The study of strength of wood-cement composites based on waste wood

2015 ◽  
Vol 5 (3) ◽  
pp. 191-199
Author(s):  
Филичкина ◽  
Maria FilichkinaM ◽  
Копарев ◽  
Vladimir Koparev
Keyword(s):  
Cement Composite ◽  
Strength Properties ◽  
Material Strength ◽  
Cement Composites ◽  
Compression Method ◽  
Waste Wood ◽  
Good Range ◽  
Wood Cement Composites ◽  
Construction Product

The article presents the results of studies on the production of wood-cement composite with various fillers, such as sawdust, gravel, bark and shavings, the binder acts as a cement. The developed technology allows producing the construction product with a good range of strength properties depending on the product. In the work carried out tests of samples on the strength of a compression method on the equipment VSFEU. The result of testing the strength of steel obtained dependence of material strength on the fraction of components in the mixture components, which then led to the conclusion that the strength limits varied from 0.38 MPa to 2.72 MPa.

scholarly journals Utilization of wastes from medium density fiberboards production as an aggregate for lightweight cement composite

2018 ◽  
Vol 174 ◽  
pp. 02005 ◽  
Author(s):  
Dorota Małaszkiewicz ◽  
Magdalena Sztukowska
Keyword(s):  
Compressive Strength ◽  
Lightweight Concrete ◽  
Medium Density Fiberboard ◽  
Cement Composite ◽  
Strength Properties ◽  
Cement Composites ◽  
Medium Density ◽  
Wood Fibers ◽  
Resin Binder ◽  
Wood Cement Composites

The possibility of recycling waste from medium density fiberboard (MDF) production into wood-cement composites was evaluated. A large quantity of lignocellulosic wastes is generated worldwide from various sources, including wood and furniture industries, leading to environmental concerns. Medium density fiberboard (MDF) is an engineered wood product, which is made from wood fibers (mainly form coniferous trees) with wax and a resin binder. This paper presents an experimental study which investigated the potential utilization of medium density fiberboard wastes (MDFW) for producing lightweight insulation concrete. The wastes were screened on #8 mm sieve to exlude big irregular elements which could negatively affect compaction and strength properties. All lignocellulosic substrates have detrimental effects on cement setting so different techniques were applied to offset the retarding effect of compounds like sugar and tannin present in the bio-based particles before mixing the wastes with cement. One type of cement CEM I 42,5 R was used in the experiment. Flexural strength, compressive strength in air-dry and wet states, and water absorption of lightweight concrete were tested. Compressive strength ranging from 0,5 to 5.3 MPa was obtained depending on the material used for the initial impregnation of MDFW fibers.

scholarly journals Lignin-Based Hybrid Admixtures and their Role in Cement Composite Fabrication

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3544 ◽  
Author(s):  
Łukasz Klapiszewski ◽  
Izabela Klapiszewska ◽  
Agnieszka Ślosarczyk ◽  
Teofil Jesionowski
Keyword(s):  
Hybrid Materials ◽  
Cement Mortar ◽  
Cement Composite ◽  
Strength Properties ◽  
Cement Composites ◽  
Mechanical Method ◽  
Efficient Manner ◽  
Sustainable Building ◽  
Organic Hybrid ◽  
Composite Fabrication

In this study, a technology for obtaining functional inorganic-organic hybrid materials was designed using waste polymers of natural origin, i.e., kraft lignin and magnesium lignosulfonate, and alumina as an inorganic component. Al2O3-lignin and Al2O3-lignosulfonate systems were prepared by a mechanical method using a mortar grinder and a planetary ball mill, which made it possible to obtain products of adequate homogeneity in an efficient manner. This was confirmed by the use of Fourier transform infrared spectroscopy and thermogravimetric analysis. In the next step, the developed hybrid materials were used as functional admixtures in cement mixtures, thus contributing to the formation of a modern, sustainable building material. How the original components and hybrid materials affected the mechanical properties of the resulting mortars was investigated. The admixture of biopolymers, especially lignin, led to cement composites characterized by greater plasticity, while alumina improved their strength properties. It was confirmed that the system containing 0.5 wt.% of alumina-lignin material is the most suitable for application as a cement mortar admixture.

Gypsum-Cement Composites Based on Volcanic Ash

2020 ◽  
Vol 1011 ◽  
pp. 136-143
Author(s):  
Tolya Khezhev ◽  
Tamerlan Badziev ◽  
Talib Soblirov ◽  
Timur Tamashev
Keyword(s):  
Portland Cement ◽  
Volcanic Ash ◽  
Water Resistance ◽  
Central Area ◽  
Cement Composite ◽  
Strength Properties ◽  
Cement Composites ◽  
Basalt Fibers ◽  
Initial Matrix ◽  
Optimization Parameters

The studies’ results to determine the gypsum, ash and Portland cement components proportions, which would ensure a decrease in the specific binder consumption, as well as the ash grain composition’s effect on the properties of the gypsum cement pozzolan composite, are presented. It was revealed that the use of volcanic ash together with Portland cement in gypsum concrete composites allows reducing gypsum consumption by up to 50% without a significant decrease in strength characteristics. At the same time, the developed gypsum concrete composites have increased water resistance. The influence of the ash particle size distribution on the strength properties of the composite is ambiguous; in the compositions with a high ash content it is advisable to use larger fractions, and with a content of less than 50% ash in the composite, - the small fractions. To study the parameters’ effect of the dispersed reinforcement with basalt fibers on the properties of a gypsum-cement composite, an experiment with such a second-order composite rotatable plan as regular hexagon was conducted. It was found that the maximum values ​​of optimization parameters are observed in the central area of ​​the plan with and . The compressive strength of a fiber gypsum cement pozzolan composite increases by 1.15-1.18 times, when bending, by 1.56-1.72 times with respect to the strength of the initial matrix.

scholarly journals Alternative vibro-dynamic compression processing of wood-cement composites using Amazonian wood

2019 ◽  
Vol 49 (1) ◽  
pp. 75-80
Author(s):  
Vinicius Gomes de CASTRO ◽  
Rafael da Rosa AZAMBUJA ◽  
Carlos Frederico Alice PARCHEN ◽  
Setsuo IWAKIRI
Keyword(s):  
Dynamic Compression ◽  
Construction Material ◽  
Cement Composite ◽  
Hydraulic Press ◽  
Cement Composites ◽  
Compression Process ◽  
Tropical Regions ◽  
Minimum Requirement ◽  
Concrete Blocks ◽  
Wood Cement Composites

ABSTRACT Wood-cement composite (WCC) is a potential construction material for tropical regions, due to its physico-mechanical properties and resistance to decay and fungi attack. However it is important to test alternative production methods and wood materials that are easier and cheaper than those traditionally used, in order to create a higher demand for this product. The aim of this work was to evaluate the use of wood from four Amazonian species (Eschweilera coriaceae, Swartzia recurva, Manilkara amazonica and Pouteria guianensis) in the production of wood-cement composites through a vibro-dynamic compression process, an alternative method to the use of a hydraulic press. The inhibition degree caused by the wood to the cement cure, measured by the factor CA, indicated that all species were compatible with Portland cement (CP II-Z). WCC with densities higher than 1,100 kg m-3 (produced with E. coriaceae and S. recurva particles) showed compressive strength values higher than 10 MPa, which fulfills the minimum requirement for lightweitgh reinforced concrete blocks for structural use.

scholarly journals Effect of Single-Walled Carbon Nanotubes on Strength Properties of Cement Composites

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1305 ◽  
Author(s):  
Jiayuan Kang ◽  
Salam Al-Sabah ◽  
Roger Théo
Keyword(s):  
Carbon Nanotubes ◽  
Single Walled Carbon Nanotubes ◽  
Cement Composite ◽  
Strength Properties ◽  
Cement Composites ◽  
Dispersion Method ◽  
Single Walled Carbon ◽  
Compressive And Flexural Strengths ◽  
Walled Carbon Nanotubes ◽  
The Relationship

This study aimed to investigate the effects of single-walled carbon nanotubes (SWCNTs) on strength the properties of cement composites when surfactant (SAA) was applied as the dispersion method. TritonX-100 (TX10) was used as the SAA to pretreat SWCNTs, which has been proved to perform well in dispersing the agglomerates of SWCNTs. In this study, four different concentration of SWCNTs, namely 0.00 wt%, 0.02 wt%, 0.04 wt%, and 0.06 wt% by the mass of cement, were used to prepare cement composite specimens. The compressive strength and flexural strength of specimens were tested and recorded. The results show that the compressive and flexural strengths of cement composites decreased with the increase in the concentration of SWCNTs without the addition of TX10. However, when SWCNT suspensions were pretreated with TX10, the strength variation pattern changed; the compressive and flexural strengths of cement composites increased as a function of the concentration of SWCNTs, although there were reductions compared to non-TX10-treated specimens at all concentrations of SWCNTs. Furthermore, the relationship between the strength of cement composites and bulk density of specimens was considered.

scholarly journals DESIGN OF CEMENT COMPOSITES WITH INCREASED IMPERMEABILITY

Vestnik MGSU ◽  
2016 ◽  
pp. 72-81
Author(s):  
Roman Sergeevich Fedyuk
Keyword(s):  
Composite Materials ◽  
Cement Composite ◽  
Vapor Permeability ◽  
Cement Stone ◽  
Cement Composites ◽  
Hydrated Cement ◽  
Body Density ◽  
Scale Levels ◽  
Positive Effect ◽  
Improved Characteristics

The paper deals with the development of composite binders for producing concrete with improved characteristics of gas, water and vapor permeability. The authors investigate the processes of composite materials formation in order of decreasing scale levels from macro to nanostructures. The criteria for optimization of the volume of dispersed additives in concrete are offered. The authors theoretically studied the technological features of the formation of hydrated cement stone structure. A positive effect of nanodispersed additives on the structure and physico-mechanical properties of cement composite materials are predicted. Thanks to its improved features, such as good ratio of strength and body density, high density and lifetime, the modified concrete may be used when solving various practical tasks of the construction branch.

scholarly journals Using scanned images to estimate salt formation on the surface of cement composites

Vestnik MGSU ◽  
2020 ◽  
pp. 1523-1533
Author(s):  
Vladimir T. Erofeev ◽  
Victor V. Afonin ◽  
Tatiana F. Elchishcheva ◽  
Marina M. Zotkina ◽  
Irina V. Erofeeva
Keyword(s):  
Building Materials ◽  
Control Sample ◽  
Cement Composite ◽  
Operating Conditions ◽  
Cement Composites ◽  
High Humidity ◽  
Grayscale Image ◽  
Salt Formation ◽  
Scanned Images ◽  
Composite Samples

Introduction. An engineering method is proposed for assessing salt formation on the surface of cement composites exposed to adverse operating conditions. The technique is based on the histogram method used to determine the dominant brightness of the half-tone image of scanned cement composites. The criterion for ranking composites is a relative dimensionless value –– a metric obtained by comparing the brightness of a grayscale image with the brightness level of white. Materials and methods. We selected three types of compositions of composites in the amount of 21 items; each of them contains three samples –– a control sample and samples exposed to high humidity and positive temperatures for 15 and 45 days. Each composition is represented by a scanned raster image of the sample surface. The images are further subjected to digital processing using a software program written in the C++ programming language and the OpenCV technical vision library. This allows you to use the available methods and classes to develop algorithms to solve the problem in question and to convert a full-color RGB image to a grayscale image. Such images are used to analyze histograms, which determine the dominant level of brightness to determine the numerical metric for quantifying the salt formation on the surface of cement composite samples on the basis of their scanned images. Results. A description of the software algorithm, used to detect salt formation on the surface of cement composite specimens that have passed performance tests under high humidity conditions at positive temperatures, is presented. The method of ranking cement composite samples using the values of their dominant brightness relative to the brightness of control samples is shown. The comparative analysis of the study is presented in the form of numerical data and explanatory diagrams. Conclusions. Software modeling is employed to demonstrate the expediency of the methodology for the assessment of salt formation on the surface of cement composites and other building materials prone to salt formation.

scholarly journals EXPERIENCE OF APPLICATION HIGH PERFORMANCE CEMENT COMPOSITES FOR CREATING DURABLE SCULPTURAL ELEMENTS

2017 ◽  
Vol 3 ◽  
pp. 286
Author(s):  
Genadijs Sahmenko ◽  
Sandis Aispurs ◽  
Aleksandrs Korjakins
Keyword(s):  
Water Absorption ◽  
High Performance ◽  
Cement Composite ◽  
Cement Composites ◽  
Freezing And Thawing ◽  
Initial Water ◽  
Good Potential ◽  
Freezing And Thawing Cycles ◽  
Material Ductility ◽  
And Control

Traditionally, sculptural and decorative elements of building facades are created from mortar mixes based on lime, gypsum or Portland cement. Generally these materials have porous and permeable structure, which determines their accelerated degradation, especially in the aggressive environment of modern cities. High performance cement composites (HPCC) have been considered for production and restoration of sculptural elements in historical buildings. For this purpose, fine-graded, multi-component and highly workable mixes were elaborated. Mix compositions were modified with micro-fillers, plasticizing and stabilizing admixtures, as well as fibers to improve material ductility and control shrinkage cracking. Basic mechanical properties and durability (such as water absorption, frost resistance) were determined and two types of HPCC were compared (>50 MPa: HPCC and >120 MPa: UHPCC). It has been confirmed that cement composite mixes are characterized by self-consolidating effect, high compressive strength, extremely high resistance versus freezing and thawing cycles and low water absorption. Surface quality was evaluated and initial water absorption (tube tests) were performed for laboratory samples and real sculptural elements after 5 years of exploitation. The results confirmed good potential for using HPCC for creating more attractive and durable architectural shapes and façade elements compared to elements made using traditional cement and lime mortar.

scholarly journals Ansys code applied to investigate the dynamics of composite sandwich beams

2021 ◽  
Vol 25 (1) ◽  
pp. 62-71
Author(s):  
Agnieszka Chudzik
Keyword(s):  
Sandwich Beam ◽  
Strength Properties ◽  
Effect Of Temperature ◽  
Material Strength ◽  
Beam Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Composite Sandwich ◽  
Viscoelastic Core ◽  
Influence Of Temperature On

Abstract A numerical analysis of the effect of temperature on the dynamics of the sandwich beam model with a viscoelastic core is presented. The beam under analysis was described with a standard rheological model. This solution allows one to study the effect of temperature on material strength properties. Calculations were performed with the Finite Element Method in the ANSYS software. The analysis of the results of the numerical calculations showed a significant influence of temperature on the strength properties of the model under test. The analysis confirmed damping properties of viscoelastic materials.

Wood fibre - cement composites by extrusion

2000 ◽  
Vol 27 (3) ◽  
pp. 543-552 ◽  
Author(s):  
Yixin Shao ◽  
Shylesh Moras ◽  
Nilgun Ulkem ◽  
George Kubes
Keyword(s):  
Cement Composite ◽  
Temperature Cycling ◽  
Wood Fibre ◽  
Flexural Behavior ◽  
Cement Composites ◽  
Building Product ◽  
Toughness Index ◽  
Composites Materials ◽  
Fibre Cement ◽  
Hardwood Pulp

Wood fibres derived from both hardwood and softwood, being relatively inexpensive and in ample supply, have gained increasing popularity in the fibre-cement building product industry. Presently, the manufacture of most wood fibre - cement composites employs the Hatschek process. The purpose of this paper is to examine the feasibility of using extrusion technology for the production. Wood fibre - cement sheets, composed of both hardwood and softwood fibres of different fibre contents, were fabricated using an auger-type extruder. The flexural behavior, moisture content, water absorption, and density of all batches were evaluated. To investigate the weathering durability of the extruded composites, materials were also subjected to a temperature-cycling test and a natural exposure weathering test. With a relative ease of manufacture and a much cleaner production, extrusion was found to be a suitable means for making cement composite thin sheets with up to 8% fibres by weight. The extruded composites exhibited a performance comparable to or even better than that of the Hatschek products. Hardwood fibres, which are cheaper and more available than the softwood fibres, were found to be more suitable for extrusion production in terms of the extrudability, finished surface, and long-term mechanical properties.Key words: wood fibre - cement composites, hardwood pulp, softwood pulp, extrusion, strength, toughness index, temperature cycling, natural weathering.

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