1 h and 5 min, end at 3 h and 15 min. Through the results of calculations, the composition of the concrete mixture was determined: a fraction of coarse aggregate (mixture 5.0-20.0), crushed stone--1203 kg, sand--696 kg, cement--416 kg, water--181 L, average density of the concrete mixture--2498 kg/m\({}^{3}\). Figure 2: Schedule of experimental studies of integral and differential characteristics of vibrated, centrifuged and vibro-centrifuged samples. The test method has distinctive features in that each manufactured base sample was used in several types of tests. One of the basic samples was tested at the ages of 7, 28 and 180 days. The first type of tests was carried out to study the integral (common, cross-section averaged) characteristics of concrete. For this purpose, three conditional quadrants, A, B, C, were selected from the total annular cross-section (see Figure 3), from which small-sized specimens were cut for subsequent tests under axial compression, axial tension and tension in bending (see Figures 4 and 5). Figure 4: Scheme of obtaining small-size concrete specimens from quadrants A, B, C along the height of experimental basic full-size specimens of annular cross-section for testing integral characteristics: (**a**) quadrant A; (**b**) quadrant B; (**c**) quadrant C.  
Figure 3: Scheme for obtaining small-sized concrete samples for testing. All samples were cut and tested in accordance with the requirements of the Russian GOST 28570-2019. For axial compression tests, 4 cubes with dimensions of 150 \(\times\) 150 \(\times\) 150 mm\({}^{3}\) were cut out from quadrant A (1-4 levels of the quadrant A in height), and 1 prism with dimensions of 150 \(\times\) 150 \(\times\) 600 mm\({}^{3}\) was cut out from quadrant A for tensile bending tests (5 th level of quadrant A in height). Further, for axial compression tests, 2 prisms with dimensions 150 \(\times\) 150 \(\times\) 600 mm\({}^{3}\) were cut out from quadrant B (levels 1 st and 2 nd of the quadrant B in height). Finally, for axial tension tests, 2 prisms with dimensions of 150 \(\times\) 150 \(\times\) 600 mm\({}^{3}\) were also cut out from quadrant C, (levels 1 st and 2 nd of the quadrant C in height). We obtained the following:  
1. The values of \(R_{b,cub}\) in the results of testing cubes on axial compression;
2. The values of \(R_{b}\), \(e_{bR}\), \(R_{ht}\), \(e_{htR}\), \(E_{b}=E_{bt}\) and the deformation diagram \"\(\sigma_{b}\)-\(\epsilon_{b}\)\" in the results of testing prisms on axial compression;
3.