Influence of Wollastonite or Plant Fiber on Performance of Autoclaved Cement Concrete

2011 ◽  
Vol 99-100 ◽  
pp. 692-695
Author(s):  
Tie Quan Ni ◽  
Li Zhang ◽  
Bing Yuan
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Bending Strength ◽  
Composition Analysis ◽  
X Ray Diffraction ◽  
Cement Concrete ◽  
Plant Fiber ◽  
X Ray ◽  
Strength Change ◽  
Chemical Composition Analysis

The influence of wollastonite or plant fiber on the property of autoclaved cement concrete is studied by chemical composition analysis, X-ray diffraction analysis, scanning electron microscopy and energy spectrum analysis. The results showed that the two fibers were benefit to bending strength of autoclaved cement concrete. The suitable content of wollastonite was about 15% of cement mass, and the increased amplitude of flexural strength was more than 30% and the compressive strength slightly increased for autoclaved cement concrete admixed wollastonite. The optimal content of plant fiber was about 1.5% of cement mass, the increased amplitude of the flexural strength was more than 20%, and the compressive strength change of autoclaved cement concrete was not significant for autoclaved cement concrete admixed plant fiber.

Optimum Autoclaved Cement Concrete Mix Design Based on Flexural Strength

2011 ◽  
Vol 189-193 ◽  
pp. 676-679 ◽  
Author(s):  
Chang Jun Ke ◽  
Qin Hu ◽  
Pan Jiang ◽  
Li Zhang
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Orthogonal Test ◽  
Mix Design ◽  
Cement Concrete ◽  
Plant Fiber ◽  
Concrete Mix Design ◽  
Strength Change ◽  
Mix Proportion ◽  
Mass Increase

optimized mix proportion of autoclaved cement concrete by orthogonal test, and studied effect of two type fibers for the flexural strength of autoclaved cement concrete by the mix proportion of autoclaved concrete. The results showed, wollastonite and plant fiber were favorable to increasing the flexural strength of autoclaved cement concrete. Content of wollastonite was about 15% of cement mass, and increase amplitude of the flexural strength was more than 40% and the compressive strength slightly increased for autoclaved cement concrete admixed wollastonite. Content of plant fiber was about 1.5% of cement mass, increase amplitude of the flexural strength was more than 20%, but compressive strength change of autoclaved cement concrete was not significant for autoclaved cement concrete admixed plant fiber.

scholarly journals Phase and chemical composition analysis of pigments used in Cucuteni Neolithic painted ceramics

2007 ◽  
Vol 34 ◽  
pp. 281-288 ◽  
Author(s):  
Bogdan Constantinescu ◽  
Roxana Bugoi ◽  
Emmanuel Pantos ◽  
Dragomir Popovici
Keyword(s):  
Manganese Oxides ◽  
Mineralogical Composition ◽  
Composition Analysis ◽  
X Ray Diffraction ◽  
Trade Routes ◽  
X Ray ◽  
Manganese Minerals ◽  
Chemical Composition Analysis ◽  
Main Components ◽  
Phase And Chemical Composition

Two analytical methods – 241Am-based X-Ray Fluorescence (XRF) and Synchrotron Radiation X-ray Diffraction (SR-XRD) – were used to investigate the elemental and mineralogical composition of pigments which decorate some Cucuteni Neolithic ceramic sherds. Local hematite and local calcite were the main components for red and white pigments, respectively. For black pigments, iron oxides (e.g. magnetite) were used. They were often mixed with manganese oxides (e.g. jacobsite), which originated from Iacobeni manganese minerals deposits on the Bistrita River. Taking into account the results of the experiments, several conclusions regarding manufacturing procedures employed, and potential trade routes during the Neolithic were drawn.

scholarly journals Effect of NaClO dosage on the structure of degummed hemp fibers by 2,2,6, 6-tetramethyl-1-piperidinyloxy-laccase degumming

2017 ◽  
Vol 89 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Liu Liu ◽  
Yeping Xiang ◽  
Ruiyun Zhang ◽  
Bei Li ◽  
Jianyong Yu
Keyword(s):  
Composition Analysis ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Hemp Fibers ◽  
Cellulosic Materials ◽  
X Ray ◽  
Chemical Composition Analysis ◽  
Degumming Process ◽  
Fourier Transfer Infrared Spectroscopy ◽  
Shed Light

In this study, different dosages of NaClO were used in the 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-laccase degumming system to remove non-cellulosic materials, and their effects on the structure of hemp fibers were analyzed and discussed. A scanning electron microscope was used to depict the surface morphology of fibers after oxidative degumming under various dosages of NaClO in the TEMPO-laccase degumming system. Chemical composition analysis was used to determine the content changes of the different components. Meanwhile, the content of functional groups was also discussed. Fourier transfer infrared spectroscopy, nuclear magnetic resonance spectroscopy, and X-ray diffraction were employed to evaluate the microstructural changes of degummed hemp fibers obtained from the degumming processes with different dosages of NaClO. The results showed that after the TEMPO-laccase system degumming process with a NaClO dosage of 16%, the cleanest and smoothest surface of degummed fibers could be observed and the non-cellulosic materials were significantly removed without any crystalline transformation or damage in the cellulose. This research could shed light on determining favorable operation parameters for hemp oxidation degumming and increasing the degumming efficiency, as well as in the oxidation control and quality assurance of hemp fibers for textile downstream end uses.

Improving Mechanical Properties of Autoclaved Aerated Concrete by Sugar Sediment

2013 ◽  
Vol 807-809 ◽  
pp. 1266-1269 ◽  
Author(s):  
Atthakorn Thongtha ◽  
Somchai Maneewan ◽  
Chantana Punlek ◽  
Yothin Ungkoon
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Crystalline Morphology ◽  
X Ray Diffraction ◽  
Quality Class ◽  
X Ray ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Scanning Electron

The comparison of microstructure and mechanical properties between the autoclaved aerated concrete (AAC) and the autoclaved aerated concrete consist of sugar sediment (AAC-SS) was investigated in this work. The microstructure of AAC and AAC-SS was analyzed by the scanning electron microscopy (SEM). The mechanical properties of AAC and AAC-SS were focused on the compressive strength, the density, the water absorption and the flexural strength. To comfirm the tobermorite phase, the phase formation of the samples was tested using X-ray diffraction (XRD). It was found that the microstructure of AAC and AAC-SS surface was the finer needle-like crystalline morphology. The compressive strength (5.9 N/mm2) and flexural strength (1.82 N/mm2) of AAC-SS were higher than that of the AAC (5.0 N/mm2 and 1.64 N/mm2). While, the value of density (0.60 g/cm3) and humidity (23.59%) of AAC-SS had little less than that of the AAC (0.61 g/cm3 and 24.11%). The increasing of the tobermorite phase, which was added by the sugar sediment, had affected to the improvement of the mechanical properties. The specimens of both AAC and AAC-SS were claimed in quality class of 4, which based on the Thai Industrial Standard 1505-1998.

Mechanical Characteristics of Concrete Exposed to External Flexural Load, De-Icing Salt and Freeze-Thaw Cycles

2011 ◽  
Vol 250-253 ◽  
pp. 33-39
Author(s):  
Xiao Lu Yuan ◽  
Bei Xing Li ◽  
Shang Chuan Zhao ◽  
Shi Hua Zhou
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Ordinary Portland Cement ◽  
Mechanical Characteristics ◽  
Concrete Strength ◽  
Mineral Admixtures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Freeze Thaw

This paper investigates mechanical characteristics of concrete exposed to external flexural load, de-icing salt and freeze-thaw cycles. Concrete specimens made with ordinary Portland cement or ordinary Portland cement incorporating fly ash with the replacement of 10% or 20%, or 0.7/10000 air-entraining agent and 20% fly ash, or ground blast furnace slag with the replacement of 15% or 30%, were made and exposed to flexural load, freeze-thaw and de-icing salt environment. Mechanical properties of concrete including compressive strength and flexural strength were measured. Phase composition of samples was determined by means of x-ray diffraction (XRD). Results indicate that increasing flexural stress ratios reduced compressive strength and flexural strength of concrete, and presented higher improvement of mineral admixtures in concrete strength. Incorporation of mineral admixtures and air-entraining agent decreased the loss of concrete strength. X-ray diffraction analysis showed the presence of abundant calcium chloroaluminate and ettringite in paste samples.

Microstructure and Properties of C-S-H/PCE Nanocomposites

2017 ◽  
Vol 898 ◽  
pp. 2089-2094
Author(s):  
He Qing Shen ◽  
Zi Ming Wang ◽  
Xiao Liu ◽  
Xiao Fan Pang ◽  
Long Xue
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Calcium Silicate ◽  
Structural Investigation ◽  
X Ray Diffraction ◽  
Enhancing Effect ◽  
X Ray ◽  
Microstructure And Properties ◽  
Composition And Structure ◽  
Early Strength

Different dosage of TPEG-polycarboxylate (PCE) copolymers were used to prepare the calcium-silicate hydrated (C-S-H)/PCE nanocomposites by precipitating C-S-H from Na2SiO3·9H2O and Ca (NO3)2·4H2O in the PCE solution. The composition and structure of the prepared C-S-H/PCE nanocomposites were characterized by XRD, SEM, FTIR methods, and the early strength of mortars was measured. The results show that structural investigation of the C-S-H/PCE nanocomposites via X-ray diffraction revealed a semi-crystalline composition, and the PCE polymers were adhered the surface of C-S-H particles in the composite. The preparation of C-S-H /PCE nanocomposites enhanced markedly the early strength of mortar, and when the dosage of PCE copolymers was up to 30%, the early strength enhancing effect was the highest, the early flexural strength increased up to 100%, and early compressive strength increased up to 120%. Therefore, C-S-H /PCE nanocomposites can improve the early strength of mortar effectively since it can lower the barrier of nucleation of the products, promote the nucleation and inhibit the growth of large grains effectively.

Hydrothermal synthesis and characterization of a new potassium phosphatoantimonate

1994 ◽  
Vol 9 (11) ◽  
pp. 2745-2746 ◽  
Author(s):  
Yonglin An ◽  
Shouhua Feng ◽  
Yihua Xu ◽  
Ruren Xu ◽  
Yong Yue
Keyword(s):  
Photoelectron Spectroscopy ◽  
Synthesis And Characterization ◽  
Composition Analysis ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Monovalent Ions ◽  
Nmr Techniques ◽  
Chemical Composition Analysis

A new potassium phosphatoantimonate with a composition of 4K2O · 4Sb2O5 · P2O5 · 8H2O, which crystallizes in a monoclinic system with a = 23.952 Å, b = 9.515 Å, c = 8.193 Å, and β = 124.77, was hydrothermally synthesized and characterized by powder x-ray diffraction, chemical composition analysis, x-ray photoelectron spectroscopy, and 31P MAS-NMR techniques. The potassium ion can be exchanged by other monovalent ions.

Effect of Curing Time on the Pore Structure of the Portland Cement Concrete

2010 ◽  
Vol 44-47 ◽  
pp. 2592-2596
Author(s):  
Wei Lun Wang ◽  
Peng Liu
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Pore Structure ◽  
Mercury Intrusion Porosimetry ◽  
Curing Time ◽  
Hydration Products ◽  
Portland Cement Concrete ◽  
X Ray Diffraction ◽  
Cement Concrete ◽  
X Ray

In this paper, the influence of curing time on the compressive strength and pore structure of the Portland cement concrete was investigated. The phase composition and morphology of hydration products of Portland cement were analyzed with X-ray diffraction (XRD). In addition, the porosity and pore distribution of the concrete were also researched using mercury intrusion porosimetry (MIP), surface area and porosity analyzer (BET). The results show that the influence of curing time on the compressive strength and pore structure of the concrete is obvious. With curing time increasing, the compressive strength of the concrete increased and the porosity decreased. The corresponding fractal dimension of the pore and the microstructure were changed, as well. With time increasing, more hydration products were produced.

Gelcasting of Mechanochemically Synthesized Hydroxyapatite

2007 ◽  
Vol 280-283 ◽  
pp. 1555-1558
Author(s):  
Yu Jia ◽  
Yuji Hotta ◽  
Kimiyasu Sato ◽  
Koji Watari ◽  
Yoshinori Kanno
Keyword(s):  
Flexural Strength ◽  
Mechanochemical Synthesis ◽  
Ir Spectrum ◽  
Bending Strength ◽  
Synthesis Method ◽  
Green Body ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uniform Microstructure ◽  
Diffraction Patterns

Hydroxyapatite powders were prepared via mechanochemical synthesis method. The starting reagents for HAP powders were vibration ball milled for 2 h and then calcined at 800°C for 1 h. X-ray diffraction patterns and IR spectrum shown that pure crystalline apatite powder (HAP) was obtained. The as-synthesized powders were gelcasted and then sintered at 1200°C for 2 h. It was observed from SEM micrographs that the prepared green body has uniform microstructure. The bending strength of the dried green body was as high as 18 MPa that is enough to be machined into required form before sintering. The sintered ceramics has a density of 2.5 g/cm3 and a flexural strength of 72 MPa with a homogenous microstructure.

scholarly journals Effect of Calcination Temperature on Mechanical Properties of Magnesium Oxychloride Cement

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 607
Author(s):  
Chenggong Chang ◽  
Lingyun An ◽  
Rui Lin ◽  
Jing Wen ◽  
Jinmei Dong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Calcination Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Scanning Electron ◽  
Oxychloride Cement

In order to make full use of magnesium chloride resources, the development and utilisation of magnesium oxychloride cement have become an ecological and economic goal. Thus far, however, investigations into the effects on these cements of high temperatures are lacking. Herein, magnesium oxychloride cement was calcinated at various temperatures and the effects of calcination temperature on microstructure, phase composition, flexural strength, and compressive strength were studied by scanning electron microscopy, X-ray diffraction, and compression testing. The mechanical properties varied strongly with calcination temperature. Before calcination, magnesium oxychloride cement has a needle-like micromorphology and includes Mg(OH)2 gel and a trace amount of gel water as well as 5 Mg(OH)2·MgCl2·8H2O, which together provide its mechanical properties (flexural strength, 18.4 MPa; compressive strength, and 113.3 MPa). After calcination at 100 °C, the gel water is volatilised and the flexural strength is decreased by 57.07% but there is no significant change in the compressive strength. Calcination at 400 °C results in the magnesium oxychloride cement becoming fibrous and mainly consisting of Mg(OH)2 gel, which helps to maintain its high compressive strength (65.7 MPa). When the calcination temperature is 450 °C, the microstructure becomes powdery, the cement is mainly composed of MgO, and the flexural and compressive strengths are completely lost.

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