scholarly journals Effect of Rubber Tyre Granules on Concrete Strength and the Microstructure Characteristics of Rubberized Concrete

2015 ◽  
Vol 773-774 ◽  
pp. 928-932
Author(s):  
Euniza Jusli ◽  
Hasanan Md Nor ◽  
P.J. Ramadhansyah ◽  
Zaiton Haron
Keyword(s):  
Concrete Strength ◽  
Ftir Analysis ◽  
Rubberized Concrete ◽  
Progressive Reduction ◽  
Cement Ratio ◽  
Microstructure Characteristics ◽  
Mix Proportion ◽  
Infra Red ◽  
The Stability ◽  
Carbon Peak

The influence of using rubber tyre granules (RTG) as aggregates on the strength of concrete and microstructure characteristics of rubberized concrete was investigated in this study. Mix proportion of cement: sand: aggregate: superplasticizer; 1:1.5:1.7:0.003 and 0.47 water cement ratio (w/c) was used. The RTG of size 1-4 mm and 5-8 mm were used throughout this study. Progressive reduction of strength was observed with the increased of RTG percentage and size. Thermogravimetry and differential thermogravimetric (TGA-DTA) analyses were performed to evaluate the decomposition process of materials heated up to 1000 oC. Less reactions the structure bonds are less at the range of 2000-3000 cm-1 wavelength were detected in Fourier Transform Infra-Red (FTIR) analysis due to the stability of the structures developed in concrete samples. In general, the main elements were calcium, carbon, silica and aluminum. The existence of SBR and carbon black of RTG in the sample can be observed by the presents of a carbon peak in EDX.

Correlation of strength, rubber content, and water to cement ratio in rubberized concrete

2005 ◽  
Vol 32 (6) ◽  
pp. 1075-1081 ◽  
Author(s):  
Ashraf M Ghaly ◽  
James D Cahill IV
Keyword(s):  
Compressive Stress ◽  
Experimental Testing ◽  
Concrete Strength ◽  
Crumb Rubber ◽  
Test Results ◽  
Rubberized Concrete ◽  
Rubber Content ◽  
Research Project ◽  
Conventional Concrete ◽  
Cement Ratio

Waste rubber tires that cannot be processed for useful applications are numbered in the millions around the world. The build up of old rubber tires in landfills is commonly considered a major threat to the environment, and it is unquestionably a burden on landfill space. This research project was an investigation into the possibility of using fine rubber particles in concrete mixtures. The experimental testing program was designed to study the effect of the addition of crumb rubber, as replacement of a portion of fine aggregates (sand), on the strength of concrete. Rubber was added to concrete in quantities of 5%, 10%, and 15% by volume of the mixture. Three different water/cement ratios were used: 0.47, 0.54, and 0.61. A total of 180 concrete cubes were made. The cubes were tested in compression at 1, 7, 14, 21, and 28 d with the load continuously and automatically measured until failure. The load values were used to calculate compressive stress as related to different rubber contents and water/cement ratios. Compression test results were used to develop several plots relating rubber content and water/cement ratio to compressive stress of concrete. Test results gathered in this research project indicated that the addition of crumb rubber to concrete results in a reduced strength as compared with that of conventional concrete. Based on the experimental results, correlations have been developed to estimate the reduction in concrete strength as a function of the rubber content in the mix.Key words: compressive strength, concrete, crumb rubber, rubberized concrete.

FABRICATION OF NANOPOROUS CHITOSAN MEMBRANES

NANO ◽  
2010 ◽  
Vol 05 (01) ◽  
pp. 53-60 ◽  
Author(s):  
XIAOLIANG WANG ◽  
XIANG LI ◽  
ELEANOR STRIDE ◽  
MOHAN EDIRISINGHE
Keyword(s):  
Low Frequency ◽  
Drug Carriers ◽  
Structural Features ◽  
Wound Dressings ◽  
Ftir Analysis ◽  
Tissue Engineering Scaffolds ◽  
Nanoscale Structures ◽  
Low Frequency Ultrasound ◽  
Chitosan Membranes ◽  
The Stability

Naturally derived biopolymers have been widely used for biomedical applications such as drug carriers, wound dressings, and tissue engineering scaffolds. Chitosan is a typical polysaccharide of great interest due to its biocompatibility and film-formability. Chitosan membranes with controllable porous structures also have significant potential in membrane chromatography. Thus, the processing of membranes with porous nanoscale structures is of great importance, but it is also challenging and this has limited the application of these membranes to date. In this study, with the aid of a carefully selected surfactant, polyethyleneglycol stearate-40, chitosan membranes with a well controlled nanoscale structure were successfully prepared. Additional control over the membrane structure was obtained by exposing the suspension to high intensity, low frequency ultrasound. It was found that the concentration of chitosan/surfactant ratio and the ultrasound exposure conditions affect the structural features of the membranes. The stability of nanopores in the membrane was improved by intensive ultrasonication. Furthermore, the stability of the blended suspensions and the intermolecular interactions between chitosan and the surfactant were investigated using scanning electron microscope and Fourier transform infrared spectroscopy (FTIR) analysis, respectively. Hydrogen bonds and possible reaction sites for molecular interactions in the two polymers were also confirmed by FTIR analysis.

Research on Modifier and Modified Process for Rubber-Particle Used in Rubberized Concrete for Road

2011 ◽  
Vol 243-249 ◽  
pp. 4125-4130 ◽  
Author(s):  
Shuai Tian ◽  
Tong Zhang ◽  
Ye Li
Keyword(s):  
Inorganic Salt ◽  
Rubber Particle ◽  
Volume Ratio ◽  
Alkaline Solutions ◽  
Rubberized Concrete ◽  
Function Mechanism ◽  
Mix Proportion ◽  
Optimum Proportion ◽  
Rubber Particles ◽  
The Impact

This paper studies the optimum proportion of rubber-particles in rubberized concrete for road, tests the impact of 12 modifiers and their modified processes in rubberized concrete and discusses the function mechanism of the modifiers in rubberized concrete. Research indicates: the optimum proportion of rubber-particles in rubberized concrete for road is low mix-proportion (volume ratio<5%); inorganic salt as modifier can markedly enhance the bonding strength between rubber-particles used in road and cement and improve the physical properties of rubberized concrete, among which CaCl2 produces the most effect; but organic solution, acidic or alkaline solutions are not fit to be used as modifiers in rubberized concrete for road.

Dispersion of TiO2 Nanoparticles in Aqueous Solution

2018 ◽  
Vol 922 ◽  
pp. 8-13
Author(s):  
Wen Xiu Liu ◽  
Peng Sun ◽  
Jun Zhang ◽  
Wen Bin Cao
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Mass Fraction ◽  
Adsorption Mechanism ◽  
Secondary Particle ◽  
Aqueous Dispersion ◽  
Ftir Analysis ◽  
Carboxylate Groups ◽  
The Stability ◽  
Potential Test

Stable TiO2aqueous dispersion with an averaged secondary particle size of about 10 nm was achieved by using commercially available dispersant Di-7N. The stability of the dispersion was measured by Zeta-potential test. And the results showed that the optimal mass fraction of Di-7N was 12 wt%. The adsorption mechanism examined by FTIR analysis indicates that the carboxylate groups in Di-7N is absorbed on the surface of nano-TiO2particles and the adsorbed structure is proposed to be bidentate chelating.

GGBS Use in Concrete as Cement Constituent: Strength Development and Sustainability Effects – Part 1

2021 ◽  
pp. 1-41
Author(s):  
Haotian Fan ◽  
Ravindra K. Dhir ◽  
Peter C. Hewlett
Keyword(s):  
Concrete Strength ◽  
Blended Cement ◽  
Data Matrix ◽  
Strength Development ◽  
Design Strength ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Granulated Blast Furnace Slag ◽  
Data Points ◽  
Class F Fly Ash

This study, third in the series, following from ground limestone and Class F fly ash, evaluates, as a cement constituent, the effect of using ground granulated blast furnace slag (GGBS) on the strength development of concrete, and consequently its embodied carbon dioxide (CO2e). The paper has been built from systematically analysing, evaluating and modelling the extensive data-matrix developed, having 85,099 data points, from the information sourced from 663 studies published in English, during 1974 to 2020, by 1,672 authors, working in 718 institutions in 49 countries, globally. It is shown that, at a given water/cement ratio, in comparison to Portland cement (PC), the use of GGBS results in a reduction in 28-day concrete strength, which increases with GGBS content, at a rate determined by the strength of concrete, GGBS fineness, and curing of concrete. It is also shown that, as to achieve a 28-day design strength, a lower water/cement ratio is required with a PC/GGBS blended cement than PC, this will reduce the actual CO2e savings that can be realised with the use of GGBS as cement constituent in manufacturing concrete. Finally, it is shown that GGBS is more effective in lowering CO2e of concrete than FA and GLS.

Synthesis, characterization, and computational study of copper bipyridine complex [Cu (C18H24N2) (NO3)2] to explore its functional properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Saleh S. Alarfaji ◽  
Sajjad Hussain ◽  
Abdullah G. Al-Sehemi ◽  
Shabbir Muhammad ◽  
Islam Ullah Khan ◽  
...  
Keyword(s):  
Computational Study ◽  
Coordination Complexes ◽  
Mononuclear Complex ◽  
Orthorhombic Space Group ◽  
Main Protease ◽  
Analysis Technique ◽  
Infra Red ◽  
Chemical Techniques ◽  
The Stability ◽  
Single Crystal Analysis

Abstract In the present study, copper (II) complex of 4, 4′-di-tert-butyl-2,2′-bipyridine [Cu (C18H24N2) (NO3)2], 1 is investigated through its synthesis and characterization using elemental analysis technique, infra-red spectroscopy, and single-crystal analysis. The compound 1 crystallizes in orthorhombic space group P212121. The copper atom in the mononuclear complex is hexa coordinated through two nitrogen and four oxygen atoms from bipyridine ligand and nitrate ligands. The thermal analysis depicts the stability of the entitled compound up to 170 °C, and the decomposition takes place in different steps between 170 and 1000 °C. Furthermore, quantum chemical techniques are used to study optoelectronic, nonlinear optical, and therapeutic bioactivity. The values of isotropic and anisotropic linear polarizabilities of compound 1 are calculated as 41.65 × 10−24 and 23.02 × 10−24 esu, respectively. Likewise, the static hyperpolarizability is calculated as 47.92 × 10−36 esu using M06 functional compared with para-nitroaniline (p-NA) and found several times larger than p-NA. Furthermore, the antiviral potential of compound 1 is studied using molecular docking technique where intermolecular interactions are checked between the entitled compound and two crucial proteins of SARS-CoV-2 (COVID-19). Our investigation indicated that compound 1 interacts more vigorously to spike protein than main protease (MPro) due to its better binding energy of −9.60 kcal/mol compared with −9.10 kcal/mol of MPro. Our current study anticipated that the above-entitled coordination complexes could be potential candidates for optoelectronic properties and their biological activity.

scholarly journals Shrinkage and Strength Properties of Coal Gangue Ceramsite Lightweight Aggregate Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yunsen Wang ◽  
Jingping Qiu ◽  
Chao Zeng
Keyword(s):  
Waste Treatment ◽  
Concrete Strength ◽  
Lightweight Aggregate ◽  
Strength Properties ◽  
Coal Gangue ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Concrete Shrinkage ◽  
Strength Tests ◽  
The Stability

It is a promising and effective method for waste treatment by using coal gangue to make lightweight aggregate concrete. However, lightweight aggregate concrete with low-density coal gangue ceramsite is prone to cracking during volume shrinkage, which limits its application in the construction industry. In an attempt to resolve the problem of cracking in shrinkage, this study investigated the effect of prewetting time and shrinkage reducing agents on shrinkage volume and concrete strength through a series of concrete shrinkage and strength tests. The experimental results show that shrinkage volume reduced at a prewetting time of 12 hrs or with a 2% addition of D-230 polyether amine reductant. With the optimal conditions of 12 hrs prewetting time and 2% addition of the reductant, the concrete shrinkage volume significantly decreased with a negligible impact on its strength. Appropriate amount of shrinkage reducing agent and adjustment of prewetting time of coal gangue ceramsite are necessary to reduce the shrinkage rate and improve the stability of the specimen. This is of great significance to wide application of lightweight aggregate concrete with coal gangue ceramsite.

scholarly journals Reuse of Excavated Clayey Silt in Cement–Fly Ash–Bentonite Hybrid Back-fill Grouting during Shield Tunneling

2020 ◽  
Vol 12 (3) ◽  
pp. 1017 ◽  
Author(s):  
Jun Xu ◽  
Chao Xiao ◽  
Huai-Na Wu ◽  
Xin Kang
Keyword(s):  
Fly Ash ◽  
Tunnel Construction ◽  
X Ray Diffraction ◽  
Shield Tunneling ◽  
X Ray ◽  
Mix Proportion ◽  
Clayey Silt ◽  
Before And After ◽  
The Stability ◽  
High Treatment

Excavated soils from tunnel construction need high treatment cost and pollute the environment. To investigate the feasibility of excavated clayey silt reused in back-fill grout, the flowability, stability and strength were taken as measurement indexes of grouting performance. The clayey silt was tested to be reused as substitutes for fly ash, bentonite and sand, respectively. The experimental results indicated that the clayey silt reused as a substitute for fly ash decreased the flowability and strength of grout mixes, and the clayey silt reused as a substitute for bentonite decreased the stability of grout mixes, and neither of them was feasible. The clayey silt reused as a substitute for sand decreased the flowability, but the grouting performance could be improved by adjusting the mix proportion to meet all grouting requirements. After adding the proportion of water to improve the flowability and increasing the cement:fly ash ratio to improve the strength, a scheme of clayey silt reutilization was suggested, which was cement:fly ash:bentonite:clayey silt:water = 280:230:100:680:660. At the end of this paper, the pore structure feature tests, X-ray diffraction (XRD) tests and scanning electron microscope (SEM) tests were performed to analyze the different morphology, microstructure and mineralogy characteristics before and after the clayey silt was reused as a total substitute for sand in grout mixes.

Conductivities of Room Temperature Molten Salts Containing ZnCl2, Measured by a Computerized Direct Current Method

2002 ◽  
Vol 57 (3-4) ◽  
pp. 129-135
Author(s):  
Hsin-Yi Hsu ◽  
Chao-Chen Yang
Keyword(s):  
Activation Energy ◽  
Direct Current ◽  
Molten Salts ◽  
Room Temperature ◽  
Current Method ◽  
Cross Linking ◽  
Infra Red ◽  
Different Temperatures ◽  
The Stability ◽  
Benzyltriethylammonium Chloride

The conductivities of the binary room-temperature molten salt (RTMS) systems ZnCl2-N-nbutylpyridinium chloride (BPC), ZnCl2 -1-ethyl-3-methylimidazolium chloride (EMIC) and ZnCl2 - benzyltriethylammonium chloride (BTEAC) have been measured at different temperatures and compositions by a d.c. four-probes method. The conductivities of the three RTMS are in the order ZnCl2-EMIC > ZnCl2-BPC > ZnCl2-BTEAC. In ZnCl2-BPC the conductivity at 70 to 150 °C, is maximal for 40 mol% ZnCl2. In ZnCl2 - EMIC, the conductivity below 130 °C is almost constant for 30 to 50 mol% ZnCl2 and has the lowest activation energy 25.21 kJ/mol. For these two systems, the conductivities decrease rapidly beyond 50 mol% ZnCl2 owing to the rapid increase in cross-linking and resultant tightening of the polyelectrolyte structure. As to the ZnCl2-BTEAC system, the conductivities at 110 - 150 °C decrease slowly for 30 - 60 mol% ZnCl2. The conductivities of the ZnCl2-EMICmelt are compared with those of the AlCl3-EMIC melt previously studied. The stability of the ZnCl2-EMIC melt system is explored by the effect of the environment on the conductivity and the Far Transmission Infra Red (FTIR) spectrum. It reveals that the effect is slight, and that the ZnCl2-EMIC melt may be classified as stable.

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