scholarly journals Prediction of Structural Performance of Vinyl Ester Polymer Concrete Using FEM Elasto-Plastic Model

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4034
Author(s):  
Kazimierz Józefiak ◽  
Rafał Michalczyk
Keyword(s):  
Vinyl Ester ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Construction Material ◽  
Experimental Studies ◽  
Analytical Formula ◽  
Material Model ◽  
Polymer Concrete ◽  
Waste Products ◽  
Structural Applications

This paper presents the methodology for predicting the mechanical performance of structural elements made of polymer concrete (PC). A vinyl ester polymer concrete composition and the results of experimental studies to determine the basic mechanical properties of the material are presented. Following the strategy for sustainable development in the building industry, the material cost of polymer concrete was lowered by reducing the consumption of raw materials and the partial replacing of the microfiller fraction with recycled waste products—calcium fly ash. An accurate computational model enabling stress analysis is a convenient way to verify the suitability of PC as a construction material in structural applications. Due to difficulty in deriving an accurate analytical formula, numerical approximation (finite element method) was used as a method for solving the problem. Constitutive modeling of PC is a very important aspect of the strength calculations and here it was done within the framework of elasto-plasticity. Numerical evaluation of the static bearing capacity of PC manhole covers is shown as an example of the proposed FEM methodology. The results of computer simulations were compared with laboratory tests. Finally, the adequacy of the numerical modeling for testing new construction and material improvements is discussed. The study showed that the concrete damaged plasticity material model can be effectively used for the description of PC mechanical behavior.

scholarly journals Crushed Bricks: Demolition Waste as a Sustainable Raw Material for Geopolymers

2021 ◽  
Vol 13 (14) ◽  
pp. 7572
Author(s):  
Gigliola D’Angelo ◽  
Marina Fumo ◽  
Mercedes del Rio Merino ◽  
Ilaria Capasso ◽  
Assunta Campanile ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Building Materials ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Construction Material ◽  
Raw Material ◽  
The European Union ◽  
Total Energy Consumption ◽  
Demolition Waste ◽  
Crushed Brick

Demolition activity plays an important role in the total energy consumption of the construction industry in the European Union. The indiscriminate use of non-renewable raw materials, energy consumption, and unsustainable design has led to a redefinition of the criteria to ensure environmental protection. This article introduces an experimental plan that determines the viability of a new type of construction material, obtained from crushed brick waste, to be introduced into the construction market. The potential of crushed brick waste as a raw material in the production of building precast products, obtained by curing a geopolymeric blend at 60 °C for 3 days, has been exploited. Geopolymers represent an important alternative in reducing emissions and energy consumption, whilst, at the same time, achieving a considerable mechanical performance. The results obtained from this study show that the geopolymers produced from crushed brick were characterized by good properties in terms of open porosity, water absorption, mechanical strength, and surface resistance values when compared to building materials produced using traditional technologies.

Use of polymer concrete for large-scale 3D printing

2021 ◽  
Vol 27 (3) ◽  
pp. 465-474
Author(s):  
Martin Krčma ◽  
David Škaroupka ◽  
Petr Vosynek ◽  
Tomáš Zikmund ◽  
Jozef Kaiser ◽  
...  
Keyword(s):  
3D Printing ◽  
Large Scale ◽  
Mechanical Performance ◽  
Construction Material ◽  
Polymer Concrete ◽  
Fused Deposition Modelling ◽  
Cast State ◽  
Content Type ◽  
Fused Deposition ◽  
3D Printed

Purpose This paper aims to focus on the evaluation of a polymer concrete as a three-dimensional (3D) printing material. An associated company has developed plastic concrete made from reused unrecyclable plastic waste. Its intended use is as a construction material. Design/methodology/approach The concrete mix, called PolyBet, composed of polypropylene and glass sand, is printed by the fused deposition modelling process. The process of material and parameter selection is described. The mechanical properties of the filled material were compared to its cast state. Samples were made from castings and two different orientations of 3D-printed parts. Three-point flex tests were carried out, and the area of the break was examined. Computed tomography of the samples was carried out. Findings The influence of the 3D printing process on the material was evaluated. The mechanical performance of the longitudinal samples was close to the cast state. There was a difference in the failure mode between the states, with cast parts exhibiting a tougher behaviour, with fractures propagating in a stair-like manner. The 3D-printed samples exhibited high degrees of porosity. Originality/value The results suggest that the novel material is a good fit for 3D printing, with little to no degradation caused by the process. Layer adhesion was shown to be excellent, with negligible effect on the finished part for the longitudinal orientation. That means, if large-scale testing of buildability is successful, the material is a good fit for additive manufacturing of building components and other large-scale structures.

scholarly journals Bio-Inspired 3D Infill Patterns for Additive Manufacturing and Structural Applications

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 499 ◽  
Author(s):  
Jan Podroužek ◽  
Marco Marcon ◽  
Krešimir Ninčević ◽  
Roman Wan-Wendner
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Peak Load ◽  
Fem Analysis ◽  
Material Model ◽  
Surface Strain ◽  
Image Correlation ◽  
Nonlinear Material ◽  
Full Field ◽  
Structural Applications

The aim of this paper is to introduce and characterize, both experimentally and numerically, three classes of non-traditional 3D infill patterns at three scales as an alternative to classical 2D infill patterns in the context of additive manufacturing and structural applications. The investigated 3D infill patterns are biologically inspired and include Gyroid, Schwarz D and Schwarz P. Their selection was based on their beneficial mechanical properties, such as double curvature. They are not only known from nature but also emerge from numerical topology optimization. A classical 2D hexagonal pattern has been used as a reference. The mechanical performance of 14 cylindrical specimens in compression is quantitatively related to stiffness, peak load and weight. Digital image correlation provides accurate full-field deformation measurements and insights into periodic features of the surface strain field. The associated variability, which is inherent to the production and testing process, has been evaluated for 3 identical Gyroid specimens. The nonlinear material model for the preliminary FEM analysis is based on tensile test specimens with 3 different slicing strategies. The 3D infill patterns are generally useful when the extrusion orientation cannot be aligned with the build orientation and the principal stress field, i.e., in case of generative design, such as the presented branching structure, or any complex shape and boundary condition.

scholarly journals Fire-resistant cellulose boards from waste newspaper, boric acid salts and protein binders

2021 ◽  
Author(s):  
Paalo Moreno ◽  
Nicole Villamizar ◽  
Jefferson Perez ◽  
Angelica Bayona ◽  
Jesús Roman ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Boric Acid ◽  
Building Materials ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Sustainable Construction ◽  
Load Bearing ◽  
Protein Binders

Abstract Housing construction consumes more materials than any other economic activity, with a total of 40.6 Gt/year. Boards are placed between construction materials to serve as non-load-bearing partitions. Studies have been performed to find alternatives to conventional materials using recycled fibers, agro-industrial waste, and protein binders as raw materials. Here, fire-resistant cellulose boards with low density and adequate flexural strength were produced for use as non-load-bearing partitions using waste newspapers, soy protein, boric acid, and borax. A central composite design (CCD) was employed to study the influence of the board component percentage on flame retardancy (UL 94 horizontal burning test), density (ASTM D1037-12) and flexural strength (ISO 178–2010). The cellulose boards were characterized by thermal analysis (ASTM E1131-14) and scanning electron microscopy. Fire-resistant cellulose boards were successfully made with low densities (120–170 kg/m3) and flexural strength (0.06–0.64 MPa). The mechanical performance and fire resistance of cellulose boards suggest their suitability for use as building materials. A useful and sustainable construction material with great potential is produced with the valorization of waste materials.

scholarly journals Lithosphere Protection with Hardening Phosphate-Containing Soil-Cement Technology

2018 ◽  
Vol 7 (4.7) ◽  
pp. 352
Author(s):  
Larisa Svatovskaya ◽  
Anastasia Sychovа ◽  
Maxim Sychov
Keyword(s):  
Raw Materials ◽  
Construction Material ◽  
Experimental Studies ◽  
Road Construction ◽  
Clay Material ◽  
Bonding Agents ◽  
Metal Compounds ◽  
Soil Cement ◽  
Good For ◽  
Ionic Contaminants

This research is relevant in the light of a need to protect lithosphere from pollution. A solution to this problem can be the exercise of a geoecoprotective function by using building and construction technologies. Phosphate-containing bonding agents usually have low solubility in water. They are made of aluminosilicates that occur in common clay. These minerals react with phosphoric acid to release phosphates and silica gel with absorption properties. The purpose of this research is to make fake rocks from phosphate clay material, intended for building and construction purposes, and to investigate their longevity. The material used was treated to neutralize and detoxify the mobile ionic contaminants and heavy metal compounds, as well as petroleum pollutants, so that at the end we could get construction material like fake rocks or improved aggregates that would be good for the environment. These cement systems are called the geoecoprotective systems. The leading methods that were applied were thermodynamic and experimental studies of service and geoecoprotective properties of phosphate-containing cement systems, more specifically fake landscape rocks. Selected studies lasted for more than 10 years, and were carried out in accordance with the guidelines, adopted in the Russian Federation. This research shows that phosphate-containing cement systems made from contaminated clay/sandy artificial soils have long-lasting properties like strength, frost resistance, water resistance and contaminant binding. From this perspective, they are good for building and construction. For example, they can be used to improve the contaminated soil on road construction sites by detoxifying it until water-resistant products, and to make long-lasting water-resistant solutions from local raw materials that would be good for waste storage.                                                      

scholarly journals PHYSICAL AND CHEMICAL STUDIES OF THE OIL SLUDGE HYDROCARBON COMPOSITION AND THE PROSPECTS FOR THEIR USE IN THE TECHNOLOGY OF EXPANDED CLAY PRODUCTION

2020 ◽  
Vol 5 (443) ◽  
pp. 28-37
Author(s):  
Bisenov Kylyshbai Aldabergenovich, ◽  
◽  
Narmanova Roza Abdibekovna, ◽  
Appazov Nurbol Orynbassaruly, ◽  
◽  
...  
Keyword(s):  
Raw Materials ◽  
Ceramic Body ◽  
Construction Material ◽  
Experimental Studies ◽  
Hydrocarbon Composition ◽  
Organic Content ◽  
Oil Sludge ◽  
Technological Parameters ◽  
Combustion Gas ◽  
Physical And Chemical

The article presents the results of gas chromatographic studies of the oil sludge hydrocarbon composition, physical and chemical and heat-producing properties, which enabled to assess the potential of oil sludge as raw materials, their assortment predisposition and possible manufacturability. It has been established that the main physical and chemical characteristics of the organic part from the averaged samples of oil sludge are similar in properties to raw materials for the production of kerosene-diesel fractions. The expediency of the use of oil sludge and weakly bloating clay materials in the production technology of the popular construction material – expanded clay is substantiated. The results of experimental studies on the development of light and porous heat insulating material by granulation method are presented herein. It is shown that oil sludge from a high viscous state is transferred to a loose conglomerate with a moisture content of 12–15% by co-mixing with finely dispersed sand dune, which ensures uniform distribution when mixed with the basic mass. The peculiarities of granules burning according to a specially developed mode without preliminary drying are considered. It has been established that the addition of oil sludge increases the organic content in the mixture, thereby intensifying the process of combustion, gas generation and bloating of the ceramic body, which will positively affect the technological parameters of obtaining а product. It is found that the proposed technology allows to obtain marketable products, which can be used efficiently. At the same time, the unconditional priority is given to waste-free technologies, as the most environmentally friendly.

scholarly journals Mechanical Properties and Mix Design of Geopolymer concrete – A review

2020 ◽  
Vol 184 ◽  
pp. 01091
Author(s):  
Vemundla Ramesh ◽  
Dr.Koniki Srikanth
Keyword(s):  
Mechanical Properties ◽  
Alkaline Solution ◽  
Raw Materials ◽  
Construction Material ◽  
Design Procedure ◽  
Mix Design ◽  
Polymer Concrete ◽  
Geopolymer Concrete ◽  
Carbon Taxes ◽  
Curing Conditions

Geo-polymer concrete (GPC) is a most viable solution to cement as the raw materials depleting down the years and, many countries have started imposing carbon taxes. After a review for the literature reveals that there is no proper mix design procedure developed yet. GPC has better mechanical properties when compared to normal concrete. Curing conditions, setting times, workability, alkaline solution to binder ratios, molarity of alkaline solution, Na2SiO3/NaOH and SiO2/Al2O3 ratios play an important role to develop GPC. This paper presents an overview of Geopolymarization process, mechanical properties and mix design of GPC. Proper mix design of geopolymer concrete can produce desired mechanical properties for ambient curing condition. And geopolymer concrete can consider as eco-friendly construction material. This paper deals with study of advancement in mix design and mechanical properties of geopolymer concrete.

A possibility of using nickel concentrate, obtained as a result of hydrometallurgical enrichment of manganese-containing raw materials, at steel alloying

2020 ◽  
Vol 76 (7) ◽  
pp. 709-715
Author(s):  
O. Yu. Kichigina
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Selective Extraction ◽  
Technological Parameters ◽  
Nickel Iron ◽  
Nickel Recovery ◽  
Nickel Concentrate ◽  
Steel Alloying ◽  
High Degree ◽  
Comprehensive Processing

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

2018 ◽  
Vol 84 (10) ◽  
pp. 23-28
Author(s):  
D. A. Golentsov ◽  
A. G. Gulin ◽  
Vladimir A. Likhter ◽  
K. E. Ulybyshev
Keyword(s):  
Experimental Data ◽  
Early Stage ◽  
Experimental Studies ◽  
Material Model ◽  
Total Charge ◽  
Cross Sectional ◽  
Practical Applications ◽  
Mechanical And Electrical Properties ◽  
Order Of Magnitude ◽  
Using Data

Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

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