The Use of Metallurgical Wastes in Road Construction

2018 ◽  
Vol 931 ◽  
pp. 674-678
Author(s):  
Rashid R. Sharapov ◽  
Evgeny V. Kharlamov ◽  
Talgat R. Gabdullin
Keyword(s):  
Fluidized Bed ◽  
Quartz Sand ◽  
Building Materials ◽  
Road Construction ◽  
Fine Grained ◽  
Mill Tailings ◽  
Metallurgical Wastes ◽  
Iron Bearing

The proposed method is a dry separation tailings. A separator developed for separating the tailings of the quartz sand and iron-bearing components. The efficiency of separation of enrichment tails in the fluidized bed separator is shown. The use of mill tailings as components in the manufacture of building materials is practically confirmed by testing samples of fine-grained concrete and asphalt.

scholarly journals Modeling the composition of fine-grained modified concrete elaborated with vibropressing technology

2019 ◽  
Vol 298 ◽  
pp. 00133 ◽  
Author(s):  
E. R. Pyataev ◽  
A. Y. Ushakov
Keyword(s):  
Portland Cement ◽  
Experimental Research ◽  
Frost Resistance ◽  
Building Materials ◽  
Road Construction ◽  
Average Density ◽  
Optimal Composition ◽  
Fine Grained ◽  
Main Components ◽  
Modifying Additive

The article analyzes the property requirements of small-piece products used in road construction, specially those related to water and frost resistance. It describes the main features of the vibration technologies involved in the manufacture of building materials, in particular, paving slabs. The article presents conclusive results, obtained through scientific research, which allow us to establish the influence of both, the costs of the main components and the parameters of vibration compression, on the properties of the final product. Combining the analysis of classical methods with the results of experimental research, a methodology has been developed for reaching an optimal composition of fine-grained vibropressed concrete modified with active additives. It is shown that the particular strength achieved from the combination of vibroformed fine-grained concrete, whose average density is 2270–2320 kg/m3, with polymer multifunctional modifiers, is mainly due to the use of Portland cement, a modifying additive, and the pressure conditions employed during the experiment..

Modelling of Flow Properties of Asphalt Mastics

2013 ◽  
Vol 752 ◽  
pp. 209-216 ◽  
Author(s):  
Róbert Géber ◽  
László A. Gömze
Keyword(s):  
Research Work ◽  
Road Construction ◽  
Test Results ◽  
Flow Properties ◽  
Rheological Models ◽  
Fine Grained ◽  
Mineral Particles ◽  
Asphalt Mastics ◽  
Rheological Modelling ◽  
Mineral Fillers

The present research work deals with the examination and rheological modelling of flow properties of asphalt mastics which are the most important components of asphalt concretes. Asphalt mastics are mixtures of fine grained mineral filler particles (d<0,063 mm) and bitumen, having a stabilizing role in asphalt mixtures and largely determining the cohesion between mineral particles and bitumen. During our examinations two types of mineral fillers – limestone and dolomite – as well as standard bitumen were tested, which are extensively used in Hungarian road construction. Asphalt mastic mixtures were prepared out of these materials and they were tested with dynamic shear rheometer (DSR). According to the test results, rheological models of mastics were determined. It has been established that at different test temperatures and shear rate ranges asphalt mastics behave as Herschel-Bulkley and Bingham-type materials.

Solids Flow Pattern in the Bottom Zone of a Rectangular Cross-Section Circulating Fluidized Bed

2003 ◽  
Author(s):  
Hong-Shun Li ◽  
Yi-Jun Wang ◽  
Shi-Ping Jin
Keyword(s):  
Flow Pattern ◽  
Fluidized Bed ◽  
Cross Section ◽  
Quartz Sand ◽  
Circulating Fluidized Bed ◽  
Rectangular Cross Section ◽  
Temperature Response ◽  
Cold Model ◽  
Hot Particles ◽  
Bottom Zone

Solids flow pattern in the bottom zone of a rectangular cross-section CFB was investigated by using hot particles as the tracer. The experiments were carried out in a cold model circulating fluidized bed. The riser has an inner cross-section of 0.3 m by 0.5 m and a height of 5.8 m. The solids were returned into the riser at a height of 0.75 m above the air distributor within an angle of about 40 degree. Quartz sand was used as the bed material. The hot particles were also quartz sand but with a little smaller size. Specially designed miniature electrically heating devices were installed flush with the inner bed wall or inside the bed. At each run, about 10–15 cm3 hot particles were slowly pulled into the bed. The temperature response around the device was measured with four copper-constantan thermocouples. Based on the experimental results, a 3-D core-annulus model describing the solids flow pattern in the bottom zone of the CFB riser is proposed.

Utilization of Circulating Fluidized Bed Combustion (CFBC) Fly Ash and Coal-Fired Fly Ash in Portland Cement

2014 ◽  
Vol 629-630 ◽  
pp. 306-313 ◽  
Author(s):  
Mao Chieh Chi ◽  
Ran Huang ◽  
Te Hsien Wu ◽  
Toun Chun Fou
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Fluidized Bed ◽  
Building Materials ◽  
Circulating Fluidized Bed ◽  
Setting Time ◽  
Fluidized Bed Combustion ◽  
Initial Setting Time ◽  
Cfbc Fly Ash ◽  
Circulating Fluidized Bed Combustion

Circulating fluidized bed combustion (CFBC) fly ash is a promising admixture for construction and building materials due to its pozzolanic activity and self-cementitious property. In this study, CFBC fly ash and coal-fired fly ash were used in Portland cement to investigate the pozzolanic and cementitious characteristics of CFBC fly ash and the properties of cement-based composites. Tests show that CFBC fly ash has the potential instead of cementing materials and as an alternative of pozzolan. In fresh specimens, the initial setting time of mortars increases with the increasing amount of cement replacement by CFBC fly ash and coal-fire fly ash. In harden specimens, adding CFBC fly ash to replace OPC reduces the compressive strength. Meanwhile, CFBC fly ash would results in a higher length change when adding over 30%. Based on the results, the amount of CFBC fly ash replacement cement was recommended to be limited below 20%.

CFD-DEM Numerical Simulation and Experimental Validation of Heat Transfer and Two-Component Flow in Fluidized Bed

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Feihong Guo ◽  
Zhaoping Zhong
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Fluidized Bed ◽  
Quartz Sand ◽  
Thermal Imager ◽  
Gas Velocity ◽  
Bed Height ◽  
Two Component ◽  
Superficial Gas Velocity ◽  
Infrared Thermal Imager

AbstractBased on the improved computational fluid dynamics and discrete element method (CFD-DEM), heat transfer and two-component flow of biomass and quartz sand have been studied from experiments and numerical simulation in this paper. During experiments, the particle temperature and moving images are respectively recorded by infrared thermal imager and high speed camera. With the increase of the velocity, the mixing index (MI) and the cooling rate of the particles are rising. Due to larger heat capacity and mass, the temperature of biomass drops slower than that of quartz sand. Fictitious element method is employed to solve the incompatibility of the traditional CFD-DEM where the cylindrical biomass are considered as an aggregation of numerous fictitious sphere particles arranged in certain sequence. By the comparison of data collected by infrared thermal imager and the simulated results, it can be concluded that experimental data is basically agreement with numerical simulation results. Directly affected by inflow air (25℃), the average temperature of particles in the bed height area (h>30 mm) is about 3 degrees lower than that of the other heights. When the superficial gas velocity is larger, the fluidization is good, and the gas temperature distribution is more uniform in the whole area. On the contrary, bubbles are not easy to produce and the fluidization is restricted at lower superficial gas velocity. Gas-solid heat transfer mainly exists under the bed height of 10 mm, and decreases rapidly on fluidized bed height. The mixing index (MI) is employed to quantitatively discuss the mixing effectiveness, which first rises accelerate, then rising speed decreases, finally tends to a upper limit.

scholarly journals PENYULUHAN DAN PERCONTOHAN PENGGUNAAN LIMBAH PLASTIK UNTUK MATERIAL BAHAN BANGUNAN DI LINGKUNGAN RPTRA, JAKARTA BARAT

2019 ◽  
Vol 1 (3) ◽  
Author(s):  
Grace Kurniawati ◽  
Lisa Oksri Nelfia ◽  
Ade Okvianti Irlan ◽  
Indrawati Sumeru
Keyword(s):  
Building Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Road Construction ◽  
Plastic Waste ◽  
Waste Processing ◽  
Public Road ◽  
House Construction ◽  
The People ◽  
Natural Aggregates

Construction is growing rapidly nowadays. Buildings, housing, industry/business centers and highways will require natural aggregates which are natural resources that cannot be renewed. Therefore, we need replacement materials able to replace these natural aggregate. The large amount of plastic waste in fields, based on existing data, causes environmental pollution through it can be reused and useful for building and road construction. Most of communities don’t even know the plastic waste processing technology that allow their use in the construction of house construction such as floors, walls, roofs, and hinges and also road construction with not heavy road loads. The purpose of this activity is to provide the knowledge to the people of RPTRA related to technology for the use of plastic waste for building materials and also road construction in the area in the RPTRA environment considering it is not a public road and hence, with not heavy vehicle. The method used is firstly observation and interview of several houses visited. Then activities about using different types of plastic waste as construction materials. Finally, evaluation of the progress of the project by conducting a survey to people who had met the criteria of being a member of the plastic waste program. The success of this program will be the people’s understanding and a significate growing of any highvalue plastic use as construction material. The benefit of this community service is to increase the knowledge and insight of the people of RPTRA, South Meruya, and West Jakarta City, related to environmentally friendly technologies such as plastic waste processing.

scholarly journals AN EFFECTIVE WAY TO RECYCLE 3D PRINTING CONCRETE SCRAP

2021 ◽  
Vol 4 (2) ◽  
pp. 12-18
Author(s):  
D.A. Tolypin ◽  
N. Tolypina
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Portland Cement ◽  
Quartz Sand ◽  
Raw Materials ◽  
Electricity Consumption ◽  
Cement Matrix ◽  
Fine Aggregate ◽  
Fine Grained ◽  
Control Samples

the article proposes a rational method for processing 3D printing concrete scrap using vibration equipment, which allows obtaining a multicomponent building material with minimal electricity consumption. As a crite-rion for the degree of grinding of concrete scrap, it is proposed to use the specific surface area of the finely dispersed part of concrete scrap, which should correspond to 400-500 m2/kg. The possibility of reusing the resulting product instead of the traditional fine aggregate of quartz sand is shown. It was found that the con-crete scrap without the addition of Portland cement hardens, reaching up to 48% of the compressive strength of the control samples by 28 days. When 10% of the binder CEM I 42.5 N was added to the concrete scrap processing product, the compressive strength of fine-grained concrete increased by 106.6%, and 20% of Portland cement - by 112.2 %, compared to the strength of control samples of a similar composition on tra-ditional quartz sand after 28 days of hardening. It is noted that this is primarily due to the weak contact zone of quartz sand and the cement matrix of concrete. The use of the product of processing concrete scrap al-lows obtaining building composites based on it with the complete exclusion of natural raw materials

Developing Environmentally Sustainable and Cost-Effective Geopolymer Concrete with Improved Characteristics

2021 ◽  
Vol 13 (24) ◽  
pp. 13607
Author(s):  
Alexey N. Beskopylny ◽  
Sergey A. Stel’makh ◽  
Evgenii M. Shcherban’ ◽  
Levon R. Mailyan ◽  
Besarion Meskhi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Building Materials ◽  
Cost Effective ◽  
Point Of View ◽  
Strength Characteristics ◽  
Geopolymer Concrete ◽  
Environmental Friendliness ◽  
Fine Grained ◽  
The Individual ◽  
Capital Construction

Improving the efficiency and quality of construction mainly depends on the cost of building materials, which is about 55–65% of total capital-construction costs. The study aimed to obtain geopolymer fine-grained concrete with improved quality characteristics that meet the construction field’s sustainable development criteria and that have environmental friendliness, economic efficiency, and advantages over competing analogues. The dependences of strength characteristics on various compositions of geopolymer concrete were obtained. It was found that the most effective activator is a composition of NaOH and Na2SiO3 with a ratio of 1:2. The increase in the indicators of the obtained geopolymer concrete from the developed composition (4A) in relation to the base control (1X) was 17% in terms of compressive strength and 24% in tensile strength in bending. Polynomial equations were obtained showing the dependence of the change in the strength characteristics of geopolymer concrete on the individual influence of each of the activators. A significant effect of the composition of the alkaline activator on the strength characteristics of geopolymer fine-grained concrete was noted. The optimal temperature range of heat treatment of geopolymer concrete samples, contributing to the positive kinetics of compressive strength gain at the age of 28 days, was determined. The main technological and recipe parameters for obtaining geopolymers with the desired properties, which meet the ecology requirements and are efficient from the point of view of economics, were determined.

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