Simulation of Concrete in Winter with Self-Limiting Heating Band

In order to investigate the temperature distribution and cracking risk of concrete in winter under the combined action of heating zone and air layer, the analytical calculation method of early age concrete temperature field of concrete component under the combined action of self-limiting temperature band, cement hydration and air layer was established by taking concrete prism with self-limiting temperature band as an example. The model is applied to calculate and analyze the temperature distribution of concrete under different boundary conditions and different additional thermal field modes. The results show that: Under the conditions of internal layout, surface layout and thermal insulation layer outside the formwork, all components reach the critical strength after heating and curing for three days, which indicates that the heating band can provide temperature conditions for concrete curing in winter. Comparing the temperature field of different layout positions of heating belt, the uniformity of temperature field of heating belt outside the formwork is better than the other two layout methods.

D'Aversa et al., (2021). Categorization of Chinese words_preprint

This study extends the examination of the difference between abstract concepts to the Chinese language and its peculiar characteristics in word formation, where components with different semantic content might be aggregated within a word. Chinese students categorized abstract and concrete words by moving the computer mouse towards the selected choice. Stimuli with a ‘semantically simple structure’ (i.e., abstract-abstract/concrete-concrete) were compared with those with a ‘mixed structure’ (i.e., abstract-concrete/concrete-abstract) to test for an effect of the conceptual content of the stimulus’s components on its overall processing. Response time and kinematic parameters revealed that: a) the semantic content of the components affected the processing of abstract but not concrete concepts, b) concepts differed when they have a semantically mixed structure, not a simple one. We extend the concreteness effect also to logographic script and provide evidence that the presence of concrete component within an abstract concept is elaborated and affects its processing.

Structural Changes in Concrete under the Influence of Reactor Spectrum Neutrons

The paper considers structural changes in the concrete composition that occur under the influence of neutrons of the reactor spectrum, using the example of the IR-100 research nuclear reactor, taking into account its real time and operating conditions. Thus, taking into account the energy output, power operation modes, and neutron flux density in the core, over time, nuclides that are not characteristic of the original composition of the concrete component are formed in the nodes of the crystal lattice. However, these changes do not lead to significant structural changes.

Prefabricated Concrete Component Geometry Deviation Statistical Analysis

The research objects of this paper were the prefabricated concrete components produced by four enterprises in China, and the dimension deviation data of more than 1400 prefabricated concrete components are measured with high-precision 3D photogrammetry technology. The nonparametric Kruskal–Wallis test was carried out for the size deviation of the same type of components produced by different enterprises. The distribution characteristics of geometric parameters of typical components of prefabricated structures in China, such as beams, columns, wall boards, and composite slabs, were analyzed by using the probability statistical method. The Kolmogorov–Smirnov goodness-of-fit method was used to test the cumulative distribution function of dimension deviation, and the size distribution of fabricated components was studied. The results showed that there was no significant difference in the size deviation of the same-type component produced by different enterprises, and the range of geometric parameter uncertainty random variables was small, which was between 0.99 and 1.02. Also, the fluctuation was small, the coefficient of variation was below 0.0093, and the variability of component size deviation was small. The transverse dimension of the component shows a positive deviation, the vertical dimension of component shows a negative deviation, and the dimension deviation of prefabricated concrete components follows the normal distribution.

Monitoring of the Production Process of Graded Concrete Component Using Terrestrial Laser Scanning

Accepting the ecological necessity of a drastic reduction of resource consumption and greenhouse gas emissions in the building industry, the Institute for Lightweight Structures and Conceptual Design (ILEK) at the University of Stuttgart is developing graded concrete components with integrated concrete hollow spheres. These components weigh a fraction of usual conventional components while exhibiting the same performance. Throughout the production process of a component, the positions of the hollow spheres and the level of the fresh concrete have to be monitored with high accuracy and in close to real-time, so that the quality and structural performance of the component can be guaranteed. In this contribution, effective solutions of multiple sphere detection and concrete surface modeling based on the technology of terrestrial laser scanning (TLS) during the casting process are proposed and realized by the Institute of Engineering Geodesy (IIGS). A complete monitoring concept is presented to acquire the point cloud data fast and with high-quality. The data processing method for multiple sphere segmentation based on the efficient combination of region growing and random sample consensus (RANSAC) exhibits great performance on computational efficiency and robustness. The feasibility and reliability of the proposed methods are verified and evaluated by an experiment monitoring the production of an exemplary graded concrete component. Some suggestions to improve the monitoring performance and relevant future work are given as well.

Analysis of methods for processing and using by-products of the technological process of asphalt concrete component manufacturing

Introduction. Currently, the problem of disposal and recycling of industrial waste is extremely relevant. The article analyzes the economically feasible and environmentally friendly ways of the processing or using waste generated during the production of the asphalt concrete component — enriched mineral filler. Problem Statement. The aim of the study was to find the most economically feasible and environmentally friendly ways to process or use waste generated during the production of enriched mineral filler at one of the enterprises of the Rostov region. Theoretical Part. The paper considers the composition of the enriched mineral filler as the main product of production and a source of by-products, the technological process of its manufacture, as well as the composition of the resulting by-products to be disposed. Based on the results of these studies, the assessment of probable ways of waste disposal was performed and the optimal method of recycling was selected. Conclusion. The choice of the most appropriate method of waste disposal from the production of mineral filler allows you to reduce the total amount of waste at the enterprise and significantly reduce the negative impact of the enterprise on the environment. To implement the proposed technology of mineral waste disposal, the relevant technical conditions and regulations are being developed.