bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Concrete Deterioration under Immersion in Simulated Seawater
Authors: Zhang Ping , Qin Hong Gen , Hou Yi Kun , Pang Chao Ming , Sun Wei , Zhou Wei Ling
Published: October 2012

The underwater performance deterioration of different mineral admixtures concrete was tested through the indoor immersion experiment. The effect and mechanism of fly ash and slag powder were studied after 360d’s immersion. The performance deterioration and internal structure changes were analyzed with chloride ion content, ultrasonic test, SEM scan and X-CT technology. The results showed that mineral admixtures can refine the pore structure and block the channel in the concrete. The mineral admixture (especially FA) can help to resist chloride penetration. The ultrasonic velocity of C50F and C50S increased first, and then decreased after 160d and 50d, respectively. After 360d’s corrosion, the porosity (holes with diameter greater than 30μm) of three samples all increased, but the shape of holes for mineral admixture concrete changed significantly. Among them, the adding of SL had greater effect on the porosity.
The Key Reconstruction Technology of the Changjiang Yihua Standingpile Wharf
Authors: Xie Yao Feng
Published: October 2012

According to the need of production and development, the coal unloading wharves of yihua harbor in the lower changjiang river need to be expanded and reconstructed. In the reconstruction, the main body can only be reinforced, not be dismounted, and the reconstruction project can not affect the unloading, so it is with great difficulty. The available plan of the reconstruction is researched and adopted. The inner force of crane girder and bridging beam is calculated by using the theory of elasticity support continuous beam. The piles are assigned with reason, the differential settlement between the new and the old building is nearly eliminated, and the bearing condition of the main structure is improved. So it is needless to carry through driving pile over water or subbottom reinforcing pile foundation under the cross frame of the former wharf . The key technology is boring a pile driving hole in added pile position on the wharf deck of the crane girder side, then to drive the precast piles through the hole on the deck of the wharf with the land vibrating pile driver. The strict restrict of driving piles on the water avoided, at the same time, the coal unloading is not affected. Pile driving on the wharf deck less difficult condition than that one on the water. The practice indicated that this methods is reliable. So it has great guidance meaning to the similar wharf reconstruction project, especially as some ones in which the bearing capacity of the piles can not meet the need under the cross bend frame.
The Appraisal Example of the Reliability and Seismic Performance of a Reinforced Concrete Chimney
Authors: Yang Fang , Lv De Peng , Cao Hua , Zhou Yan Fang , Wu Yu Rong
Published: October 2012

In the state that the chimney is being used, we evaluate the seismic performance of the reinforced concrete chimney on the basis of testing the tilt, mechanical properties and chemical composition, configuration of the steel and construction measures, the lining damage, the cylinder damage, the subsidiary systems and dynamic characteristics of the chimney. The results show that: For the long-term wind action, corrosion and hot action, and lower level of construction and lower design standards, the reliability of the chimney structure can’t meet the current standards requirements, and need to take appropriate measures to be reinforced; but the seismic performance of the chimney structure can meet current standards requirements.
Applied Research Of BP Neural Network In Earthquake Prediction
Authors: Hu Wu Sheng , Nie Hong Lin , Wang Hao
Published: October 2012

Nowadays, earthquake prediction is still a worldwide scientific problem, especially the prediction for short-term and imminent earthquake has no substantial breakthroughs. BP neural network technology has a strong non-linear mapping function which could better reflect the strong non-linear relationship between earthquake precursors and the time and the magnitude of a potential earthquake. In this paper, we selected the region of Beijing as the research area and 3 months as the prediction period. Based on BP neural network and integrated with the conventional linear regression method, a regional short-term integrated model was established, which gives the quantitative prediction for the earthquake magnitude. The results show that the earthquake magnitude prediction RMSE (root mean square error) of the integrated model reaches ± 0.28 Ms. Compared with conventional methods, the integrated model improves significantly. The new model has a good prospect to use BP neural network technology for earthquake prediction.
DEM Simulation for the Effect of Rolling Resistance on Shear Band
Authors: Tang Hong Xiang , Zhang Xing , Chu Xi Hua
Published: October 2012

Three different numerical tests, i.e. no rolling test, free rolling test and rolling resistance test, in the framework of discrete element method (DEM) are carried out to simulate the micro-structure development in shear bands. The rotational angles and effective strain in the specimen under different conditions are given out. By contrast, it can be concluded that the development of shear bands in granular material can be simulated well when the rolling resistance is taken into account in DEM.
In Situ Monitoring Test for Rock Slope Stability in Li County Earthquake Zone of Sichuan Province
Authors: Liu Jian Hua
Published: October 2012

Combined with the highway from Lixian to Xiaojin, the in-situ monitoring test for Baozizui rock slope was carried out in Li County earthquake zone of Sichuan province, and three earthquakes whose magnitude exceeds 4.8 times had occurred during the monitoring period. According to monitoring results, the main conclusion was shown that the slope deformation attenuated and tended to be stable after two month of construction. Considered the anti-inclined structural face in the slope, the compacting deformation action, which was beneficial to slope stability. Moreover, seismic load had great influence on horizontal deformation of structural face in surface rock layer. And the reason was that there was regional stress bearing compression and shear in the nappe structures located on the thrust fault upper plate of this slope. The variation of horizontal deformation was frequent in earlier stage located at the road curve, in which there existed the traffic load, seismic excitation effects. And the later observational data indicated that the deformation has been basically stabilized.
Study on the Influence of Active Earth Pressure Caused by the Ditch behind Retaining Wall
Authors: Sheng Guang Qi , Chen Ying Hui , Sun Fang , Wei Bo , Pan Yan Lian
Published: October 2012

To study the influence of active earth pressure caused by the ditch after retaining wall, we will treat the ditch as unloading, and use the resolve of uniformly distributed load on half-infinite plane boundary to get the calculation method to get the influence of active earth pressure caused by the ditch after retaining wall. At last, from an example, we will get the picture of active earth pressure caused by the ditch after retaining wall, and analysis the regular pattern and characteristics.
The Strength of Fresh Concrete after Simulated Earthquake at Magnitude of 9
Authors: Liu Bin , He Guang Jie , Li Gu Hua , Xu Ming Qiang , Wei Jian Dong , Wang Ke
Published: October 2012

This study concentrates on investigating the 28d strength of fresh concrete after the occurrence of a simulated earthquake at magnitude of 9. The experiment has been carried out through the simulated earthquake that was generated by a high-performance vibrating platform with a size of 6m×6m, provided by the Nuclear Power Institute of China. There were 14 kinds the fresh concrete (C30 and C50) with seven ages (6 hours, 12 hours, 24 hours, 48 hours, 72 hours, 168 hours, 336 hours) acted by a types of ground acceleration (0.50g). The modified El centro was used to take the recordings of the time series of parameters. The results show that the strength of the fresh concrete undergoing the simulated earthquake can be well recovered after 28 days. It is nearly the same to the concrete which not vibrated by the earthquake in the same curing condition. Also the effect mechanism of the earthquake upon the fresh concrete had been analyzed.
Research on The Internal Force and The Normal Displacement of The Storage Tank under Earthquake Action
Authors: Yu Yang , Guan Hai Wei , Zhang Yun Feng , Yuan Zhao Qing
Published: October 2012

Vertical storage tank is widely used as a liquid storage container in the oil deposit, petrochemical industry and related enterprise. It always stores inflammable, explosive medium. The consequences are very serious, when the earthquake disaster occurs. In this paper, we build models of model tank and 30,000 m3 tanks with the finite element method, and analyze their vibration characteristics and seismic response. We wish that the research can provide fundamental data for the similar studies.
Grey Forecasting Model Refining in Deformation Prediction Based on Semi-Parametric Regression
Authors: Gao Ning , Cui Xi Min
Published: October 2012

Accurately estimating the deformation of dangerous rock is an important work for surveyors. Aiming at the limitation of the traditional GM (1,1) model, we propose that the error term in GM(1,1) model have an important influence on this model’s precision and adaptability. From this point of view, a novel new model termed SRGM (1, 1) is proposed. In this proposed model, the work modifies the algorithm of GM (1, 1) by integrate within semi-parametric regression model to eliminate the error term resulted from the traditional calculation of background value and initial value. According to the experimental results, our proposed SRGM (1, 1) model obviously can improve the precision of prediction and therefore can be adopted to deformation data analysis.
Stepwise Regression Arithmetic and its Application on Slope Safety Monitoring
Authors: Chen Lan , Wu Bang Bin , Liu Jing Yang
Published: October 2012

Considering the effect of time, rainfall and temperature on slope deformation, deformation factors and expressions were deeply analyzed. Statistical regression model of slope deformation was established by Matlab software and stepwise regression algorithm, thus slope deformation can be regression analyzed and predicted. Through analyzing the deformation monitoring data of a hydropower station spillway left high slope, the result showed that statistical regression values of slope deformation are in good agreement with measured values, multiple correlation coefficients were good and the residual standard deviations were small. This model can reflect slope deformation and trend. It provided guidelines to analyze on security status and prediction of deformation trend with great practical value.
Analysis of Shear Capacity of Stirrup Corroded RC Beam Based on the Truss-Arch Theory
Authors: Zhang Ke Bo , Zhang Zhi , Zhang Jian Ren , Liu Bin
Published: October 2012

On the basis of truss-and-arch model and the concrete softening strength criterion under ultimate state, a formula for shear capacity of reinforced concrete (RC) beam with diagonal reinforcement was established and verified. Accordingly, six RC beams with diagonal reinforcement and corroded stirrup were tested along with control group, the tested results were analyzed by liner regression to modify the formula given. Hence a formula for inclined section shear capacity of stirrups corroded RC beam with diagonal reinforcement was proposed and compared with a preceding formula without a consideration of diagonal reinforcement in corroded RC beam .The results showed that the existence of diagonal reinforcing steel bars enhanced the behavior of vertical compression web member in truss institutions, therefore increasing the shear force shared by truss mechanism. The inclination of diagonal web member is a crucial parameter of truss model. As the stirrup corrosion aggravating, the shear bearing capacity of such RC beams does not decrease drastically.
Structural Nonlinear Damage Detection Based on ARMA-GARCH Model
Authors: Cheng Cong , Yu Ling , Chen Liu Jie
Published: October 2012

Two economic models, i.e. auto-regressive and moving average model (ARMA) and generalized auto-regressive conditional heteroscedasticity model (GARCH), are adopted to assess the conditions of structures and to detect structural nonlinear damage based on time series analysis in this study. To improve the reliability of the method for nonlinear damage detection, a new damage sensitive feature (DSF) for the ARMA-GARCH model is defined as a ratio of the standard deviation of the variance time series of ARMA-GARCH model residual errors in test condition to ones in reference condition. Compared to the traditional DSF defined as the ratio between the deviations of ARMA-GARCH model residual error in two conditions, the successful outcomes of the new DSF can give obvious explanation for the current states of structures and can detect the nonlinear damage exactly, which enhance the worth of structural health monitoring as well as condition-based maintenance in practical applications. This method is finally verified by a series of experimental data of three-story building structure made in Los Alamos National Laboratory USA.
Analysis Computational Model and the Equivalent Stiffness at the Elastic Stage of the Coal Ash Wall Board Filled with Core Powder
Authors: Zhao Qing Shuang , Xu Ming Xia
Published: October 2012

The coal ash wall board filled with core powder is a new kind of light and hollow board that can be produced in factories. It uses cement with high strength, coal ash and auxiliary chemicals as its raw material, after pouring concrete and reinforcing bars into its cavity, it will get ability to bear loads. In this paper, aiming at the material characteristic of coal ash, according to the structure of wall filled with core powder, create a simplified calculation model. According to its deformation characteristics and the formula of the frame - shear wall, we can get the equivalent strength of the wall to simplify the calculation to apply to engineering project.
Development and Application of Spatial Analysis and Management System of Dammed Lake Based on 3D GIS
Authors: Chai Fu Xin , Sun Tao , Li Xiao Tao , Huang Shi Feng
Published: October 2012

Using Skyline and GIS technology, true three-dimensional scene of the Wenchuan earthquake is built in the area affected by the "5.12" earthquake in Sichuan is. And then the system development and model structures are done by the application development software of Visual Studio 2005. The decision analysis platform is built including the functions of the dynamic monitoring based on remote sensing for dammed lake, the lake recognition and feature extraction for dammed lake (rapid identification, the calculation of barrier dam, storage capacity calculation), submergence analysis (upstream submerged analysis, downstream image evaluation), and the function of disaster assessment and risk assessment. It can provide support for the Monitoring, and Early-Warning and aid decision-making for dammed lake.
Experimental Study of Damage Identification on Space Rigid Frame Structure
Authors: Fang Zhi Hua , Yue Peng Fei , Zhang Wei Na
Published: October 2012

Damage identification method of space rigid frame was based on change rate with the difference of the first axial modal, which applied to the model of space rigid frame on experiment. With extracting the experimental modal data to calculate the change rate with difference of the first axial model, the result shown that the change rate with difference of first axial model increased significantly in the injury site, and could identify well the damage location of single or multiple injuries, which was an ideal space frame damage labeled amount because of high sensitivity, less work of measure and calculation.
Influences of Temperature and Time on Concrete Compressive Strength after Natural Cooling
Authors: Zi Wei , Yu Zhi Wu , Liu Peng , Li Zuo Shan
Published: October 2012

The mechanical properties of C40 ordinary concrete after different temperature and time were experimentally researched. A detailed review of experimental phenomena and the influence of the significant parameters were given, and the relationship between the compressive strength and temperature and time were discussed. The experiment showed that with the exposure of temperature and time increasing, the concrete cubic compressive strength tends to decrease generally. According to the experiment results, the formula for strength-temperature-time relationship after the fire was built. According to the coupling effects of temperature and time to the compressive strength, a new fire size classification standard was established.
Analysis of the Fatigue Crack Propagation Life-Span Based on Linear Elastic Fracture Mechanics
Authors: Jiang Zheng Wen , Wan Shui , Cheng Chen
Published: October 2012

Abstract. The fatigue crack propagation life-span of the engineering structure is studied. Linear elastic fracture mechanics is applied to analyze the life-span of fatigue crack growth of specimen, which is under constant amplitude load. The software of Fatigue is used to calculate the life-span of a center crack plate steel specimen. The result show that the calculated values of the life-span are basically well with the experimental data.
Treatment Technology for Embankment Landslide Caused by Expansive Soil Foundation Instability
Authors: Tang Xian Yuan , Li Yong Peng
Published: October 2012

The embankments built on expansive soil foundation with a transverse are prone to crack and slide failure. In this paper, the embankment in a certain section of Bailong highway destroyed due to cracks and rainfall. A group of steel piles and reinforced concrete beams is used to strengthen the toe of slopes, and steel piles and reinforced concrete framework beams is utilized to strengthen embankment slopes, then pressure chemical grouting is used to reinforce soil. The treatment effect is good.
Stability of Cable-Arch Structure
Authors: Kang Hou Jun , Zhao Yue Yu , Zhu Hai Ping
Published: October 2012

Cable-arch structure is a combined structure, which utilizes flexibility of cable and rigidity of arch. Cable-arch structure has been widely used in bridge engineering. In this work, we proposed a novel mechanical model of cable-arch structure. The out-of-plane buckling and in-plane buckling were studied using the energy method. The formula of critical loads of both the first order out-of-plane buckling and in-plane buckling were derived using Rayleigh-Ritz method. An example is ultimately investigated numerically. The results indicate that the cable can improve considerably the out-of-plane and in-plane stability of arch. Therefore, the research about the stability of cable-arch structure are both valuable not only in theoretical research but also in design of engineering structure.
Research on Interface Critical Fracture of Different Materials Based on Critical Fracture Curve
Authors: Zheng Heng Xiang , Chen Cai Ying
Published: October 2012

In order to get the interface fracture curve of different materials under the four-point loading test pieces, firstly the displacement of fracture interface was obtained based on the finite element method. Then the first and second stress intensity factors of two different materials interface cracks in a beam specimen were calculated by the extrapolation method. Comprehensively considered the type of fracture specimen and the relative proportions between first and second section stress intensity, the variables K' , the first and second stress intensity factor were calculated according to the observed values of fracture load when the fissure appeared. By regression analysis of a six-groups of rock-concrete specimens with prefabricated fissure, the interface fracture criterion of different materials was got which was the interface fracture curve of rock-concrete samples. At last the calculated results of this method were compared and verified with the other related research results.
Crack Analysis on Reinforced Concrete Beams Strengthened by Externally Prestressing Vertical Tensioning Method
Authors: Shi Bo Wen , Wang Tian Wen
Published: October 2012

In this paper, seven reinforced concrete beams (two contrast beams and five externally reinforced beams) were tested. The crack regularity under different tension stresses was analyzed through experimental data. Taking the stress mode under pressure for the triangle area, in the tension zone in the shape of a trapezoid , the crack resistance equation of externally prestressing reinforced rectangle beam is derived from balance method of the internal forces and moment, and the results coincide with the experiment results well.
Effect of Migrating Corrosion Inhibitor on Corrosion Rate of Reinforcing Steel in Concrete with Various Admixed Chloride
Authors: Liu Zhi Yong , Zhou Xin Gang , Li Xiu Lin
Published: October 2012

Effect of surface applied inhibitor on the durability of chloride contaminated reinforced concrete has been investigated in this paper. The C30 concrete samples contaminated with 0.5%,1.0%,1.5% NaCl by mass of the cementitious materials in the mixing process were experienced adequate curing and subjected to 1 months exposure tests after painting with 400 g/m2 MCIs. The corrosion behavior of the steel rebar in concrete samples was monitored by using electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and corrosion currents. The results indicate that, after painting the MCIs for 28d on the surface of concrete samples with 0.5% and 1% NaCl, the average corrosion rate of reinforcements in concrete samples （0.34μA/cm2 ）is lower than that of the control one (No.0, no painted inhibitor), and about 1/4 of the initial corrosion current of the samples with 0.5% and 1% NaCl before painting MCI. But the corrosion current of rebar in No.3 sample with 1.5% NaCl is still higher than that of the control one (No.0). Therefore, painting MCIs on the surface of samples is very effective to inhibit the corrosion of steel bar in concrete at low or middle chloride conditions, but it is not enough to repair severely corroded steel bar in high chloride contaminated concrete.
Design Method for Embankment under Consideration of Wind Erosion in Non-Wind-Eroded Area
Authors: Yao Xiao Ping , Xu Hai Bin , Zhang Lin E , Liu Kai Feng
Published: October 2012

Wind erosion may appear because of the construction of embankment in a non-wind-eroded area. It can cause the destruction of the embankment and bring about flying dust, to which little attention has been paid. Based on analysis of the embankment-caused acceleration of wind, a design method under consideration of wind erosion is put forward for embankment in the non-wind-eroded area. Then protection range for the embankment is suggested and countermeasures against wind erosion are given. The results of this paper help render the design of embankment more reasonable and environmentally friendly.
Laminated Composite Beam with Bonded CFRP Reinforcement Stress Performance Analysis
Authors: Wang Yong Wei , Guo Yan Qin , Li Hong Xia
Published: October 2012

Based on the test of 7 reinforced concrete beam reinforcement test data comparison analysis shows that only the ordinary reinforced concrete beams with externally bonded CFRP, effectively improve the bearing capacity of members, but due to the lower tensile reserves and the upper compression reserve is relatively insufficient, make a component similar over-reinforced beam brittle failure, its ultimate bearing capacity was significantly lower than the upper part at the same time a laminated layer of the RC beam. Laminated paste CFRP composite reinforced RC beam damage characteristics and common reinforced concrete beam was no essential difference, but the laminated layer thickness reaches to a certain degree, the CFRP can also occur with sudden local cleavage fracture.
Chemo-Damage Model for Concrete Anisotropic Expansion Caused by Alkali-Aggregate Reaction
Authors: Pan Jian Wen , Xu Yan Jie , Jin Feng
Published: October 2012

A chemo-damage model for concrete affected by alkali-aggregate reaction (AAR) is presented. Redistributing weights, determined by the applied stresses in the concrete, are introduced to control the anisotropic expansion of the AAR-affected concrete. Accelerated tests are analyzed using the proposed model. The computed strains of the specimens are compared with the experimental measured strains. It demonstrated that the proposed model can consider the effects of applied stresses on AAR-induced expansion with reasonable accuracy.
Influence of Slag Fineness on Durability of High-Performance Concrete
Authors: Liu Hui , Li Ping , Jin Qiao Lan
Published: October 2012

This research focuses on investigating the high performance concrete durability containing slag with different fineness and dosage. For this purpose, the 28-day compressive strength, chloride ion penetration, and frost resistance were investigated, with slag surface area 420m2/kg, 530m2/kg, 610m2/kg, and 720m2/kg, and replacement percentage 0%, 20%, 40%, and 60%, respectively. It was found that chloride ion penetration resistance were affected by the fineness and dosage of slag, and concrete frost resistance property was mainly controlled by dosage of slag rather than the fineness, and the 28-day compressive strength increased with slag incorporation.
Modeling Coupled Flow-Stress-Damage during Creep Deformation
Authors: Wang Ru Bin , Xu Wei Ya , Zhang Jiu Chang
Published: October 2012

In order to reflect the tertiary rheological characteristics of hard rocks at the high stress states, a new nonlinear visco-elastic-plastic model is proposed on the basis of linear visco-elastic-plastic model and nonlinear visco-elastic-plasticity. And then the corresponding constitutive model are deduced, which can be used for describing rocks’ long-term strength characteristics and their creep deformational behavior and time-dependent damage under interaction of coupled seepage-stress field in rock engineering. At last, considering the time effect of rock damage in the process of tertiary creep, a coupled seepage -stress creep damage model for investigating the whole creep deformation behavior, including tertiary creep failure process is established, and the related equations governing the evolution of stress, creep damage and rock permeability along with the creep deformation of rock is introduced.
Effect of Cement Composite’s Ductility on the Flexural and Cracking Behavior of Reinforced Cement Composite Beams
Authors: Yun Hyun Do , Kim Ju Ne Su
Published: October 2012

Abstract. Fiber-reinforced strain-hardening cement composite (SHCC) shows multiple cracking, higher tensile strain capacity and tensile strength than conventional concrete and fiber-reinforced cement composite (FRCC). These characteristics of SHCC materials improve crack-damage mitigation. Current application of SHCC materials includes bridge decks, building dampers, retaining wall, and irrigation channels. During SHCC’s hardening, higher shrinkage occurred because SHCC’s mixture is richer than conventional cement composite. In this study, an expansive admixture was utilized for SHCC mixture to control the shrinkage of SHCC materials. The objective of the study is to investigate the effect of cement composite’s ductility and shrinkage on the flexural and cracking behaviors of reinforced cement composite beams. Test result indicates that cement matrix’s ductility has a significant effect on the flexural and cracking behavior of reinforced cement composite beams and the phenomenon is remarkable for a beam with shrinkage-compensating SHCC replaced a part of cement by expansive admixture.
Numerical Simulation on Failure Modes of Light Steel Columns under High Temperature and Explosion
Authors: Yan Shi , Qi Bao Xin , Yan Han , Yang Lu
Published: October 2012

The nonlinear finite element method (FEM) was used in the paper by using LS-DYNA software to numerically study the failure mechanism of light steel columns under fire and explosion. The constitutive model under the combined effects of fire and explosion was established, and the numerical simulation analysis of the columns under combined effects of fire and explosion was performed. The results showed that the failure modes of the mentioned columns were all bending shear failures. The deformation diagrams of the column under the blast and different temperatures, respectively, were proposed and this will provide a foundation for establishing the failure modes and the simplified calculation method. According to the relationship between rotation angles at the ends of the column and temperatures, the damage index of D was proposed in this paper for the evaluation of the damage level of the simulated light steel column.
On Fire Protection Problems and its Countermeasures about Chinese Ancient Architecture
Authors: Li He Qun , Yu Yang , Yu Xiang
Published: October 2012

The most ancient buildings of China are formed by wooden elements, such as columns, beams, so they are prone to fire and are difficult to fire control due to the lack of fire channel. The cause of the fire includes two aspects of human and nature. The basic countermeasures of ancient building fire mainly include display in such aspects as opening fire channels, doing well the construction of fire water sources, the use of advanced fire protection technology, managing the fire of life and maintenance strictly and so on. Meanwhile, handle the relationship between fire and protection of cultural relics.
Bridge Disaster Prevention and Disposal Methods in Mining Area
Authors: Wen Qing Jie , Lu Hui
Published: October 2012

Surface subsidence caused by mining operation can amount to several meters, which is far above the standard value in design code. Once mining collapse occurs, bridges’ large deformation can result in bridge disasters. In order to prevent bridge disasters in mining area, bridge disaster characteristics in different districts in working face of mining are analyzed on the base of large deformation regularity of ground. A method of avoiding location of piers at inferior fovea and superior fovea in the migrated basins is presented to reduce the deformation of bridges on condition that subsidence area can’t be bypassed. And smooth joints between road and bridge are also advised to be designed to reduce staggering of joint and cracking. Moreover, applicability of several prevention methods for bridge disasters is demonstrated based on different bridge design and foundation treatments in mining area. The results show that geological disasters of bridges can be prevented by choosing reasonable foundation and structure type, which provides reliable basis for bridge construction in mining area.
Seismic Isolation Design of Multistory Building
Authors: Song Xiao , Li Peng , Xu Guang Sheng
Published: October 2012

Design process and the nonlinear time history analysis for base isolation system is performed in this paper. The results show that the earthquake acceleration and displacement response of isolated structure can be significantly reduced. Application of the isolation system to improve the seismic capacity of the structure,can effectively reduce the response of upper structure of in earthquake.
The Modeling of the Real Building Object by Using the Model of a Two-Layer Beam of Variable Rigidity on an Elastic Basis
Authors: Vladimir Igorevich Andreev , Elena Vjacheslavovna Barmenkova
Published: October 2012

In the present paper is given the calculation of the real building object by using the model of a two-layer beam of variable rigidity on an elastic basis. The lower layer of a two-layer beam simulates the foundation, and the upper - the structure, at the same time is considered the weight of each layer. The characteristics of the upper layer change on length. To solve this problem were used an analytical and numerical methods of calculation. On the basis of the calculations can make the following conclusion: for the calculation of system «structure-foundation-basis» for the stage of pre-proposals it is advisable to apply the simplified model as sandwich beams and plates on elastic basis.
The Study of Relationship between Aspect Ratio of the Buildings and the Sunshine Spacing
Authors: Wujin Gao Wa
Published: October 2012

According to principle of sunshine and the national standards, taking residential building facing to the north-south in Baotou as the research object,we obtained the critical value of both the aspect ratio of buildings and the coefficient of the residential buildings sunshine spacing by the data deduction and the computer software applications. The results show that the aspect ratio of the buildings is a significant influence factor of the residential sunshine spacing.
Experimental Study on Impact of Production Process Parameters on Rubber Asphalt Performance
Authors: Hou Wei
Published: October 2012

In order to better master the production process and the road performance of rubber asphalt, the paper studied the influence law of mixing method, mixing temperature, mixing time and rubber powder content on the performance of rubber asphalt. The results show that all the indexes except the viscosity of rubber asphalt has little change with different mixing methods, and the rubber asphalt has the best performance under the high-speed stirring molding method but the worst performance under the high-speed shearing molding method. Meanwhile, the performance of rubber asphalt change visibly with different mixing temperatures, on which the excessively high or low production temperature has negative significance, so the optimal production temperature would be recommended as 180~200°C. Furthermore, the mixing time and the rubber powder content are the two critical factors which may greatly affect the performance of rubber asphalt, followed by the mixing temperature and the mixing method.
Cement Hydration Kinetics Research Based on Center-Particles Hydration Model
Authors: Wu Lang , Yan Bing , Lei Bin
Published: October 2012

Abstract: Based on the center-particles hydration dynamic model proposed by Park, a micro-structural hydration model of Portland cement that was built considering the decrease of the hydration rate due to the reduction of free water and the reduction of the interfacial area of contact between the free water and the hydration products. It can be used to predict the variation relationship of the hydration rate increases with the change of hydration degree. The results showed that: the revised model can simulate the variation curve of the cement hydration speed with hydration degree in this paper and the model results agree well with the experimental results.
Mechanical Properties Test Research on Mass Concrete Mixed with Different Fly Ash Bulk Volume
Authors: Liu Jing Hong , Liu Xiao Hua , Han Wen
Published: October 2012

The concrete would crack when the temperature stress caused by hardening concrete hydration heat and shrinkage action were over the concrete’ tensile strength. The concrete were added with different amount of fly ash in order to increase concrete’ tensile strength and ultimate tensile strain capacity or consider economic perspective. The mechanics performance tests were carried on mass concrete with different fly ash bulk volume. The test results showed that the fresh fly ash concrete’ workability, hydration heat, compressive strength and durability were obvious superior compared with ordinary concrete.
Experimental Research of Reclamation Performance of Recycled Asphalt Pavement Material at Weihai Area
Authors: Gong Ben Hui , Ji Hong Jie , Wang Peng Jie
Published: October 2012

Based on the recycled asphalt pavement material rooted out during road net reconstruction, this paper uses modified rejuvenating agent technology to study the reclamation performance of recycled asphalt pavement material, the mixture is AC-16 designed with new and old asphalt mixture. The results show that modified rejuvenating agent technology can improve the high temperature stability performance, the low temperature crack resistance performance and the moisture susceptibility performance of recycled asphalt pavement material effectively.
Relationship of High-Temperature Performance and Aggregate Gradation of Asphalt Mixtures Based on Fractal Theory
Authors: Huang Jing Bo , Yu Xun
Published: October 2012

Fractal theory was introduced to study the asphalt mixture aggregate gradation which shows visible fractal characteristics, and the fractal dimension of seven different gradations of ATB-25 were calculated quantitatively. Then the rutting test was carried out, and the results show that the fractal dimension of aggregate gradation has a good correlation with the dynamic stability of asphalt mixture. Finally, the paper proposes a multiple linear regression formula which may more accurately predict the high-temperature stability of the asphalt mixture with different gradations.
Applied Research on Straw Bale in Northwest Rural Residential Building
Authors: Li Xue Ping
Published: October 2012

The straw bale is a kind of eco-energy saving building material. Straw bale construction is a building which it use straw bales as the wall materials. Based on the investigation of rural residential buildings status, climatic characteristics and energy consumption status in northwest rural areas, raw material supply, construction cost and construction technology of straw bale building, thermal insulation and fire resistance properties of straw bale, environmental protection characteristic and so on were analyzed, it could make people aware of the straw bale can be used as an ideal material instead of solid clay brick in northwest rural residential building, and it could be extensive used and popularized in rural residential building.
Hydration Performance and Pore Structure of Fly Ash-Cement Pastes
Authors: Li Xiang , Dong Yun , Yang Hua Quan
Published: October 2012

The hydration performance and pore structure of fly ash-cement (FC) pastes were investigated by means of XRD, TG, ex-situ leaching (ESL) and MIP. The results reveal that the influence of curing age to the kinds of hydration products of FC pastes is unconspicuous. As the content of fly ash increase, the Ca(OH)2 content decrease gradually. However, the content of Ca(OH)2 left in every paste is almost constant after 28d, regardless of the replacement ratio of fly ash and water-binder ratio. The decline of alkalinity of pore solution is not endless, even though the contents of fly ash in FC pastes is very high(65%).The incorporation of fly ash in proper ratios could increase the ratio of harmless pores and improve the microstructure of the FC pastes. Ca(OH)2 was not consumed heavily or exhausted when cementitious material was hydrated due to the low reaction degree of fly ash.
Synthesis and Characterization of Comb-Like Polycarboxylate Superplasticizer
Authors: Fang Yun Hui , Jiang Zhuo Jun , Ke Yu Liang , Chen Xiao Lu , Zheng Fei Long , Lan Zi Dong , Guan Meng Qin , Lai Guang Xing , Lin Tian Xing , Gui Miao Miao
Published: October 2012

Polycarboxylate superplasticizers have become the superstar for high-performance concrete. Because their molecular structure can be easily manipulated by impart new materials to acquire new performance. In this paper, the synthetic parameters adjusting experiment is utilized to get the optimal synthetic formulations. The reaction control factors and polymerization mechanism are also discussed. After characterization, we concluded that the expected performance of polycarboxylate superplasticizer could fabricate through radical graft copolymerization reaction by molecular designing.
The Strengthening Scheme Optimization of a Homogeneous Earth Dam
Authors: Tang Ke Dong , Xu Zi Shuai , Wang Guo Jun
Published: October 2012

There will be a variety of problems in the process of dam using. The common problem is that the saturation line is high. When the saturation line is too high, it will not only lead to the increase of downstream leakage, but it may also cause dam break and finally causing the loss of life and property. So we need to pay much attention to the saturation line of the dam. When the saturation line is too high, it should be noted and if necessary we should adopt the measures of strengthening. This paper through the comparison and selection of several schemes and finally to determine the reasonable reinforcement method.
Frost Resistance of Steel Fiber Reinforced Micro-Expansive Concrete Filled Steel Tube
Authors: Mou Ting Min , Zhou Xiao Jun , Fan Bi Kun , Ding Qing Jun
Published: October 2012

Abstract. This investigation was done based on the concrete filled steel tube (CFST) winter construction of Ganhaizi Bridge. Steel fiber reinforced micro-expansive concrete (SREC) with high frost-resistance ability, excellent fluidity and good self-compacting ability was prepared. Strength development mode under low temperature was illustrated. Scanning electron microscope (SEM) was used to analyze the morphology features of hydration products at the age of 28 days. It was confirmed that when the content of sodium nitrite was 0.4%, SREC did not frost under -5°C. In addition, SEM showed that ettringite and CSH gels were in good growth state, and concrete structure was very dense. Furthermore, 6 CFST short columns were poured in the winter construction site of Ganhaizi Bridge, and another 27 short columns were cut from emitting slurry pipe filling with concrete emitted from main girder. The bearing capacity of all the CFST specimens was tested when the environment temperature rose to about 25°C. The experimental results indicated that the mechanical performances of CFST specimens with anti-freezing admixture did not exhibit degradation when cast in site under a low temperature and tested at 24.3°C. The concrete presented in this research substantially met the need of Ganhaizi Bridge CFST construction in winter.
A New Constitutive Model of Superelastic SMA
Authors: Ren Wen Jie , Jia Jun Sen , Chen Xiang Shang
Published: October 2012

The shape memory alloys (SMAs) have received increasing interest attributed to their unique superelastic effect and the shape memory effect. The existing models of superelastic SMAs are generally complex for practical use. In this paper, cyclic loading tests of superelastic SMA wires are first performed. Based on the experiments, a simple constitutive model is set up. Simulations testify that the model can approximately describe the hysteretic characteristics of the superelastic SMA and the simulated mechanical parameters agree well with the experimental values.
Tension Stiffening and Cracking Behavior of Ultra High Strength Strain-Hardening Cement Composite (UHS-SHCC) Ties in Monotonic and Cyclic Tension
Authors: Song Young Jae , Yun Hyun Do
Published: October 2012

This study investigates the tensile response of reinforced ultra high strength strain- hardening cement composite (UHS-SHCC) ties in directly monotonic and cyclic tension. The UHS-SHCC exhibits valuable material properties such as high compressive strength, tensile strain-hardening and ductility. However, UHS-SHCC requires high volume of cement, which leads to more shrinkage than conventional concrete. Authors have considered replacing a part of cement by the expansive admixture (EXA) for compensating the shrinkage of UHS-SHCC. Specifically, this paper explores the structural application of a shrinkage-compensating UHS-SHCC to improve tension stiffening in structural members. The cement composite type and EXA replacement were taken as experimental parameters. All specimens had a square cross-section dimension of 100 x 100mm and length of 1,500mm. The test results indicate that the shrinkage compensating UHS-SHCC is very effective to improve tension stiffening behavior and initial crack load of reinforced cement composite ties.
Experimental Research on Physical and Mechanical Properties of EPS Recycled Concrete
Authors: Rao Ya Xian , Liang Chao Feng , Xia Ying
Published: October 2012

In order to develop a new building material by recycling wasted concrete and expanded polystyrene (EPS), the EPS recycled concretes of different density were designed, and their basic physical and mechanical properties were studied. The results show that the EPS recycled concrete’s fluidity and saturated bibulous rate increase with the increase of EPS volume content. However, the dry apparent density, compressive strength, split tensile strength and thermal conductivity of EPS recycled concrete decrease linearly with increased EPS volume content. When the EPS volume content is 60%, the EPS recycled concrete’s cubic compressive strength is 4.0MPa and its thermal conductivity is 0.27W/m•K. Therefore, EPS recycled concrete can be widely applied to the non load-bearing lightweight insulation masonry.
Study on the Design of Steel-Bamboo Composite Member
Authors: Huang Jun Guo , Li Yu Shun , Yang Bo , Du Yong Fei
Published: October 2012

In order to make good use of bamboo resource in China and to promote the establishment and promotion of green structure system, which is light, energy saving and environmentally friendly, this paper presents the production method and section requirements of various steel-bamboo composite members such as steel-bamboo composite beams, composite columns, composite walls and composite slabs.
Experimental Study on the Influence of Ceramist Properties Compressive Strength of Shale Ceramist Concrete
Authors: Yang Wei Jun , He Zhi Gang , Yong Yi
Published: October 2012

There are 6 group of experimental research to explore the relationship between shale ceramist concrete compressive strength and ceramic cylinder compressive strength, particle size, absorption time. The result shows that the strength of shale ceramist concrete is not only relevant with the ceramic cylinder compressive strength, but also relevant with the aggregate size, absorption time. For single graded particle size concrete, the strength of concrete decreased with grain size increasing. The longer time of ceramic absorption, the more sufficient the ceramist concrete strength development.
Effects of Ceramsite Concrete Strength on Natural Frequency Based on ANSYS
Authors: Wang Hao Qing , Kong Qiu , Yu Zhou Ping , Yang Wei Jun
Published: October 2012

By separate modeling analysis based upon ANSYS, SOLID65 unit of the entity is selected to simulate ceramsite concrete, and reinforcing performance is selected to simulate the effect of reinforcing steel bar. The strength on natural frequency’s effects was studied through changing the ansys model’s material parameters of ceramsite concrete. The strength of ceramsite concrete can be determined and applied to the anti-seismic design according to the size of the environmental vibration frequency.
Effects of Sn on Mechanical Properties of Magnesium Alloy AZ61
Authors: Liang Jun You
Published: October 2012

The effects of Sn on the mechanical properties of magnesium alloy AZ61 have been investigated. The results show that the addition of 0.5wt.% Sn can refine the grain size, improve the morphology of β-Mg17Al12 phase, and cause the formation of Mg2Sn phase. The improved microstructure results in the enhanced mechanical properties of magnesium alloy AZ61 at room temperature and 150°C.