Table of Content

15 April 2017, Volume 36 Issue 4

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Measurement and Analysis of Optical Constants of Float Glass Based on Genetic Algorithm

2017, 36(4):  1107-1112. 

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The optical constant of float glass is the basis of optical design and quality control of the coated product.Because the reflected light can not reflect the material absorption characteristics,as well as the multiple reflection of the glass two interface to generate the depolarization problem,to make use of ellipsometry to analyze the optical constants of float glass is not applicable.In this paper,by using the spectrophotometer to measure the transmission spectrum 300-2500 nm range of float glass,based on the spectral characteristics,a composite oscillator model with the core of gaussian and pole oscillators was established,a total of 15 unknown parameters,using genetic algorithm to obtain the optimum oscillator parameters according to the transmission spectrum,the corresponding optical constants were obtained,which were in accordance with the basic optical properties of float glass.

Transport State of Chloride Ion in Concrete Crack Area under Dry-Wet Cycle

DONG Rong-zhen;GAO Yin;WEI Jun;QI Yun-xuan;LIU You

2017, 36(4):  1113-1119. 

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The chloride ion concentration distribution and crack-influenced area in concrete crack area under dry-wet cycle are studied.Concrete samples with different widths of transverse crack are exposed in the chloride dry-wet cycle environment for accelerating chloride ion erosion into concrete.The chloride ion concentration in the side of the crack and from the surface of the specimen to the steel bar of different erosion cycles is regularly detected.The test results show that chloride concentration decreases with the increase of transmission depth, and achieves stability at 20 mm.With the dry-wet cycle progressing, after 20 dry-wet cycle periods, chloride concentration in specimen with crack width from 0.1 mm to 0.5 mm is over 0.1% on the side of crack by 30 mm, which means the steel in this section is in danger of corrosion.Meanwhile, because of the influence of two dimensional transmissions, the greater crack width, the higher chloride concentration of same transmission depth is.

Optimization Design on Proportion of Filter Concrete for Stream

XIE Ying-bing;JIANG Hui

2017, 36(4):  1120-1124. 

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Based on the experiment factors of gravel, cement, sand, SR-3 and water, and according to prepare the filter concrete samples by laboratory test, the influence of compressive strength,the porosity and pH on filter concrete is studied with the uniform design of 4 factors and 5 levels.The range of filter concrete proportion for stream governance is obtained by the analysis of contrast experiment.The proportion are 1546-1578 kg/m3, 250-280 kg/m3, 80-100 kg/m3, 4.7-5.5 L/m3, 72.5-109.2 L/m3, for gravel, cement, sand, SR-3 and water respectively, which can provide reference value for actual engineering of eco-concrete slope.

Mechanism of Interaction between Different Clay Minerals and Polycarboxylate Superplasticizer

GUO Yu-lin;HU Jia-bing;TAN Hong-bo;MA Bao-guo;GU Ben-qing

2017, 36(4):  1125-1129. 

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The interaction mechanisms between different clay minerals and polycarboxylate superplasticizer (PC) were discussed with XRD, IR and TOC, saturated water absorption and fluidity.The results show that the side chains of PC can be intercalated into the interlayer of montmorillonite (MMT), thereby causing the interlayer absorption, whereas PC is not able to be inserted into the interlayer of kaolinite, sepiolite and illite;and the only surface adsorption can be observed and the order of adsorption amount montmorillonite > kaolinite > sepiolite > illite.The results of saturated water absorption indicate that the orders of different clay minerals are montmorillonite > kaolinite > sepiolite > illite.The presence of clay minerals would reduce the fluidity of cement-PC paste, and the effect of montmorillonite is the greatest.Therefore, the main reason for the fluidity loss is attributed to absorption of free water and adsorption of polycarboxylate superplasticizer caused by clay minerals.

Chloride Transport Model and Parameter Analysis of Unsaturated Concrete

YU De-mei;GUAN Bo-wen;SHEN Ai-qin;CHEN Hua-xin

2017, 36(4):  1130-1135. 

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Most of the concrete structure in entity engineering is always in the unsaturated state with alternating wet and dry seasons.It is of great importance to do the research chloride salt erosion in unsaturated concrete for concrete durability.According to the chloride ion transmission mechanism,the chloride convection-diffusion control equation in unsaturated concrete was derived by considering the difference of moisture transmission the dry-wet alternate process.Crank-Nicolson method was engaged to develop the finite difference format of equation above.The results of proving experiment reveal that the results of model calculation have a good correlation with the measured results.The parameter sensitivity analysis result shows:chloride ion concentration increases decreases with the increase of dry and wet ratio surface and pore saturation.The chloride ion concentration gets its highest with the concrete initial saturation is 0.3.

Conversion Relationships between Compressive Strength Indexes of Recycled Lightweight Aggregate Concrete

ZHANG Xiang-gang;WANG Fang;YANG Jian-hui;FAN Yu-hui

2017, 36(4):  1136-1142. 

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In order to study cube compressive strength and prism compressive strength of recycled lightweight aggregate concrete, and conversion relationship between the two with the replacement rate of recycled lightweight coarse aggregate as change parameters, 15 standard cube test blocks and 15 standard prism test blocks were produced to carry out the test.Then compressive strength of test blocks were measured, and the regularity of different replacement rate of recycled lightweight coarse aggregate influencing compressive strength of recycled lightweight aggregate concrete was discussed, as the method of statistical regression adopted, the conversion relationship between of axial compressive strength and cube compressive strength of recycled lightweight aggregate concrete was obtained.The results show that compressive strength of recycled lightweight aggregate concrete are lower than compressive strength of ordinary concrete;and that compressive strength of recycled lightweight aggregate concrete gradually decreases as replacement rate of recycled lightweight coarse aggregate increases;as well as, the conversion relationship between axial compressive strength and cube compressive strength of recycled lightweight aggregate concrete is different from ordinary concrete;based on the experimental data, conversion relationship formula between compressive strength indexes of recycled lightweight aggregate concrete was established.

Effect of ZnO on Structure and Properties of ZnO-B2O3-SiO2 Low-melting Glass

ZHENG Wei-hong;SHENG Li;ZHOU Ying;LIU Xin-yue;CUI Jing-jing;PENG Zhi-gang

2017, 36(4):  1143-1148. 

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The ZnO-B2O3-SiO2 glass is an important sort of the low-melting glass which has important applications in deep processing field of glass.In the ZnO-B2O3-SiO2 glass,the ZnO content have a significant influence on the structure and properties of the glass.The influence of ZnO on the structure and properties of ZnO-B2O3-SiO2 low-melting glass was studied by DSC,FTIR,CTE test,chemical stability test and he coating application.It was found out that the increase of ZnO could reduce the characteristic temperature of ZnO-B2O3-SiO2 low-melting glass,and increase the CTE and chemical stability.The results showed that Zn2+ with a form of [ZnO4] entered the network structure of glass,and there was a transition [BO4] tetrahedral structure to [BO3] trihedral structure with the increase of ZnO.The optimum amount of ZnO was 32%.In this situation,ZnO-B2O3-SiO2 low-melting glass had the lowest Tg (495 ℃) and Ts (529 ℃),and the CTE was 8.96×10-6 /K.The chemical stability was A level.In the coating application of low-melting glass,the glass in that ZnO content is 32% present the best hardness which is 648.9 Hv.

SiO2 Nanoparticles Removal from 7003 Aluminum Alloy Surface in Post-CMP Cleaning

WU Zhong-hua;BIAN Da;ZHAO Yong-wu

2017, 36(4):  1149-1153. 

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With the wet chemical cleaning method and ultrasonic in the weak acid aqueous solution, the cleaning of the 7003 aluminum alloy surface after chemical mechanical polishing (CMP) was investigated.The cleaning slurry are mainly composed of the non-ionic surfactant, polyoxyethylene octylphenyl ether, and corrosion inhibitors, disodium dihydrogen pyrophosphate and benzotriazole (BTA).With scanning electron microscope (SEM) and atomic force microscope (AFM) analysis, it is found that polyoxyethylene octylphenyl ether could keep SiO2 particles in the state of physical adsorption which could easily be removed from the surface, combining with ultrasonic synergy.With the increasing mass fraction of surfactant, particles removal efficiency gradually improved.When the mass fraction increased to 2%, the SiO2 particles remaining on the surface are substantially removed, and no corrosion phenomenon happens.Besides these, surfactant layer was formed on surface after cleaning, which could prevent the particles adsorption again.

Compound Dispersion of Ultrafine Boron Nitride Powder in Anhydrous Ethanol

GUAN Yun-lai;ZHANG Zhen-zhong;LI Zhen;ZHAO Fang-xia

2017, 36(4):  1154-1158. 

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For the deficiency of submicron h-BN powder easy to reunite and poor interfacial compatibility with polymeric materials, the dispersion process of ultrafine h-BN powders in the anhydrous ethanol was studied.Firstly, the pH-Zeta potential of the h-BN ultrafine powders in anhydrous ethanol had been measured.Based on the results, the anionic dispersants (SA/OA/SDBS), nonionic dispersants (PVP/KH570/ Span85) and polymeric dispersant (PEG4000) were selected.The dispersion properties of different dispersing agents on the h-BN ultrafine powders were measured after being dispersed by ultrasound.According to the results of the last step, three kinds of dispersant had been chosen to form different composite dispersion systems and their dispersion properties had been tested.The results show that compound dispersion system has a better dispersive property compared with single dispersant, (PEG4000/SA) compound dispersant dispersive property increased by 18%;(KH570/SA) compound dispersant dispersive property increased by 11%.The best dispersion process of the h-BN ultrafine powders in anhydrous ethanol are: the quality fraction of SA(4wt%) and PEG4000 (1wt%) or SA(1wt%) and KH570(4wt%), at a pH of 9 and the ultrasonic (560 W) time for 90 min in anhydrous ethanol.

Kinetics and Thermodynamics Study on Congo Red Adsorption by CTAB Modified Bentonite

SUN Zhi-yong;YAN Biao;WANG Ai-min;BAI Ni

2017, 36(4):  1159-1163. 

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The modified bentonite was prepared using bentonite modified with cetyltrimethyl ammonium bromide (CTAB).The structure of this modified bentonite was characterized by fourier transform infrared spectra (FTIR) and XRD.The effects of the dosage and pH value on the adsorption of Congo red from water were studied.The thermodynamics and kinetics of Congo red adsorption on the modified bentonite was stuied also.It is shown that the CTAB could be inserted into the interlayer of bentonite with the removal rate as high as 97.15% when the dosage is 4 g/L and pH is 4.The adsorption process of Congo red on the modified bentonite followed the pseudo-second order kinetic equation and the adsorption behavior fited with the Langmuir sorption isotherm equation.The results of thermodynamic analysis are:enthalpy (ΔH)< 0,Gibbs free energy (ΔG)<0,and entropy (ΔS)<0,which suggest that the sorption is an exothermic, spontaneous and decreasing entropy process.

Early Crack Experiments of Steel Plate Concrete Composite Shear Wall

HUA Jian-min;FENG Chao;ZENG Liang;HUANG Le-peng;KANG Ming

2017, 36(4):  1164-1168. 

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The early shrinkage and early flat restraint cracking experiments of concrete were designed to study the crack resistance and shrinkage-reducing performance of high strength and high performance concrete in steel plate concrete composite shear wall.Four kinds of conditions were considered in the experiment,such as adding expansive agent,internal curing agent,steel fiber and the mixture of expansive agent and internal curing agent.The results show that the early shrinkage of concrete can be reduced by adding expansive agent, internal curing agent,steel fiber and the mixture of expansive agent and internal curing agent.And for the mixture of expansive agent and internal curing agent,it significantly improves the expansion effect of the expansive agent,so that the expansion strain and the expansion time of the concrete are increased,and the 28 d shrinkage is reduced by 87.6%.It also makes the concrete early cracking time delay,the crack width and number are significantly reduced.These results are good references for the the control of the early crack of steel plate concrete composite shear wall.

Chrysotile Fiber Reinforced Lightweight Porous Diatoms Brick

LIU Huan;LIU Kun;TANG Xun-kun;LU Jia

2017, 36(4):  1169-1174. 

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Lightweight porous diatoms brick was prepared through compression molding and calcination using diatomite,chrysotile and kaolin as raw materials.The systematic investigations on the bulk density,water absorption,porosity,rupture modulus and moisture absorption-desorption of the diatomite brick were carried out.The structure and morphology of the diatomite brick were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM),respectively.The results show that water absorption and porosity of the diatomite brick decrease with the increase of chrysotile content and calcination temperature.On contrary,the rupture modulus of the diatomite brick was increased significantly.The rupture modulus,bulk density and apparent porosity of the diatoms brick are 10 MPa,1.18 g/cm3 and 47.97%,respectively,when the chrysotile content and calcination temperature are 10wt% and 900 ℃.These indicate that the diatomite brick has the prominent advantage of high strength,light weight,porous and well moisture absorption-desorption properties.

Synthesis of Hierarchical γ-AlOOH via Template-free Hydrothermal Method and Its Adsorption Performance

GUO Xiao-rui;QUAN Ting-ting;XIE Tian-yi;MENG Fan-cheng

2017, 36(4):  1175-1179. 

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Long-sphere like hierarchical γ-AlOOH was prepared by a facile template-free hydrothermal method at 180 ℃ for 12 h with aluminum nitrate (Al(NO3)3·9H2O) as an aluminum source and urea as a homogeneous precipitation solvent.The obtained sample was characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and N2 adsorption desorption technique, respectively.The possible formation mechanism of the long-sphere like γ-AlOOH was discussed.The adsorption properties for Cr(VI), Methyl orange, Congo red were also examined.The results indicate that the size of the obtained long-sphere like hierarchical γ-AlOOH is an average length of 1.5 μm and an avarege width of 1 μm.The sample has the specific surface area of 146.33 m2/g and an average pore volume of 0.37 cm3/g.Also, the hierarchical γ-AlOOH shows the superior removal efficiency for Cr(VI), Methyl orange and Congo red with the maximum adsorption capacities of 14.36, 84.93 and 258.02 mg/g, respectively.

Influence Factors on the Crystallinity and Morphology of Ferrierite

HU Hai-qiang;KE Ming;ZHANG Ka;YU Pei;LIU Qiang

2017, 36(4):  1180-1186. 

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Ferrierite zeolite was synthesized by hydrothermal method using silica sol,sodium aluminate and ethylenedianmine as silicon source,aluminum source and organic template separately.The influence of synthsis factors such as crystallization time,crystallization temperature,alkalinity,ageing and the amount of seed on the crystallinity and crystal morphology were investigated.The samples were characterized by XRD and SEM.The result indicates that the pure ferrierite zeolite could be synthesized with a suitable alkalinity(0.12-0.15),crystallization temperature(160 ℃) and crystallization time(60 h).The higher the crystallization temperature,the bigger the crystal size was,but the crystallinity went up at first and then downd as the crystallization temperature increased.The crystallinity and crystal size increased initially as the crystallization time extended and stabilized afterwards.A suitable ageing temperature and time could reduce the crytal size, while the adding seed could change the morphology and size significantly.

Preparation of Low-temperature Sintered Ba2Ti9O20 Ceramics Doped with BZB by Different Ways

JIN Biao;WANG Xiao;YANG Liu-shuan

2017, 36(4):  1187-1192. 

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Ba2Ti9O20 ceramics were synthesized by the traditional solid-state reaction method, using BaCO3 and TiO2 as raw materials.In order to reduce the sintering temperature of Ba2Ti9O20 ceramics, liquid-phase method was used to dope Bi2O3-ZnO-B2O3(BZB) by precursor solution (BiCl3,Zn(NO3)2 and H3BO3) instead of mixing BZB powder directly with Ba2Ti9O20 ceramics.The optimal concentration of BZB was found to be 0.3 mol/L, and the derived Ba2Ti9O20 ceramic sintered at 1150 ℃ for 3 h presented good microwave dielectric properties of εr=37 and Qf=23485 GHz, which is much better than those of mixing BZB powder directly with Ba2Ti9O20 ceramics(εr=34 and Qf=16985 GHz).

Effect of Mineral Admixture on Workability and Mechanical Properties of Box Girder C50 Concrete

XIA Liang-liang;NI Tao;LIU Zhao-yang;WANG Jin-chun

2017, 36(4):  1193-1197. 

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The effect of composition and dosage of admixture that consist of fly ash and slag powder on workability and mechanical properties of box girder C50 concrete were studied by using fly ash/slag powder as a composite replacing part of the cement amount, and the microstructure of concrete was observed by SEM.The results show that the optimum mass ratio of fly ash to slag powder is 1∶2 in admixture.The workability of C50 concrete is improved, but the compressive strength of 3 d, 10 d, 28 d, 56 d decreased when dosage of admixture increased from 0% to 30%.It can be observed by SEM that the amount of hydration product C-S-H gel are less in the systems that admixed some of fly ash and slag powder.Then the bonding strength of interface of concrete decreased, and resulted to compressive strength reduced.

The Structure,Properties and Catalytic Performance of the Perovskite-type Materials

ZHAN Hai-juan;LIU Wan-yi

2017, 36(4):  1198-1202. 

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This paper has summarized the chemical structure characteristics of perovskite-type materials and the non-stoichiometry characteristic, adsorption performance, acid-base property, thermal stability, oxidation-reduction performance have also been illustrated.Based on the special structural characteristics and excellent properties of perovskite, its applications of photocatalysis, catalytic oxidation, water-vapor transformation, synthesis of both higher alcohol and methanol have been introduced.

Research Advances in the Remodeling and Functionalization of Vermiculite

LI Chuan-chang;YANG Li-xin;XIAO Gui-yu;ZENG Ling;HE Zhong-ming;CHEN Jian

2017, 36(4):  1203-1208. 

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The remodeling and functionalization of vermiculite to prepare composite materials is part of higher value applications of layered silicate.The modifications of vermiculite were concluded, and research progress on vermiculite-based functional composites for thermal storage, catalysis, environment, thermal insulation, anti-microbial, and sound insulation were discussed.Meanwhile, it is pointed out the developing trend of vermiculite-based functional composites.

Application of Biomineralization in Environmental Protection

2017, 36(4):  1209-1215. 

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The heavy metals consolidation by biological mineralization process was summerized.First, the method and mechanism of biomineralisation were discussed.Secondly,the common creature with biomineralization and the various influence factors was presented.Lastly, the research progress on biomineralization process in water and soil remediation was discussed.The paper also highlights the major difficulties associated with this process in practice application.The possible applications of this process were discussed.

Advances in Effect of Fiber Species on Improving Mechanical and Thermal Insulation Properties of Silica Aerogel

LIANG Yu-ying;WU Hui-jun;YOU Xiu-hua;YANG Jian-ming

2017, 36(4):  1216-1222. 

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Fiber/silica aerogel composite exhibits extensive application prospects in building,energy and material fields owing to its excellent mechanical and thermal properties.Based on size and morphology of fibers,the fibers were classified into regular bundle fiber,preform fiber and nano fiber.Preparation processes and structure characteristics of the three kinds of fibers reinforced aerogel composites were summarized,followed by advances in improving mechanical and thermal properties.Furthermore,Existing problems of the three kinds of fibers/aerogel composites were discussed,and thereby proposed the research perspective.

Research and Development Trend of Phase Change Concrete

ZHAO Si-xie;YAN Hua;LI Yun-tao;WANG Hong-tao;HU Zhi-de

2017, 36(4):  1223-1227. 

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The temperature cracks of the concrete aroused more and more people's concern, the phase change concrete is a new way to solve the concrete crack.On the basis of analyzing the reason of concrete temperature crack, the design thinking of the phase change temperature control of concrete was putted forward and the composite phase change materials for phase change concrete were reviewed.At last, the performances of phase change concrete were summarized, and analyzed the current existing problems, and the future trend was forecasted.

Research Progress on the Application of Waste Glass in Concrete

YAN Jian-hua;BAI Xiao-qiang;CUI Su-ping;HAO Ting-yu;HAN Ce

2017, 36(4):  1228-1233. 

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The research progress on the application of waste glass in concrete was reviewed.Waste glass has been reused both as aggregate and supplementary cementitious materials in concrete.The intrinsic cracks of the waste glass aggregate have been found to result in ASR in concrete and the ASR effect was supposed to be suppressed by replacement of some cement with fly ash or glass powder in concrete.As the particle size became smaller, waste glass became less in ASR effects and of more pozzalanic reactivity.The pozzolanicity of glass powder was better than that of fly ash in concrete at earlier age.The long term resistance of concrete to both chlorine penetration and sulfate attack was suppressed when a part of cement was replaced by glass powder.The application of glass aggregate and glass powder in concrete was closely related to both the national environmental policy and the region concerned in China.

Research Progress of Clay Minerals as Liquid Crystal Materials

JIN Hui-ran;WANG Zhi-hui;ZHANG Li-jing;DING Shi-jie;CHEN Jing

2017, 36(4):  1234-1240. 

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Clay minerals, composed of clay rock and soil of the main minerals, is a magnesium, aluminum-based hydrated silicate minerals.It is found that the clay mineral liquid crystal materials compared with organic liquid crystal, the former has the advantages of light, electricity, magnetic energy, good thermal stability, low price and so on.The current research status of clay mineral liquid crystal materials and their forming mechanism was introduced.The preparation methods of liquid crystal materials were reviewed on the studies of lamellar clay liquid crystals, fiber type clay liquid crystals, analogs of clay liquid crystals.Different effects, such as concentration, dispersing medium, external electric field, ionic strength and gravity etc.on the phase transition properties of the materials were discussed.The application and development of clay mineral liquid crystal materials were summarized as well.

Reverse Osmosis Technology of Brackish Water Desalination

CAO Ning;GAO Ying;XU Gen-qi

2017, 36(4):  1241-1244. 

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With the sustainable development of society, the water resource was seriously polluted and the phenomenon of water resources shortage was occurred, which not only limited the development of society, but also endangered the survival of mankind.In order to relieve the strain on water resources situation, the processing of brackish water recycling has become the best way to solve the water problem.In this paper, the research progress of reverse osmosis technology desalination and new energy recycling technology in brackish water area were introduced, the properties and characteristics were analyzed and the shortages were pointed in application process.Finally, the future application trends were discussed.

Research Status and Development Trend of Magnesium Phosphate Cement

MENG Qin;LIAO Zi-jun;LI Yun-tao

2017, 36(4):  1245-1253. 

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With good performance and wide application of magnesium phosphate cement,the preparation from phosphate, magnesium oxide and admixture were reviewed.And the hydration mechanism from hydration process, hydration products and retarding mechanism were discussed.Then the research progress of work and mechanical properties of magnesium phosphate cement were summarized.Magnesium phosphate cement was summarized on the problems existing in the application process, and on the basis of magnesium phosphate cement for the future development trend were discussed.

Research Development on Mechanism of Polymer Modified Cement Based Materials

WANG Chao;LIU Zhao-shuang;ZHAO Wen-jie

2017, 36(4):  1254-1257. 

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The mechanism of polymer modified cement based materials was reviewed in recent years at home and abroad, from the angle of theory, the mechanism of polymer modified cement based materials has carried on the induction and summary,the modified mechanism of the polymer modified cement base material was discussed mainly from four aspects, the influence of polymer to cement hydration process include physics and chemistry function;The effect of polymer on the microstructure was made from latex particle dispersion and the formation of polymer film.From the pore structure, polymer changed the pore size distribution, the characteristics of the pore diameter and average pore diameter and most probable aperture, porosity of cement based materials, and so on, and improves the cohesive strength.In terms of the structure of the polymer itself,the chain structure and state of aggregation structure of polymer directly affects the performance of cement based materials.

Optimum Mix Ratio of Magnesium Cement Concrete Based on Nondestructive Testing Method under Different Environment

2017, 36(4):  1258-1265. 

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According to the demand of corrosion-resisting concrete in the western salt lake area and combining with the local conditions, the performance of magnesium cement concrete was studied by relative elastic modulus, relative quality, comprehensive evaluation parameters and scanning electron microscope under dry and immersed environment.The results show that the best mix ratio of the six mixes of magnesium cement concrete is mix ratio 2, and the proportion of materials used is: water∶MgO∶MgCl2∶stone∶sand∶phosphate∶water-reducing agent=1∶2.87∶1.09∶8.57∶4.61∶0.07∶0.12, after one year test by nondestructive testing method.

Calculation Model of Cement Hydration Degree under the Influence of Mineral Admixture at-3 ℃

2017, 36(4):  1266-1271. 

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Aiming at the problems of concrete maintenance in the engineering construction in permafrost regions, by 10%, 20% and 30% of the ground granulated blast furnace slag(GGBS) and fly ash(FA) replacing cement content, the hydration heat of cement pastes with 0.38 water cement pastes at different ages was tested under the condition of constant temperature curing at-3 ℃, and the hydration degree of cement was calculated.The influence of age and mineral admixtures on the hydration degree of cement was analyzed, and the calculation model of the hydration degree of cement was established.The results show that the-3 ℃ constant temperature curing, mineral admixture replacing cement, the hydration degree of cement paste can be reduced, FA to reduce the degree of hydration value than GGBS.With the increase of the age, the effect of mineral admixtures on the hydration degree of cement is gradually decreased with the increase of the age of the same mineral admixture.At the same time, with the increase of mineral admixture, the effect of mineral admixtures on the hydration degree of cement is gradually increasing.The cement hydration degree were mixed with 15% FA and GGBS were calculated by using the model, compared with the measured values, the deviation is less, higher prediction accuracy.

Effect of Technological Conditions on Performance of Ceramic Mould Gypsum

RU Xiao-hong;WANG Yu-jiang;GUO Lei-ming;QIAN Yue-jin

2017, 36(4):  1272-1277. 

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Effects of water-plaster ratio, stirring rate, stirring time and water temperature on the mould gypsum performances of setting time, strength, water absorption were studied through contrast tests, then the mechanisms were investigated by SEM XRD.The result shows that: the optimized conditions are plaster-water percentage of 65%-70%, stirring speed of 400-500 r/min, stirring time of 2-3 min, water temperature of 25-30 ℃;the degree of crystallinity and crystal morphology of the hardened mould gypsum are influenced by all of the four processing parameters.

Effect of Al Dosage on the Performance of ZnO Polycrystals

LIU Dan-dan;SONG Shi-jin;QIU Xing-huang;TAN Wen-peng;YU Lan

2017, 36(4):  1278-1282. 

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Zn1-xAlxO(0≤x≤0.005) polycrystalline bulks with hexagonal wurtzite structure were prepared by solid-state reaction method.The micro morphology and the thermoelectric properties of Zn1-xAlxO bulk were investigated.Doping Al made ZnO grain increased and grain boundary decreased.The results show that the spinel ZnAl2O4 appeared while x=0.005.Secondarily sinterd samples have 1-2 orders of magnitude decrease of resistivity.The semiconductor behavior of bulks transform metallic behavior after Al doping in ZnO.Al doping is responsible for the carrier concentration and mobility remarkable increase.At x=0.004 the minimum of resistivity of primarily sintered sample is 10 mΩ·cm.The seebeck coefficient and power factor S2/ρ increase with the increasing temperature at 300-950 K.The maximum of the power factor is 0.11 mW/m·K2 at room temperature.The saturated solution of Al doping in ZnO is between 0.004 and 0.005.

Application of Refractories and Secondary Kiln Shells in Reducing Surface Heat Loss of Cement Kiln

YE Jun;PAN Geng;YANG Jia-song;KAO Hong-tao

2017, 36(4):  1283-1287. 

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The main heat in the cement production process is wasted in the kiln end preheater exit gas to take away the heat, the kiln system surface to the environment through the radiation, the convection way conduction heat, the clinker clinker cooler take away the heat and the cooler clinker away Heat loss and so on.It is an important measure to improve the energy efficiency of cement plant by studying the heat dissipation of the surface of the cement preheater and the heat recovery technology of the rotary kiln.In order to use new energy cement kiln system more efficient energy audit analysis.In this paper, the energy utilization and loss of the precalciner kiln system are analyzed from the view of energy balance.The influence of the refractories on the heat loss of the preheater tube and the recovery of the residual heat of the rotary kiln by the secondary kiln shell is studied.The energy of cement kiln system is improved.

Effect of ZrO2 on Structure and Properties of Pharmaceutically Medium Borosilicate Glass

DU Tao;TIAN Ying-liang;LI Yong-ming;SU Yin;WANG Yong-qing;LU Ping

2017, 36(4):  1288-1292. 

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Pharmaceutically medium borosilicate glass were prepared by using melt cooling method,which replaced aluminum oxide with equal quantity of zirconium oxide.The structure of glass was analyzed by infrared spectroscopy.The density,coefficient of thermal expansion,high-temperature viscosity and chemical stability were also tested.The experiment results shows that with the content of zirconium oxide increasing,the quantities of [BO3] increase,the numbers of [BO4] decrease.And the density gradually increases.The coefficient of thermal expansion and high-temperature viscosity both increase firstly and then reduce.When the zirconium oxide added,it has little effect on water and acid resistance,but the alkali-resistance improves significantly.

Preparation and Properties of Red Ceramic Inks

HE Jing-jing;PEI Xin-mei

2017, 36(4):  1293-1297. 

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A kind of red ceramic ink with appropriate color and qualified properties was prepared by solution of metallic salts method.The effects of composition of ceramic ink and basic glaze on chromatic performance were investigated.The color mechanism was discussed by analyzing the sintered ceramic surface with the ink.Results show that the properties can meet the requirement of ink-jet printers such as surface tension,viscosity,pH and so on.The ink has excellent chromatic performance on the high calcium transparent basic glaze when the ratio of Cr/Sn is 0.04∶1.

Enhancement Performance of Desulfuration Gypsum Whisker on Cementitious Materials

ZHANG Xiao-ting;SONG Qiang;WANG Xiao;YANG Liu-shuan

2017, 36(4):  1298-1302. 

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Mortar samples were prepared by using different desulfuration gypsum whisker(0,0.5wt%,1wt%,2wt%,3wt%) as toughening agent.The samples' mechanical properties at different ages(3 d,7 d,28 d), microstructure of gypsum whisker and it distribution in cement matrix were detected.It was found that the flexural strength and compression strength of sample added with 1wt% desulfuration gypsum whisker were increased by 28.41% and 45.65%, respectively.The mechanisms of the reinforcement of desulfuration gypsum whisker on cement were also discussed, the mechanical improvement can be explained by the energy-dissipating processes owing to crack bridging, crack deflection, and whisker pull-out at the crack tips.

Exploration of Optimal Sintering Tempertature in the Preparation from Refractory Material of Fly Ash

YANG Jing;MA Li-ping;LI Jian-duo;LIU Hong-pan;ZHAO Si-qi;CUI Xiao-jing

2017, 36(4):  1303-1308. 

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Fly ash based refractory materialsas were prepared using fly ash(from a coal power plant in Anning City) as the main raw material and sludge and industrial alumina the auxiliary materials.viability of their industrial application was analyzed theoretically.The microstructure was analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques.On the basis of meeting the national standard ,we tried to explore the best sintering temperature range.The results show that at sintering temperature of 1300 ℃ and fly ash content of 68%,the incorporation,porosity,water absorption,compressive strength,flexural strength,refractoriness,permanent heating of the product meets the national standard.XRD results indicate that the higher the sintering temperature (1100-1300 ℃),the more and stronger the mullite peaks became.SEM results show that when the sintering temperature is increased from 1100 ℃ to 1300 ℃,the dominant shape of mullite shifted from neddle to columnar.At the temperature of 1300 ℃,dense mullite structure is observed.In comparison,when the sintering temperature is 1400 ℃,less columnar in loose mullite structure is found.

Performance Evaluation of Phase Change Materials Based on VIKOR Method

FAN Jing

2017, 36(4):  1309-1314. 

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The choice of phase change materials need to consider phase change enthalpy, specific heat, thermal conductivity, density, degree of super-cooling and price and so comprehensively.In order to solve the problems of the conflict and different dimensional attribute, the index system of different levels and phase change material performance evaluation model are established based on VIKOR method.Determine the weight of the index system by the AHP method and sort all kinds of phase change materials based on the evaluation model for the comprehensive performance.Research showed that the evaluation model based on VIKOR method was in conformity with the actual research to indicate that the VIKOR method had strong theoretical and practical.

Effect of Synthesized Grinding Aid to Titanium Slag Cement

QIAO Huan-huan;JIANG Yong;LU Tao;HU Guang-lin

2017, 36(4):  1315-1320. 

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Triisopropanolamine, diethanolamine, acrylic, HPEG400 and other materials were used to composite a new cement grinding aid.We examined the grinding effect of the new grinding aid for titanium slag cement, and the physical and mechanical properties and the hydration products of the cement were studied.The results show that the surface area of titanium slag cement increase of 9.5%-14.7%, 3 d and 28 d compressive strength respectively increased by 9.0%-21.2% and 7.2%-10.6% after adding this new grinding aid.The test results of XRD and TG/DTA indicate that the new grinding aid can promote hydration of cement, but does not produce new phase hydration.

Weibull Statistical Analysis on Tensile Strength of Adhesive Joint in PMMA

ZHOU Fan;HOU Shao-jing;ZHENG Chen-chao;TANG Xiao-yu;HU Yu;CHEN Zhi-ping

2017, 36(4):  1321-1325. 

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Tensile strengths of PMMA specimens with adhesive joints made by four kinds of bonding technologies (conventional bonding, quick bonding, ultraviolet light polymerization bonding and ultraviolet light polymerization bonding with heat treatment) were tested.The Weibull distribution theory was used to evaluate the dispersion of tensile strength data.The results show that Weibull distribution function can well describe strength distributions.Average strength of specimens by quick bonding technology was higher and the dispersion of strengths was lower.The bonding coefficient was obtained to be 0.83.Besides, the bonding process consumed less time.So the quick bonding technology is more suitable for bonding of PMMA structures in large engineering.

Experimental Investigation on Preparation Technology and Performance of Rubber Powder Modified Asphalt

XU An-hua;WANG Xiao-wen;XIONG Rui;CHEN Hua-xin;FANG Jian-hong;KUANG Dong-liang;WANG Xiao-lei;LIU Zi-ming

2017, 36(4):  1326-1332. 

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In order to prepare the applicable rubber powder modified asphalt used for asphalt pavement aiming at the influence factors such as the particle size of crumb rubber, the dosage of powder, shearing time, preparing temperature and shearing rate, the orthogonal test of 5 factors and 4 levels was applied in this paper, Meanwhile, elastic recovery rate, shear strength, segregation softening point difference and viscosity-temperature regression coefficient |B| were selected as evaluation indexes.Based on that, the optimal scheme of preparation of rubber powder modified asphalt was selected and the rubber modified asphalt was prepared well and its mechanism and road performance were analyzed.The results show that the asphalt modified with rubber powder under the condition of 30 mesh rubber powder with content of 24%, shear time of 60 min, preparation temperature of 205 ℃and shear rate of 5000 r/min has better performance.The porous powder particles uniformly dispersed in the asphalt system absorb the light components of asphalt, produces swelling and weak chemical reaction and presents the space network cross-linked structure, which is the main reason for the excellent performance of rubber powder modified asphalt.

Effect of Mineral Admixtures on the Hydration of Sulphoaluminate Cement under Seawater Condition

LIAO Yi-shun;LIU Chu-ming;KANG Shuang;LIAO Ming-yong

2017, 36(4):  1333-1338. 

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The influence of silica fume, fly ash and ground granulated blast furnace slag on the compressive strength, chemical shrinkage and hydration products of sulphoaluminate cement under seawater condition were investigated.The results show that the compressive strength of cement paste is higher than the control sample when the dosage of silica fume is 2.5%.The compressive strength of cement paste with 10% of slag at 28 d evidently surpass that of silica fume and fly ash.The compressive strength at 60 d is even higher than the control sample.The chemical shrinkage of cement paste increase with 2.5% of silica fume, while the low pozzolanic activity of fly ash and slag during early hydration decrease the chemical shrinkage of cement paste.The hydration reaction of sulphoaluminate cement during 3 d is accelerated when the content of silica fume reached 10%, and the amount of ettringite is increased, which enhanced its early strength compared to others, but the rapidly volume expansion will destroy its internal structure and has a negative effect on the strength development.

Preparation of ZrB2 /Al2O3 Composite Powders by Self-propagating High-temperature Synthesis with ZrO2 Fibers as Template

LI Quan;XIAO Guo-qing;DING Dong-hai;ZHANG Wei

2017, 36(4):  1339-1344. 

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Preparation of ZrB2 fiber or composite powder containing ZrB2 fiber is great significance for the development of fiber reinforced ultrahigh temperature structural ceramic matrix composites.The ZrB2/Al2O3 composite powders containing ZrB2 fiber was prepared by self-propagating high-temperature synthesis method with ZrO2 fibers,B2O3 and Al powders.The phase composition,micro-morphology and chemical composition of the products were characterized by X-ray diffraction,field emission scanning electron microscopy and X-ray energy dispersive spectroscopy.The reaction process of raw materials in the heating process were studied by DSC-TG.The state of ZrB2 and the effect of argon pressure on the phase composition of the combustion synthesis products and structure of the ZrB2 fiber were analyzed emphatically.The results show that the phase composition of the SHS products are ZrB2 and Al2O3 with the argon pressure of 1.5 MPa.A part of ZrB2 were formed as ZrB2 fibers with ZrO2 fibers as the template,another part of ZrB2 are dispersed in ZrB2/Al2O3 composite powders in granular form.The ZrB2 fibers have a rough surface and a relatively complete structure with a diameter of about 10 μm.

Temperature Response of Concrete Influenced by Different Environment

CHEN Yong-feng;JIN Zu-quan

2017, 36(4):  1345-1350. 

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Temperature responses of concrete in service environment affect the hydration process, water/ions transportation and rebar corrosion in concrete.The temperature and RH (relative humidity) evolution of saturated concrete and Non-saturated concrete with RH=45%, 65% and 80% rising and cooling process at 5 ℃, 45 ℃, 65 ℃ and 85 ℃ temperature were studied.And the thermal conductive coefficient of non-saturated concrete was also tested.The results of the experiment prove that temperature response time of concrete was increased with decreasing RH.Compared with response time of saturated concrete in rising and cooling process, the time of concrete with RH=45% prolonged 6-7 and 7-8 times, respectively.And the time of thermal flow to 10 mm depth of concrete with RH=45%-65% would be 30-50 min.The temperature response time of concrete would be shortened with decreasing distance to thermal source when concrete subjected to rinsing and cooling process.The inner RH of concrete increased firstly, and then trended toward steady in the temperature rising and cooling process.The interaction effects between thermal conduction and RH transportation was observed in this experiment.Additionally, the thermal conductive coefficient of concrete increased with increasing RH in concrete, and extending curing age.

Bending Capacity of RC Beam with CFRP Pasting on Edge Compression Zone

ZHANG Tong;LYU Xue-tao;TONG Xu-yang

2017, 36(4):  1351-1357. 

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Two suitable reinforced concrete beams with CFRP plate at the compression zone for four-point bending beam static load testing, two respectively of a layer and two layers of beams strengthened by CFRP plates on edge compression zone.The load-deflection curve were measured;The failure pattern, effects of bending capacity, deflection and strain variation of the beams with CFRP plate at the compression zone;Finally, it is necessary to put forward its role in reinforcing concrete structures and deduced the bending capacity calculation formula of rectangular cross section which pasting CFRP plates for flexural members.

Compound Fining Agent of Float Glass by HTMOS

JIA Yang;JIANG Hong;YU Lin;LIU Yuan;LI Chang-jiu

2017, 36(4):  1358-1364. 

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By means of High Temperature Melting in situ Observing and record System(HTMOS), the effects of multi-compound fining agent on the generation, growth and elimination of bubbles in soda-lime-silica flat glass melt are explored.The results are that by means of HTMOS device,cascade fining effect is observed in situ after Na2SO4, C and CeO2 are compounded.Compare with the fining agent of Na2SO4 or CeO2 alone, the glass without clarifying agent has more bubbles.The mixed clarifying agent of C+ Na2SO4+CeO2 can reach cascade fining effect and lower the fining temperature, it is conducive to lower the melting temperatures and reduce the melting time.

Experimental Investigation on the Pullout Properties of Concrete Structures Strengthened by FRP Influenced by Anchorage Depth

WANG Zhen;KANG Jing-fu;WANG Kun;JING Rui

2017, 36(4):  1365-1370. 

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FRP anchors are proposed to be advanced in impeding debonding failure between strengthened concrete surface and FRP.Influence of varied depth of FRP anchors on pullout properties of FRP strengthening concrete structures is comparatively investigated by pullout experiment that is in light of ACI experimental guidance.The parameters are set by control specimen and experimental specimens which are armed with 3 groups of anchors whose depth are 15 mm,30 mm and 45 mm,respectively.To analyze the results,the failure modes of debonding inside of shallow concrete,concrete cone,concrete cone combined with partial anchors pullout,debonding inside of shallow concrete combined with anchor rupture and debonding in both shallow concrete and FRP are totally derived.Moreover,the bond strength of FRP and concrete surface are increased with depth of FRP anchors.As well,the depth of the anchors are supposed to set more than 30 mm when applied to concrete with cylindrical compressive strength of 30 MPa.To sum,conclusions for this experiment is available to aid design of FRP anchors.

Effect of Cement Content on Reflection Crack Based on FLAC3D Numerical Simulation

ZHENG Da-wei;YAN Ni;HAO Lian-xue

2017, 36(4):  1371-1376. 

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To solve the problem of the semi rigid base course, which was easily to produce reflection cracks and set out the pavement structure which was suitable for Liaoning area.This paper taked the example of a municipal road in Fushun city as the research object, using temperature shrinkage test and finite difference numerical software FLAC3D, and researching and analyzing on the mechanical properties of asphalt concreted pavement under the action of temperature load then paving the test road.The results show that the suppression of reflection cracking effect of graded broken stone is better.The conclusion can provide reference for road design, construction and management of asphalt pavement rut engineering personnel, which is a certain social and economic benefits.

Effect of Temperature on the Compressive Strength of the Mortar Made of Alkali Activated Recycled Concrete Debris

LI Qin;ZHANG Chun-hong;CHEN Qiu-ling;SUN Ke-wei

2017, 36(4):  1377-1382. 

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The recycled debris mortar compressive strength and micro porosity were chosen as indexes to research the influence on compressive strength with alkali-activated at different temperature, which was combined with the XRD diffraction pattern of part recycled debris mortar samples.It is found that alkali-activated and temperature have important influence on strength by comparing the experimental research.It is found that the alkali and the recycled concrete powders ratio and the curing temperature had great influences on stimulating recycled concrete powder mortar strength.If alkali excitation temperature is too low, the reaction rate is too slow and during a certain period, the gelling material is less, and the compressive strength of recycled mortar in high porosity is lower.And vice versa.Therefore, the alkali-activated reaction at the most suitable temperature brings most gelling material, and the compressive strength of the mortar is the best.

Research on Clarification of Refining Agent on High Strain Point Glass

MA Li-yun;ZHAO Feng-yang;SHAN Chuan-li;CAO Xin;SHI Li-fen;HONG Wei;PENG Shou

2017, 36(4):  1383-1387. 

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High strain point glass as a new style glass has rapid development in recent years.High strain point glass has high impact resistance and high scratch resistance;it is widely used in CIGS solar energy substrate and touch devices.In this paper, the clarifying effects were investigated by different agent and content.Area refraction, mean bubble size and number of bubbles were analyzed quantitatively in the clarification process.An adequate mode of clarification is set up for high strain point glass, which can provide some guidance suggestions for glass production enterprises.

Analysis on the Deterioration of Bonding Performance between Concrete and Reinforcement in Corroded Reinforced Concrete Beam

YANG Xiao-ming;SUN Guo-jun;CHEN Yong-lin;WU Tian-yu

2017, 36(4):  1388-1394. 

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The deterioration of bonding performance between reinforcement and concrete is one of main reasons for the decrease of load carrying capacity of RC component.Based on the experimental results of corroded RC beam, the finite element models were built by Solid 65, Link8 and Combin39 element in ANSYS and updated according to the curves of load vs.displacement of the test beams.The suitable correction coefficients for deteriorate bonding strength between reinforcement and concrete were obtained from the former work.Finally, the curve fitting on these correction coefficients vs.corrosion ratio was used to obtain the equation for calculating the bonding strength bonding strength in corroded RC beams.The equation can be used to calculate the load carrying capacity of existing concrete structures and their condition assessment.

Effect of Sillimanite Content on Microstructure and Properties of Lightweight Mullite-Corundum Refractories

GAO Guang-bin;YAN Wen;LI Nan;ZHANG Zhen-yan

2017, 36(4):  1395-1400. 

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Using porous spherical mullite as aggregate, tabular corundum as powder, sillimanite and clay as marix, four groups of lightweight mullite corundum specimens were prepared and sintered at 1400 ℃, 1500 ℃ and 1600 ℃ for 3 h.The phase composition and microstructure were investigated through X-ray diffractometry (XRD) and scanning electron microscopy (SEM).Effect of sintering temperature and sillimanite content on physical properties and microstructure of lightweight mullite-corundum refractories were studied.The results showed that: (1) When the sintering temperature increased from 1400 ℃ to 1600 ℃, the apparent porosity of specimens decreased, the bulk density increased, the linear shrinkage increased, the cold compressive strength first decreased and then increased.(2) When the sillimanite content increased from 4% to 8%, the apparent porosity and bulk density of the specimens remained constant which was sintered 1400 ℃.When the sillimanite content was more than 8%, the cold compressive strength decreased significantly;after sintered 1600 ℃, the bulk density of the specimen decreased, the cold compressive strength decreased, and the linear shrinkage decreased from 2.5% to 1.5% with the increase of sillimanite content.(3) The specimen with 6% sillimanite content which was sintered at 1400 ℃ has low linear shrinkage(0.86%), high cold compressive strength(36.1 MPa),low thermal conductivity(0.249 W/(m·K),300 ℃) and smaller average pore size in the matrix of specimen(d50=46.7 μm).

Simulation and Analysis on the Heat Source in Parallel and Breathe Freely Furnace

XU Bao-hai;WANG Xiao-gang;LI Yang;WU Ze-min;REN Xiao-lei;DUAN Xiao-bo

2017, 36(4):  1401-1405. 

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Structure character and the radical theory of the technology on SiC synthesis by means of new designed furnace were introduced.The variation of temperature and pressure field were studied,simulation and experiment results were comparatively analyzed.The results show that the heat source in parallel and breathe freely furnace can Increase the reaction area.Pressure in furnace maintain between 0.101 and 0.113 MPa.The CO gas can be taken out from the exhaust system smoothly.The maximum velocity of gas in no more than 0.6 m/s,so it can effectively prevent the spray accident and toxic gases harm to personnel,the density of synthetic products has improved significantly.

Experimental Research on Physical and Mechanical Properties of Soda Residue Mixing Soils Used for Filling Embankment

ZHAO Xian-hui;LIU Chun-yuan;WANG Wen-jing;ZHU Nan

2017, 36(4):  1406-1411. 

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Soda residue was mixed with class F fly ash and sodium sulfate to synthesize the mixing soils using for filling embankment.Several physical and mechanical tests were conducted to compare and analyze the effects of sodium sulfate and the engineering properties of mixing soils.Results show that the chemical interaction between soda residue and fly ash can be confirmed by the results of boundary moisture content and particle analysis at different curing time.The instantaneous chemical reactions have happened between Ca(OH)2 and CaCl2 to produce NaOH and CaSO4.The pores among solid particles are filled with gel substances from the alkali-activated fly ash and the cementation of soil structure is improved.The mechanical properties of soda residue mixing soils are significantly improved by sodium sulfate,and are increasing with contents in the range of 0%-8%.But the frost resistance performance of mixing soils is poor.And it is recommended that a small amount of cement or NaOH be added to improve the frost resistance performance.

Influence of Polyester Fiber Contents and Freeze-thaw Cycles on Water Stability of Asphalt Mixture

WU Jin-rong;QI Da-jun

2017, 36(4):  1412-1416. 

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In order to study the influence of polyester fiber contents and freeze-thaw cycles, asphalt mixture specimens were mixed with polyester fiber whose contents were 0,0.1%,0.2%,0.3%.Asphalt mixture specimens were used to do freeze-thaw split tests.The results indicate that freeze-thaw split tensile strength of asphalt mixture ascended then descended with the increase of polyester fiber.Optimal content of polyester fiber is 0.2%.At the same time, when freeze-thaw cycles is 0 times and the content of polyester fiber are 0.1%,0.2%,0.3%, the freeze-thaw spilt tensile strength of asphalt mixture is increased by 19.8%,30.2%,13.4% compared with the strength of asphalt mixture without polyester fiber, and water stability is improved because of polyester fiber.When the content of polyester fiber is 0.2% and freeze-thaw cycles are 2,4,6,8 times, freeze-thaw split tensile strength ratios of asphalt mixture are 86.0%, 80.2%, 70.1%, 61.5%.Water stability of asphalt mixture is decreased with the increase of freeze-thaw cycles.

Experimental Research on Solidified Mechanism of New Soda Residue-Fly Ash-based Grouting Materials

ZHAO Xian-hui;LIU Chun-yuan;LIU Yu-fei;PANG Yun-ze

2017, 36(4):  1417-1423. 

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Soda residue, fly ash and sodium silicate solution were synthesized as grouting materials.Considering different solid mass ratios and curing conditions, temperature and shrinkage were observed while compressive strength and FTIR tests were conducted to explore the effect of each material and solidified mechanism of new slurry.Results show that Ca(OH)2 in soda residue and CaO in the fly ash have the exothermic reaction with sodium silicate solution.The early strength of slurry is dependent on hydrate calcium silicate gels from the reaction of CaCl2, Ca(OH)2 and CaSO4 with sodium silicate solution.7-50 d compressive strength increment is determined by aluminosilicate polymer gel generated by alkali-activated fly ash.FTIR results confirm the coexistence of C-S-H and N-A-S-H gel in this system.The properties of slurry are ensured well by raw materials on the shrinkage, mobility, segregation and stone rate.

Preparation and Characterization of Magnetic Calcined Layered Double Hydroxides for the Removal of Humic Acid from Aqueous Solution

LI Shao-xiu;YANG Yu-he;HUANG Ting;WANG Zhi-hong;LI Dong-mei;CUI Yi-yang;PAN Zheng-yu

2017, 36(4):  1424-1429. 

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Magnetite particles were coated on layered double hydroxides by one-step co-precipitation method,then the prepared solids were calcined to obtain magnetic metal oxides,which were used to remove humic acid from aqueous solution.The results show that magnetic calcined Zn-Al LDHs (M·Zn-Al LDO) performed a effective adsorption for humic acid removal.The effect of preparation conditions on the removal of humic acid was investigated,and the preparation conditions were optimized by orthogonal test.The results of adsorption of humic acid by M·Zn-Al LDO show that the humic acid removal rate is obtained 97.96% with the M·Zn-Al LDO dosage of 0.2 g/L at 30 min in initial humic acid concentration of 20 mg/L.The adsorbent is characterized using X-Ray,FT-TR,TG-DSC and SSA analysis,the results demonstrat that typical layered structure of hydrotalcite is not affected by introducing a certain amount of magnetic substrates which are Fe3O4 and γ-Fe2O3.The calcined products are metal oxides and still held excellent magnetic property,whose specific surface area is 80.00 m2/g.The humic acid removal by M·Zn-Al LDO is performed by surface adsorption and intercalation of small size functional groups in humic acid when the structure of hydrotalcite built again on memory effect.

Effects of Silicon and Sodium Content in Alkali Activator on the Formation of Geopolymer Prepared by Circulating Fluidized Bed Fly Ash

HAN Fu-qian;QIAO Xiu-chen

2017, 36(4):  1430-1435. 

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The mixture of metakaolin and calcite or gypsum instead of circulating fluidized bed (CFB) fly ash was used to investigate the influence of SiO2/Al2O3 and Na2O/Al2O3 on the setting time and compressive strength of geopolymer.The results of X-ray diffraction (XRD) and Raman spectrum proved that there are 10 chemical reactions occurred in the preparation of metakaolin-based geopolymer.The experimental results also showed that: the variation of sodium components in alkali activator controlled the amount of complex silicon or aluminum anion group, and the formation of CSH and (Na, Ca)-PSS depended on the amount of complex silicon anion group.In the SiO2-Al2O3-CaO-Na2O system, the formation of hydrogarnet showed negative effect on the strength development of geopolymer when Na2O/Al2O3≥1.1, and the geopolymer product set too fast to mix properly when SiO2/Al2O3≥3.0.

Effect of Modified-talc Powder on the Agglomeration of Fertilizer

SONG Ya-mei;HUANG Shan-xiu;LI Peng-ju;MA Ming-jie;SHEN Yu-xia

2017, 36(4):  1436-1441. 

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The talc powder was modified by using stearic acid, aluminate and titanate, though activation index and contact angle as characterization index, the good surface modification technology were stearic acid, titanate, aluminate content of 3%,2.5%,3%, reaction time of 1.5 h and reaction temperature of 65 ℃.The particle size and topography of modified talc powder and unmodified talc powder were investigated by particle size analysis and scanning electron microscopy, the particle size of the modified talc powder was decreased, and the dispersion was improved.After leaving along for 42 d, the caking rate of carbamide and compound fertilizer without talc powder was 26.79% and 12.96%, and the caking strength was 868.38 N/kg and 1974.11 N/kg.When 3% titanate modified talc power was added as anti-blocking agent, the caking rate of carbamide and compound fertilizer was 0.59% and 0.46%, and the caking strength was 30 N/kg and 40 N/kg.

Experimental Study on Calcination of Sparingly Soluble K-bearing Ore with Composite Additive of NaCl and CaCO3 for Potassium Chloride Extraction

LI Xiao-yan;WAN Fu-wei;CHEN Chang-hua

2017, 36(4):  1442-1446. 

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To better make use of sparingly soluble K-bearing ore and extract potassium chloride, halite and limestone were chosen as the composite additive for the calcination of sparingly soluble K-bearing ore.The influence of Na/K mol ratio, calcination temperature and time, limestone amount, volatility of K and Na on the potassium extraction rate was investigated.K extraction rate of 84.6% is obtained for the sample with Na/K mol ratio of 4 and limestone amount of 12.5wt%, calcined at 900 ℃ for 90 min.The phase analysis of the filter slag from leaching the calcined product was analyzed by XRD and the mechanism of NaCl and CaCO3 for the decomposition of potassium feldspar was discussed.The mass ratio of the NaCl-CaCO3 composite additive to sparingly soluble K-bearing ore is 0.73.Compared with other systems, the additive amount is largely reduced.

Axial Behavior Experimental Study on Thin-walled Steel Stub Columns Filled with Slag Concrete

LIU Qing-shi;GUAN Li-pei;HAN Zheng-wei

2017, 36(4):  1447-1451. 

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Considering the core slag concrete strength,steel ratio,substitution rateof slaglump as experimental parameter,through the axial test on 12 thin-walled steel stub columns filled with slag concrete and large-scale slag the context analyzed the collapse mode and mechanism,axial load-displacement relationship of the new short columns,also discussed the impact of axial bearing capacity of three factors of the new short column.The result shows that all specimens have occurredshear destruction,and specimens have high axial compressive bearing capacity and the ability to resist deformation;The influence of the core slag concrete strength grade on the axial compression bearing capacity of the new short columns is the largest,followed by the steel ratio,and the least influence is substitution rateof slaglump.Research results indicate that thin-walled steel stub columns filled with slag and large-scale slag have more advantages in capacity,ductility,it is worthy of further research and extension applications.

High Temperature Resistance Performance of Portland Cement

CAO Ji-shu

2017, 36(4):  1452-1456. 

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High temperature resistance performance of portland cement in 20 ℃, 200 ℃, 400 ℃, 600 ℃, 800 ℃ and 1000 ℃ was studied by the appearance change, mass loss and compressive strength in different high temperature.And the mechanism of stability change in different temperature of portland cement was studied by the scanning electron microscope (SEM), X-ray diffraction analysis (XRD) and differential thermal analysis (DTA).The results indicate that the Portland cement still keep the unbroken appearance and compressive strength under 400 ℃.Conversely, it is a sharp drop in stability,and there are abound of alveolate viods within cement.Then C-S-H del is decomposed and compressive strength is loss when the temperature exceed 600 ℃ that there are abound of alveolate voids within cement result in the destruction of C-S-H gel and loss of compress strength.