bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Density, High Compressive Strength: Experimental Investigation with Various Particle Sizes of Sand for Different Mix Designs of Cement Mortar Manufacturing
Authors: Rmdan Amer Akrm A , Mustafa Al Bakri Abdullah Mohd , Yun Ming Liew , Faheem Mohd Tahir Muhammad , Wazien Ahmad Zailani Warid , Ahmad Faris Meor
Published: July 2020

Concrete density was optimised by substituting part of the normal-density aggregates (fine aggregate, coarse aggregate, or both) with that of comparable quantities of low-density aggregate, which enhanced structural efficiency (strength to density ratio), improved hydration and decreased transportation costs. These days, focus is given on enhancing the characteristics of concretes in order to make them more efficient. A factor associated in compressive strength, packing particle, water absorption and density is concrete proportioning. A good proportioning mix results in greater strength for concrete at optimum density and specified age. The filler effect is regarded as a physical feature pertaining to small particles for a concrete material since it allows generating extra compressive strength by filling voids by making mortar or concrete more homogeneous. This behaviour allows conferring additional compressive strength as well as optimise or minimise the concrete’s density without having to use a pozzolanic reaction or a chemical reaction. Mainly, this objective has been implemented through using three different lightweight particle sizes of sand group a-(1.18 mm ≤ Sand size < 200 ɱm), b-(2.36 mm ≤ Sand size < 1.18 mm) and (5.0 mm ≤ Sand size < 2.36 mm). The parameters that are taken consideration during the investigation were sand particle size, water/cement ratio, cement/sand ratio. In general, the results demonstrated that there was a decrease in compressive strength when the sand’s particle sizes increased. In case the particle size group (b) and (c) used the decrease rate in compressive strength was 7.97% and 12.39% respectively in comparison with particle size group (a) where the optimum values of the water/cement and cement/sand ratio were used. On the other hand, low density was achieved at the point of the higher compressive strength, whereas 4.4% and 3.66 % increase in the density was recorded over the particle sizes of sand (b and c) respectively. Meanwhile, we put forward the relationships existing between the compressive strength as well as density of concrete mixtures with various proportions of the lightweight aggregates as given above. The conducted experimental studies showed that there were tendencies to possibly utilise various quantities of fine lightweight aggregates as well as their combinations to yield concrete mixtures based on the requirements in practical application. As per the study conclusion, the considered mixtures could be used to yield structural elements that need high compressive strength and lower density.
Single Objective Optimization of Net Zero Energy Residential Building in Tropical Climate
Authors: Leman A M , Sharif H Z , Krizou A N , Al-Tarawne M T A , Subbiah M , Al Farsi M , Irfan A R
Published: July 2020

The Building sector is the largest consumer of energy worldwide. Net Zero Energy Residential Building (NZERB) is one of the prudent approaches to reduce pressure on primary sources of energy. The main objective of this study is to use Taguchi simulation based on orthogonal arrays approach to optimize thermal envelope of a building, SEER value of HVAC system, lighting power density, and ventilation level to reduce the Building Energy Intensity (BEI) 50% lower than the base case building according to International Energy Conservation Codes 2015. In this study whole building energy simulation was performed by Hourly Analysis Energy Program and PVWatts calculator was used to estimate the size of the PV system for balancing the energy demand of the house. The results of Taguchi simulation approach show that by decreasing the U value of wall, windows, roof, floor to 0.1, 0.8, 0.1, 0.2 W/m2. °K respectively and ventilation rate 0.15 l/s-m2, lights of 110 lm/W and SEER of the HVAC system 4 (W/W option) reduce BEI from 147.78 kWh/m2/year for base case building to 67.085 kWh/m2/year for optimal design case. PV system size estimation was performed with PVWatts calculator. PV Watts recommended the size of 13kW DC rating system (open rack type) of 15% efficiency for the weather of Johor Bahru to meet the annual energy demand of the proposed optimal building design.
Comparative Study on Application of Extended Kalman Filter and Unscented Kalman Filter in Target Tracking
Authors: Hu Xiao-Fei Deng Xiao-Tong , Zhao Qin Guo Cui-Xia Zeng Si-Qi , Zhou Kai-Qing
Published: July 2020

This paper mainly describes the basic principles of extended Kalman filter and unscented Kalman filter and the application of them in target tracking based on observation distance At last the two algorithms are compared by Matlab software The simulation results show that unscented Kalman filter has better matching effect than extended Kalman filter and the former has smaller error variation and better convergence than the latter
A Comparative Study on Different Parameter Factors and Velocity Clamping for Particle Swarm Optimisation
Authors: Lim S P , Hoon H , Song W H
Published: July 2020

Optimisation is an interesting topic because various optimum results can be obtained using limited resources. This is the reason that researchers are interested in further investigating the possibility of optimisation by testing numerous optimisation methods. As the current research trends are preferred to solve the problems using Artificial Intelligence (AI) methods, hence more nature-inspired optimisation methods are developed. Particles Swarm Optimisation (PSO) is one of the well-known optimisation methods in Swarm Intelligence (SI). It can be used to solve many problems. However, PSO is easily trapped in local optimum and encountered premature convergence problem, which indirectly affects its performance. Besides that, its performance with different parameter factors and velocity clamping is always not considered by researchers. Therefore, the objective of this research is to compare the performance of PSO with different parameter factors and velocity clamping using average fitness values. 10 different types of PSO models are applied and tested using 10 benchmark functions. Based on the experimental results, PSO10 with constriction factor and velocity clamping is proved to be the best PSO model because it can obtain 10 out of 10 minimum average fitness values. The outcomes can assist the researchers while applying the method to their research.
In-process Estimation of Ascorbic Acid Assay Using Machine Learning Algorithms
Authors: Felipe M A , Baldovino R
Published: July 2020

Demand for greater volume of pediatric vitamin C syrups become higher every year whilst maintaining an expected high quality Current laboratory techniques employ costly time-consuming and destructive testing which inhibit manufacturers to attain higher process efficiency In this study machine learning methods: random forest RF support vector machine SVM artificial neural network ANN and adaptive neuro-fuzzy inference system ANFIS are used for the estimation of percentage ascorbic acid %AA assay Likewise these methods are compared to conventional linear regression LR model and to each other pH specific gravity viscosity and %AA assay measurements were used for the training of the network Preprocessing technique involving data smoothing was employed on each nonlinear main effect relationship to reduce the noise and achieve better prediction accuracy Upon training it was found the ANN coupled with Bayeasian Regularization exhibited 02314 MSE a higher accuracy among other algorithms Furthermore it generally pushed ANN to be relatively more accurate than ANFIS with a minimal MSE of 030810
Learning Convolution Neural Network with Shift Pitching based Data Augmentation for Vibration Analysis
Authors: Esa M. F. M. , Mustaffa N. H. , Omar H. , M Radzi N. H. , Sallehuddin R
Published: July 2020

Data augmentation is a common approach that been implemented in order to increase the training data quantity for Convolutional Neural Networks in signal processing, image recognition and speech recognition. However, the conventional data augmentation methods usually implement the window slicing and overlap window slicing methods in the bearing fault analysis. Meanwhile, the audio deformation approach such as time stretching and pitch shifting methods have been commonly used as data augmentation approach in speech recognition. Thus, this paper proposed a data augmentation based on shift pitching technique for the vibration signal. The relationship between the audio and the vibration signal is evaluated for a bearing fault analysis using Convolution Neural Networks. The new dataset produce by the data augmentation is used to increase the number of training dataset and to improve the Convolutional Neural Networks training performance. The result shows that the shift pitching based data augmentation method able to achieve higher training accuracy compared to the window sliding data augmentation. The combinations of all ratio pitch obtain 93% accuracy whilst the accuracy for a single rate pitch are between 81% to 91%.Thus, the proposed method is competent and able to improve the performance of bearing fault classification
Design and Development of Young Coconut Shell and Husks Shredder Machine
Authors: Amear Syed Ariffin Syed , Chun Lin Saw , Chee Guan Choong
Published: July 2020

Young coconut shell and husk shredder machine is designed for shredding the husks after the process of coconut shell crushing. The main objective of this machine is to reduce coconut shell waste after the completion of harvest. The machine contains of two shafts of 25 blades per shafts (1st stage) and another two shafts of 30 blades per shaft (2nd stage) placed side by side in order to put pressure on the coconut shell and husk during the cutting process. At stage 1, which is the shredding stage, it has 2 shafts which both rotate in the opposite direction. The blades have bigger surface area, thick, hard-faced cutting surfaces and run in low rotation per minute (rpm) in order to crush the coconut shell and husk. At stage 2, which is the cutting stage, it consists of 2 shafts which rotate in the opposite direction and each shafts consist of 30 blades. The blades in stage 2 is thinner compared to the blades in stage 1, sharp cutting edge and the distance from each blades are closer to each other in order to cut and shred the coconut shell and husks into small, fine and desired size. Furthermore, the rotations of the blades are both in opposite directions toward each other which mean that the cutting process will consists pressure into the shell and husks. The output for the machine is able to produce 50 - 80 kg of young coconut shell and husks after the shredding process hourly. The machine uses electrical motor to reduce sound pollution. Besides that, a 1420 rpm motor is fitted to run the machine entirely which is equivalent to 1 Horsepower (Hp). The output power achieved is 544 kiloWatt hour (kWh) with an efficiency of 73%. Lastly, the objectives are achieved, that is to reduce young coconut shell and husks waste by converting to animal feeds.
Poly(ethylene-co-vinylacetate) Copolymer Based Nanocomposites: A Review
Authors: Fazlina Osman Azlin , Rasyidah Abdul Hamid Asna , Fareyhynn Mohammed Fitri Tuty , Amalia Ahmad Fauzi Asfa , Anwar Abdul Halim Khairul
Published: July 2020

Nowadays, there is huge demand for novel materials which are desired for new functions and new technological advancements. All technological demands for new applications cannot be implemented by many of the well-established materials, such as single plastics, metals or ceramics. Hence, engineers and scientists realized that, in comparison with pristine counterparts of material, the mixtures of materials can produce much better properties. Polymer nanocomposites is a new form of materials that resulted by the combination of polymers and nanofillers which contributed to various benefits over the neat polymer such as improvement in biocompatibility, biostability, thermal stability, flame retardancy, mechanical and barrier properties. Due to these factors, nanocomposites have received an extraordinary consideration for use in broad range of applications. However, the polymer nanocomposites which comprised of copolymer as matrix material are not widely studied, especially those involved poly(ethylene-co-vinyl acetate) (PEVA). The production of PEVA copolymer-based nanocomposites for various applications has been reported by few research papers. In this communication, a review on the properties of PEVA-based nanocomposites with different types of nanofiller was summarized, revealing the high potential of this class of nanocomposite for advanced applications.
Effect of Cascade Aerator Height and Flow Rate on Removal of Iron and Manganese from Groundwater at Rumah Nur Kasih
Authors: Faiz Syazwan Md Razif Muhammad , Remy Rozainy Mohd Arif Zainol Mohd , Jamil Rhahimi , Rahim I A
Published: July 2020

The quality of groundwater at Rumah Nur Kasih consist high concentration of iron (6.12 mg/L) and manganese (0.56 mg/L). The groundwater only used for external usage such as cleaning purposes. In order to reduce iron and manganese, it is proposed cascade aerator system for oxidation process. The oxidation process can reduce iron and manganese in water by increasing the dissolved oxygen. Cascade aerator is greatly influenced by the flow rate along the step and the dimension of the cascade aerator. In this study, two lab scale cascade aerators with different in height of cascade were used to find the highest removal of iron and manganese. It was found out that the optimum flowrate for both cascade aerator was 22 ml/s. Model B with higher in height has higher dissolved oxygen and removal efficiency. The removal of iron and manganese for model B are 45.2% and 21.68% respectively. The removal of iron and manganese for model A are 39.95% and 12.09% respectively.
Effect of Environmental Temperature and Humidity on Different Metal Oxide Gas Sensors at Various Gas Concentration Levels
Authors: Nabil Abdullah Abdulnasser , Kamarudin Kamarulzaman , Muhammad Mamduh Syed , Hamid Adom Abdul , Hadi Mohd Juffry Zaffry
Published: July 2020

Metal Oxide (MOX) semiconductor gas sensors have been widely used in monitoring targeted gases that are present in the environment. This type of gas sensor can also be utilized as a safety device to detect the source of gas leakage. Their uses in many applications are due to being user-friendly, lower in cost, high sensitivity and relatively quick response time. However, there are several factors that could affect their performance. This work investigates the effects of the changes in ambient temperature and humidity on the readings of these sensors at various gas concentration levels. A PCB board was developed, which consists of temperature and humidity sensors, as well as eight different MOX gas sensors (TGS2600, TCS2602, CCS803, MiCS552, GM-402B, GM-502B, GM-702B and MiCS6814). The board was subjected to various temperatures (16˚C to 30˚C) and humidity levels (45% to 75%). At each of these parameter settings, the gas sensor responses were recorded at different ethanol gas concentrations. The results of the study showed that the temperature and humidity affected all the gas sensor response. The magnitude of the sensors responses was observed to decrease with rising temperature and humidity levels, except for MICS6814 (NH3 sensor) which responses in the opposite manner. Hence, there is the need to take into consideration of the drift of gas sensors’ responses when there are changes in temperature and humidity.
Analysis of the Behaviour and Effect of Grounding Filler Materials on Grounding System
Authors: Aqilah Sofiyah Hasni Nur , Nizam Md Arshad Syahrun , Md Ariffen Amizah , Helmei Halim Nasrul , Chin Leong Wooi , Izuan Fahmi Romli Muhammad , Abu Bakar Osman
Published: July 2020

The grounding system plays an important role in the electrical system part as it gives protection during fault or lightning occur. The main purpose of the grounding system is to protect humans, electrical appliances and buildings from electrical shock due to lightning or another form of electricity that hazardous. Thus, to install an excellent electrical system and complete its circuit, a grounding system performance must be taken into account. But, in certain cases, due to the geological condition, the soil resistivity is not good enough. Therefore, enhancement filler material has been used to reduce grounding resistance. In this project, it is aimed to elaborate on the usage of Coconut Husk, Paddy Husk, and Bentonite as grounding filler materials to reduce the soil resistivity and improves the grounding system. The result showed that Bentonite showed better performance compared to Coconut Husk and Paddy Husk.
Review on RTV Silicone Rubber Coatings Insulator for Transmission Lines
Authors: Huzaimah Kamal Hamadi Siti , Isa Muzamir , Nizam Md Arshad Hashim Syahrun , Othman Mardianaliza
Published: July 2020

Nowadays, the usage of RTV Silicone Rubber as Insulator coatings are increased due to its advantages to avoid pollution flashover of contaminated insulator. Besides, the coatings can reduce the maintenance cost and scheduled routine. This paper had introduced the advantage of RTV Silicone Rubber coatings on insulator, such as good adhesion, nominal thickness range and good hydrophobicity. There are three method of coatings application, such as brushing, spraying and dipping. Suitable method is used to specific insulator application. Meanwhile, this paper also explained about installation of coated insulator in the field.
Mechanical Design and Evaluation of Kapok Fibre Seeds Separator
Authors: Ikman Ishak Muhammad , Rosli M U , Ahmad Termizi S N A , Khor C Y , Asrul Abdullah Muhamad , Nawi M A M
Published: July 2020

The demand on Kapok fibre-based products has currently shown an increase particularly those from small business traders in comparison to massive market sellers due to lower cost offered. However, the small business traders commonly use manual technique to separate the Kapok fibre from its seed before continuing to the next stages, thus, leading to labour-intensive work, longer processing time, and low output. The aim of the study was to design and develop a Kapok fibre seeds separator to efficiently perform the work. A number of idea generation and concept development phases were undertaken. The finalised concept was the transformed into a three-dimensional (3-D) model using a computer-aided design (CAD) software. A computational 3-D finite element analysis (FEA) was conducted to evaluate the structural performance under simulated loadings. Also, the product prototype was built and its usability has been tested. The outcomes of 3-D FEA showed that the highest mechanical stress recorded within the structure was favourable with low tendency towards failure. Whilst, the results of usability testing demonstrated that the proposed product reported an increase of 52.8% in the amount of separated seeds. Thus, the new design of Kapok fibre seeds separator is found to be superior in solving the problems issued by the manual processing technique.
Effect of Using Soap Nut as Natural Foaming Agent on Mechanical Properties and Pore Distribution of High Strength Aerated Concrete
Authors: Abdullah M A H , Rashid N A , Abdul Rani A L , Omar M F , Tan C C
Published: July 2020

Aerated concrete is a type of concrete that contains pore in its matrix structure. This pores could provide spaces for water absorption which makes aerated concrete more durable toward freeze-thaw cycle. Many methods have been studied in forming an aerated concrete and using soap nut as aerating agent is more sustainable than other chemically formulated agent. Forming of pore inside concrete not only improve freeze-thaw cycle durability but also as places to store healing agent in concrete. This is important in developing a self-healing concrete especially a microbial induced healing. This paper aims to study the effect of using soap nut in high strength concrete. Four types of high strength concrete samples were prepared which are Control sample, AE2 with 2% of aerated soap nut, AE4 with 4% of aerated soap nut and AE6 with 6% of aerated soap nut. Total of 3nos. of 100mm cubes and 3nos. of 50mm cubes from each type of samples were prepared. Cubes samples of 100mm dimension were tested for water absorption and compressive strength while cube samples of 50mm dimension were split and analysed for pore distribution. The results showed that increase in addition of soap nut in concrete mixture resulted in decrease of compressive strength but minimal effect on its water absorption rate. Pore formation and dispersion were optimum in concrete with 4% and 6% inclusion of soap nut. In conclusion, 4% of aerated soap nut in high strength concrete present the optimum characteristic in producing well-dispersed pores of high strength aerated concrete.
Effect on Product Yield and Tar Composition through Co-Gasification of Pretreated Palm Kernel Shell and Mukah Balingian Coal
Authors: Ahmad Razi , Azlan Mohd Ishak Mohd , Nasulhah Kasim Nur , Ismail Khudzir
Published: July 2020

In this study, co-gasification of palm kernel shell (PKS) and Mukah Balingian (MB) coal was carried out in a fixed bed reactor. The effect of sample pretreatment of both samples were explored via co-gasification towards product yields and tar composition. Results indicated that, pretreated blending samples produced higher gas yield with lower tar and char yield than the untreated blending samples. This was due to low moisture and oxygenated components of the pretreated samples prior to co-gasification. The tar composition of the pretreated blending samples showed increasing in the aromatic and aliphatic alkane, whereas, noticeable decreasing of phenol and carbonyl. Thus, pretreated of PKS and MB coal have prominence influence on the distribution of product yields and tar composition through co-gasification.
Design for Manufacturing and Assembly (DFMA): Redesign of Joystick
Authors: Nasyitah Mohammad Nor , Rosli M F , Fadzly M K , Syaiyidah Mohamad Salikan Nur , Effendi M S M
Published: July 2020

Design is the first step in any manufacturing process where the most crucial decisions are made which affect the product’s ultimate cost. The researchers used DFMA method in this study to redesign and improve a joystick in order to achieve the goal to decrease the number of parts, handling and insertion time, and improve the design efficiency for a joystick. The main emphasis in this research has been on the design stage of a product development, with a view to accomplishing an optimal design approach for current product.DFMA principles have been used to develop new design ideas and the final design will be evaluate and compared to the current design. In result, the assembly time for redesign then increased by 21 % with a decrease in the assembly time from 294.2s to 232.44s and an improvement in design efficiency by 26.5 % from 20.4 % to 25.8 %.
Application of Building Information Modeling in Data Center design
Authors: Rybakova Angelina , Kagan Pavel
Published: July 2020

The constant increase in operating costs of data centers (DC) is the driving force behind innovations to increase their efficiency. Today, one of the newest ways to improve the design and functionality of data centers is the integration of building information modeling (BIM). The aim of the work is to analyze the possibilities of increasing the efficiency of the data center design stage based on the use of BIM-technologies, and the task is to design data center systems of all levels of certification of the Uptime Institute. The integration of the capabilities of BIM-technologies during design increases the efficiency of both the general design of the facility and special design indicators of data centers. This article sets out the basics of integrating BIM and data centers, a working mechanism for their interaction when designing the required level of functionality of the Uptime Institute with the design, as well as the possibility of using BIM-data from the design stage in the subsequent stages of installation and operation.
Application of Green Roofing Technologies as Site Landscaping
Authors: Luchkina Veronika
Published: July 2020

Due to the problems of the urban environment, people began to develop the technologies for “green” roofings as site landscaping. The purpose of the study was to examine the design methods of “green” roofings and to identify their unique positive properties. The research objectives consisted of the analysis of the “green” roofing technology and the identification of their weak points. The study examined external and internal environmental factors characterizing the possibility of using the roof of the building. The following normative characteristics were considered as design methods for “green” roofings: load-bearing bases and slopes, load calculation, waterproofing, roots protecting barrier, protective layers, thermal insulation, vapor barriers, and building units. The results of the study are organizational and technological design solutions for a “green” roofing using regulatory documentation. The weak points of the “green” roofing can be solved by competent design and high-quality performance. “Green roofings” can be more widely developed especially in multi-storey constructions. Any one-time costs in the design and construction of any facility are economically justified if they provide low operating costs when using these facilities. The developers pay attention to the compositions and design concept of the layers of the cultural environment for growing plants, as well as methods of preserving the plant substrate. The design concepts related to operating roofs are of great interest: arrangement of sports grounds, pools, walking paths. The arrangement of a green roof is a multi-directional technological task and, if necessary, the purpose of the subsequent research. We can single out the implementation of forecasting the further development of green roofing technologies. In the future, a large number of green roofings can increase the ecological rating of the area.
Sustainable use of industrial-waste as fine-aggregate of Foam Concrete
Authors: Vu Kim Dien , Bazhenova Sofya , Tang Van Lam , Cong Ly Nguyen
Published: July 2020

The benefits of using industrial waste as a replacement for natural sand and cement in light-weight concrete are also discussed. The paper presents the use of fly ash and blast furnace slag to replace 100% sand in foam concrete with a wet density of 1700 kg/m3 and 900 kg/m3 as well as their mechanical properties. The absolute volume method was used to calculate the ratio of foam concrete mixture. Besides, the foam concrete mechanical properties are determined according to the Russian standard GOST 10180-2012. Research results indicate that at the age of 28 days with Series I, the value of compressive strength obtained from 13.91MPa to 42.35 MPa, flexural strength from 0.53 MPa to 1.06 MPa and water absorption between 0.92% and 5.78% with Series II these values from 1.69 MPa to 8.22 MPa for compressive strength, from 3.25 MPa to 6.72 MPa for flexural strength and the result for water absorption is in the range of 12.35% and 22.16%. Besides that, research results also indicate that the correlation between dry density and compressive strength has a positive linear relationship. The results of this study have proved that foam concrete uses fly ash and blast furnace slag can replace traditional concrete in construction as well as replacing clay bricks will not only improve concrete strength but also reduce costs as well as protect the environment.
Study on particle size distribution of aggregate from coal ash for heat-resistant concrete
Authors: Phuong Do Thi , Lam Nguyen , Duc Vu Minh
Published: July 2020

In Vietnam, the current amount of thermal ash (fly ash and bottom) remains nearly 100 million tons, causing great environmental and social impacts. The recycling and reuse of this source of waste is an effective solution towards sustainable development. The paper introduces the results of study on some properties and particle size distribution of aggregate from thermal ash, Duyen Hai factory for refractory concrete. Particle composition is calculated and selected according to the density of particle size arrangement with the maximum number of points of contact. The continuous particle size distributions of thermal ash is calculated by Andersen’s formula with Dmax = 5 mm. The bulk density and porosity of the particle mixture corresponding to the vibrating modes is determined. By the experimental planning method (Design of experiments - DoE), the optimal aggregate particle composition was determined with the calculated value of n = 0.387 and the vibration time of 90 s gives the maximum bulk density of 1313.17 kg/m3 and the smallest actual porosity is 34.69%.
Methodology for the integrated assessment of design solutions for foundation pit fences based on the theory of active systems
Authors: Zheglova Yulia , Titarenko Boris
Published: July 2020

To automate the selection of design solutions for foundation pit fences, it is necessary to build an integrated mechanism. However, for the real construction projects with various engineering and geological conditions, there are many design solutions for foundation pit fencing that satisfy the calculations for the limiting conditions. A rather difficult task is the issue of optimizing various parameters that must be taken into account when developing a design solution, as well as evaluating various possible options and choosing the most appropriate need from them, not only in terms of cost, but also the safety of residents. The paper proposes a methodology for assessing design solutions for foundation pit enclosures based on the theory of active systems.
Anchoring devices for mounting reticulate catchers on rocky sections of roads
Authors: Lelikov Georgy , Prostakishin Dmitry
Published: July 2020

This paper discusses an important aspect of ensuring safety during construction work at height, as well as when installing protective elements that catch possible falling parts of the terrain, when it is adjacent to the roadway and other communication routes. The purpose of the field tests was to verify the stability of products on the terrain with the application of static and dynamic loads. The stability test was carried out during installation on different rocks and also different regions of the CIS countries. Dynamic tests simulating cargo stall at various factors, followed by researching the ways to stop the falls. Static tests were carried out using manual tension systems - tackles. Tests in the laboratory were carried out in order to determine the destructive load on the product. For this, a special test mold was made that simulated the natural conditions. All tests were carried out using anchoring devices of various sizes, as well as with different options for the installation depth and support of the anchor. During the tests, a number of features based on the design form were discovered. The results of laboratory tests are displayed in the table with data for all test samples. A comparison was made of the bearing characteristics. As a result of this work, both the positive and the negative aspects were identified, it was especially important that the question arose of the need to possess the necessary competencies for installing this type of device.
Maintenance of comprehensive safety of tunnel-type road interchanges
Authors: Ginzburg Alexander , Kachanov Sergey , Kozminikh Sergey
Published: July 2020

Numerous people, dead and injured as a result of road accidents at the tunnel-type interchanges proves that the measures, taken for prevention of emergency situations in tunnels are insufficient. At the same time, various monitoring systems are installed at such facilities, being not connected among themselves. So, they cannot reduce, but can even increase the consequences severity in case of emergency situation because of the inconsistency of joint operation of the automated control systems for safety and life support at the road interchanges of tunnel type. The analysis of possible types of threats for the road interchanges of tunnel type allows to conclude, that some adequate measures for ensuring their safety can be taken only with the use of automated systems of remote monitoring of the facilities condition, modern communication systems, organization of the proper training of specialists for complex safety of facilities as well as advanced trainings of designers in this sphere. The main causes of emergency situations at the road tunnel-type interchanges are considered to achieve this goal. The causes of insufficient efficiency of the existing technologies and technical means of ensuring complex safety of tunnels are also analyzed. The technology of complex safety of the road tunnel-type interchanges is developed and approved on the basis of the carried-out analysis and with the use of methods of systems analysis and the theory of experiment. Experimental studies were carried with the use of the theory of experiment and the use of certified measuring instruments. It was proved scientifically and confirmed experimentally, that the offered technology of complex safety of the road interchanges of tunnel type allows to reduce risk of emergency situations and people’s death in tunnels by more than 50%.
On the Nature of the Acoustic Oscillations in Gas Explosions
Authors: Polandov Iurii Kh. , Korolchenko Anton , Dobrikov Sergei
Published: July 2020

The possible existence of acoustic oscillations (oscillating combustion) in gas explosions in unclosed volumes is known. A significant increase in risks was confirmed, if it happens indoors, which makes studies in this direction relevant. But the solution to this problem has proven difficult for two reasons. First, the results of the experimental studies turned out to be reproducible with weak reliability. This circumstance takes place, despite the fact that the first classical experiments, resulting in acoustic oscillations during gas heating, date back to the 19th century. The second reason why research is difficult is that by now there are no reliable mathematical models describing the process of excitation and development of oscillating combustion in gas explosions. The gas explosion simulation using the example of cylindrical chamber with a diameter of 200 mm and a length of 1.5 meters and a window on the lateral surface. The chamber in the initial state is filled with propane-air mixture, which is ignited at the left end along the chamber axis. The validity of mathematical model was checked by comparing the results of the gas explosion development calculation in the tube with other known results obtained in the closed circular tubes.
Estimation of loads’ main statistics for hot materials silo
Authors: Maj Marek , Ubysz Andrzej
Published: July 2020

The paper presents a statistical description of the values of random variables of pressure and temperature as the most important loads on wall of silo, in which hot materials, such as cement, clinker, fly ash, and raw meal are stored. An attempt to statistically describe the pressure and temperature and their additive share in loads are clearly present in the standards and guidelines for reinforced concrete (RC) silo design. The authors conducted many experiments and measurements of pressure and temperature that impact on the silo walls. For example, in a silo for a hot cement, variable pressure and temperature of the silo wall were measured simultaneously. In this example, coincidence coefficients for temperature and pressure were calculated using many statistical methods. For the pressure, a statistical determination of characteristic values was proposed.
Determination of the scale factor in the physical modeling of reinforced concrete structures exposed to emergency loads
Authors: Korenkov Pavel , Chemodurov Vladimir , Manaenkov Ivan , Korenkova Olesia
Published: July 2020

The article proposes a solution to the problem of more accurately taking into account the influence of scale factors on the qualitative and quantitative indicators of the stress-strain state obtained by testing both individual structures and structural systems made of reinforced concrete. Methodical approaches to modeling tests for static and dynamic loads are considered, with the aim of taking into account the scale effects that occur during the manufacture of prototypes of models of individual structures and structural systems made of reinforced concrete. Comparative analysis estimated effect of different geometric proportions for free opera statically determinate beams and for a fragment of a monolithic reinforced concrete frame multistory buildings, experimental studies which were performed by the authors earlier. Analytical patterns were established to assess the impact of large-scale factors on the particular static and dynamic deformation of structures and structural systems of reinforced concrete. The results can be taken into account when conducting experimental studies of model reinforced concrete structures for dynamic emergency loads
Reliability of building structures in case of an air blast wave
Authors: Mkrtychev Oleg , Savenkov Anton
Published: July 2020

The analysis shows that the parameters of the air shock wave vary significantly and have a pronounced random nature. In general, in structural analysis, design parameters of the shock wave are random functions or random variables; therefore, the reaction parameters of the system under consideration will also be random. Then, fulfillment of certain conditions (for example, strength) is only possible with a certain probability, and the reliability of the system under consideration can be estimated using methods of building structures reliability, methods of mathematical statistics and probability theory. As a result, a probabilistic model of an air shock wave has been developed and the reliability of a free-standing wall has been estimated for random exposure parameters, as well as for random strength characteristics of materials. Based on the calculation results, it was concluded that the calculation of reliability using methods of mathematical and statistical probability theory makes it possible to bring the strength analysis of building structures closer to actual operating conditions.
On ignition of combustible material in a gas explosion in the premise
Authors: Korolchenko Dmitriy , Kh Polandov Iurii , Evich Andrey
Published: July 2020

Introduction. There are known cases of fires after gas explosions in domestic residential premises, exacerbating an already dangerous situation. Determining the conditions for the occurrence of such fires, as well as the process of behaviour of combustible materials during the short-term thermal effect of a gas explosion, allows us to hope for the possibility of reducing fire risks through research and the development of appropriate measures. Methods Experimental studies were carried out in a cubic chamber with a volume of 10 m3 filled with a propane-air mixture. Explosion pressure and video inside the chamber were recorded. To assess the magnitude of the effects of flame and combustion products of a gas explosion on combustible material, specially developed indicators with a sensitive element – sheet of paper. Results. The images of sensitive elements of indicators with the level of brightness after exposure to a flame and combustion products of a gas explosion are presented. Frames from a video camera installed inside the camera are also presented. Discussion. The conditions for ignition of combustible materials are: low heat capacity, position in the volume of premise and the entry of outside air. Conclusions. It is established that combustible materials in the corners of premise are less affected by the flame and combustion products of a gas explosion. Combustible material ignites when external air enters after an explosion.
Analysis of the accuracy of CPT and leading parameters methods to determination of the pile bearing capacity
Authors: Polańska Bernadetta , Szabowicz Hubert
Published: July 2020

The paper presents a comparison of various methods used to calculate the bearing capacity of columns and the results of static loads. In the first part of the article, the methodology for the calculation of the load bearing capacities based on CPT static probes and using leading parameters are presented. Next, the investment and the hydrogeological conditions in which the columns were made are described and then subjected to test loads. The results include a summary of the dependence of the length of the columns on their load bearing capacity calculated with three methods for two different CPT sounds. A comparison of the results of calculated settlement of the column head depending on the amount of force applied to them and the results from static loads is also provided.
Application of Synthetic Aperture Focusing Technique to visualize GPR data from reinforced concrete structures
Authors: Dinh Kien , Pham Tung T. , Nguyen Tu T. , Vu Hiep H.
Published: July 2020

Ground Penetrating Radar (GPR) has been proven to be the most effective technology for imaging and evaluating the condition of concrete structures. That said, this paper presents an algorithm to automatically visualize GPR data collected from reinforced concrete structures. Specifically, the algorithm is based on the synthetic aperture focusing technique (SAFT) and is executed with two GPR data sets collected in a perpendicular survey grid. In the first step, for each scan line in a data set, a B-scan is reconstructed from the corresponding raw data using the SAFT technique. In the second step, the linear interpolation is employed, for each data set, to generate missing information between B-scans and create a 3D image of the surveyed object. Finally, by retaining the maximum amplitude of each corresponding voxel in the two images obtained from the second step, a combined 3D model is created.
Interaction of shock waves with elastic-plastic medium
Authors: Khudainazarov Sherzod , Donayev Burxon , Abdimuminov Erkin , Suyunova Yulduz
Published: July 2020

The problem of spherical shock wave propagation in an elastic-plastic medium is solved analytically and numerically by the method of characteristics on the basis of the strain theory, including the generalized equations of state of the medium. The spherical shock wave propagation in an elastic-plastic medium with a more complex equation of state for the medium forming is studied. The results show that an account for nonlinear–elastic shock diagrams leads to an increase in circular stress wave compared to an elastic medium. It was found that the stress concentration is higher on the spherical cavity than on the cylindrical one.
Evolutionary-based optimization of steel moment frames using direct analysis method
Authors: Nguyen Tran-Hieu , Vu Anh-Tuan
Published: July 2020

Steel moment frames are widely used in multi-story buildings due to their advantages such as robust as well as flexibility in architectural planning. This paper proposes a design method of steel moment frames based on an optimization algorithm called Differential Evolution. In the optimization problem, the design variables are the cross-sections of the steel members while the objective function is the total weight of the frame. The frame is designed based on the direct analysis method which is specified in the ANSI/AISC 360-10 “Specification for Structural Steel Buildings”. A program, called FrameOpt, is developed using Visual Basic for Application language to implement the optimization algorithm. This program connects to the SAP2000 analysis program for the steel design through the open Application Programming Interface feature. An example is conducted to demonstrate the applicability of the proposed method.
Application of Building Information Modeling (BIM) for automatic integration of construction costs management information into 3D models in consideration of Vietnamese regulations
Authors: Quoc Toan Nguyen , Thi Thu Hang Nguyen , Nam Le Hoai , Hong Duyen Dang , Phuong Nam Tran
Published: July 2020

Some countries concentrate to study on BIM as an effective tool in quantities taking-off and costs estimating. In contrast, due to special features of Vietnamese law regulations, issues on BIM application for these works are still not considered properly in Vietnam. Therefore, in this research, the authors would like to review studies performed on BIM uses on these works in Vietnam, and to analyze the necessities and difficulties when using BIM for automatically taking off quantities and estimating construction costs, then to propose technology methods for addressing this issue. Two methods are proposed to automatically calculate construction works quantities and costs based on models designed in Revit, more specifically, the first one is using Keynote to develop a database on components codes and to establish the components schedule in Revit; the second is using Dynamo to develop connection nodes between Revit models and Excel Sheets, facilitating the data export from Revit to Excel, then using Excel to adjust data in consistency with models.
Mathematical and mental modeling for ecological reconstruction of the environment of construction objects
Authors: Slesarev Mikhail , Kovrigin Arthur , Kafanova Julia
Published: July 2020

It seems very timely and relevant mathematical and mental modeling for ecological reconstruction of the environment of construction objects because it is almost the first attempt to algorithmize, by analogy with artificial intelligence, the modeling processes for managing the activities of the decision-making Manager, and helps to algorithmize the decision-making processes by placing mental models in the conscious activity of the Manager, and mathematical models in his personal gadget for environmental reconstruction. For a simple case of ecological reconstruction, oral calculations are sufficient, or you can use a verbal (mental) model, in a more complex case, you will need a sheet of paper to analyze the problem problem, and in an even more complex case, you will need a computer for modeling, and finally, you can use a special optimization computer program. Any modeling is aimed at making adequate management decisions. Modeling using computer tools, including mobile gadgets (iPhones, smartphones, tablets, etc.) becomes a common stage in decision-making in all areas of activity, in managing any process and achieving the desired result. Therefore, the development of modeling methods and techniques, the principles of building mental and mathematical models, and the choice of means for their implementation, using modern software products, is of paramount importance today for supporting decision-making by a Manager, engineer, designer, designer, Manager, business analyst, etc. The problem of the innovation process in energy construction cannot be solved without using mathematical tools. The human brain is not able to predict all possible consequences of innovation in a timely manner, so forecasting and modeling the future and consequences of the innovation process requires simulation based on mathematical and mental modeling for its solution. Examples of models of ecological reconstruction of the environment of construction objects are given.