Application of Micro-Structure Testing in the Analysis of the Cause of Concrete Cracks

2014 ◽  
Vol 629-630 ◽  
pp. 121-129
Author(s):  
Chen Chun ◽  
Ya Mei Zhang ◽  
Rui Xing Wang ◽  
Jie Yang

Scanning electron microscope, differential thermal analysis, thermo-gravimetric analysis, fluorescent analysis and X-ray CT et.al. have become usual means used in the research of concrete material science. This paper proposed a new method to evaluate the causes of cracking of in-situ concrete based on the investigation by using these comprehensive technologies for analysis of micro-structure. The proposed new method is more reliable and objective than the traditional method which is mainly based on experience and chemical analysis. A case investigation using the new method to explore the causes of cracking in a real project was introduced.

2016 ◽  
Vol 75 (3) ◽  
pp. 581-586 ◽  
Author(s):  
Zheng Zhou ◽  
Aiqin Shan ◽  
Yuxia Zhao

In this study, a novel magnetic polyacrylamide (PAM) coagulant based on the core of magnetite (Fe3O4), with oleic acid serving as modifier and acrylamide as monomer, was synthesized to remove suspended solids in kaolin-suspended water. The composites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermo gravimetric analysis and scanning electron microscopy. The results demonstrated that 82.8% of turbidity removal rate was obtained in 5 min of static settling in simulated kaolin-suspended water. This proved to be superior to that of PAM and poly aluminum chloride. Also confirmed in this study was the fact that zeta potential was significantly correlated with turbidity removal.


2014 ◽  
Vol 979 ◽  
pp. 307-310 ◽  
Author(s):  
W. Siriprom ◽  
S. Kongsriprapan ◽  
K. Teanchai

The present study aims to investigate the physicochemical properties of the methyl cellulose. The information of this investigate has been used to reference in preparing biodegradable film. It was observed that the Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy show the hydrogen bond’s formation and the Energy Dispersive X-Ray Fluorescence (EDXRF) show the chemical and level of the composition element, which Copper (Cu) has the highest accumulate. Another that, the XRD spectra which investigated by X-Ray Diffraction (XRD) show the methyl cellulose had lowered crystalline. Another that, the Thermo-Gravimetric Analysis (TGA) was used to investigate the effect of heating and influence of thermal.


2013 ◽  
Vol 832 ◽  
pp. 816-820
Author(s):  
N.N. Hafizah ◽  
Mohamad Hafiz Mamat ◽  
Mohd Hanafiah Abidin ◽  
Che Mohd Som Said ◽  
Mohamad Rusop

The polymer matrix of poly (metyl methacrylate) (PMMA) has been introduced with the titanium dioxide (TiO2) nanopowder to study the effects of the TiO2size on the properties of the nanocomposites. The particle size is playing an important role in determining the properties of the nanocomposite. The decrease the filler size has increase the thermal decomposition of the nanocomposites due to the higher amount of the filler between the polymer chains. The results of X-ray diffraction (XRD) and Energy Dispersive X-Ray Spectrometry (EDS) also were discussed in this paper.


2011 ◽  
Vol 221 ◽  
pp. 302-307 ◽  
Author(s):  
Hui Huang ◽  
Zhong Cheng Guo ◽  
Wei Zhu ◽  
Fa Chuang Li

Conductive polyaniline/zirconia (PANI/ZrO2) composites have been synthesized by in-situ polymerization of aniline in the presence of ZrO2 nanoparticles. The structure and morph- ology of composites were characterized by Fourier-transform infrared spectra (FTIR), thermo- gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscope (SEM). The conductivity was also investigated. The results showed that PANI and ZrO2 nanoparticles were not simply blended, and a strong interaction existed at the interface of ZrO2 and PANI. It was probably a composite at molecular level. The composites were more thermal stability than that of the pure PANI. XRD analyses confirmed PANI deposited on the surface of ZrO2 nanoparticles had no effect on crystallization performance of ZrO2 nanoparticles. Electrical conductivity measurements indicated that the conductivity of PANI/ZrO2 composites was much higher than that of PANI and the maximum conductivity obtained was 11.27S/cm at 15 wt% of ZrO2 nanoparticles.


2015 ◽  
Vol 1104 ◽  
pp. 3-8 ◽  
Author(s):  
Tong Qing Zhou ◽  
Ting Chen ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Xiao Jun Zhang ◽  
...  

Corundum structurealumina (α-Al2O3) powders were prepared via a non-hydrolytic sol-gel (NHSG) method using aluminum as raw material, ethanol as solvent, and iodine as catalyst. X-ray diffraction (XRD), differential thermal analysis (DTA), thermo gravimetric analysis (TG) were used to characterize the crystal phase of the products, while scanning electron microscopy (SEM) and transmission electron microscope (TEM) were employed to analyze the morphology. The results indicated that γ-Al2O3 was completely changed to α-Al2O3 at 1100 o C with a bit of aggregation. When 3 wt.% polyethylene glycol 600 (PEG 600) was introduced on the NHSG process, the dispersion was improved and the particle size decreased to100 nm.


2007 ◽  
Vol 124-126 ◽  
pp. 1717-1720 ◽  
Author(s):  
Sun Sang Kwon ◽  
Sang Hoon Jeon ◽  
Jeong Kuk Shon ◽  
Duck Hee Kim ◽  
Ih Seop Chang ◽  
...  

To improve lipase activity and make the particulate carrier for practical application, lipase was conjugated to chitosan(Mwavg=80,000) by immine reaction. The lipase activity of conjugate was 93% of its initial activity at room temperature for 7 months, whereas the intact lipase activity decreased to 40%. And then, lipase-chitosan conjugate was intercalated within porous silica. The composite was characterized by X-ray diffraction, scanning electron microscopy, thermo gravimetric analysis. The Pore size was regulated in the range of 5~15nm. The maximum enzyme activity of lipase-chitosan conjugate needs the structure with 15nm pore of mesoporous silica. The resultant composite was found to have the free flowing property and keep up inner lipase activity.


2017 ◽  
Vol 76 (10) ◽  
pp. 2842-2850 ◽  
Author(s):  
Min Xia ◽  
Chunsong Ye ◽  
Kewu Pi ◽  
Defu Liu ◽  
Andrea R. Gerson

Abstract Selective removal of Ca and recovery of Mg by precipitation from flue gas desulfurization (FGD) wastewater has been investigated. Thermodynamic analysis of four possible additives, Na2CO3, Na2C2O4, NaF and Na2SO4, indicated that both carbonate and oxalate could potentially provide effective separation of Ca via precipitation from Mg in FGD wastewater. However, it was found experimentally that the carbonate system was not as effective as oxalate in this regard. The oxalate system performed considerably better, with Ca removal efficiency of 96% being obtained, with little Mg inclusion at pH 6.0 when the dosage was ×1.4 the stoichiometric requirement. On this basis, the subsequent recovery process for Mg was carried out using NaOH with two-step precipitation. The product was confirmed to be Mg(OH)2 (using X-ray diffraction and thermo gravimetric analysis) with elemental analysis suggesting a purity of 99.3 wt.%.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012097
Author(s):  
S Vandana ◽  
Cyriac Joseph

Abstract Single crystals of Lanthanum oxalate [La2 (C2O4)3]1OH2O and Dy3+ doped Lanthanum oxalate [La2-xDyx (C2O4)3]10H2O with x=0.1, 0.15, 0.2 were grown by gel method and characterised by X-ray powder diffraction analysis. Thermal stability of sample was investigated by thermo gravimetric analysis. UV-Visible absorption and photo-luminescent studies were also conducted. The emission spectrum on exciting at 271nm and 364 nm were recorded in which Dy3+ ions showed four emission bands at positions 458nm (blue), 478 nm (blue), 572 nm (yellow) and 655 nm (red) corresponding to transitions 4I15/2→ 6H15/2, 4F9/2→ 6H15/2, 4F9/2→ 6H13/2 and 4F9/2→ 6H11/2 respectively. The CIE coordinates, colour purity and CCT values were calculated, and all these parameters show that Dy3+ doped lanthanum oxalate single crystals are suitable candidates for white light emitting applications.


2021 ◽  
Author(s):  
Maryam Mehravar ◽  
Bi Bi Fatemeh Mirjalili ◽  
Elaheh Babaei ◽  
Abdolhamid Bamoniri

Abstract Background: The nano-sized particles enhance the exposed surface area of the active part of the catalyst, thereby increasing the contact between precursors and catalyst considerably. In this study, nano-SiO2/1,5-diazabicyclo[4.3.0]non-5-en was synthesized, characterized and used as a heterogeneous nanocatalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives. Fourier Transform Infrared Spectroscopy, Field Emission Scanning Electron Microscopy, Brunauer–Emmett–Teller plot, Energy Dispersive X-ray Spectroscopy and Thermo Gravimetric Analysis were used to discern nano- SiO2/1,5-diazabicyclo[4.3.0]non-5-en.Results: Tetrahydrobenzo[b]pyrans were synthesized by using nano- SiO2/1,5-diazabicyclo[4.3.0]non-5-en via one-pot three-component condensation of malononitrile, aldehydes and dimedone in H2O/EtOH at 60 °C. The results indicate that tetrahydrobenzo[b]pyrans were synthesized in good to high yields and short reaction times.Conclusions: The fundamental privileges of this method are short reaction time, plain procedure, recyclability of catalyst and high yields of products.


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