bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Stress Relaxation Properties of GFRP Rebars/Bolts
Authors: Yuan Guo Qing , Dong Guo Hua , Ma Jian
Published: December 2010

Glass fiber reinforced plastics (GFRP) rebars / bolts are more and more being applied in construction projects with its superior corrosion resistance. To improve the economical efficiency of their application it is very significant to develop the prestressed GFRP rebars/bolts structure system. Therefore it is very valuable to probe the stress relaxation properties of GFRP rebars/bolts. With an innovation ends anchoring method for stress relaxation specimens of GFRP rebars/bolts, the stress relaxation properties has been tested in this paper. Results show that the relaxation rate of GFRP rebars/bolts increases with the initial stress increasing and with test time prolonging. It is increasing more rapidly at the beginning stage and it becomes slow after 24 hours. The relaxation law of GFRP rebars/bolts is similar to the law of CFRP and AFRP rebars/bolts. The relation between the relaxation rate and the logarithm of test time in hour follows also better linear law. The relaxation rate of GFRP rebars/bolts is bigger than CFRP ones and smaller than AFRP ones. The mechanical properties do not change obviously after 120h relaxation test.
Synthesis Technology of Silica Aerogels/Polystyrene Core-Shell Composite Materials
Authors: Geng Gang Qiang , Guo Jing Tao , Zou Jun Jun , Bian Gong Xun
Published: December 2010

In order to obtain super aerogels heat insulating composite materials with silane coupling agent on the in-situ surface treatment. The core-shell structure composite materials have been prepared by dispersion polymerization process of polystyrene grafted on the SiO2particles. By TEM on these samples the impact of the system components initiator polymerization parameters and dispersion process was discussed. The results showed that the system component of the greatest impact on conversion rate is the ratio of aerogels /St ,the optimum reaction temperature is 75 °C.With organic initiator KPS as initiator after a unique ultrasound technique to obtain the core-shell composite materials structure which coating is 70%.
Research on Moisture Porosity Test of Liner Materials by Explosive Lining
Authors: Wang Hai Liang , Yu Jian Xin
Published: December 2010

This paper measure moisture porosity to test pieces of explosive lining. So are the test pieces curing in standard condition and curing in equal condition. The measured moisture porosity data of the three kinds of test pieces after flooding is analyzed. The results indicate that the moisture porosity of explosive lining test pieces is higher than that of curing in standard condition and curing in equal condition. And the different value of moisture porosity increase as the standing time moves on. There is no significant difference in water-loss porosity among the explosive lining test pieces and curing in standard condition ones and curing in equal condition ones.
Experimental Study on Impact-Mechanics Properties of Basalt Fibre Reinforced Concrete
Authors: Fan Fei Lin , Xu Jin Yu , Bai Er Lei , He Qiang
Published: December 2010

In this paper, in order to investigate impact-mechanics property of basalt fiber reinforced concrete (BFRC), impact test on BFRC with four kind of volume content (0, 0.1%, 0.2, 0.3%) was carried out using 100mm-diameter split hopkinson pressure bar (SHPB) device. Obtained dynamic stress-strain curves and testing data. Testing results were analyzed. The testing results showed that BFRC has favorable impact-mechanics properties, strain rate and fiber volume content have large effects on impact-compression strength and toughness of BFRC; impact-compression strength and toughness show strain rate strengthening effect, strain rate sensitivity of impact-compression strength is stronger and the impact-compression strength and toughness are higher relatively when fiber volume content is 0.1%; there is approximate linear function relation between the dynamic strength increase factor and the strain rate logarithm, there is approximate quadratic polynomial function relation between the peak strain and the strain rate logarithm.
Research on Stability of High Strength Aluminum Alloy Columns Loaded by Axial Compressive Load
Authors: Zhai Xi Mei , Wang Yu Jin , Wu Hai , Fan Feng
Published: December 2010

This paper reports experimental study of 17 high strength aluminium alloy specimens of type of 6082-T6 under axially compressed load including I-section column, rectangular hollow section. The general-purpose non-linear finite element analysis software ABAQUS is adopted to simulate the mechanical performance and overall buckling of aluminium alloy columns. The feasibility of finite element method has been verified through the comparison between the simulation results and the test finding. Finally, based on the experimental data and numerical calculation results, a useful column curve formulation to calculate the coefficient of stability of 6082-T6 aluminium alloy columns loaded by axial compressive load is derived. Comparison between column curves from proposed formulation and different code and test results has been presented, from which the validation of the proposed formulation has been verified.
Experimental Study on Improving the early Strength of Fly Ash Concrete
Authors: Niu Hui , Yang Kai , Zhao Ke Bin , Chi Huan Zheng
Published: December 2010

This manuscript makes experiments on the macroscopic concrete strength improvement of fly ash activation at early age. At the same time we test the microstructure of fly-ash waste residue concrete cementious materials and calculus, analyzing HPC preliminary mechanism tentatively. The mechanism of improving the early concrete strength by fly ash activation is expatiated, which improves activation mechanism and technology of fly ash.
Repeatability of Workability Test Methods of Self-Consolidating Concrete
Authors: Long Wu Jian , Khayat Kamal Henri , Xing Feng
Published: December 2010

In general, in the evaluation of a test method, the repeatability tests must be performed to establish upper and lower bounds for the precision of a test method. The repeatability is calculated as a standard deviation and relative error of test results. In order to evaluate the repeatability of the workability tests used in self-consolidating concrete (SCC) applications, an SCC mixture proportioned with 0.38 w/cm, Type MS cement, 480 kg/m3 of binder , and crushed aggregate with MSA of 12.5 mm was used. The dosage rate of the HRWRA of the SCC was adjusted to secure two initial slump flow consistency levels of 630 ± 10 mm and 700 ± 10 mm for the repeatability tests. For each consistency level, the concrete was batched five times (for a total of 10 mixtures). Each test was repeated five times by the same operator in order to establish the single-operator precision values. Furthermore, five different operators were used to perform each of the workability tests in order to assess the multi-operator error that could occur during testing. Based on the relative errors obtained in the repeatability tests, relatively low error values were obtained for the slump flow, J-Ring flow, and L-box blocking ratio tests. Relative errors for recommended SCC workability test methods were also summarized.
Geometric Nonlinearity Analysis of Composite Laminated Box Beam
Authors: Su Qiang , Wu Ya Ping
Published: December 2010

In this paper, the differential equations of composite laminated box beams are established based on the principle of minimum potential energy and the variational method. Considering shear lag and shear deformation effects, elastic stiff matrix, geometric nonlinearity stiff matrix and equivalent nodal forces vector of composite laminated box beam element are given. And a finite element program is developed, then a new computing analysis theory for composite laminated box beam is given, both considering shear lag, shear deformation and geometric nonlinearity effects.
Evaluation of Earth Pressures Against Rigid Retaining Structures with RTT Mode
Authors: Song Fei , Zhang Jian Min , Zhang Lu Yu
Published: December 2010

The evaluation of earth pressure is of vital importance for the design of various retaining walls and infrastructures. Experimental studies show that earth pressures are closely related to the mode and amount of wall displacement. In this paper, based on the reveal of the formation mechanism of earth pressures against rigid retaining wall with RTT mode, a new method is proposed to calculate the earth pressure distribution in such conditions. Finally, the effectiveness of the method is confirmed by the experimental results.
Effect of Fly Ash, MgO and Curing Solution on the Chemical Shrinkage of Alkali-Activated Slag Cement
Authors: Fang Yong Hao , Gu Ya Min , Kang Qiu Boa
Published: December 2010

The chemical shrinkages of alkali-activated slag cement (AASC), and the effect of fly ash, MgO burnt at 900°C and the curing solutions were studied. The shrinkages were compared with that of ordinary portland cement (OPC). The results show that the chemical shrinkage of AASC is lower than that of OPC. Adding fly ash and light-burnt MgO reduced the early age chemical shrinkage, while the shrinkage-reduction effect decreased with the age. The alkality of the curing solution has significant effect on the hydration and shrinkage of AASC. The chemical shrinkage of AASC increased with the alkali concentration of the curing solution. The mechanisms of fly ash, MgO and curing solution on the shrinkage were discussed.
Research and Application of New Technologies in Engineering Disaster Prevention
Authors: Zhang Ji Chao , Xu Kai , Xu Yong
Published: December 2010

The systematic study various kinds disasters which are likely to meet in civil engineering and construction of Guang dong Science Center. The research includes the study of environmental geotechnical engineering, the technology for treatment of large -area soft soil, the art of seismic isolation, the fire resistance, and the study of wind resistance of large-span shell structures. Based on these theoretical and experimental results, the authors have put forward some new technique for the key problems in design and construction.
Effects of Silicone Modified Acrylate Emulsion , Silicone Oil Modified Wollastonite and Self-Made Emulsifying wax on Contact Angle of Exterior Wall Paint
Authors: Jiang Bo Quan , Hu Shu Fen , Zou Jian Guo , Yu Xiao Ying
Published: December 2010

The exterior wall paint was prepared with silicone modified acrylate emulsion , silicone oil modified wollastonite and self-made emulsifying wax as main raw materials. The response surface experiment method was applied to investigate the effects of the three main raw materials on the contact angle of the finished coating. The results showed that the optimum ratio of pigment to base material, use level of silicone-acrylic emulsion and use level of emulsifying wax were separately 2.5, 20 g and 2.5 g under which the contact angle of the finished coating was 139.2 °and the coating exhibited good hydrophobic effect. The second multiple regression equation established by use of software of Design-expert 6.0 was in good agreement with the experimental results and can be applied to predict the contact angle under different level groups of the three main raw materials.
Research on the Mechanical Behavior of Styropor Concrete at High Strain Rates
Authors: Hu Ze Bin , Xu Jin Yu , Zhu Jie , He Qiang , Li Gang , Lin Wei
Published: December 2010

Mechanical behavior of Styropor concrete(EPSC) added with various volumetric fractions of EPS subjected to high strain rates were studied by using the Large-Diameter-SHPB. The infection of volumetric fractions and average strain rate to dynamic properties of EPSC were investigated. The experimental results show that under high strain rate condition, the dynamic strength, dynamic strength increase factor(DIF) and limit strain of EPSC are strain rate dependent, the strain rate effect can be expressed by linear approximations, and the relationship between elastic modulus and average strain rate is independent.With the addition of volumetric fractions of EPS, the impact compressive strength and elastic modulus of EPSC declines, and the toughness of EPSC is reinforced.
Performance Evaluation of Flame-Retardant NSCFR-Treated Laminated Veneer Lumber(LVL) PartⅠ:Thermal, Physical and Mechanical Properties
Authors: Wu Yi Qiang , Yao Chun Hua , Qing Yan , Lv Jian Xiong , Hu Yun Chu
Published: December 2010

This study aimed at evaluating the physical, mechanical and thermal properties of a structural laminated veneer lumber(LVL) prepared with self-made fire-retardant NSCFR being applied to the adhesive. Cone calorimeter(CONE), thermogravimetry(TG-DTG) and universal testing machine were utilized to assess the performances. Results showed that: fire-resistant and smoke-suppression characteristics of the fire-retardant treated LVL (FRLVL)were satisfactory. The heat release rate(HRR) of it was smaller than that of the untreated wood and it did not exhibit the typical second pkHRR of wood-based materials. It had a residual mass rate of 33.32% after exposure to fire. Overall production rate of CO and CO2, average specific extinction area and average smoke rate for it were remarkably less than that of unprocessed wood. In addition, FRLVL possesses acceptable physical and mechanical properties. It showed higher density and lower thickness swell after 24h water immersion than the control group and the strength parallel to glue-line parameters in static bending----modulus of rupture(MOR), modulus of elasticity(MOE), shear strength(SS) were 38.698 Mpa ,6.376 GPa and 4.389MPa separately, all of which met the corresponding requirements for structural LVL specified in the China National Standard GB/T 20241-2006.
Discussion about the Application and Importance of Building Energy Conservation in Building Design
Authors: Hu Zhi Feng , Wang Liang
Published: December 2010

Along with developing at top speed of city construction, building energy consnmption rises substantially,and the huge building energy consnmption has been became heavy relieve of economic social development.In the realm of superstructure, specially in the building design link, conserve energy overall has great significance.The paper mainly discuss about energy conservation design of regional space integration or external environment, energy conservation design of building monomer,and new energy-efficient technology or material for energy saving application in building design,and so on.
Flexural Fatigue Behavior of PAN Fiber Reinforced Concrete under Cyclic Loading
Authors: Zhuo Wei Dong , Ping Shang Guan , Gu Yin
Published: December 2010

The flexural fatigue performance of polyacrylonitrile (PAN) fiber reinforced concrete (PANFRC）was investigated by third-point loading tests. Based on the previous research work, optimum mixture proportions of PANFRC for highway overlays and bridge decks that satisfied both the minimum compressive and bending strengths, and showed excellent mechanical properties, were selected for fatigue testing. The experimental program included a total of 69 flexural specimens, 15 of which were plain concrete specimens, and the remaining 54 specimens were PANFRC specimens. Three mixes containing 0.0%, 0.1 %, and 0.15% of PAN fiber volume fractions were selected. For each mix, 4 different target load ranges were applied: 10–75%, 10–80%, 10–85%, and 10–90% of the ultimate flexural capacity, as obtained from the corresponding control static test. The bending fatigue life of PANFRC specimens under various stress ratios are proved to follow two-parameter Weibull distribution. Both a semi-logarithm and a double-logarithm P-S-N equations with various failure probabilities are derived from the experimental measurements. The denifition of the fatigue damage variable and damage evolution equation for PANFRC are furtherly proposed based on theory of continuum damage mechanics.
Microcosmic Analysis on Bonding Performance of Polypropylene Fiber Concrete
Authors: Xuan Wei Hong , Wang Yan , Chen Yu Zhi
Published: December 2010

In the process of pull out testing polypropylene fiber, the performance of bonding of tested and untested objects has been microscopically analyzed; both the interface of polypropylene fiber-cement-based material, the hole morphology of cement-based material after the polypropylene fiber being pulled out by force and the condition after the polypropylene fiber being pulled out of concrete-based material are observed. Attachment phase analyses of the surface of the polypropylene fiber and cement-based transverse cracks after the polypropylene fiber being pulled out have both confirmed the fact that the performance of bonding of the polypropylene fiber-cement-based material can effectively transmit the outer force borne by the polypropylene fiber and that the performance of bonding of the polypropylene fiber-cement-based material is better.
Permanent Deformation Prediction Model of Graded Gravel under Repeated Load
Authors: Wang Xiu Shan , Ding Xiao Jun , Xie Yong Li
Published: December 2010

In order to predict the permanent deformation of graded gravel, through to the existing flexible pavement granular base permanent deformation estimate model's contrastive analysis, combined with repeated dynamic triaxial test , selects Wei Mi permanent deformation estimate model as the loose aggregate permanent deformation of the estimate model, using 1stopt statistical analysis software carries on the nonlinear curve fit for the parameter, obtained two kinds of norms of graded broken stone aggregates forecast model of the correlation among the types : permanent deformation of the coefficient and water content and resilient modulus, and their reliability was analyzed. Analysis result shows that when load acting time reaches 10 000, the minimum and average correlative coefficients of the regression formulas is 0.4144 ,0.6340 and 0.5080, which is greater than the critical value of 0.3993, and the correlative coefficient between theoretical curve and measured one is more than 0.96. So the reliability of the proposed prediction formulas of permanent deformation for graded gravel is higher, can be used to forecast China's Asphalt Pavement Rutting.
Binary Superposition Mix Design Method for SFRC Part I: Principle and Evaluation
Authors: Zhao Shun Bo , Huo Hong Yuan , Song Chen Xiao , Song Li Sha
Published: December 2010

The binary superposition mix design method is constructed to quantitatively calculate the compositions of steel fiber reinforced concrete (SFRC), which brings into sufficient cement paste wrapping steel fibers to strengthen the boundary surfaces of steel fibers with base concrete. The principle of the method is firstly introduced. The experiments were carried out to evaluate the validity of the method. In the experiment, the cubic and axial compressive strength as well as the splitting tensile strength of SFRC affected by the fraction of steel fiber by volume and the average thickness of cement paste wrapping steel fibers were tested. The results are analyzed on the basis of former studies specified in the current technical specification for fiber reinforced concrete structures, which show that the larger strengths especial the splitting tensile strength of SFRC in grade CF50 can be got by the method, but the less splitting tensile strength of SFRC in grade of CF40 should be further studied.
Experimental Study on Mechanical Properties of Fine Aggregate Concrete Made after Wet-Sieving Coarse Aggregate
Authors: Zhao Shun Bo , Liang Na , Liu Li Xin , Sun Li , Yang Su
Published: December 2010

The validity of the wet-sieving concrete technique for building the reinforced composite concrete wall are demonstrated in the paper. The fine aggregate concrete made by ordinary concrete passing the sieve with square mash of 15 mm was cast for the surface layer, the recomposed concrete mixed by the residual concrete stayed on the sieve with the ordinary concrete was cast for the reinforced concrete structural wall. The mechanical properties such as the cubic and compressive strengths, the elastic modulus and the splitting and flexural tensile strengths of the fine aggregate concrete, the recomposed concrete and the ordinary concrete were tested and analyzed. The results show that the elastic modulus and splitting tensile strength of fine aggregate concrete reduce in some extent compared with that of ordinary concrete, the mechanical properties of recomposed concrete are almost the same as that of ordinary concrete.
MODELLING of Delfcetion Performance in Partially Bonded CFRP Prestressed Beams
Authors: Deng Yu , Liang Jiong Feng
Published: December 2010

six partial bonded concrete beams prestressed with CFRP tendons are tested under monotonic loads. deformation of this kind of beams with varying unbonded length are systematically investigated. full-range analysis for deflection performance of partial bonded CFRP prestressed beams is performed by using ADINA. The analytical results agree well with the experimental results.
Application and Exploration of Isolated Technology for Custom Steel Structure Residence
Authors: Zhao Feng Hua , Yang Jun
Published: December 2010

Adopting the two systems-common base and base isolation and inputting El-Centro wave as the earthquake wave, in this paper, comparative analysis of structure’s earthquake-resistant performance was conducted on a 6-layer custom steel structure residence in Changzhou area. The result shows that the gradually matured isolated technology can be applied to steel structure as well, which means the isolated steel structures possess the same characteristics as other isolated structures. With the satisfaction of required bearing capacity, the structural reaction to earthquake has been effectively reduced and its safety has been guaranteed after considering the isolation of steel structure residence; moreover, the storey accelerations reaction has also been greatly declined, meeting higher requirements towards comfortableness of residence structure. Meanwhile, by nonlinear dynamic analysis of simple Bouc-Wen hysteretic model, the requirement towards the biggest ductility was discussed and a brief analysis of the life cycle cost of this residence was worked out. The analysis result demonstrates that the isolation layer has effectively controlled the vibration of superstructure, which would contribute to the reduction of seismic hazard.
Study on Self-Igniting Gangue Concrete
Authors: Zhou Mei , Zhang Xiao Fan , Guan Feng Jiao , Wang Zhen Shuang
Published: December 2010

Self-igniting gangue concrete from C15 to C40 was successfully produced with fine and coarse aggregate of coal gangue through mix design method of lightweight aggregate concrete. It concluded that Self-igniting gangue concrete with reasonable grading can reach to the target strength. The basic properties of Self-igniting gangue concrete between Coal Gangue Portland cement and Portland cement were investigated, and mechanism was analysis. The coal gangue content was from 705 to 80% in the concrete. The technology can not only relief the scarcity of natural aggregate, but also employed the solid waste, and it was suitable for sustainable development in 21 century.
Experimental Study on the Heat Transfer in Rock Layers with the Vertical Downhole Heat Exchanger
Authors: Tang Ying Chun , Ou Xiao Duo , Wang Bao Tian
Published: December 2010

Through the in situ experiment of the ground-source heat pump (abbreviated as “GSHP”) system in Nanning Guangxi, this article has observed the temperature variation rules of the rock layers, by the temperature sensors buried in different depths and different locations from the Heat Exchanger. In addition, this article has also tried to explore the thermal environment of the rocks by analyzing the heat transfer of the soil layers acted under the thermal load in Southwest China regions where the ground water is abundant.
Effects of TiO2 on Crystal Phases of Mold Fluxes
Authors: Sun Li Feng , Wang Hong Po , Jiang Mao Fa , Lin Qi Zheng , Liu Chun Lai , Zou Yong
Published: December 2010

Under the experimental condition,the crystal phases of mold fluxes contained cuspidine, wollastonite and melilite. The addition of TiO2 could stimulate Perovskite to be precipitated in mold fluxes whilst the growth of cuspidine and wollastonite were inhibited. At 1300°C mold fluxes existed mainly in glass phase, with few melilite phases existed in several sections while after TiO2 was added, perovskite was precipitated and melilite was dissolved.
Nonlinear Coupling Analysis on Working Behaviour of Pile Group
Authors: Wang Rui Fang
Published: December 2010

The numerical analysis of finite element coupling infinite element is recently used to simulate the effects of unbounded foundation of stresses and displacements. In this thesis, the finite element analysis is adopted to simulate the piles and the near soil; between the pile and the soil a joint element is designed to imitate the relative settlement while the infinite element is used to imitate the distant soil. elastic analysis way for concret elements and infinite elements are used, K-G model and E-U model for near soil.Calculation results show that using Goodman contact element to simulate the interaction of pile and soil has the advantage of flexibility;and the graphic formula of the calculation curves of nonlinear model and K-G model accords with that of the measure curve while the elastic calculation curve is far from the measure curve;the skin friction and pile-tip resistance pressure of the corner pile is the largest, the side pile less, and the center pile the least.The analysis of one example shows that the analytical model adopted in the thesis is reasonable, the results are both reasonable and accurate.
Establishment of the Principle of Total Potential Energy with Least Value in Elastic System Dynamics
Authors: Chen Rui Lin , Huang Yun Qing , Xiang Jun , Ma Shi Cheng , Yin Chang Jun , Dong Hui , Yang Guo Yue
Published: December 2010

The principle of total potential energy with least value in elastic system dynamics is established ,based on the principle of total potential energy with stationary value in elastic system dynamics which is drawn from the principle of virtual work and the principle of d’Alembert. It is sufficiency and necessary conditions for the real displacement of the equilibrium system of statics corresponding to dynamics system that total potential energy is the least value in elastic system dynamics.The testify of the principle provide a new method to establish differential equations in elastic system dynamics. Especially for complex system, The method is effective.
Research Development in Void Formation Mechanism and Elimination Method during RTM Process
Authors: Yang Mei , Zeng Qing Shen , Wang Hong Yu , Zhang Wei Xing
Published: December 2010

Resin transfer molding (RTM) is a very important category of low cost fibre reinforcement composite material manufacturing technique. But void which mainly formed at the process of filling and infiltration is able to reduce the performance of products. This paper first introduced how harmful the void is, and then formation theory, finally focus on the technical feature and resent evolution. Numerical simulation is always a mature and efficient research method for this field of investigation. Formerly, scientists also attribute their effort to such investigation, but, at that time, their simulation was 1D or 2D which can not represent the process accurately enough. Therefore the results are not so significant. Recently most studies pay attention to 3D simulation and how factors (such as injection pressure, structure of preform and so on) work. With the development of mathematic theory and simulation software some new numerical simulation methods present itself. Researchers may copy the course of resin’s filling in RTM more integrity to make their relation close to reality. Based on their achievement, the technique of RTM also improved to eliminate void’s emergence. However the real flow of resin is more than complex, more work should be done to avoid it and then set up a controllable industrial production system.
Elasto-Plasticity Solution on Bearing Characteristic of Cast-in-Place Concrete Pipe Pile with Large Diameter in Layered Soil under Lateral Load
Authors: Zhang Jian Wei , Liu Han Long , Yang Gui
Published: December 2010

Aimed at problems lying in the exiting methods for calculation of laterally loaded piles installed in layered soils, the elasto-plasticity solution of cast-in-place concrete pipe pile with large diameter (PCC pile) in layered soil under lateral load based two-parameter foundation model and unity limiting force profile, deduced the finite difference solution based unity limiting force profile(LFP), established the calculation program of the displacement and internal force of pile. It was shown that the calculated pile moment and pile displacement coincided very well by computation and comparison of model test and FEM, verified the method’s correction. Meanwhile, the method was more precise and efficient than the existing conversion methods of subgrade modulus. Therefore, it could be useful for the design and analysis of PCC pile under lateral load.
The Research of Pull-out Method to Inspect Concrete Strength
Authors: Li Feng Quan , Wang Chen , Jiang Hong Bin , Li Xue Ying
Published: December 2010

Post-embed pullout tests are applied to the concrete cubes of C15-C60. Based on the result of 50 concrete samples, the relationship between pull-out resistance and compressive strength of concrete has been discussed in detail, and the formula used for calculating the concrete strength is given out. Its related coefficients and relative standard can meet the requirement. The simulation method is used on the base of curving failure surface. The paper presents the destruction mechanism of pull-out method in concrete property test, and good correlation between the date of pullout force and cube strength is explained.
Structural and Optical Properties of InSnO3 Sol-Gel Coatings to Use in Windows Glass Buildings
Authors: Dominguez Gallegos Lazaro De Jesus , López Rodríguez Angélica Silvestre , Sifuentes Gallardo Pio , Hernández Rivera Miguel Angel , Garnica Romo María Guadalupe , Díaz Flores Laura Lorena
Published: December 2010

Indium stannate (InSnO3) films doping with small amounts of copper are made highly useful as architectural window coatings. Indium-tin-oxide (ITO) has attracted intense interest due to some of its unique characteristics; it has high optical transmittance in the visible region, low electric resistivity, and chemical stability. Therefore, ITO thin films have been found to play an important role in opto-electronic applications. In this work, uniform and transparent ITO films were deposited onto glass substrates using a sol-gel process. The initial sols were prepared by mixing solutions of indium chloride prepared in anhydrous ethanol with tin chloride and mechanically stirring and refluxed 2 hours and aged 2 week, the resultant mixture until a clear and sticky coating sol was obtained. The glass substrates were spin-coated and annealed at 500 °C. Because annealing conditions affect the microstructures, the properties of the resultant ITO films can be controlled. The optical transmittance of 200 nm thick ITO film was more than 80% in the visible region. The surface morphology examined by SEM appears to be uniform over large surface areas. The structural, microstructural and optical properties of the coatings and powders made from the sols were extensively characterized by using XRD, AFM and spectrophotometer techniques
Cost Risk Assessment of Construction Projects Based on Entropy-Weighted Matter-Element Model
Authors: Xie Ming Hui , Yang Ying
Published: December 2010

As modern projects are getting increasingly complicated in the changeable environment, the risk in cost faced by construction enterprises increase. Therefore it is necessary to analyze all sorts of cost risks to guide decision-making. A entropy-weighted matter-element model for assessment of cost risk is established in the article, and an example is used to explain that the model makes a good application.
The Effectiveness Experiment Study on The Hidden Karst Detection Method of City Tunnel Engineering
Authors: Xie Zhong Qiu , Xiao Hong Bin , Li Zhen Yu , Wang Yong Sheng
Published: December 2010

Lateral variations of the karst of deep buried tunnel engineering is big. The heterogeneity of it is strong. The tunnel is combined with Changsha Rail Transit Line 2 at one section of the first phase construction. Under the urban environmental conditions, it is considered to use auxiliary seismic wave imaging method assistanting with Rayleigh surface wave method. It is the detection and prediction method of comprehensive geological analysis of karst hazard, which identified the underground targets of deep buried tunnel effectively. To avoid a single technique multiple solutions, it can reflect the complexity of karst formations geological features objectively. Therefore, it can reduce the risk of drilling and take appropriate treatment measures to provide adequate and reliable basis.
Shape Optimization Study of Mild Steel Slit Dampers
Authors: Xu Yan Hong , Li Ai Qun , Zhou Xing De , Sun Peng
Published: December 2010

This paper presented a new mild steel slit damper(SSD). The new shape was parabolic according to all the cross section having the same maximal stress, and the elastic stiffness and yield displacement formula were derived. Finite element analysis showed that the parabolic shaped damper had a more reasonable load - displacement curve compared with the previously proposed shape. The theoretical stiffness and yield displacement were consistent with the results by finite element method (FEM), and that indicated the presented design method was simple and feasible.
The Research of Low Temperature Performance of Asphalt Mixture
Authors: Zhang Cai Li , Wei Lian Yu , Meng Qing Ying
Published: December 2010

To address Superpave graded and AC graded asphalt mixture, bending test at low temperature and thermal stress restrained sample tests are used respectively to evaluate the low temperature performance of asphalt mixture. Meanwhile, contrast analysis of the two test methods and the low temperature performance of two asphalt mixture are studied, too. The results show that Superpave method can effectively improve low temperature perfomance of asphalt mixture. In the thermal stress restrained sample tests, freezing temperature and transition point temperature can evaluate the low temperature cracking resistance of Superpave asphalt mixture well. In bending test at low temperature, bending strain energy density should be considered as evaluation index to the characterization for low temperature performance of asphalt mixture. That also closely meets the result of the rmal stress restrained sample tests.
Testing Study on DJM Pile Composite Foundation under Flexible Load
Authors: Xiang Xian Chao , Jiang Guo Sheng , Zhu Chang Qi
Published: December 2010

Dry jet mixing (DJM) piles are widely used in silt foundation treatment to improve foundation stability and control post-construction deformation. As the work mechanism of DJM composite foundation is very complex, though many useful calculation theories have achieved, the theoretical study of DJM pile composite foundation is still far behind engineering practice, the settlement and stress calculation precision is unsatisfied. Then it is still necessary to reveal the work mechanism of DJM pile comprehensively. A field test of DJM pile composite road foundation is carried out and many measurement methods are adopt to collect the test information, such as soil pressure sensors, pore pressure sensors, settlement plates, inclinometer tubes, stratified settlement pipes, multi-point displacement meters in piles and so on. Then the surface settlement, internal deformation and stress developing of soils and piles are monitored Real-time. Through in-site test, the settlement and internal deformation of piles and soils, the stress ratio between pile and soil, and the negative friction around pile are studied.
Risk Analysis and Management for the Collapses of Tunnel
Authors: Lei Yue , Zeng Xiong , Huang Fang
Published: December 2010

The evaluation of the correct stability factor of tunnel is a critical element in the various design and construction phases of a tunnel excavated in difficult geotechnical conditions. An innovative, and well-applied, procedure for optimize the construction phase management is described in this article. The starting point of this procedure involves the verification of the results of numerical methods obtained from referenced analytical methods. In the first step of the procedure the results obtained through the analytical method are verified by means of a numerical method in order to evaluate the practical consequences in terms of development of deformations and plastic zone. In this manner, the assumed design risk is evaluated for the different methods and the solution that gives the best correspondence with numerical simulation is selected. Finally, residual uncertainties and parametric variations are incorporated in the analysis and Monte Carlo simulation is used to calculate the statistical distribution of the face-stabilizing pressure and the design value is selected on the basis of an acceptable probability of failure.
Design Measures of Low Carbon Buildings with Exterior Envelope Made of ETFE Air Pillows
Authors: Zhao Xiang , Long En Shen , Huang Lu Hong
Published: December 2010

Energy saving and low carbon footprint are becoming key issues in recent architectural design. It's necessary to develop new materials and new building forms for this purpose. After introducing some famous model projects appling ETFT air pillows, this paper lists major physical properties of this new product and puts forward some design measures such as passive solar heating, great span structure system, natural lighting and cavity ventilation for energy saving and low carbon footprint buildings.
A Study of Wind Generator Set Planetary Gear Transmission Dynamics Analysis
Authors: Zhang Jian Jie , Sun Wen Lei , Ma Lei Lei
Published: December 2010

This paper on wind generator set planetary gear had a simple introduction, and finite element method was used on the planetary gear transmission dynamics analysis, the conclusion was drawn that the different planetary gear in the direction of the force and deformation, so as to improve the quality of the gear is designed to provide a scientific basis.
Basic Properties of Woodceramics Made from Furane Resin/Wood Powder Composite
Authors: Zhou Wei Hong , Yu Yun Shui , Xiong Xue Liang
Published: December 2010

A new woodceramics was developed by furane resin and wood powder. Microstructures of woodceramics were performed by scanning electron microscopy(SEM). The effect of content of furane resin on carbon yield ratio,dimension shrinkage,apparent density,comprehensive strength and volume electrical resistivity of woodceramics were investigated. The results show that the woodceramics is a kind of carbon/carbon composite composed by wood charcoal and glassy carbon, the content of furane resin has a significant effect on the microstructure of woodceramics. With the increase of furane resin, generated glassy carbon increases and the connection between wood charcoal and glassy carbon will be strengthened. Carbon yield ratio, apparent density and comprehensive strength increase, and dimension shrinkage and volume electrical resistivity decrease as the content of furane resin increases.
The Manufacture and Test of Advanced Composite Material Flange
Authors: Tao Guo Quan , Liu Zhen Guo , Lv Ming Yun , Chen Si Si
Published: December 2010

Due to the problems of potential corrosion and thermal expansion differences between traditional metal connecting pieces and carbon fiber poles, it is difficult for them to meet the operating requirements of truss structures in the environment of stratosphere. Based on the large scale composite space truss structure of stratosphere aerostats, the carbon fiber flange connection joints were studied in the present paper. Adopting the three-dimensional full five-directional braiding technology, Toray T700S – 12K carbon fiber is used as the raw material to manufacture flange joint preform, and to manufacture flange forming by RTM(resin transfer molding) process. As demonstrated by tension tests, the composite flange joints have equivalent mechanical properties with flanges manufactured by common aviation aluminum alloy, and meet requirements of stratosphere truss structure connecting pieces.
Application of Biot Consolidation Theory to Analyze Land Subsidence
Authors: Wang Shu Fang , Zheng Ming Xin
Published: December 2010

Based on the summary of the status of land subsidence research, Biot Consolidation Theory is proposed to analyze the coupling of seepage field caused by precipitation. By use of Biot consolidation two-dimensional plane finite element calculation programmed, the land subsidence of the WenZhou Yongqiang plain caused by the exploitation of underground water was analyzed. The results are more in line with the measured data, so the method for analysis of possible land subsidence is practicable.
Optimum Design Study on Leveling Variable Stiffness of Composite Foundation with Rammed Soil-Cement Pile
Authors: Zhang Zhen Shuan , Deng Yu , Zhang Wei , Ju De Sheng
Published: December 2010

According to the practical project, settlement, reaction and bending moment of composite foundation with rammed soil-cement pile are recalculated, which based on the change of the original area replacement ratio, pile length and foundation thickness. The method of optimum design study on leveling variable Stiffness is investigated.
Intelligent Simulation and Recognition of Metro Station Excavation Based on Differential Evolution and Finite Element
Authors: Jiang An Nan , Wang Jun Xiang , Yu De Hai
Published: December 2010

Differential Evolution (DE) is a new algorithm. Displacement back analysis method based on the algorithm can effectively solve the problems of rock mechanics parameters which are not accurate. Constitutive integration algorithm divided into explicit and implicit integration is the key points of finite element analysis, which affect the convergence and accuracy of the results. Return mapping algorithm avoiding directly solving the equivalent plastic strain is a kind of implicit integration algorithm, which would achieve rapid and accurate for the solution of constitutive equations. This article describes the theoretical framework based on elastic-plastic, von Mises yield criterion conditions, using C + + language to carry out plastic simulation of Dalian metro station CRD excavation and parameter identification based on differential evolution algorithm. The calculated stress, displacement and deformation can determine the surface subsidence and the development of plastic zone, the stability analysis to provide a reference for the construction.
Application for Quick Lime Improving Strength of Loess Subgrade
Authors: Li Ping , Li Hui Shan , Liu Han Qing , Wang Xiu Li
Published: December 2010

Quick lime has been widely applied for improving strength and water stability of loess due to its lower costs and better effect on subgrade construction. Taking collapsible loess of Dingxi section of Luoding Freeway in Gansu province as investigation object, CBR were done in cases of different quick lime contents, water contents and compaction times as well as immersion times. The results indicated that compaction degree of lime soil would be lower than that of loess as subjected to the same compaction times. The strength and water stability of loess mixed with quick lime would obviously improve. The optimal quick lime contents were equal to 3%. A dual linear regression equation of CBR was put forward and applied in six test sections of Luoding and Baotian freeways.
Influence of Mineral Admixtures on Mortar Brittleness
Authors: Xiao Ben Lin , Li Li Hua , Tang Hui Ming
Published: December 2010

The influence of mineral admixtures on mortar brittleness is analysed in this paper. Test results show that the mortar brittleness increases with the increasing of compressive strength and the passage of age. When the content of binding materials rises, the compressive strength also increases, but the brittleness decreases at the same time. The more the content of fly ash is, the more the brittleness falls. Silica fume added can not only enhance compressive strength but also reduce brittleness of the mortar. MgO added can cut down the brittleness, but can reduce the compressive strength a little at the same time, especially for early compressive strength.
Determination of Sulfate Concentration of Soil Used for Assessment of the Sulfate Attack to Concrete
Authors: Zhang Xu , Liu Qiao Ling , Jia Li Qun , Xu Li Na
Published: December 2010

In order to evaluate the class of exposure to sulfate attack of soil, different methods were intended to measure the sulfate concentration of soil in contact with concrete in different countries. Different methods of soil extracts preparation were used to determine the sulfate ion content of soil in this paper. Two artificial soils and one natural soil were prepared in these tests. The experimental parameters investigated in the study were: acid or water extract, water to soil ratio and agitating time. When samples were prepared by water-extracting method, water to soil ratio (2:1, 5:1 and 10:1) and agitating time (3min, 6h, 16h and 24h) were considered. The results show that the difference of sulfate concentration determination results using different methods was significant. The determination results of dilute hydrochloric acid extracting solution are higher than that of water extracting solution of the same soil sample. The sulfate concentration determination results of the same soil sample have increased with the increase of water to soil ratio or agitating time. The water to soil (W/S) ratio is more sensitive than agitating time to the sulfate concentration determination results.
Cement Chemical Shrinkage Prediction Model Research Based on the Mineral Composition Content of Each Phase at Early Age
Authors: Wu Lang , Song Gu Quan , Lei Bin
Published: December 2010

Based on the microstructure evolution of cement hydration, using the relationship between the hydration rate and hydration degree, chemical shrinkage prediction model of cementitious materials are proposed. This model can simulate chemical shrinkage curve of cement-based material well. In the early period, increasing water-cement ratio can increase chemical shrinkage. While in the middle period, its influence on chemical shrinkage is negligible. Increasing temperature accelerates the hydration process significantly, therefore, increases the chemical shrinkage.
Numerical Analysis of Dynamic Compaction based on Large Deformation
Authors: Xie Neng Gang , Chen Yun , Ye Ye , Wang Lu
Published: December 2010

In the numerical analysis of foundation consolidation by using dynamic compaction, many kinds of non-linear conditions exist. This paper adopts large deformation on the relationship between strain and displacement. Non-linear governing equation of soil, based on finite element method, is established. Iterative calculation form is raised. Finally, non-linear numerical analysis is done to a calculation example.