Experimental Research on High-Strength Super Sulphate Cement Paste Mixed with Superfine Mineral Admixtures

2014 ◽  
Vol 629-630 ◽  
pp. 150-155
Author(s):  
Jun Wang ◽  
Bao Ying Yu ◽  
Long Yang ◽  
Yu Xin Gao ◽  
Jia Yu Xiang
Keyword(s):  
Silica Fume ◽  
High Strength ◽  
Hydration Product ◽  
Mineral Admixtures ◽  
Hydration Reaction ◽  
X Ray Diffraction ◽  
Cement Ratio ◽  
X Ray ◽  
Early Strength ◽  
Scanning Electron

Aimed at the performance affect of high-strength super sulphate cement (SSC) paste mixed with superfine mineral admixtures, influence of microbead and silica fume replacing SSC quantity on high-strength SSC paste compression strength were studied under water-cement ratio 0.18; Hydration product morphology and phase were further compared by scanning electron microscopy and X-ray diffraction analyzer in this paper. Results show that, compared with sample HS-1, 3-day strength of HS-2 and HS-3 were increased by 5% and 10%, 28d strength basically unchanged; Furthermore, early strength of HS-7 sample slightly higher and late strength basically unchanged. SSC by adding 5% microbead and 3% silica fume (HS-11) has compressive strength 50.8MPa at 3 days and 86.1MPa at 28 days is significantly higher than other samples. Early strength of HS-11sample mainly depends on hydration reaction of SSC and particle filling effect of admixtures, later strength is due to accelerating consumption of gypsum and promoting formation of ettringite.

Synthesis of Ca(OH)2 Nanoparticles Aqueous Suspensions and Interaction with Silica Fume

2012 ◽  
Vol 629 ◽  
pp. 482-487 ◽  
Author(s):  
V. Daniele ◽  
G. Taglieri ◽  
A. Gregori
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silica Fume ◽  
Calcium Silicate Hydrate ◽  
Thermal Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrate Phase ◽  
Work Interaction ◽  
Scanning Electron

In this work, interaction at ambient temperature between silica fume and artificially produced Ca(OH)2 nanoparticles by two different methods was analyzed. Initial products and formed hydrated phases were characterized by several investigations including X-ray diffraction, thermal analyses, transmission and scanning electron microscopy. Synthesized Ca(OH)2 nanoparticles appeared regularly shaped and hexagonally plated, with side dimensions from 200nm to less than 20nm. Characterization analyses showed that, by reducing particles dimensions, calcium silicate hydrate phase formation was evident already after 7 day of hydration and a nearly complete consuming of free Ca(OH)2 after 28 days was observed. Besides, formed hydrate phases showed a highly wrinkled layer with marked crumple and rough-edge surfaces.

scholarly journals Microstructural Analysis of Silica Fume Concrete with Scanning Electron Microscopy and X-Ray Diffraction

2020 ◽  
Vol 10 (3) ◽  
pp. 5845-5850
Author(s):  
B. Uzbas ◽  
A. C. Aydin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Hydroxide ◽  
Silica Fume ◽  
Hardened Cement ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mechanical And Microstructural Properties ◽  
Scanning Electron

The effects of using different ratios of silica fume on the mechanical and microstructural properties of hardened cement paste and concrete were investigated in this study. Portland cement was replaced with 5%, 10%, 15%, and 20% silica fume (SF) by weight. Microstructural properties of obtained samples were investigated by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The XRD analysis showed that the ratio of calcium hydroxide (CH), which is produced by hydration, decreases depending on the concrete age and the amount of silica fume. The SEM analysis showed that the use of silica fume decreases gaps and calcium silicate hydrate (C-S-H) which is also a hydration production. Silica fume content of up to 15% improved the observed mechanical and microstructural properties of concrete. At the optimum value of 15%, improvement in the paste was observed due to the filler effect and the reaction between the silica fume and calcium hydroxide, leading to a reduction in calcium hydroxide in the concrete.

Effect of Aluminum Insertion Material on the Properties of AAC

2016 ◽  
Vol 703 ◽  
pp. 406-410
Author(s):  
Yun Feng Pan ◽  
Wan Ming Huang ◽  
Ya Qing Jiang ◽  
Qiang Song
Keyword(s):  
Volume Ratio ◽  
High Strength ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Hydration Degree ◽  
Scanning Electron Microscope Analysis ◽  
X Ray ◽  
Electron Microscope Analysis ◽  
Aerated Concrete ◽  
Scanning Electron

Study on the compressive strength, shrinkage and effect of aluminum insertion materials on the hydration products of Autoclaved Aerated Concrete (AAC). The types and properties of hydration products are studied by X-Ray Diffraction Analysis (XRD), Differential Thermal Analysis (DTA), Scanning Electron Microscope analysis (SEM) and so on. The results showed that the strength and the shrinkage resistance capability of the product could be improved effectively. Al3+successfully doped into C-S-H gel and tobermorite crystals, then replaced si4+of tobermorite and formed the system of C-A-S-H. Tobermorite in aluminum insertion aerated concrete is smaller and more compact. All hydration products interlace to form a whole, then the structure turns denser. Low porosity, high crystal gel volume ratio and high hydration degree are the key of the high strength aluminum insertion aerated concrete. Aluminum insertion materials improve the performance of the products.

Influence of Silica Fume/Nanosilica on the Strength and Microstructure of Phosphoaluminate Cement

2011 ◽  
Vol 291-294 ◽  
pp. 1447-1449
Author(s):  
Chen Jing Lv ◽  
Shu Xia Ren ◽  
Xiu Shu Tian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silica Fume ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
Hydration Time ◽  
X Ray ◽  
Hydration Rate ◽  
Splitting Strength ◽  
Scanning Electron

The influence of Silica fume/Nanosilica on the Performance of phosphoaluminate cement was studied in the paper. The microstructure and morphology was determined by X-ray diffraction and scanning electron microscopy. The experimental results show that the phosphoaluminate cement with 4% of added Silica fume/Nanosilica(1:1) by weight of cement has an optimum splitting strength, in which the increase of splitting strength are about 15.1%,11.8% and 24.6% at 3days,7days and 28 days. The reason for causing the above results are the hydration rate and the amount of the hydrates of PALC with 4% Silica fume/Nanosilica have been increased significantly at different hydration time because of the role played by Silica fume and Nanosilica together.

Effect of Preparation on Standard Dry Density and Strength of Foamed Cement by Orthogonal Test

2014 ◽  
Vol 577 ◽  
pp. 1119-1122
Author(s):  
Na Li ◽  
Qi Wang ◽  
Peng Song
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
High Strength ◽  
Xrd Analysis ◽  
Orthogonal Test ◽  
Dry Density ◽  
Light Weight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this paper, we studied the effect of preparation on standard dry density and strength of foamed cement by orthogonal test. The results indicate that the more excellent combination is A1B1C1, namely G1, the standard dry density is 376 kg/m3, the flexural and compressive strengths are 0.43 MPa and 0.8 MPa respectively, and the thermal conductivity is 0.074 W/(m·K), which conforms to the characteristics of light weight and high strength. Fewer Ca (OH)2 crystals and more C-S-H gel generated in G1 through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis is the reason for its high strength.

High Strength Mg-Zn-Y-Ce-Zr Alloy Bars Prepared by RS and Extrusion Technology

2005 ◽  
Vol 488-489 ◽  
pp. 495-498 ◽  
Author(s):  
Xuefeng Guo ◽  
Jacob Kinstler ◽  
Lilia Glazman ◽  
Dan Shechtman
Keyword(s):  
Grain Boundaries ◽  
High Strength ◽  
Submicron Particles ◽  
Commercial Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Extrusion Technology ◽  
Scanning Electron ◽  
Zr Alloy

Based on the commercial alloy ZK60 which contains 6%Zn, high strength Mg-6.0%Zn-1.0%Y-0.6%Ce-0.6%Zr magnesium alloy bars of 10 to 50 mm in diameters were prepared by rapid solidification (RS) and extrusion processes （RSE）. For those RSE solid bars, the ultimate tensile strengths steadily maintain on a level of 490 to 520 MPa, the elongations are between 6 to 10%. The HV50 hardness is between 85 and 90. In order to reveal materials microstructures both RS ribbons and RSE solid bars, the Mg-6.0%Zn-1.0%Y-0.6%Ce-0.6%Zr alloy was analyzed with an optical microscopy (OM), a scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrometer (EDS) and an X-ray diffraction apparatus. It was found that the microstructure of the RS ribbon consists of super saturated (Mg) solid solution; thermally stable Mg3Y2Zn3 (W) and Mg7Ce2 intermetallic compound particles which uniformly dispersed interior grains and W and Mg7Ce2 compound networks at grain boundaries. After extrusion, the microstructure of RSE Mg-6.0%Zn-1.0%Y-0.6%Ce-0.6%Zr solid bar consists of the same phases as the RS ribbons. The networks existing at RS ribbon’s grain boundaries were break up into submicron particles and dispersed uniformly on the matrix formed after extrusion.

Microstructure and Durability of RC in Boric Acid

2011 ◽  
Vol 250-253 ◽  
pp. 252-256
Author(s):  
Hui Zhen Jin ◽  
Qiang Li ◽  
Xian Yu Jin ◽  
Ye Tian ◽  
Nan Guo Jin
Keyword(s):  
Boric Acid ◽  
Nuclear Power ◽  
Acid Corrosion ◽  
Hydration Product ◽  
Concrete Surface ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acid Environment ◽  
Scanning Electron

Boric acid (H3BO3) is often used for cooling the heat in nuclear power plant. Though the drastic measures have been taken, the potential leakage still can not be fully eliminated. Therefore, an attempt to understand the durability mechanism of RC subjected to boric acid is of vital importance. In this paper, specimens cured in a standard moist room at a temperature of 20 ±3 °C after 28days were immersed in three different concentration of boric solution (2000ppm, 8000ppm, 30000ppm) artificially simulated to accelerate the corrosion of acid environment. The hydration products are investigated. Microstructure of reinforced concrete on the surface, 2cm and 4cm away from the surface at ages of 60, 90 and 150 days are examined using X-ray diffraction (XRD) and scanning electron microscope (SEM) respectively. Results indicate that main hydration product is Ca(BO2)2,boric acid corrosion to concrete surface can only be detected from the specimens in 30000ppm solutions at the ages of 150 days and its effect is slight. However, the inner part of the concrete was not affected. The results of XRD coincide with those of SEM.

Preparation and Characterization of Cement-TiO2 Composites

2015 ◽  
Vol 804 ◽  
pp. 133-136
Author(s):  
Noosara Kaewgabkam ◽  
Nittaya Jaitanong ◽  
Suparut Narksitipan
Keyword(s):  
Composite System ◽  
Low Cost ◽  
High Photocatalytic Activity ◽  
Chemical Compositions ◽  
Hydration Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Content ◽  
Scanning Electron

Titanium dioxide (TiO2) is the most widely used photocatalyst because of its high photocatalytic activity and reasonably low cost. Moreover, TiO2 has strong chemical stability in a large variety of environmental conditions. The combination of TiO2 with cementatious materials has been widely investigated, and the effects of the TiO2 contents (10-40% by weight) were studied in this research. The crystalline structures and chemical compositions were analyzed using x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS), respectively. Moreover, its microstructure was investigated by scanning electron microscopy (SEM). It was found that the intensity of CS and CH decreased with an increase in the TiO2 powder content. This was because when adding more TiO2 powder to the composite system, more water was needed to add to the hydration reaction.

Experimental Study on High Strength Composite Ceramsite Using Fly Ash and Waste Glass

2013 ◽  
Vol 357-360 ◽  
pp. 1337-1342
Author(s):  
Lei Hong ◽  
Wei Cheng
Keyword(s):  
Experimental Study ◽  
Fly Ash ◽  
Raw Materials ◽  
High Strength ◽  
Waste Glass ◽  
Technological Condition ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The high strength composite ceramsite was prepared by using fly ash and waste glass as main raw materials and some admixtures such as binder and bubble-forming agent. The suitable technological condition of preparing high strength composite ceramsite was given by studying the influence of the different mix proportions and different sintering systems on the properties of ceramsite. The test results indicate that the compressive strength in cylinder of high strength composite ceramsite which was prepared under certain technological condition can reach 9.9MPa and its bulk density is 974Kg/m3and the water absorption in one hour is 3.6%. The XRD(X Ray Diffraction) and SEM (Scanning Electron Microscope) analyses show that a large number of amorphous gel phases which affect the strength of ceramsite were produced in the process of sintering fly ash and waste glass and abundant even bubbles were formed inside of the ceramsite.

CLAYEY SOIL TREATED BY CEMENT AND QUICKLIME BY MICROSTRUCTURE: A MINERALOGICAL ANALYSIS

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Husam Hikmat Baqir ◽  
Aqeel Al-Adili ◽  
Kawther Al-Soudany ◽  
Ali Shareef
Keyword(s):  
Clay Soil ◽  
Clayey Soil ◽  
Dry Weight ◽  
Dry Density ◽  
Hydration Reaction ◽  
X Ray Diffraction ◽  
Mineralogical Analysis ◽  
Maximum Dry Density ◽  
X Ray ◽  
Scanning Electron

Soft clayey soil was treated by a combination of cement (PC) and Quicklime (LQ) in order to modify and stability. This study shows an improvement of clay soil brought from Garma Ali site in the Al Basra governorate, Iraq. The PC was added in percentages of 0, 2, 4, 6, 8, and 10%, and LQ was added to 2 and 4%, of dry weight. Also, this research used Microstructure Analysis by Scanning Electron Microscope (SEM) testing and Mineralogical Analysis by X-Ray Diffraction (XRD) testing on the examination soil treated with mix between cement (PC) and Quicklime (LQ) for the purpose of knowing the reasons for the increase in the shear strength and decrease maximum dry density. Through the micrographs that result from the scanning electron microscoping and the curves of X-ray that demonstrate presentence, the formation of the hydration reaction product (CSH gel) shows tiny bristle (rod) crystals. The CSH gel and the tiny bristle (rod) crystals worked on coating and contact the particles together. The micrographs for soils treated with (2% LQ + 10% PC) show an increase in the amount hydrated gel (CSH) compared to the soil treated with 6% PC and 2% LQ and 8% PC and 4% LQ, but the number of bristle-like crystals decreases compared to soil treated by 8% PC and 4% LQ.

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