scholarly journals Research of Mechanochemical Processes of Activation of Building Materials by Air-Impact Method

2021 ◽  
Vol 304 ◽  
pp. 02009
Author(s):  
Igor Kravchenko ◽  
Mihail Erofeev ◽  
Aleksandr Fedorov ◽  
Valeriy Kondrashchenko ◽  
Diana Abdumuminova ◽  
...  
Keyword(s):  
Building Materials ◽  
Initial Period ◽  
Experimental Studies ◽  
Activation Process ◽  
Design Strength ◽  
Concrete Mixtures ◽  
Operational Characteristics ◽  
Proposed Model ◽  
Local Materials ◽  
Control Composition

To increase the specific surface area of the binder and accelerate the strength gain of fast-hardening concrete mixtures, a model has been created for calculating aeroactivators as part of mobile complexes based on new equipment for cement activation, sand enrichment, local materials, and production waste. The proposed model establishes the dependence of the rate of destruction of the dusty shell of particles on the mechanical impact of the beaters and materials` physical and mechanical characteristics. To improve the operational characteristics of the cement aeroactivator, experimental studies were carried out, the results of which made it possible to determine the rational parameters of the developed installation. Based on the test results, it was found that the use of the cement activation process with additives accelerates the hardening process of concrete and mortar mixtures in the initial period, increases the design strength of concretes and mortars by 20–40% in comparison with the strength of the control composition at the same cement consumption, and also reduces the consumption cement up to 17% to obtain concretes and mortars equal to the control composition at the design age.

scholarly journals Study of the Implementation of Fibrous Materials and Earth in Hollow Body Slab in Reinforced Concrete: Case of Laterite, Borassus Aethiopum and Calamus Deerratus Woods

2021 ◽  
Author(s):  
Yemalin Daniel Agossou ◽  
Thomas Dèkandji Ekpo ◽  
Rémi Boissiere ◽  
Edmond Codjo Adjovi ◽  
Edem Chabi ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Social Housing ◽  
Building Materials ◽  
Experimental Studies ◽  
Fibrous Materials ◽  
Market Values ◽  
Local Materials ◽  
Push Out ◽  
Borassus Aethiopum

Abstract This work enrolls in the context of eco materials. It concerns the field of transformation of local shrub forest resources and lateritic earth with low market values into building materials and is developing a process for the valorization of lateritic nodules, Borassus aethiopum (palmyra) and Calamus deerratus (rattan) in the engineering of modern reinforced concrete structures. The objective of this process is to promote the rational use of these local materials in the realization of the floors of social housing. Experimental studies of physical and mechanical characterizations of the lateritic concrete formulated, of the palmyra and rattan woods were carried out. Through tests of tearing and sliding of the interface between normal concrete and laterite concrete (push-out tests), it has been highlighted the adhesion of palmyra wood to concrete and the contribution of rattan lianas to oppose the longitudinal sliding of the interface between two concretes of different nature. The case study of a hollow body slab in mixed concrete (normal and laterite concrete) reinforced with palmyra and rattan woods, showed the structural effectiveness of lateritic earth, of palmyra and rattan woods in the realization of social housing modern slads with a range of up to 5 meters.

A Relativistic Newtonian Mechanics Predicts with Precision the Results of Recent Neutrino-Velocity Experiments

2014 ◽  
Vol 6 (1) ◽  
pp. 1032-1035 ◽  
Author(s):  
Ramzi Suleiman
Keyword(s):  
Null Hypothesis ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Newtonian Mechanics ◽  
Speed Of Light ◽  
Symmetry Principle ◽  
Proposed Model ◽  
Significant Difference ◽  
The One ◽  
Complete Collapse

The research on quasi-luminal neutrinos has sparked several experimental studies for testing the "speed of light limit" hypothesis. Until today, the overall evidence favors the "null" hypothesis, stating that there is no significant difference between the observed velocities of light and neutrinos. Despite numerous theoretical models proposed to explain the neutrinos behavior, no attempt has been undertaken to predict the experimentally produced results. This paper presents a simple novel extension of Newton's mechanics to the domain of relativistic velocities. For a typical neutrino-velocity experiment, the proposed model is utilized to derive a general expression for . Comparison of the model's prediction with results of six neutrino-velocity experiments, conducted by five collaborations, reveals that the model predicts all the reported results with striking accuracy. Because in the proposed model, the direction of the neutrino flight matters, the model's impressive success in accounting for all the tested data, indicates a complete collapse of the Lorentz symmetry principle in situation involving quasi-luminal particles, moving in two opposite directions. This conclusion is support by previous findings, showing that an identical Sagnac effect to the one documented for radial motion, occurs also in linear motion.

An analytical model for predicting the shear strength of unsaturated soils

2022 ◽  
pp. 1-57
Author(s):  
Tuan A. Pham ◽  
Melis Sutman
Keyword(s):  
Shear Strength ◽  
Analytical Model ◽  
Unsaturated Soils ◽  
High Performance ◽  
Micromechanical Model ◽  
Experimental Studies ◽  
Stress Equilibrium ◽  
Proposed Model ◽  
New Equation ◽  
Multi Phase

The prediction of shear strength for unsaturated soils remains to be a significant challenge due to their complex multi-phase nature. In this paper, a review of prior experimental studies is firstly carried out to present important pieces of evidence, limitations, and some design considerations. Next, an overview of the existing shear strength equations is summarized with a brief discussion. Then, a micromechanical model with stress equilibrium conditions and multi-phase interaction considerations is presented to provide a new equation for predicting the shear strength of unsaturated soils. The validity of the proposed model is examined for several published shear strength data of different soil types. It is observed that the shear strength predicted by the analytical model is in good agreement with the experimental data, and get high performance compared to the existing models. The evaluation of the outcomes with two criteria, using average relative error and the normalized sum of squared error, proved the effectiveness and validity of the proposed equation. Using the proposed equation, the nonlinear relationship between shear strength, saturation degree, volumetric water content, and matric suction are observed.

Impact of Curbside Parking on Bicycle Lane Capacity in Nanjing, China

2018 ◽  
Vol 2672 (31) ◽  
pp. 120-129 ◽  
Author(s):  
Xiaofei Ye ◽  
Xingchen Yan ◽  
Jun Chen ◽  
Tao Wang ◽  
Zhao Yang
Keyword(s):  
Middle Position ◽  
Capacity Model ◽  
Operational Characteristics ◽  
Proposed Model ◽  
Volume Relationship ◽  
Lane Width ◽  
Relationship Model ◽  
Bicycle Lane

As roadway resources are being occupied by curbside parking and because of the operational characteristics of parking maneuvers, the capacity of the adjacent travel lane can be significantly reduced. To analyze the influence of curbside parking on the capacity of the bicycle lane, a conflict technique based on additive conflict flow was applied to establish the base capacity model. The actual capacity of the bicycle lane with curb parking was then established by adjusting the base capacity to reflect the influence: lane width, the time influence of parking maneuvers, and proportion of e-bikes. Eight datasets from the exclusive bicycle lanes with different widths and parking maneuvers were collected in Nanjing, China for calibration and evaluation purposes. As a result of a higher number of parking maneuvers, the Emeiling Road was taken as the main case study. The capacity of the bicycle lane was calculated, and the effectiveness of the proposed method was validated by the speed-density-volume relationship model. The proposed model was applied to analyze the effect of different positions of parking berths on the capacity. The results indicate that, with around 65% share of e-bikes, the estimated capacity of Emeiling Road is 2622 bicycles/h, decreasing by 47.10% under the influence of curbside parking. The results also imply that the berths near the openings of the isolation belt have less influence than those in the middle position. These findings could be helpful and useful for practitioners to improve the capacity of bicycle lanes under the influence of curbside parking.

scholarly journals Concrete based on sulfur binder being modified with inorganic additives

2018 ◽  
Vol 212 ◽  
pp. 01013
Author(s):  
Vadim Balabanov ◽  
Victor Baryshok ◽  
Nikita Epishkin
Keyword(s):  
Frost Resistance ◽  
Building Materials ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Strength Properties ◽  
Climatic Conditions ◽  
Freezing And Thawing ◽  
Concrete Mixtures ◽  
Irkutsk Region ◽  
Water Saturated

The sharply continental climate of the Irkutsk region is characterized by wide temperature intervals throughout the year. The repeated cyclicity of freezing and thawing of building materials in the water-saturated state influences the change in technical characteristics and the durability of concrete products and structures. The concrete products’ features in such climatic conditions create the need for the production of concretes with improved indicators of physical and mechanical properties. The effect of modifying additives on the technological characteristics of sulfur concrete is established. The effect of all elements of sulfur concrete on its strength and frost resistance. The composition of sulfuric concrete is obtained, which meets all the requirements and also has high strength and increased frost resistance. Formulations with a certain ratio of structural sulfuric concrete mixtures were developed. As a result of the use of technical sulfur in the composition of concrete products, the problem of utilizing annually accumulating reserves of technical sulfur is partially solved. The strength properties of sulfuric concretes easily compete with high-quality brands of concrete, special types of concretes that have in their composition additives.

scholarly journals Analytical Model for Restraint Strains and Self-stressed in Expansive Concrete Filled Steel Tubes (ECFST) estimation

2020 ◽  
pp. 93-98
Author(s):  
Viktar V. Tur ◽  
Radoslaw Duda ◽  
Dina Khmaruk ◽  
Viktar Basav
Keyword(s):  
Experimental Data ◽  
Experimental Studies ◽  
Steel Tube ◽  
Development Model ◽  
Steel Tubes ◽  
Concrete Core ◽  
Expansive Concrete ◽  
Proposed Model ◽  
Comparison Results ◽  
Concrete Filled Steel Tubes

In this paper, a modified strains development model (MSDM) for expansive concrete-filled steel tube (ECFST) was formulated and verified on the experimental data, obtained from testing specimens on the expansion stage. The modified strain development model for restraint strains and self-stresses values estimation in concrete with high expansion energy capacity under any type of the symmetrical and unsymmetrical finite stiffness restraint conditions was proposed. Based on proposed MSDM a new model for expansive concrete-filled steel tubes is developed. The main difference between this model and other previously developed models consists in taking into account in the basic equations an induced force in restrain that is considered as an external load applied to the concrete core of the member. For verification of the proposed model-specific experimental studies were performed. As follows from comparison results restrained expansion strains values calculated following the proposed model shows good compliance with experimental data. The values predicted by the proposed MSDM for concrete-filled steel and obtained experimental data demonstrated good agreement that confirms the validity of the former.

scholarly journals Ensemble of Deep Capsule Neural Networks: An Application to Pneumonia Prediction

2022 ◽  
Author(s):  
Jyostna Bodapati ◽  
Rohith V N ◽  
Venkatesulu Dondeti
Keyword(s):  
Performance Measures ◽  
Laboratory Testing ◽  
Deep Neural Network ◽  
Routing Algorithm ◽  
Experimental Studies ◽  
Single Model ◽  
Appropriate Treatment ◽  
Pediatric Pneumonia ◽  
Proposed Model ◽  
Pneumonia Diagnosis

Abstract Pneumonia is the primary cause of death in children under the age of 5 years. Faster and more accurate laboratory testing aids in the prescription of appropriate treatment for children suspected of having pneumonia, lowering mortality. In this work, we implement a deep neural network model to efficiently evaluate pediatric pneumonia from chest radio graph images. Our network uses a combination of convolutional and capsule layers to capture abstract details as well as low level hidden features from the the radio graphic images, allowing the model to generate more generic predictions. Furthermore, we combine several capsule networks by stacking them together and connected them with dense layers. The joint model is trained as a single model using joint loss and the weights of the capsule layers are updated using the dynamic routing algorithm. The proposed model is evaluated using benchmark pneumonia dataset\cite{kermany2018identifying}, and the outcomes of our experimental studies indicate that the capsules employed in the network enhance the learning of disease level features that are essential in diagnosing pneumonia. According to our comparison studies, the proposed model with Convolution base from InceptionV3 attached with Capsule layers at the end surpasses several existing models by achieving an accuracy of 94.84\%. The proposed model is superior in terms of various performance measures such as accuracy and recall, and is well suited to real-time pediatric pneumonia diagnosis, substituting manual chest radiography examination.

scholarly journals Barite-containing radiation protective building materials

2020 ◽  
Vol 21 (1) ◽  
pp. 94-98
Author(s):  
Nikolay V. Novikov ◽  
Svetlana V. Samchenko ◽  
Galina E. Okolnikova
Keyword(s):  
Building Materials ◽  
Protective Coatings ◽  
Relevant Literature ◽  
Cost Effective ◽  
Nuclear Facilities ◽  
Linear Absorption ◽  
Environmental Friendliness ◽  
Operational Characteristics ◽  
Wide Range ◽  
The Creation

Due to the active development of industries using nuclear technology, the creation of highly effective and cost-effective building materials for protection against hazardous ionizing radiation is of increasing interest. Widespread in the field of radiation-protective building materials are barite-containing concrete. The purpose of this article is to establish the prospects of their use in nuclear facilities, as well as to find ways to improve their technical and operational characteristics. For this an analysis of relevant literature and scientific research in the field of radiation-protective materials and, in particular, barite-containing concrete was carried out. The advantages of barite-containing concrete are high radiation-protective properties, environmental friendliness, high density, as well as economic indicators. The disadvantages are high susceptibility to shrinkage deformation and poor resistance to cyclic temperature effects. The addition of barite to the concrete composition allows to increase the coefficient of linear absorption of -rays of the material; also, with the proper selection of the composition, such material may have strength characteristics equal to or superior to the characteristics of concrete with standard compositions. Barite-containing materials have a wide range of applications and can be used both for the production of heavy concrete in the construction of load-bearing structures and in the creation of radiation-protective coatings for walls and floors.

scholarly journals ANALYSIS OF THE INFLUENCE OF INDUSTRIAL WASTE IN THE FORM OF CERAMIC CHIPS CRUSHING DROPOUTS ON THE MAIN PROPERTIES OF CEMENT COMPOSITES

2021 ◽  
Vol 4 (1) ◽  
pp. 27-34
Author(s):  
S-A.Yu. Murtazaev ◽  
A. Uspanova ◽  
M. Hadzhiev ◽  
V. Hadisov
Keyword(s):  
Building Materials ◽  
Environmental Problem ◽  
Raw Materials ◽  
Housing Stock ◽  
Cement Composites ◽  
Optimal Composition ◽  
Ceramic Brick ◽  
Concrete Mixtures ◽  
Technogenic Raw Materials

during the implementation of the program to restore the housing stock of the Chechen Republic, as well as during the planned demolition of dilapidated housing, significant volumes of technogenic raw materials were generated, in particular, large volumes of brick and concrete scrap. Enterprises for the production of building materials and products also produce significant volumes of production defects, which accumulate over the years at landfills. Ceramic broken brick and broken brick dropouts are used to fill the roadbed, and the main part still goes to the dump and landfill, which is also an environmental problem. One of the promising ways to use dropouts and broken brick itself is to use them as secondary aggregates in concrete and mortars. This article discusses the issues of improving the quality of ceramic concrete mixtures, choosing the optimal composition and technology for mixing concrete mixtures using dust fractions of dropouts for crushing ceramic brick bricks

scholarly journals Mechanical Strengths of Sawdust-Ash-Admixed Gum Arabic Concrete

2021 ◽  
Vol 8 (1) ◽  
pp. 12-29
Author(s):  
Augustine Uchechukwu Elinwa
Keyword(s):  
Cement Content ◽  
Gum Arabic ◽  
Strength Ratio ◽  
Design Strength ◽  
Conventional Concrete ◽  
Cement Material ◽  
Cement Ratio ◽  
Setting Times ◽  
Concrete Mixtures ◽  
Mechanical Strengths

Gum Arabic and sawdust ash were used both as an emulsifier admixture and supplementary cement material to address some of the gaps between pozzolanic and conventional concretes. Four concrete mixtures of 1: 2.24: 2.71, with a water-cement ratio of 0.5, and cement content of 370 kg/m3, was used. The concrete mixtures were designated as M-00, M-00GA, M-10GAS, and M-30GAS, signifying the control, control with gum Arabic (GA), and mix with both gum Arabic and sawdust ash (GAS), respectively. The dosage was 0.5 % of GA and the SDA replacement by wt. % was at 10 % and 30 %, respectively. The concrete samples were cured for 90 days, and tested for mechanical strengths. The results showed that adding GA alone to concrete mixture improved the mechanical strengths of the concrete and the gum Arabic acted like an accelerator. When both GA and SDA were used together in the dosage of 0.5 % with 10 % and 30 % proportions respectively, the mechanical strengths of the concrete decreased. The findings also reported that the two-third strength ratio at 28-days of curing which is used for the conventional concrete in stripping the formwork, may not be appropriate for use on pozzolanic concrete. This is because of the delay in setting times and thus, attaining the required design strength. Therefore, it is proposed to be taken at an age beyond 28 days of curing to carter for the pozzolanic effects which starts well above 28-days.

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