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.

scholarly journals Corrosion Behavior of Pre-Rusted Rebars in Cement Mortar Exposed to Harsh Environments

2020 ◽  
Vol 10 (23) ◽  
pp. 8705
Author(s):  
Gankhuyag Burtuujin ◽  
Dasom Son ◽  
Indong Jang ◽  
Chongku Yi ◽  
Hyerin Lee
Keyword(s):  
Corrosion Rate ◽  
Cement Mortar ◽  
Cement Composite ◽  
Harsh Environments ◽  
Experimental Program ◽  
Cement Composites ◽  
X Ray Diffraction ◽  
Half Cell ◽  
Cell Potential ◽  
X Ray

Rebar embedded inside reinforced concrete structures becomes corroded due to various factors. However, few studies have focused on the corrosion of pre-rusted rebar embedded in cement composites, and the findings reported thus far are inconsistent. Therefore, in this study, an experimental program was undertaken to examine the effect of pre-rusting on the further corrosion of reinforcements in cement composites. Pre-rust was induced using two different solutions (CaCl2 and HCl). The corrosion rate in the cement composite was analyzed using the half-cell potential and polarization resistance methods. In addition, scanning electron microscopy with energy-dispersive X-ray analysis and X-ray diffraction analysis were used to examine the morphology of the rust. The results show that the corrosion rate of the rebar embedded in the cement composite can be increased by more than 3.8 times depending on the pre-rust conditions (RE: 0.0009 mm/year, HCl: 0.0035 mm/year). In addition, we found that the corrosion products in the pre-rusted layer were comparable to those of the rebar corroded in the marine atmosphere.

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.

Influence of Silica Based Carbon Nano Tube Composites in Concrete

2017 ◽  
Vol 26 (1) ◽  
pp. 096369351702600
Author(s):  
BLP Dheeraj Swamy ◽  
Vaibhav Raghavan ◽  
K Srinivas ◽  
K Narasinga Rao ◽  
Mahadevan Lakshmanan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Cement Composite ◽  
Small Scale ◽  
Cement Composites ◽  
Potential Candidate ◽  
Carbon Nano Tube ◽  
Portland Cement Paste

This study focuses on the utilization of highly densified materials in cementitious composites with objectives of improving the mechanical performance and minimizing the number and size of defects. Due to their excellent mechanical properties, carbon nanotubes (CNTs) are now viewed as potential candidate for reinforcement in cement composites. The present paper reports the use of carbon nanotubes (CNTs) as reinforcement to improve the mechanical properties of portland cement paste and creating multifunctional concrete. In order to increase the bonding, and strength, a material with intermediate fineness, highly densified silica fumes, was also utilized. The densified silica fumes along with CNT are added to cement mortar in various proportions. Small-scale specimens were prepared to measure the mechanical properties as a function of nanotube concentration and distribution. Furthermore, properties like shrinkage, permeability and alkalinity of the resultant composite were also investigated. The study addresses the significance of CNT as an additive to the enhancement of properties of cement composite.

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.

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 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 Inhibition of Cracks on the Surface of Cement Mortar Using Estabragh Fibers

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Tahereh Soleimani ◽  
Ali Akbar Merati ◽  
Masoud Latifi ◽  
Ali Akbar Ramezanianpor
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bending Strength ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Cement Composite ◽  
Cement Composites ◽  
Surface Cracks ◽  
Reinforced Cement ◽  
Mortar Matrix

The influence of adding Estabragh fibers into the cement composites of mortar on surface cracks and mechanical properties of mortar has been studied at various fiber proportions of 0.25%, 0.5%, and 0.75%. The mortar shrinkage was evaluated by counting the number of cracks and measuring the width of cracks on the surface of mortar specimens. Although the Estabragh fibers loss their strength in an alkali environment of cement composites, the ability of Estabragh fibers to bridge on the microcracks in the mortar matrix causes a decrease in the number of cracks and in their width on the surface of the mortar samples in comparison with the plain mortar. However, considering the mechanical properties of specimens such as bending strength and compressive strength, among all fiber proportions, only the specimens with 0.25% of Estabragh fiber performed better in all respects compared to the physical and mechanical properties of reinforced cement composite of mortar. Consequently, by adding 0.25% of Estabragh fibers to the cement mortar, a remarkable inhibition in crack generation on fiber-containing cement composite of mortar is achieved.

Structure–Property Relationships in Photoluminescent Bismuth Halide Organic Hybrid Materials

2021 ◽  
Author(s):  
R. Lee Ayscue ◽  
Valérie Vallet ◽  
Jeffery A. Bertke ◽  
Florent Réal ◽  
Karah E. Knope
Keyword(s):  
Hybrid Materials ◽  
Structure Property ◽  
Organic Hybrid ◽  
Structure Property Relationships

New Methacrylate-Functionalized Ba and Ba−Ti Oxoclusters as Potential Nanosized Building Blocks for Inorganic−Organic Hybrid Materials:  Synthesis and Characterization

2007 ◽  
Vol 46 (9) ◽  
pp. 3459-3466 ◽  
Author(s):  
Alberto Albinati ◽  
Francesco Faccini ◽  
Silvia Gross ◽  
Guido Kickelbick ◽  
Silvia Rizzato ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Building Blocks ◽  
Synthesis And Characterization ◽  
Materials Synthesis ◽  
Organic Hybrid
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