Self-ignition temperature of the dust accumulations for sunflower and wood powders

Spontaneous combustion is a phenomenon that results from the heating of combustible organic powders by slow oxidation and which occurs through the air passage (created by an air depression) through the mass of dust. The oxidation phenomenon of combustible powders represents their reaction with atmospheric oxygen resulting in products of carbon dioxide, carbon oxide, water and other gases whose content depends on the temperature at which the oxidation takes place. The self-ignition of combustible dusts depends on their chemical composition, the properties of component substances, on the particle size and geometry of the material mass and, last but not least, on the temperature of the environment. Due to global worries of sustainability in construction engineering the trend is to use ecofriendly organic waste to various purposes as in construction materials. The challenge is that by using this kind of materials one should ensure the safety related to the process of such organic materials which are known to have combustible properties. The purpose of this work is to present the self-ignition behavior of combustible dusts such as sunflower and wood by means of drying tests under constant temperature conditions.

Comprehensive Evaluation of BIM Calculation Quantity in Domestic Construction Engineering Based on Fuzzy Comprehensive Evaluation

Nowadays, with the leap-forward development of computer technology and the transformation of information technology management concepts, China’s construction industry is quietly entering the era of refined management. Accurate estimation and cost control have become among the key considerations of the construction industry. For the calculation of engineering quantity, there are already many software devices that can be used for the calculation of engineering structure quantity, which means that the incorrect operation of personnel has been reduced to some extent, improving the work efficiency and measurement accuracy. The purpose of this paper is to solve the problems of computational missing, computational errors, inefficiency, data loss, and repetitive system in traditional computing based on the advantages of BIM computing system, which provide a reliable basis for cost forecasting and control. At the same time, using BMI calculation system to solve the problem of steel reinforcement in construction engineering, as well as the use of personnel, the existing calculation software still needs a lot of time and energy. We proposed a comprehensive evaluation study of reinforcement calculation in domestic construction engineering BIM calculation system based on a fuzzy comprehensive evaluation. This paper first summarizes the BIM calculation system of construction engineering, uses fuzzy comprehensive evaluation system as an important evaluation index system in domestic construction engineering BIM calculation system, through the judgment of various factors affecting the actual effect of the calculation system, and uses the fuzzy evaluation system combined with a case to demonstrate the superiority of the proposed research. Therefore, through the above research and experiments, it is concluded that the research method of this paper solves many problems in the process of engineering structure reinforcement calculation and provides a good reference method for the establishment of comprehensive evaluation system of reinforcement calculation, as well as providing an effective validation for the widespread use of BIM technology in the construction industry. Finally, it is also beneficial for users to comprehensively evaluate the BIM calculation system of the construction industry and provide a basic reference condition for different industries to use and choose BIM calculation systems.

Influence of BIM-Based Teaching Methodology on the Spatial Abilities of Construction Engineering Students

Spatial visualization skills are considered essential for a variety of professional careers, especially those related with architecture, engineering, and construction (AEC). A number of studies have proven that these skills are progressively acquired by AEC students during their years in college, being necessary specific pedagogical approaches for this purpose. Other 3D native design software has been proved to exert a positive influence on the spatial abilities of students in several fields, such as fine arts or civil engineering. In the field of AEC, BIM software stands out as an appropriate tool for this purpose, as it supports 3D-native design. This study was conducted to clarify the influence that working with BIM models has on the spatial abilities of the students to visualize constructive components in 3D; it was hypothesized that the effect would be positive to some extent, as in similar disciplines. To that end, an experiment was conducted with 73 undergraduate students in construction engineering, who attended an intensive 4-week workshop where they had to work with BIM models. The improvement in their spatial abilities was measured by the Mental Rotation Test (MRT) and, besides, a satisfaction survey was conducted. The results indicate that MRT scores improved between 3.8% and 15.5% and that students felt highly satisfied with this pedagogical approach. These results aim to help in implementing BIM in the academic curricula to maximize the educational outcomes of the students while gathering their assessment of BIM-based teaching methodologies.

3D printing-A Review of Materials, Applications, and Challenges

Now a days 3-Dimensional Printing (3DP) technology is used world widely and it can actually print each and every thing with the desired computer program. In Construction engineering the challenges are like availability of skilled man power, time constraint, cost effectiveness and complicated shapes etc. But with the help of an automated machine, the 3D printing technology, has huge potential to have faster and more accurate construction of complex and more laborious works. This technology can build three-dimensional (3D) objects by connecting layers of materials and can be applied to convert waste and by-products into new materials. The 3DP in concrete construction is increasing thanks to its freedom in geometry, rapidness, formwork-less printing, low waste generation, eco-friendliness, cost-saving nature and safety. This paper attempts to review the digital printing technology introduced in the construction industry and the also highlights the impact on concrete technology. It also discusses about the materials used in 3DP, mix design, various applications and challenges in the construction industry. Keywords: 3D printing, Concrete, 3DCP, Mix design.

The Flame-Retardant Mechanisms and Preparation of Polymer Composites and Their Potential Application in Construction Engineering

Against the background of people’s increasing awareness of personal safety and property safety, the flame retardancy (FR) of materials has increasingly become the focus of attention in the field of construction engineering. A variety of materials have been developed in research and production in this field. Polymers have many advantages, such as their light weight, low water absorption, high flexibility, good chemical corrosion resistance, high specific strength, high specific modulus and low thermal conductivity, and are often applied to the field of construction engineering. However, the FR of unmodified polymer is not ideal, and new methods to make it more flame retardant are needed to enhance the FR. This article primarily introduces the flame-retardant mechanism of fire retardancy. It summarizes the preparation of polymer flame-retardant materials by adding different flame-retardant agents, and the application and research progress related to polymer flame-retardant materials in construction engineering.