bluuebunny/crossref_metadata_2025 huggingface dataset:
Unity Equation of Torsional Capacity for RC Members Subjected to Axial Compression, Bend, Shear and Torque
Authors: Men Jin Jie , Shi Qing Xuan , Wang Qiu Wei
Published: December 2010

The mechanics performance of reinforced concrete members subjected to axial compression, bending, shear and torque is very complex. Several calculation models have been established to estimate the torsional capacity of combined torsion members; however, the calculation results of different models have a great variation. In this paper, variable-angle space truss model is adopted to analyze the mechanics performance of reinforced concrete members subjected to combined torsion. With respect to various shapes of specimens, various load modes, and various strength of concrete, a unity equation about torsional capacity of combined torsional member is obtained. Based on the unity equation, the torsional capacity of 59 combined torsional specimens is calculated. In contrast with the equation of ACI and the code of China, the torsional capacity calculated by the unity equation agrees well with the results of experiment and much better than the results of ACI code and China code. It is concluded that the unity equation can provide valuable reference for calculation and design of combined torsion members.
Study on Interface Slips in Concrete Filled Square Steel Tubular Column
Authors: Liang Bin , Meng Fan Shen , Mao Rui
Published: December 2010

Based on the principle of minimum potential energy, the interface slips in concrete filled square steel tubular column is calculated. According to the study of bond-slip behaviors of steel reinforced concrete and steel tube concrete, a pull-out mechanics model of concrete filled square steel tubular column has been built. The slip displacement on the interface of steel and concrete of the column along the embedment length is derived by the principle of minimum potential energy. The calculation results show that the slip curves have the basic characteristics of quadratic curves distribute. The results can be used to describe the interface slips between steel and concrete under complicated loads.
Design of Simple-Supported Reactive Powder Concrete Railway Bridge with Span of 32m
Authors: Yan Zhi Gang , Ji Wen Yu , An Ming Zhe
Published: December 2010

Reactive Powder Concrete (RPC) is a new kind of engineering material with high strength, high elastic modulus and high durability. In order to satisfy the low-height requirement, RPC is adopted to design the railway bridge. One simple-supported RPC T-beam with span of 32m is designed and applied in railway bridge engineering. The height of the beam is 1.8m and the height to span ratio is 1/17.8. It is supper low-height beam for railway bridges. The parameters of material properties, mixing proportion, section size and prestressed steel strand cable arrangement of the RPC T-beam are presented. The load bearing capacity, the deflection and the crack resistance safety coefficient are calculated and the results can satisfy the requirements of the code. It is useful for the design and application of RPC in structure engineering.
Design Principle of Crack Control of Large Multi-Story Frame Structure and its Application
Authors: Ding Cui Hong , Gu Jian Wen
Published: December 2010

Crack control design of reinforced concrete structure focuses on the cracks caused by temperature and shrinkage stress, which is traditionally controlled through “resistance” or “relieving”. Related standard of China adopts easier way of expansion joint to relieve temperature and shrinkage stress. This method, however, is difficult to apply to modern super large buildings. Principle of “resistance in conjunction with relieving” was adopted in the design of Yongjin Plaza in Zhejiang province. No running through expansion joint was made in 136m×124m cast-in-situ multi-story concrete frame, instead, expansion joint is adopted in partial roof and floor. Steel bar quantity in coumns and beams was determined by factors of both load and temperature. Later-poured-zone, low expansion concrete, limited cement ratio and good curing measure were adopted to control cracks successfully.
Experiment and Analysis of Flexural Strength for Shrinkage-Compensating Steel Fiber Reinforced Shotcrete
Authors: Huang Wei , Ma Qin Yong , Cui Peng Bo
Published: December 2010

The flexural strength of shotcrete which prepared for cementitious material incorporated with cements,accelerating agents and expensive agents is studied.By changing the fraction of steel fibers by volume and the addition percentage of expensive agent in binding material,the influence on flexural strength of the two factors is investigated,the mechanism of steel fibers and expensive agents work together to reinforce the shotcrete and the strength development law are analyzed.The result shows that, the flexural strength of steel fiber reinforced shotcrete is improving with the volume fractions of steel fibers increasing.And the flexural strength of shrinkage-compensating shotcrete is decreasing with the addition percentage of expensive agent in binding material adding except 6%. The flexural strength of shotcrete is rather better when the fraction of steel fibers by volume is 1.2%~1.6% and the addition percentage of expensive agent in binding material is 8%,which indicates that the restriction effect of steel fibers can enhance the flexural strength of shrinkage-compensating shotcrete,embodies the effect of synergistic enhancement and compounding effect with steel fibers and expensive agents.
Microstructure and Mechanical Properties of Mg-12Gd-2Y-Sm-0.5Zr Alloy
Authors: Li Ke Jie , Li Qua Nan
Published: December 2010

The Mg-12Gd-2Y-Sm-0.5Zr (wt. %) alloy was prepared by casting technology and the microstructure and mechanical properties of the alloy have been investigated. It was found that the alloy was composed of a-Mg matrix, Mg5Gd phase and dispersed long-period ordered β' precipitates. With temperature increasing from 20 to 300 °C, the tensile strength increased and reached to the maximum strength at 300°C, namely 316.3 MPa. The value was superior to those of the conventional heat-resistant magnesium. The improved strain hardening and critical crack propagation stress were the key factors for experimental alloy possessed anomalous temperature dependence of tensile strength.
Die Wall Lubricated Warm Compaction of Fe-Ni-Cu-Mo-C Powders
Authors: Ke Mei Yuan , Xiao Zhi Yu
Published: December 2010

The combination of warm compaction and die wall lubrication, called die wall lubricated warm compaction was used to make Fe-Ni-Cu-Mo-C powder metallurgy material. Results showed that the green density could be 7.38 g•cm-3 under the pressure of 700MPa at the temperature of 120°C. The sintered density could be 7.34 g•cm-3 and dimension change was 0.19% when sintered at 1200°C for 50 minutes. Both green density and spring back effect gradually increased as the compacting pressure rose. The relation between compacting pressure and green density could be described by Huang Pei-yun double logarithm equation. Different forming conditions effecting green density in turn from big to small were compacting pressure, lubrication, compacting temperature, mixing method and compacting speed.
Fabrication of Combined Type Insulation Wall in a Field Emission Display with Carbon Nanotube Emitters
Authors: Wang Feng Ge , Li Yu Kui
Published: December 2010

Using insulation slurry as material, the combined type insulation wall was developed with the high-effective screen-printing process. Two parts were mainly included for the combined type insulation wall, which was the lower insulation wall prepared on the cathode panel and the upper insulation wall fabricated on the anode panel, respectively. The fabricated combined type insulation wall possessed better insulation performance, and was used to separate the cathode and anode panel. Using carbon nanotube as cathode material, the field emission display with the combined type insulation wall was fabricated, and the detailed manufacture process was also presented. The sealed field emission display showed high luminance brightness, stable emission current and good field emission properties.
The Application of Extension Theory on Pavement Performance Evaluation
Authors: Ling Cheng , Zhou Lan , Gu Fan
Published: December 2010

Pavement performance evaluation is a reasonable safeguard for the conservation plan and an important basis for investment decisions. In order to obtain a precise and quantitative evaluation result, a general evaluation model based on Extension Theory is established, and a concrete index is raised to indicate the pavement real condition. Practical pavement detection data of Jing-hu highway in Jiangsu Province is used to validate this model. The result shows that the evaluation model based on Extension Theory gives an accurate evaluation on pavement performance, and reflects the pavement condition well. It could provide solid foundation for pavement maintenance orders, and may have a bright future.
Study on Wheat Straw/ Sodium Sulfate /Water Glass Shaped Phase Change Plate for Walling Material
Authors: Hou Gui Hua , Zhu Xiang , Cui Yui Chi
Published: December 2010

Novel shaped phase change plate was made of wheat straw impregnated with Na2SO4solution and water glass as cementing agent. The plate was subsequently inserted into the concrete bricks with rectangular holes, assembled as phase change bricks. The latent heat of phase change of the plate was measured by DSC, the microstructure of the plate was observed by SEM, and the performance of the plate was also measured. In addition, the heat insulating property of the brick was investigated. The results are as follows. The wheat straws can encapsulate 1.86 times Na2SO4•10H2O in mass,and the phase change heat of the plate is 113 J/g. The microstructure shows that the straws and hardened water glass play an encapsulating action for Na2SO4•10H2O. The weight loss of the plate was 1.8% after 30 times of phase change cycles. For the concrete bricks (size: 240×240×115 mm) inserted with phase change plates, when the heated surface temperature was 80 oC for 5 h or 8 h , the cold surface temperature increased by only 1.8 oC and 4.4 oC respetively ,that is, the temperature difference between the cold with hot surface was 63.7 oC and 61.1 oC. This study reflects that if the brick is used as walling material, interior temperature does not fluctuate, even in extreme heat summer. It has dramatically saving energy and the effect of improving inhabited environment.
The Hypothesis of Free Deposited Permeability of Gob Areas and its Application
Authors: Wang Hong Gang , Yan Zhen Guo , Wu Feng Liang
Published: December 2010

It is difficult to determine the magnitude and distribution of permeability in gob areas, which are therefore treated as homogenous and isotropic generally. Another way to computer the distribution of permeability is based on the presupposed distribution of expanding coefficient of falling rocks. In view of the complex geological conditions of gob areas, the two methods are both subjective and arbitrary in a large degree. By importing the conception of boundary layer, the hypothesis of free deposited permeability of gob areas is put forward here. By setting the reasonable limit magnitude of permeability, namely the free deposited permeability as maximum whereas the sufficient compressed permeability as minimum, a more exact method is deduced to analyze and determine the distribution of permeability in gob areas. The application of this hypothesis in the numerical simulation of seeping flow filed in a gob area indicated that the distribution of permeability based on the hypothesis is more compliant to the fact.
The Low-Velocity Impact Response of Sandwich Panels
Authors: Zha Xiao Xiong , Wang Hong Xin
Published: December 2010

The low velocity impact response of sandwich panels at different energy levels has been investigated by conducting drop-weight impact tests using an instrumented falling-weight impact tower. Impact parameters like maximum impact force and the extent of the damage were evaluated and compared for different types of sandwich panels. Finite elements simulations have been undertaken using the LS-DYNA software; the results of FE simulations have a good agreement with the experiments. It shows that, the impact force increased with thickness of face-sheets and foam core, the extent of the damage increased with the impact energy, sandwich panels with steel face sheet has a good impact resistance in comparison with sandwich panel with aluminum face sheets.
CFSC for Positive and Negative Temperature Sensing by Resistivity Measurement
Authors: Wang Shou De , Lu Ling Chao , Cheng Xin
Published: December 2010

Carbon fiber reinforced cement could sense its own temperature based on the temperature resistivity effect. In contrast with Portland cement, sulphoaluminate cement has much better freeze- resistance. As a result, carbon fiber sulphoaluminate cement composite (CFSC) has the superior potential to sense its own temperature than carbon fiber reinforced Portland cement in the negative and positive temperature, especially for the negative temperature range. The temperature resistivity effect of CFSC was discussed in the positive and negative temperature. And the lower and the upper temperature limit of temperature resistivity effect were investigated. The results indicated that temperature resistivity effect of CFSC was related to the hot expansion and the electric carrier activating. And the electric carrier activating was the primary influence factor. Temperature sensors could be made by CFSC based on its good temperature resistivity effect in positive and negative temperature range. Therefore CFSC has the advantage to sense positive and negative temperature by resistivity measurement.
Current Use of Prestressed Concrete Pipe Piles Founded in Silty Geomaterials
Authors: Yu Feng , He Jing Yu , Zhang Zhong Miao
Published: December 2010

Prestressed concrete pipe piles have been increasingly used as deep foundation structures for decades. Despite the availability of a limited number of well-instrumented load test results, pile designers would like to know the general performance of such piles in case of lacking adequate experience. An attempt is made in this study to establish a database composed of more than one thousand of pile tests. All piles are founded in silty soil that is one of the competent bearing geomaterials. Short and medium-length piles with slenderness ratios ranging from 20 to 80 are most widely used. The capacity of pile increases with increasing the pile slenderness ratio until a limiting value is achieved. Use of very long piles to reduce settlement is unfavorable and the rebound rates for piles with various lengths are similar. An independent case study is also conducted to witness the success of employing the empiricism-based analyses in the preliminary design of concrete pipe piles.
A Lithium Salt Accelerator for Deepwater Low-Temperature Cementing: its Acceleration Mechanism and Performance Evaluation
Authors: Wang Cheng Wen , Wang Rui He , Cheng Rong Chao , Chen Er Ding
Published: December 2010

A study on a new lithium salt accelerator was conducted in this paper aiming at the low temperature environment in deepwater cementing. The acceleration mechanism and comprehensive performance of the lithium salt accelerator were thoroughly discussed. Results show that the lithium salt accelerator can accelerate the low-temperature hydration rate of C3S and C2S by speeding up the rupture of protective hydration film and shortening the hydration induction period, and thereby significantly shortens the low-temperature thickening time and the 48-240 Pa transition time for the static gel strength of oil well cement slurry, dramatically improves the compressive strength at low temperatures and shows no effect on the initial consistency of cement slurry. The lithium salt accelerator shows favorable low-temperature early strength accelerating property and has no effect on the types of hydration product, which still remains the same with that of conventional oil well cement, namely the calcium silicate gel, Ca(OH)2 crystal and a small amount of ettringite AFt crystal. But the micro-structure of the system with the lithium salt accelerator is more compact than that of conventional set cement.
Damage Effective Functions Described Based on Combination of Macro and Micro Damage Mechanics
Authors: Qiu Zhan Hong , Zhang Wo Hua , Chen He Long
Published: December 2010

The model of Helmholtz free energy serves as the constitutive functional expression for a damaged material, and was expanded into Taylor's series with respect to some state variables εij and Ω, the generalized expressions of isotropic elastic damage constitutive equations and the damage strain energy release rate with a configuration of isotropic damage scale were derived directly from the second law of thermodynamics. From the aspect of relationship between the porosity and damage variable, the different influence to damage effective functions were discussed theoretically and some valuable conclusions were carried out from the variation of material properties. The limitations of the classical damage constitutive equation based on the well-known strain equivalence hypothesis were overcome, and the method developed in this article can be applied to study different damage problems. It is shown that the applied method and obtained conclusions are useful to study the damage mechanics problems further.
Research on Activation of Abandoned Mortar Power Construction Waste
Authors: Ma Bao Guo , Su Lei , Jian Shou Wei , Song Xue Feng , Zhai Yu Dong
Published: December 2010

Through crushing, screening and grinding, abandoned mortar power can be used as a mineral admixture to replace cement. Physical-activated, alkali-activated and composite-activated have been researched on activity of abandoned mortar power. Mechanical properties and microstructure were tested by compressive strength, flexural strength, XRD, TG-DSC-DTC and SEM. The results show that: Mechanical grinding and activator can significantly improve the activity of mortar power. Stimulating effect of single activator was not obvious. Composite activator has better effect than signal activator and it can promote further hydration of cement. The mortar which is stimulated by composited activator had higher strength than mortar with single activator. It can be seen from micro-test, the mortar with composite activator had more ettringite and other hydration products, having compact structure.
Study on Hot-Pressing Technology of Cement Bamboo Particleboard
Authors: Li Xin Gong , Zheng Xia , Wu Yi Qiang
Published: December 2010

The hot-pressing technology of cement bamboo particleboard was studied by changing hot-pressing temperature, adhesive/bamboo ratio, board density and additives amount of NaHCO3. Then variance analysis and regressive analysis were conducted on technological parameters. The results indicated that the optimizing technology parameters of cement bamboo particleboard are hot-pressing temperature 130 , adhesive/bamboo ratio 2.8, additives amount of NaHCO310%, boardl density 1.2g/cm3.
Research on ANSYS Slope Model Automatic Generation Based on GIS
Authors: Zhao Jun Lan , Chen Ke Ren
Published: December 2010

This paper studied a sort of way on modeling based on GIS raster model, which can complete preprocessor of finite element analysis, and developed an interface program to complete data conversion from GIS to ANSYS, overcoming the weakness that the process that set up slope model by ANSYS was inconvenient.
Study of Transmission Electromicroscope of Polyaluminum Chloride
Authors: Ning Xun An , Liu Jing Yong , Yang Zuo Yi
Published: December 2010

Three series of polyaluminum chloride with aluminum concentration 2.50 mol/L (A, C, D series)have been prepared under simulated industrial production conditions and a series with Al concentration 0.150~0.336 mol/L has been obtained using a low-speed alkaline titrimetry(B series). The test results of transmission electromicroscope indicate that the particles of A, C and D series specimens are in the dispersing state, there no particles appear in the flocculating mass and branching state, while the particles of B series specimens at middle and lower basicity appear in the flocculating mass and branching state, at hingher basicity they are in the dispersing state.
Debonding Effects on Internal Force and Stiffness of Single Tube Concrete-Filled Steel Tubular Arch Rib
Authors: Tu Guang Ya , Yan Dong Huang , Shao Xu Dong , Yi Zhuang Peng
Published: December 2010

In this paper the relationship of total internal force between complete debonding situation and complete bonding situation, the calculation formulas of moment distribution between steel tube and filled concrete on the complete debonding condition are deduced from the complete debonding calculation model of CFST arch rib and corresponding differential equations of geometry and internal force. Based on principle of virtual work, the relationships of radial displacement between complete debonding situation and complete bonding situation are deduced, and the results were verified by finite element method. The research results for constant section single tube CFST arch rib indicate that the total internal force of any section on the situation of complete debonding is equal to that on the situation of complete bonding if the axial strain is ignored; the moments of steel tube and filled concrete are distributed according to the ratio of their bending stiffness; the stiffness of CFST rib does not decrease with pure debonding.
Bio-Based Rigid Polyurethane Foam from Liquefied Products of Wood in the Presence of Polyhydric Alcohols
Authors: Zheng Zhi Feng , Pan Hui , Huang Yuan Bo , Chung Y. Hse
Published: December 2010

Rigid polyurethane foams were prepared from the liquefied wood polyols, which was obtained by the liquefaction of southern pine wood in the presence of polyhydric alcohols with sulfuric acid catalyst by using microwave-assistant as an energy source. The properties of liquefied biomass-based polyols and the rigid polyurethane foams were investigated. The results indicated that the foams exhibited excellent mechanical properties.
Random Adjusted Calculation Method for 3D Aggregate of Concrete
Authors: Xu Yin , Chen Sheng Hong
Published: December 2010

Discrete element method is emerging as a useful numerical analysis tool for engineers interested in granular materials such as soil, concrete, or pharmaceutical powders. Simulated the concrete’s microscopic property and its impact on the macroscopic property by using particle discrete element method is one of the important research topics. Obviously, the first step in a discrete element simulation is the generation of the geometry of the system concerned, the quality of which will directly decide the quality of the simulation result. An integrated approach termed random adjusted calculation method is proposed in this paper after detailed analysis of the advantages and disadvantages of the existing aggregate delivery methods. The new method is a method which combined both the advantages of random method and non-geometry methods, such as hopper method and explosive repulsion method. Through out the analysis of the basic process of aggregate delivery and indicated by the result of the examples, random adjusted calculation method has the advantages of good overall density and easily controlled grading; and the computational time is smaller than the existing methods of non-geometry aggregate delivery; furthermore, the new method is easily carried out and provides a new idea for the delivery of concrete aggregate.
The Optimal Intelligent Algorithm on Orthogonal Five-Variate Wavelet Packets
Authors: Li Lan
Published: December 2010

In this article, the notion of orthogonal nonseparable four-dimensional wavelet packets which is the generalizaion of orthogonal univariate wavelet packets is introduced. A new approach for constructing them is presented by iteration method. The orthogonality properties of five-dimensional wavelet packets are discussed. Three orthogonality formulas concerning these wavelet packets are estabished.
The Crack Resistance and Impermeability Properties of Mortar with PP Fiber and Capillary Crystalline Material and their Mechanism
Authors: Huang Wei , Wang Ping , Yin Wan Yun , Zhang Li , Shu Wei
Published: December 2010

According to the principle that fiber resist crack and cement-based capillary crystalline impermeability, the paper chose the mortar added with polypropylene fiber and SJ capillary crystalline material as the research object. Experiments on mechanical properties, crack resistance and impermeability of mortar were conducted with one material being added to the mortar as well as both materials being added to. The test results indicate that the ratio of compressive strength to flexural strength of mortar could be reduced, the time of cracks occurrence in mortar matrix would be delayed, and the minimum cracking coefficient can amount to 5% on the condition that the two materials are both added to the mortar, moreover, the mortar’s first and second impermeability is significant. Furthermore, the paper also discusses the mechanism of mortar’s crack resistance and impermeability which is mixed with polypropylene fiber and capillary crystalline material.
The Design of a Novel Heat Exchanger without Water Treatment
Authors: Wang Yong , Wang Zi Yun , Fu Xiang Zhao
Published: December 2010

The Low-Carbon economy enhances the use of renewable energy for indoor environmental control. River water could be a nice renewable energy as it can be used as a lowstand heat/cold source to control the indoor environment through Water Source Heat Pump (WSHP) units. However traditional WSHP units are not applicable because the high cost of water treatment to improve the present water property, and the advantages of the WSHP are badly restricted. To overcome the limits of the present WSHP units, we develop an integrated heat exchanger for which the river water or waste water can be effectively used as a cooling medium while heat exchange is keeping and the exchanger is being cleaning. The newly-developed heat exchanger can keep effective operation and well realize the energy saving.
Electromagnetic Shielding Effectiveness of Carbon Black -Carbon Fiber Cement Based Materials
Authors: Huang Shao Wen , Chen Guang Hua , Luo Qi , Xu Yu Hua
Published: December 2010

The electromagnetic shielding effectiveness (SE) of cement based composites filled with carbon black and carbon fiber were discussed in this paper. Results show the SE of cement composites will get obvious improvement as the carbon black mass fraction increases beyond 6%. Carbon fiber is a much more effective additive than carbon back. The shielding effectiveness were gradually improved with the increase of content of carbon fiber, the maximum attained 21 dB at 1.5GHz. Adding carbon black and carbon fiber, SE of the cement based materials get more upward gradient, the maximum SE reached 27 dB in tested frequency range.
Modification of Polypropylene Fibers by Acrylic Acid and its Influence on the Mechanical Property of Cement Mortar
Authors: Ning Chao , Li Guo Zhong , Zhang Shui , Yuan Hai Yan
Published: December 2010

The surface of the PP fibers were modified by acrylic acid and grafted by suspension in water medium. The effect of modified PP fibers on mechanical properties of cement mortar was studied. The microstructure of fibers surface, the active functional groups of fibers and the profile of cracked samples were analyzed by SEM and IR. The results show that, crylic acid was grafted on surface of PP fibers after modification; the flexural strength of cement mortar reinforced by modified PP fibers improved markedly, compared with cement mortar reinforced by ordinary PP fibers.
Explore Shallow Ground Temperature of Railway Embankment in Permafrost Regions on Qinghai-Tibet Plateau
Authors: Chou Ya Ling , Liang Ya Xiong , Li Yu Wen , Zhu Yan Peng
Published: December 2010

Based on observed temperature values in Beiluhe on Qinghai–Tibet Plateau, this paper sets up a regression equation using statistics methods between the temperature at shallow ground depth (0.5 m)and the direct solar radiation on embankment horizontal surface. There is a good linear relation between the temperature and the solar radiation after the phase difference is removed. Correlation coefficient R2 is 0. 9321, and the regression equation is: T = aQ – b where, T—temperature (°C) on horizontal surface of shallow ground (0.5m); Q—solar radiation after the phase difference is removed (W.m-2); a,b—constants, is 0.5552and 16.549, respectively. The equation is validated and allows the temperature on horizontal surface of railway embankments. Whether it applies to other places needs further study. And based on this conclusion, combining with the law of documents and materials, and considering local factors, such as vegetative cover, snow, lithology, soil moisture and so on, we further prove there is obvious linear relation between the temperature and the direct solar radiation on horizontal surface.
The Visco-Elastic Behaviors of PVC Coated Fabrics under Different Stress and Temperatures
Authors: Zhang Ying Ying , Zhang Qi Lin , Zhou Chuan Zhi
Published: December 2010

The visco-elastic behaviors of coated fabrics are important for the design of membrane structure. In this paper, Ferrari 1002 is taken as the research object. The tests of creep and stress relaxation are carried out under five temperatures (23, 40, 50, 60, and 70 ) and three initial stresses (4, 15, and 26 kN/m), respectively. Results show that temperature and initial stress has great effects on the visco-elasticity of coated fabrics. With temperature and initial stress increasing, the visco-elastic behaviors are more obvious. The creep strain can be ignored compared with the corresponding elastic strain. After 24h, the remaining stress is less than 80% the initial stress. This paper can be references for the design of membrane structure.
Parameter Calculation of Viscous Damper Applied in the Truncated Model Test Design of a Deepwater Semi-Submersible Platform
Authors: Qiao Dong Sheng , Ou Jin Ping
Published: December 2010

In the equivalent water depth truncated model test design of a deepwater semi-submersible platform, the viscous damper is designed to simulate the contribution of mooring damping to total damping of floating platform. The dissipated energy by a mooring line from the floating platform as a result of its oscillation is applied to calculate the mooring-induced damping. The mooring line and seabed interaction is based on the hypothesis of rigid seabed. The fluid drag force and inertia force on the mooring line are calculated according to the Morrison formula. The non-liner dynamic analysis of mooring line is executed in the time domain based on the finite element method. The mooring induced damping is obtained from the results. The value difference of mooring induced damping between the truncated and full-depth mooring line is linearized to provide parameter for the design of viscous damper.
Shrinkage Properties of Cement Solidified Sludge with High Water Content
Authors: Wang Zhe , Xu Si Fa , Yan Li Li , Guo Ping , Chen Qian
Published: December 2010

Solidified sludge as backfill material exists serious phenomenon of shrinkage and cracking, and the project's strength, permeability and stability will be adversely affected. The material used in this study is sludge with high water content from the Metro construction sites in Hangzhou. In this paper, our main research is the influences of the initial water content of sludge, curing period and cement content on the curing shrinkage of silt. The results show that the shrinkage increases with initial moisture content, decreases with the increase of the cement content, and increases with curing period. Strength decreases with the increase of initial water content, increases with cement content, and increases with curing period. The test has a certain reference value to the engineering practice.
Experimental Research on Compressive Strength and Storage Period for Dry-Mixed Material of Shotcrete
Authors: Zhang Jing Shuang , Ma Qin Yong , Han Xing Teng
Published: December 2010

According to dry-mixed materials of shotcrete which composed of raw materials in mix proportion the concrete quality as field mixing were included. Through the experimental research on the storage period of using dry-mixed materials in shotcrete, variations of compressive strength were obtained. In according with the studies on the storage period of dry-mixed materials in 7d, 11d, 15d, 20d and 28d, compared with 0d, the loss of compressive strength were obtained under different sand water content (0%, 0.5% and 1.0%). The results shown that strength loss rate of C30 concrete was 6.7% when the sand water content was 0.5% in the 28d and while strength loss rate was 12.0% when the sand water content was 1.0%. The studies on storage period provide supports to the using of dry-mixed shotcrete in engineering application.
Preparation of Interior Latex Coatings by Recycling Banknote Printing Wastewater
Authors: Qiu Zu Min , Zeng Yan Yan , Liu Zhong Wei
Published: December 2010

This paper related to the recycling of banknote printing wastewater, using which as raw materials, a low cost interior latex coatings has been developed. This coatings is formulated based on styrene-acrylic emulsion and silicon sol as main film former. It has been shown that the performance of of this product meets the state standard of GB/T 9756-2009.
Non-Linear FEM Analysis for the Layered Rock-Mass Tunnel Based on the Twin Shear Strength Criterion
Authors: Wang Xiang Qiu , Zhou Zhi Guo , Zhang Yu Hong
Published: December 2010

According to the geotechnical conditions, A FEM model has been established to analyse the mechanical characteristics of the highway tunnel in the layered rock mass. In this model the layered rock mass and the soften joint are simulated by the transversal isotropic material, the interfaces between layers are simulated by the element of rotational Goodman interface, but the interface between the lining structure and surrounding mass is proposed to simulate by an interface element with thickness, and the supporting of tunnel is simulated by the straight beam element. In the meantime, based on the twin shear strength criterion, the mechanical characteristics of rock, the stiff matrix of element for the layered rock mass, soften joint and interface have been discussed. The analytical model has been demonstrated by comparing the results of layered surrounding rock-mass FEM with the test data in situ.
Mechanical Properties of Steam-Cured Concrete with Combined Mineral Admixtures
Authors: He Zhi Min , Liu Jun Zhe , Wang Tian Hong
Published: December 2010

In precast concrete elements manufacturing, steam-cured concrete incorprating 30% mineral admixtures encountered the problem of too low demoulding compressive strength. To resolve it, this paper mainly studied the influence of mineral admixtures on the compressive strength, the tensile-splitting strength and the flexural strength of the steam-cured concrete. The experimental results indicated that, compared with steam-cured concrete incorprating mineral admixtures, the later strength of steam-cured concrete incorprating 0% mineral admixtures has lower increment degree and its increment of tensile-splitting strength and flexural strength inverted to some extent. The demoulding compressive strength is too low for the high volume fly ash concrete mixtures. The problem of too low demoulding compressive strength is solved by incorprating composites of ground blast furnace slag(GBFS) and fly ash. Different varieties of mineral admixture used in the concretes can produce a certain degree of potentiation.
Effect of Macro-PP Fiber on Uniaxial Tensile Behavior of Concrete
Authors: Wang Xiao Fei , Ding Yi Ning
Published: December 2010

Based on different direct tensile test methods of concrete in the present studies, the effects of specimen shape and grip method on the stress distribution in specimen were discussed and a series of tests were carried out by using epoxy adhesive method. Influences of fiber content and fiber type on tensile strength, tensile strain and residual strength of concrete have been studied. The specimen dimension was 100mm×100mm×200mm and the content of Macro-PP fiber was 6 kg/m3, 7 kg/m3, 8 kg/m3, 9 kg/m3 and 10 kg/m3, respectively. The content of steel fiber used in the contrast test was 30 kg/m3 and 40 kg/m3. The test results indicate that Macro-PP fiber can enhance the tensile strength and tensile strain at peak load effectively. Compared with plain concrete, it was found that the tensile strength and tensile strain at peak load of concrete with 9 kg/m3 macro-PP fiber increased by 43 % and 41% respectively.
Structure Characteristics and Mechanical Properties of Fiber Reinforced Concrete
Authors: Deng Wen Qin , Zhao Jing
Published: December 2010

Mechanical properties of fiber reinforced concrete with polypropylene fiber, alkali-resistant glass fiber and basalt fiber separately were studied in this paper. The internal structure of fiber reinforced concrete was researched by testing chloride ion diffusion coefficient and scanning electron microscope (SEM) analysis. The results show that adding a certain amount of three fibers separately into concrete have all increased splitting strength. Compared with referenced concrete, compressive strength of alkali-resistant glass fiber reinforced concrete and basalt fiber reinforced concrete are both improved. According to analysis, the effect of srengthening and toughening for basalt fiber is particularly significant. The order of chloride ion diffusion coefficient from lower to higher is alkali-resistant glass fiber reinforced concrete, referenced concrete, basalt fiber reinforced concrete, polypropylene fiber reinforced concrete. This result indicates that alkali-resistant glass fiber bonds cement paste best and makes internal structure densest by SEM analysis.
Abrupt Gush Problem of Foundation Pit Considering the Influence of Shear Strength of Soil
Authors: Liu Jin Long , Liu Jie Qun
Published: December 2010

In traditional calculation method, the critical thick of water-resisting layer at foundation pit can be got by comparing the gravity of water-resisting layer and water pressure of artesian aquifer, which had not considered the influence of shear strength of soil. The result of traditional calculation method is conservative to reality. Based on force equilibrium analysis of water-resisting layer, equations for calculating safety factor of abrupt gush and critical thick of water-resisting layer is suggested in this article, which considered the influence of shear strength of soil. Some cases have been studied with those new equations. It had been found that the result of those new equations is coincident with realities. In order to ensure the security of foundation pit, it is advised that foundation pit can be adjudged safety only both the safety factor of abrupt gush and critical thick of water-resisting layer satisfied requirements.
Modelling Pervious Concrete under Compression Loading – a Discrete Element Approach
Authors: Lian Chun Qi , Yan Zhu Ge , Beecham Simon
Published: December 2010

With the increasing popularity of pervious concrete as a pavement material, researchers and concrete manufacturers have paid more attention to research needs. Pervious concrete is currently used in low traffic volume areas such as parking lots, footpaths and driveways. This is because it generally has lower strength than conventional concrete. This paper aims at developing a computational model to simulate the behaviour of pervious concrete under compression. Since compressive strength is one of the most important properties for concrete, a virtual model will provide a better understanding of its mechanical performance, which in turn will improve both the mix design and the material strength in the future. The discrete element method was applied and the results of calculations based on particle flow analysis are compared to the experimental data.
Structural System and Conceptual Model Test of Solar Chimney
Authors: Zhang Xing Qiang , Yuan Xing Fei , Li Li Min
Published: December 2010

The solar chimney power station is a renewable energy system consisting of solar collector, wind turbine, and chimney. To improve the efficiency of energy generation, the higher chimney is the better. Considering the difference between the solar chimney and the traditional high-rise structure, the study on the chimney from the structural point of view is produced in this paper. The existing and planed chimneys are first introduced. Then the solar chimney is classified according to material, structural system, and constraint condition. Followed that, application of prestress technology including adoption of prestressed concrete, introduction of circumferential prestress, arrangement of stayed cable or cable net, and utilization of tensegrity system in the solar chimney is involved, which can improve the structural behavior of the chimney significantly. On this basis, conceptual models of three different structural systems are designed, and the performance of the models is tested under the horizontal force to show the effect of stayed cable and spokewise cable.
Transformer Fault Diagnosis Based on Cluster Analysis and Statistical Theory
Authors: Zhao Wen Qing , Niu Dong Xiao
Published: December 2010

A new method for transformer fault diagnosis based on cluster analysis and statistical theory is presented. First, the fault diagnosis results are obtained according to the distances between the state sorts of transformer. Then, the final fault diagnosis is accomplished according to the concentration distribution of typical fault gases in higher dimensional space. The proposed approach is constructing the most accuracy model from few training samples supporting. Moreover, by comparing with the other methods, it cost less time for diagnosing by the proposed model and the accuracy for transformer fault diagnosis is improved using our proposed model.
Discussion on HRBF500 Grain Reinforcement and C100 High-Performance Fiber Reinforced Cementitious Composites (HPFRCC) in the Civil Air Defense Work
Authors: Yao Shan , Zhang Ji Wen , Tu Yong Ming
Published: December 2010

The clearance requirement of civil air defense work is a critical question; existing design will lead higher cost and the inconvenience in construction. Through introduction the material properties of HRBF500 reinforced and high-performance fiber reinforced cementitious composites (HPFRCC), calculated the design value of strength and the coefficient of strength for the two materials, provided theoretical for civil air defense work design for the future use HRB500 and the C100 HPFRCC. Based on the practical projects, contrast the frame beam using the HRB335 and C40 with HRBF500 and C100 HPFRCC for reinforcement and cross-section, the results showed that: with the same beam width and same reinforcement, the new material can effectively reduce the high of beams. The combination of these two new materials has a long-term significance in the civil air defense work.
Application of Engineered Cementitious Composites for Earthquake Resistance and Disaster Mitigation of Structures
Authors: Yao Shan , Zhang Ji Wen , Tu Yong Ming
Published: December 2010

This paper begins by discussing the need for damage mitigation for building structures under performance-based design by Wenchuan earthquake. Based on this concept, the character of Engineered Cementitious Composites and the application of the on-site Engineered Cementitious Composites device is discussed. Moreover, a new precast Engineered Cementitious Composites device is suggested. Based on the practical projects, A 6-story frame structure with and without such Engineered Cementitious Composites devices was calculated in 8-degree earthquake zone. The results indicate that Engineered Cementitious Composites devices can reduce the drift angle of the base story from 0.145 to 0.1, reduce the displacement of the top story from 20.23mm to 13.37mm. Engineered Cementitious Composites devices are confirmed to have significant potential as a new structural technology for earthquake resistance and disaster mitigation.
Bending Toughness of Zinc Phosphate Steel Fiber Reinforced Concrete before and after Corrosion
Authors: Sun Min , Wen Di Jiang , Xie Peng
Published: December 2010

The interface bond between steel fibers and concrete matrix is the key of carrying capacity of steel fiber reinforced concrete(SFRC). In marine tidal fluctuation zone and splashed area, steel fibers will be rusty, and the bending toughness of SFRC was weakened. In this study, we tried to improve corrosion resistance of steel fiber and the interface bond strength by depositing zinc phosphate coating on steel fiber. These zinc phosphate steel fiber reinforced concrete(ZSFRC) have higher anti-corrosion ability. After corrosion they still have higher bending toughness than common SFRC.
Rearch on Design of Aluminum Truss Bridge
Authors: Wen Qing Jie , Qi Yan Jun
Published: December 2010

In recent years aluminum bridges have been constructed in China, but lack of aluminum design and construction standards limits its development. Traditional design theory of concrete and steel can’t be completely adopted for its application in bearing structures. In order to solve technical difficulty, material type, deflection under live load, frequency and bucking of aluminum bridges are analyzed based on aluminum half-opened truss bridges constructed in China. Compared with related design standards at home and abroad, recommendations are put forward to provide theoretical basis for further application and research of aluminum truss bridges.
Improved Water Resistance of Waterborne Polyurethane
Authors: Luo Sui Lian , Gong Guo Fei , Deng Jun Qiang , Shi Guang , Zhu Hong
Published: December 2010

The introduction of hydrophilic groups, such as -COOH, -SO3, -OH, -O-, into the polyurethane resin, so that waterborne polyurethane products in the water resistance, solvent resistance, weather and other aspects of performance are worse than solvent borne systems. In our work, to improve the water resistance of the films for waterborne polyurethane, we incorporated C=C bond into the side chain of polyurethane by using pentaerythritol diacrylate as an extension agent. By measuring the cured polyurethane films absorption and mechanical properties, we determine the conditions for UV curing, 3% TMPME, photoinitiator (2959) and to UV light application time for 30s. With the increase of the amount PEDA, water resistance, hardness and tensile strength increase. Furthermore, with the improved water resistance, it is hoped that the performance of waterborne polyurethane can be comparative or superior to the solvent-borne systems.
Statistics and Analysis of Influential Factors on Shear Strength of Reinforced Saline Soil with Wheat Straw and Lime
Authors: Li Min , Chai Shou Xi , Du Hong Pu , Wei Li
Published: December 2010

As one of complex body, the strength of reinforced lime-soil with wheat straw was influenced by many factors. In order to gain quantitative contributed proportion, traxial compression tests of reinforced lime-soil, which took some factors like reinforced length, reinforced ratio and consolidation in account, were carried out by orthogonal design, and then evaluated by methods of range analysis and principal component analysis. Results are as follows. (1) Contributed proportion of consolidation is the highest, while, successively, of reinforce ratio and of reinforced length. Consolidation has the positive contribution to cohesion which the correlation coefficient can be up to 0.81, however, reinforced ratio takes negative contribution and the correlation coefficient is (-0.71). (2) The optimal reinforced condition of wheat straw is 20 mm in length and 0.25% in ratio as to the sample diameter of 61.8mm. (3) Results of principal component analysis and range analysis are both corresponded with that of experiment. These two kinds of statistics analysis methods are suitable in the domain of reinforced soil.