Method of coefficient of subgrade reaction evaluation by CPT data is described in the article. To work out the method, experimental field investigations were carried out. At the first step, results of the parallel coupled soil tests with CPT and standard stamp according to GOST 19912-2011 and 20276 -1999 were obtained. After processing the experimental data obtained, the correlation design formula is offered to determine the modulus of the total linear soil strain, this formula is the basis for coefficient of subgrade reaction evaluation. At the second step, field investigations at three sites composed of dispersed cohesive soils were carried out. The paper presents results of pile horizontal load test and results of soil CPT – the values of soil resistance under the cone end along the whole depth of pile penetration. The experimental data obtained allowed diagrams plotting by which the ultimate horizontal load could be determined in dependence upon depth of pile penetration and averaged value of resistance under the cone end. While diagrams plotting, method of extrapolation of data obtained when 8 and 12 meter length pile horizontal load test was used. Parabolic dependences of the pile ultimate horizontal load upon its length and soil resistance value under the cone end while CPT are shown. The above parabolic dependences were straitened to obtain the design linear dependences and the overall chart for the interval of plasticity of dispersed cohesive soils: “tough – very soft consistency”. The offered method of analysis of the pile ultimate resistance under horizontal load allows obtaining results without labor-intensive, long-term and expensive CPT.
Early as antifreeze additive for concreting construction company uses traditional additive sodium nitrite. While the concrete using the same stacking technology and warming gaining strength in the project deadlines. To determine the causes of degradation of concrete specialists VPO UGNTU studies were carried out samples of slabs structures by X-ray analysis and simultaneous thermal analysis (TG DSC). X-ray analysis was carried out on rentgenogram received diffractometer “D2 Phaser” (Bruker), treated with a licensed version of the program “Diffrac. Eva” using licensed databases “PDF- 2”. Simultaneous thermal analysis was carried out on material obtained by simultaneous thermal analysis instrument “STA 449 F3 Jupiter” and mass spectrometer “QMS 403 C Aeolos” (Netzsch). The results were processed using licensed programs “NetzschProteus. ProteusAnalysis” and “Aeolos. Dispsav”. Investigation of the processes of structure formation of concrete floor slabs in connection with their destruction due to changes in the composition and technology of concrete when designing the winter concreting on one of the construction sites in the city of Ufa. Methods of x-ray phase analysis and simultaneous thermal analysis effectively an examination of the structures of concrete and found out the reason of its destruction. Proven change in the composition of concrete in its design, due to the introduction of other supplements to replace the current. Research efforts showed that by X-ray analysis and simultaneous thermal analysis can be efficiently set up kinds of additives used in concrete, and use methods under consideration for the examination of concrete compositions. Concretes considered in relation to the use of potash has been proven and lignosulfonates in winter concreting.
The fire heating process control in terms of quality, technical and economic efficiency (by the example of hydrothermal treatment of concrete products)
The problems of optimization of the thermal treatment of concrete products based on the use of self-contained heating devices that run on natural gas. Refer the problem and proposed hardware implementation of solutions to the optimization problem of the heat treatment of gas flow when the constraints on the strength of concrete products. We propose an automated process control system and reviewed the results of its use in industrial applications. Described the construction of a gas stove (air heater), which has a low metal content, with a system of discrete switching burners. The control device is finite-state regulator. It is shown that the complex “heater – automatic control system” provides a rate increase quality concrete products (strength) and low specific energy consumption per unit of production.
Problem of building and designing on semi rocky soils (lower Permian soils) is problematic for many regions. In particular, in Russia the problems of building on semirocky soils are not given clearly enough in national construction norms and standards. Approximate calculation methods of end-bearing pile point resistance on weak fissured semi rocky soils, based on SP 24.13330.2011 "Pile foundations" are presented. Some results of static load test are confirms the approximate calculation method results. This method is recommended to use in engineering practice.
Selection of recipe of bitumen binder with addition of roofing crumb and features of the technology making asphalt mixtures
The influence of the temperature on the process of the connection of bitumen with mineral filler in the technology for preparation of asphalt mixtures is considered. Two-factor experiment was planned and carried out, whose task was to select the optimum number of roofing crumb in the binder and the temperature of the preparation of road concrete mix. Dependences of properties of asphalt concrete from the studied factors were obtained and plotted.