bluuebunny/crossref_metadata_2025 huggingface dataset:
Hard Kaolin High Yield and Stoping Technology in Suoli Mine
Authors: Yang Ren Shu , Meng De Jun , Guo Dong Ming , Xu Peng , Wang Yan Bing
Published: June 2012

The backward blasting of the mine technology and stoping technology will lead to a long time of blasting, high labor intensity and low production efficiency, which also cause roof collapse and the blast of fly rock, support fall and overthrowing the chain-trigger, which cause a larger hidden of production. Through using the mechanical mining technology of the high yielding and efficiency of kaolin, which fundamentally improve the working conditions of workers and safety working condition, will laid the foundation for the increasing of production and efficiency. The production has been promoted from 250-300t/d to 550-650t/d now, which the efficiency is increasing more than 120%. Meanwhile, the optimal of blasting parameters is benefit to roof control after blasting, which can improve the efficiency of blasting, reduce the unit consumption of dynamite, which can save about 0.115kg/ m3; and reduce the intensity of the workers and the damage of the support. This construction technique can provides a reference significance for safe and efficient construction of the mine under similar geological conditions.
Stability Numerical Simulation of Daping Landslide Group to Sunjiaya Tunnel
Authors: He Wen She , Yuan Long , Chang Shuang Mei
Published: June 2012

The stability of two profile, with No.Ⅲ landslide of Daping landslide group near the tunnel engineering of Sunjiaya, was respectively discussed using limit equilibrium and numerical simulation method at operation one (gravity) and two (gravity+rainstorm) in this paper. The dangerous sliding surface and corresponding safety factors was calculated by limit equilibrium method, to upper and lower parts of No.Ⅲ landslide in two different work conditions. The model of two calculation profiles was established and the dangerous sliding surface and corresponding safety factors was simulated by finite difference software of FLAC3D for upper and lower parts of No.Ⅲ landslide at two operations. Compared with limit equilibrium, FLAC3D is a simple and easy method to analyze the stability of slope.
Study on the Settlement Characteristics of Inclined Single Pile Subjected to Inclined Loadings
Authors: Sha Ling , Wang Guo Cai , Yang Yang
Published: June 2012

Inclined angles of piles and applied loadings have serious effect on the pile’s bearing capacity and settlement. In order to reveal this effect, this paper uses the nonlinear finite element software Adina 8.2 and analyzes the settlement characteristics and the influence factors on the settlement of inclined pile subjected to inclined loadings. From the analysis, it can be seen that: at given pile-soil physical properties, the settlement of inclined angle of the pile is smaller than that of the pile installed vertically subjected to vertical loadings; it is not good for larger inclined angle of inclined pile when the pile subjected to inclined loadings and the pile top settlement is always smallest when the inclined angle of the loadings agrees with that of the pile; The location of the horizontal stress balance point is related to the factors, such as loading value, pile inclined angle, et al., when subjected to vertical loadings. The conclusions obtained can have some reference value for the design and construction of inclined pile that subjected to inclined loadings.
Experimental Studies on Loads on a Single Pile under the Wave-Current Flow
Authors: Zhu Zhao Qing , Qiu Hang , Dai Guo Liang
Published: June 2012

Indoor model experiments were made to study loads on single pile under the wave-current flow. Take three different velocities of the current and three different diameters of piles in the experiments to get the variations of loads. Drag and lift forces were measured by a two-component balance. Analysis on experiment results shows that, both drag force and lift force increase with the increase of the pile diameter and the current velocity. The drag coefficient Cd increases with the increase of Kc number until Kc researches 12, when Kc is more than 12, Cd decreases with the increase of Kc; while the inertia force coefficient Cm decreases with the increase of Kc, when Kc is more than 12, Cmchanges little. And the lift coefficient shows no correlation with the Kc number.
Fast Compressional Wave Scattering from Cylinder in Porous Media
Authors: Lu Xu Jing , Han Yang Jun , Cui Zhi Wen , Wang Chun Xia , Wang Ke Xie , Dong He Feng
Published: June 2012

A mathematical model is presented to describe the scattering of a fast compressional plane wave (fast P-wave) incident at an arbitrary angle on isotropic cylinder embedded in a fluid-saturated porous medium. The expressions of components of solid and filtration displacement, pore fluid pressure and stress tensor in porous medium are obtained by potential function using the Biot’s theory and that of isotropic cylinder are also given. We investigate the properties of the form function of a backscatted fast P-wave for cement and steel cylinder system. It shows the influence of incident angle on form function for steel is more obvious than that for cement cylinder and form function curves are very different between steel and cement cylinder.
Influence of Engineering Dewatering on Soft Soil’s Density Characteristics
Authors: Yuan Hua , Li Yun Hua , Zhang Jian Wei
Published: June 2012

The change of Shanghai soft soil’s density with drainage time during foundation pit dewatering was investigated, through taking samples in each soil layer to be laboratory tested after the groundwater level of observation hole in project site had been lowered below the position soil sampled for at least 5 days. Experimental results show that groundwater included in drainage zone couldn’t be discharged immediately with the drop of groundwater table, which may be named as “lag draining” phenomenon; soil’s water-holding density can also be deduced from soil saturated density and specific field except directly measured from laboratory test. The effect of engineering pumping will reduce the discrete of soil density distribution; a centralized distribution of soil density emerges after dewatering.
Research on Liquefaction Processing of Sand Foundation
Authors: Zhang Chun Mei , Zhao Gen Tian , Zhi Guan Peng
Published: June 2012

sandy foundation easily liquefies under seismic load, which leads to damage to buildings and even collapse. Liquefiable sandy foundation is analysed and researched in the paper. Through the processing of sandy foundation we will see, CFG pile and Gravel pile together will improve the bearing capacity of liquefied foundation with obvious effect of liquefaction resistance. So the processing method is right and feasible.
On the Bearing Capacity Parameters of a Single Pile of Hammering Sunk Shaft Rammer Pile
Authors: Peng Hao Ming
Published: June 2012

This paper studies the bearing capacity parameters of a single pile of hammering sunk shaft rammer pile with engineering practice, proposes three parameters: the shape factor of expanded head α, correction factor of pile tip resistance β and the uplift height h, modifies the calculation formulae of bearing capacity of a single pile and expanded head based on these parameters, and validates the application of these parameters with engineering practice..
Evaluation on Effect of Building Settlement due to Adjacent Deep Excavation
Authors: Chen Jun Sheng , Mo Hai Hong , Liu Shuo Zhuo
Published: June 2012

A compound method which includes overall site stability analysis, stratum stability analysis on deep excavation boundary and 3D FEM is proposed to evaluate the effect of building settlement due to adjacent deep excavation. A typical deep excavation project was used to evaluate the feasibility of the compound method. The analysis results indicate the ground stability analysis is useful to understand the stratum situation of deep excavation and adjacent area. In 3D FEM, undulate stratum can simulate the supporting system of more accurately. The compound method brings a new analysis method for foundation pit project in complex environment and complex geological conditions.
The Improved Soil Model of Finite Compressible Layer
Authors: Yao Li Na , Yang Guang Hua , Wang Peng Hua
Published: June 2012

Choosing an accurate soil model is the key point in calculating the foundation settlement. The commonly used models in engineering practices are the Winkler’s model, elastic half space model and finite compressible layer model. Among these models, the finite compressible layer model is widely used in the designing of raft foundation. As the finite compressible layer model can not reflect the nature of the in situ soil and the nonlinear settlement, in this paper we try to modify the elastic modulus E by the secant modulus in order to improve the soil model of finite compressible layer.
Simulation Study on Influence of Various Parameters on Vibration Piling Process
Authors: Li Xiao Peng , Liu Ya Li , Guo Hao , Liu Jing Nian
Published: June 2012

The liquefaction of soil around the pile and the friction resistance between the pile-soil may be greatly affected by the various vibration conditions in the process of vibration piling. The efficiency of the pile may be affected by the above situation. And how to increase the piling speed is the key component studied in related field. The plane contact element is adapted in this paper to establish the system of pile-soil dynamics model. The piling process is simulated by changing the parameters such as, the amplitude and frequency of vibration force, and the stiffness and damping of soil. Then the influence on piling speed by every parameter can be studied. The way to raise piling speed can be achieved, and it provides theoretical guidance for practical application.
Floor Heave Controlling Technology of Deep Soft Rock Roadway
Authors: Li Zhan Jin , Li Shi Bo , Zhao Xue Li
Published: June 2012

The floor heave is one of soft rock roadway distortion. Based on soft rock supporting theory and engineering practice, the program bolt-mesh-anchors and floor corner, bolts coupling support to control floor heave of the soft rock roadway is proposed. Numerical simulation results show that bolt-anchors can mobilize the strength of the deep adjacent rock, at the same time, and properly arranged floor corner bolts with high bending rigidity can cut the slip-line field and achieve the goal of controlling floor heave effectively.
Field Test on Sub-Enlarged Pressure-Dispersive Ground Anchor
Authors: Liang Yue Ying , Liu Guo Nan , Li Zhong Guo , Yang Jie Ping
Published: June 2012

Based on stress distribution characteristics of pressure-dispersive ground anchor, a new construction equipment was developed for sub-expanding, thus the effective diameter of anchoring body was enlarged, the anchoring capacity was enhanced and the project cost was saved. With on site pull-out test of this type anchor, the study on anchoring mechanism and its application value showed that it could greatly improve the safety and reliability of the anchoring technology.
The Application of Pseudo Static Method in the Pile Soil Dynamic Interaction
Authors: Meng Qing Juan
Published: June 2012

Pseudo static method is a common method in the research of pile-soil interaction. In this paper pseudo static method was major introduced, the p-y relationship of saturated degraded soil was applied to Winkler foundation beam model to perform pseudo static calculations on the basis of previous studies. Through the practical calculation of test data in literature [1], the feasibility of this method was verified.
Laboratory Model Test on Foundation Reinforcement by Locating Lime-Soil Pileat both Side of Strip Footing
Authors: Zhou Ji , Liu Xi Yuan , Dou Yuan Ming
Published: June 2012

Using similarity theory as guidance ,the paper designs the laboratory model test on foundation reinforcement by locating lime-soil pile at both side of strip footing, and researches foundation bearing capacity, p-s curve, the magnitude and distribution discipline of the foundation stress before and after reinforcement, and analyzes the load-bearing mechanism, strengthening mechanism and reinforcement effect of the strengthening technology. The results show that the lime-soil pile can effectively improve the foundation bearing capacity, and reduce the amount of ground settlement; under the role of the lime-soil pile, the stress spread lesser to the outside of pile in the ground, and causes the foundation stress to the deeper place.
Buckling and Post-Buckling Behavior for Roof Strata in Longwall Mining
Authors: Song Qun , Yang Zhi Lin
Published: June 2012

In accordance with the occurrence behavior of roof strata and the fracture characteristics of key stratum in shallow seam longwall mining, this paper studied the post-buckling behaviors of key roof stratum in the process of mining by using initial post-buckling theory, which derived a critical load and a breaking span of the main roof during the first weighting, determined the final subsidence for broken key stratum, and presented an application with the example of Daliuta 1203 face. The results indicate that the rock blocks a in are state of non-equilibrium after main roof breaking, the equilibrium path of main roof is unstable from breaking to final subsidence; thick unconsolidated layers above roof have effect on post-buckling behaviors of key stratum; the stability for bifurcation point equilibrium configuration and post-buckling equilibrium path of roof strata could be revealed and an effective method for determining displacement field of imperfection structure could be provided by using initial post -buckling theory.
The Elasticity-Plasticity Analysis of Composite Foundation with Lime-Soil Pile by FEM
Authors: Cui Ying , Zhang Guang Wei
Published: June 2012

With a certain actual lime-soil pile composite foundation project for background, the Finite Element Method (FEM) model of composite foundation was carried out by using the Drucker-Prager theory and ANSYS FEM procedure. By imitating the status of composite foundation under the construction load and analyzing the factors such as stress, settlement, stress ratio between pile and soil, carrying capacity of composite foundation with lime-soil pile has been gained. The conclusions offer some beneficial references to design and construction of actual projects.
Experimental Study on Creep Property of Similar Material for Jin Tan Salt Rock Gas Storage Medium
Authors: Duan Kang , Zhang Qiang Yong , Cai Bing , Xu Xiao Bin
Published: June 2012

Uniaxial compression creep tests have been performed on a kind of rock salt similar material and laminated salt rock similar material on the base of salt rock gas-storage in Jintan. The creep tests show that the rheological property of the similar material is basically the same with the original rock. Under the uniaxial compression, the deformation gradually approaches to be constant after the early short stage of creep attenuation. The similar material shows stress-dependent behavior obviously under different stress stage, the greater the load the higher the creep ratio and creep deformation. A creep constitutive equation which is suitable to rock salt is used to the similar material, and it fits with the obtained creep data very well. The results show that the similar material developed in this passage has the same creep property as the original salt rock,and this material can be used to simulated the deformation and failure of underground gas storage constructed in bedded salt deposits.
Markov Model for Dynamic Analysis of Rock-Soil Structure
Authors: Wei Zhen Hai , Wang Meng Shu , Zhang Ding Li
Published: June 2012

Dynamic analysis of structure of rock-soil material is a difficulty in structure analysis of rock-soil material. Dynamic analysis referred here is equivalent to plasticity analysis in classical elasticity/plasticity theory. But, for the structure of rock-soil material, the granules form a structure in the form of network, which makes dynamic analysis especially complex. We attempt to simplify granular form in this study, and construct a Markov model of structural evolution of system according to finite connection modalities between granules. Connection modality distributions for each structural state are obtained using recursion technique. Next, depending on connection modality distribution, we obtain the mechanical and geometric parameters of the system, thus stiffness-strength-displacement relation can be established. This relation serves as the basis for building dynamic constitutive relationship for rock-soil material. Literature on relevant subjects has been rarely found so far, and our discussion is only a tentative exploration.
Study on Determination Method for Parameters of Rock’s Shear Strength through Least Absolute Linear Regression Based on Symmetric Triangular Fuzzy Numbers
Authors: Lin Bin , Chen Zhi Bo , Fang Qing
Published: June 2012

In view of the randomness and fuzziness of the parameters of rock’s shear strength, first, use symmetric triangular fuzzy numbers which can reflect the interval features of parameters express the parameters of rock’s shear strength. Second, put forward to a new determination method for parameters of rock’s shear strength through least absolute linear regression based on symmetric triangular fuzzy numbers according to criteria of least absolute. Finally, the analysis of practical engineering computation and comparison to other methods shows that the new method is reasonable.
Consolidation Coefficient Calculation Based on Consolidation Rate Attenuation Method
Authors: Li Zheng , Zhang Xiao Feng
Published: June 2012

This paper proposes a new partial-analytical consolidation coefficient calculation method as consolidation rate attenuation method based on the 1st-order series solution to one-dimensional Terzaghi theory. According to the consolidation rate attenuation curves, consolidation coefficient can be obtained by the linear attenuation part fitting. Least square principal is used to get fitting parameters of the extracted linear attenuation data by computer. This new developed method has rigorous formula which avoids mapping human factors, the effect of initial settlement and secondary consolidation. By the evaluation comparison of different methods, this new method is accurate, which also means the test process will be speeded up
Finite Element Analysis of Parameters Sensitivity Analysis of Landslide Stability
Authors: Li Peng Fei , Guo Tao , Liu Zhong Yang
Published: June 2012

On the basis of quantitative analysis, based on a real landslide of a specific profile of C, cohesion, internal friction angle and finite element mesh for landslide stability factor sensitivity. Through the analysis and calculation to determine the stability coefficient and the parameters related to changes in the relationship between, find out the effect on the stability of the most sensitive factors.
A Study of Chinese Gooseberry Soil Evaluation Based on GIS
Authors: Zhang Lei , Wang Yan Yun , Liu Wen Bao
Published: June 2012

In this article, with rich production of Chinese gooseberry in Zhouzhi County of Shaanxi Province as an example, conducted an application of GIS based soil fertilization management. First, soil nutrient data (9 kinds) is interpolated as raster with GIS methods; then nutrient level is graded, and composite nutrient level is graded. At last, composite evaluation model, output-fertilize model is constructed. This method is a successful application of GIS based data management and spatial analysis in the use of soil fertilization management, and make soil nutrient data management with raster and soil nutrient data composite analysis as reality. So it is a useful request and is meaningful in theory and application realm.
Application of Neural Network in Identifying Soil Strata by CPT or CPTU Data
Authors: Li Jun Hai
Published: June 2012

In geotechnical engineering, assessment of the depth location of stratigraphic interfaces and the depth and thickness of thin layers can be critical in the design process. For example, stratigraphic interfaces can promote anisotropic soil strength response and potentially provide preferential slip planes that create slope instability. Similarly, the presence of thin, high permeability layers can alter groundwater flow regimes and rates of consolidation, which can hinder or accelerate methods of ground improvement. The piezocone penetration test (PCPT or CPTU) is an extension of the cone penetration test (CPT) and is able to measure cone tip resistance, sleeve friction and generated pore-water pressures simultaneously. The piezocone’s functionality is through the measured excess pore pressure profile, which reflects changes in the drainage conditions, and therefore soil conditions. In this paper the relationship between CPTU parameters and soil types and strata is analyzed, and the structure of a general regression neural network (GRNN) is designed, and the application program is programmed with MATLAB language. The results, identifying soil strata by CPTU, have confirmed that GRNN can be used to carry out the automatically identifying soil strata.
The Application of Decision Tree Method to the Identification of Formation Types in Tight Gas Reservoirs
Authors: Han Hai Ying , Wang Zhi Zhang , Wang Li Chang
Published: June 2012

Numerous test data accumulates in the process of gas reservoir exploration and development, so it is necessary to apply the data mining technology to this process. Influenced by the geologic factors such as structure, deposition and diagenesis, tight sandstone gas reservoir formation types are so diversified that traditional cross-plot analysis technique hardly identify the formation types. In this paper, the formation types of tight sandstone gas reservoir in Daniudi area are successfully identified using the decision tree algorithm of data mining based on hierarchical decomposition theory, facilitating the development of the gas reservoir.
Optimization Design of Geotechnical Engineering Based on Reliability and Lingo
Authors: Zheng Yi , Jia Jin Qing , Xiong Wei Shi , Shen Xiao Jun , Gao Fei , Li Li
Published: June 2012

Algorithm of most optimization calculation is favor for the most technology personnel, for its result is ideal and it doesn’t need derivative of performance function. Combined with theory of nonlinear programming and optimization algorithm of reliability, calculating program is written by means of Lingo, which optimization calculation of geotechnical engineering based on reliability, and source program is grasped for the engineers. Combined example, calculating program is given, which are realized by means of Lingo, which is nonlinear programming software. By the studying, the aim is to improve calculating efficiency for most of engineers and to push forward application of structural reliability theory in geotechnical engineering.
Influence of early Low-Temperature Curing on Strength of Stabilized Super Chloride Saline Soil
Authors: Yu Hao , Deng Xiao Xuan , Peng Zhi Ping , Chen Yao Guang , Cheng Yin , Yang Jun , Huang Xin
Published: June 2012

Super chloride saline soil with 12.5% soluble salt is stabilized by self-made stabilizer S, and the influence of early low-temperature curing to the strength of the stabilized soil is studied through the laboratory tests and the field tests. The results indicate that the strength of the stabilized soil increase slowly when they are cured in low-temperature. The strength of the stabilized soil cured in 5°C at 28-days age is only 44.7% of the standard strength. However, if the curing temperature rises to the standard temperature after 28-days age, the strength can reach the 28-days age standard strength after 150-days age.
An Experimental Study of the Ductility of Concrete-Filled Square Steel Tubular
Authors: Cai Chuan Guo
Published: June 2012

Abstract: In view of the seismic design requirement for ductility, a group of the cyclic loading experiment is carried out on seven concrete-filled square steel tubular with different axial load ratio, slenderness ratio and concrete grade. After that, the load-displacement curves and the skeleton curves of these frame columns are attained, together with the load-displacement value of each step. Based on these data, an analysis on various factors that affect the ductility of concrete filled steel tubular columns is conducted. The results show that the decline of the bearing capacity in the end-column is mainly due to the germination and expansion of the plastic hinge of pillar. Furthermore, increasing the axial compression ratio will lead to the earlier emergence of plastic hinges, which correspondingly reduces the ductility and horizontal anti-shearing capacity of the frame column. In addition, increasing slenderness ratio can contribute to delay the emergence of plastic hinges, which improves the ductility and energy dissipation capacity of columns, but decreases the horizontal anti-shearing capacity. As a result, adopting the higher grade concrete can effectively reduce the negative effects from the large values of axial compression ratio and slenderness ratio. The experimental results perfectly support the data from the finite element calculations.
Preparation and Photoluminescence of Nano-Sized Green Phosphors by Solution Combustion Synthesis
Authors: Chen Z. , Zhang Li Qiang , Wang Miao Miao , Zhao Zhi Ying , Liu De Hui , Yan You Wei , Zhang Jun Hong
Published: June 2012

By adopting a facile solution combustion synthesis (SCS) method, pure well-crystallized (Ba,Sr)MgAl10O17:Mn green phosphors were successfully prepared. The crystallinity, particle size, morphology, and luminescent properties were characterized by XRD, FE-SEM and spectrofluorometer respectively. The results indicated that the obtained phosphors have spherical morphology, good crystallinity, and strong green emission. The emission spectra of obtained nanophosphor on 147nm excitation consist of a wide band with the peak at 518nm, which corresponds to the transition from the 3d5(4T1g) excited state to the 3d5(6A1g) ground state of Mn2+. The synthesized phosphors can be efficiently excited at VUV light and have potential application in Plasma Display Panels (PDPs), 3D displays and mercury-free fluorescent lamps
Magnesium Oxychloride Cement Modified by Aluminum-Leached Coal Fly Ash
Authors: Wu Cheng You , Zhang Hui Fang , Yu Hong Fa
Published: June 2012

Effects of aluminum-leached coal fly ash residue on water-resistance, compression strength and efflorescence of MOC cement have been investigated. The results show that the compression strength of MOC cement curried for 28 days increases with the dosage of ACFAR. The water resistance of MOC cement can be improved obviously. This study has proved that aluminum-leached coal fly ash residue can be used as the filling material of MOC cement with high compression strength and good water-resistance.
Effect of Trace Boron on Low Temperature Impact Toughness of Hot-Rolled Nb-Added HSLA H-Beams
Authors: Cui Guo Tao , Wang Zuo Cheng , Sun Tao , Guo Wei Min , Gao Jun Qing
Published: June 2012

In this research, trace boron (4ppm, 8ppm, 11ppm) was added into the Nb-added HSLA H-beams. The impact toughness of H-beams with/without boron was examined by Charpy impact test (V-notch). The morphologies of the microstructure and the fracture surfaces of the impact specimens were observed by metalloscope, stereomicroscope and electron probe. The experimental results prove that the absorbed impact energy at -40°C for the 4ppm, 8ppm, 11ppm boron-added steels respectively reaches up to 80J, 126J, 85J from 15J and H-beams with boron have a lower FATT than that without boron. It is also found that the total oxygen content affects the absorbed impact energy to a certain extent. It is discovered by transmission electron microscope (TEM) that boron mainly exists in solid solution state, except that a little amount of Fe23(C, B)6is formed at the grain boundaries, and the distribution of Nb(C, N) is also influenced by boron addition.
The Effects of Water-Reducer on Early-Age Plastic Shrinkage of Concrete
Authors: Qin Hong Gen , Fei Zhi Hua , Guo Wei , Tian Qian
Published: June 2012

Water-reducer is one of the dispensable components in modern concrete, can improve the workability and mechanical performance of concrete, and also has an important influence on the plastic cracking resistance of concrete. In this paper, the flat cracking test was used to evaluate the effect of water reducer on the plastic cracking resistance of concrete, meanwhile, capillary pressure; plastic settlement and evaporation rate were also tested. The results showed that water-reducer could improve the plastic cracking resistance of concrete significantly, and the effectiveness of polycarboxylate water reducer were o better than that of wood calcium and naphthalene water reducer.
Effect of Variability of Recycled Aggregate on Properties of Concrete
Authors: Wan Chao Jun , Chen Xu , Li Teng , Huang Tai Zhong , Deng Tian Ming
Published: June 2012

Low, medium and high variability of aggregates of concrete were designed and prepared and the influence of variability of recycled aggregates on the mechanical properties and durability of concretes was investigated. The experimental results indicated that the kinds of strengths, static compressive elastic modulus and durability of recycled concrete were decreased at engineering-acceptable level compared with natural aggregate concrete; the most properties of recycled concrete with high variability of recycled aggregates are not very different from that of recycled concrete with medium variability of recycled aggregates even that of natural aggregate concretes; however, the variability of properties of recycled concrete with high variability of recycled aggregates are much different from that of medium variability of recycled aggregates and more different from that of natural aggregate concretes, which means if only one or limited properties of recycled concrete were tested, the existing high variability of properties of concrete may not be revealed to a full enough extent, and the possible neglect of this high variability may result in potential engineering risk in application of high variability of recycled aggregate; the content of hardened cement paste and mortar attached to the recycled aggregate is found to be the essential factor to influence the properties of recycled concrete.
Effect of V and N on Microstructures and Properties of Cold Drawn High Carbon Steel
Authors: Zhou Peng , Liu Hong Yu , Liu Jianhua , Chen Xiaolong
Published: June 2012

In order to enhance the strength of cold drawn high carbon steel and improve its comprehensive properties ,the law of change in microstructures and properties of high carbon steel with various contents of V and N were investigated .The size of pearlite colony，interlamellar spacing of pearlite and mechanical properties with various contents of V and N were measured; the change of magnetic properties of wires with different cold drawing strains were measured by VSM. It is shown that V can decrease the size of pearlite colony and interlamellar spacing of pearlite when V content is less than 0.06 wt %; N can decrease the size of pearlite colony and increase slightly the interlamellar spacing of pearlite. The tensile strength is enhanced with increasing V or N content, but V decrease plasticity of wire and N has little effect on it. The cementite in wire is dissolved with increasing cold drawing strain. The volume fraction of cementite is decreased to 4.4%，dissolution of 7.8%，as the true strain is increased up to 3.19.
Application of a New Environmental Protection Building Material in Steel Structural System
Authors: Sun Cheng Fang , Liu Xiao Fan , Gu Qian
Published: June 2012

The cavity wall material is a kind of new saving energy and environmental protection building material having good physical and mechanic performance including lightweight, high strength, heat insulation and thermal insulation. Making full use of good physical and mechanic performance, as the infilling wall of steel frame structure, a new cavity composite masonry wall material is put forward, which can bear lateral load with steel frame together. Based on test of two specimens, the failure process and pattern is analyzed in detail in this paper, and the hysteretic behavior, energy dissipation and stiffness degeneration under the seismic force. Comparing with the steel frame, the cavity composite masonry infilling wall steel frame structure has higher strength, light weigh, higher stiffness, good anti-seismic behavior and ductility. The conclusion is reference for the seismic design of the infilling wall steel structure.
Experimental Analysis of Relationship between Pore-Structure and Frost-Resistance of Concrete
Authors: Zhang Ying , Cai Jiang Dong , Xu Shan Lin , Hu Zhi Jun
Published: June 2012

The influence of admixture on concrete pore structure was analyzed by using the mercury intrusion method and the rapid frozen-thaw method under the condition of the same water/binder ratio in this paper, and thus the relationship between pore structure and frost resistance of concrete were analyzed. When the compound mineral ad-mixture is mixed, the porosity rate of concrete can be decreased and the harmful hole is in-creased, the less-harm hole and the no-harmful hole are decreased. The early strength of concrete is not decreased. But the strength has the increasing trend in the late, which is more favorable for the impermeability and corrosion resistance. But the improvement of the freezing resistance is not obvious. The admixture of air entraining agent can increase the porosity and more-harmful hole, and the concrete strength will be decreased, which will be not favorable for the freezing resistance of concrete. If these two substances are admixed at the same time, the concrete porosity is increased, and the pore size distribution of concrete can be reasonable. The decrement of concrete strength is not obvious, but it is favorable for the freezing resistance of concrete.
Effect of Surface Applied Inhibitor on Corrosion Rate of Steel Bar in High Strength Concrete with Various Admixed Chlorides
Authors: Lan Wen Jian , Wu Baohong , Liu Zhi Yong
Published: June 2012

Effect of surface applied inhibitor on the durability of high strength reinforced concrete with various chloride content has been investigated in this paper. The C60 concrete specimens contaminated with 0.5%,1.0%,1.5% NaCl by mass of the cementitious materials were prepared and experienced in months exposure tests after painting with 400 g/m2 inhibitor. The electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) of the steel rebar in specimens was tested. The results indicate that after surface painting the inhibitor for 28d the bars in concrete specimens with 0.5% NaCl and bar with 25mm cover in specimen with 1% NaCl show the average corrosion rate lower than that of control one (No.0, no painted inhibitor). While the corrosion current of rebar (38mm cover) for No.2 specimen with 1% NaCl and bars for No.3 specimen with 1.5% NaCl are still higher than that of the control one (No.0). The results indicate that the surface painted inhibitor on C60 concrete are effective to inhibit the corrosion of bar concrete at low or middle chloride conditions and not enough to repair the bars in high chloride contaminated concrete. The lower organic nitrogen content in 40-50mm depth also indicates that the inhibitor is harder to penetrate into deeper parts of high strength concrete compared with low or middle grade concrete.
Design and Impermeability of High Durability Reinforced Concrete Segment
Authors: Wang Xin'gang , Chen Fang Bin , Ye Xu Na , Zhang Wei Qin
Published: June 2012

Reinforced concrete segment is the main body of structure in shield tunnel, and its durability has an important effect on shield tunnel. The durability of High Durability Reinforced Concrete Segment (abbr. HDRC Segment) was investigated by impermeability of single segment and chloride diffusion coefficient of core-drilling. HDRC Segment had high compact cover, concrete cover and high strength structural-layer. Permeable height of HDRC Segment was approximately 0.5 mm when Keeping 4 hours in the constant water pressure of 0.8 MPa, and chloride diffusion coefficient of HDRC Segment was only 4.9×10－13m2/s by NEL method. As for Water impermeability and chloride ion penetration resistance, HDRC Segment is far superior to those of conventional Reinforced Concrete Segment (abbr. conventional RC Segment). It is advantageous to increase durability of HDRC Segment and service life of tunnel engineering.
The Application of New Building Materials in the North Insulation Sheepfold of Sheep Breeding Fluff
Authors: Bi Quan Chao , Wang Chun Xin , Zhang Ming Xin
Published: June 2012

Sheepfold is the important place for the sheep growth and ropagation, its internal environment parameters on the growth of sheep is essential, therefore, to the sheep with a suitable growth and reproduction of the living environment, is our science and one of the key research. The northern cold region sheepfold of sheep breeding fluff construction insulation materials are analyzed and discussed, and the actual construction provides suggestions for sheepfold.
Mortar Mixed with Flax Stalk Fiber and its Economic Analysis
Authors: Zhang Guo Zhi , Zhang Man
Published: June 2012

The article mainly develops and analyzes the technical and economic indicators of mortar mixed with flax stalk fiber and the material used for producing mortar mixed with flax stalk fiber. The length-fineness ratio and the proportion of flax stalk fiber in mortar have been determined by experiments. Additionally, this article also analyzes various economic indicators of mortar mixed with flax stalk fiber. Proper mixture of flax stalk fiber with mortar can improve and enhance thermal insulation performance of buildings and the crack resistance capability of plaster layers. The result shows that this method can lower the weight of plastering by 42.46 per cent and reduce the cost of plastering by 33.36 per cent. This new material has shown its superior energy saving and environmental friendly features. Therefore, the material has a broad practical potential in constructions.
Effect of Glass Powder on Strength and Microstructure of Ultra High Performance Cement-Based Materials
Authors: Liu Shu Hua , Xie Guo Shuai , Li Li Hua , Liu Yu , Rao Mei Juan
Published: June 2012

The effect of glass powder on strength and microstructure of ultra high performance cement-based materials was investigated in this paper, which aimed to provide an additional option for glass recycling and potentially reduce the high costs of this kind of materials. Compressive strength of pastes and mortars with different glass powder content were tested and their microstructure properties were analyzed by scanning electron microscopy (SEM). Test result showed that the compressive strength rose initially with the increase of the amount of glass powder, and reached to the peak at 20% replacement ratio, then decreased a little. The glass powder in ultra high performance cement-based materials had exhibited pozzolanic reaction and filling effect, contributing substantially to strength increase. In addition, no ASR micro-cracking ring was found around the large glass powder particle due to the enough fineness of glass powder and the existing of silica fume.
Preparation of Foamed Concrete with High-Strength and Low-Shrinkage
Authors: Liu Xun , Jiang You Xin
Published: June 2012

Due to flaws of foamed concrete (e.g. low strength, high shrinkage and easily cracking), a new-type foamed concrete with high-strength and low-shrinkage was prepared using a combination of polypropylene fiber reinforcement and alunite expansive agent compensating shrinkage. Compared to conventional foamed concrete prepared under the same conditions, the modified foamed concrete with the optimal parameters has notable improvements: the 28 d shrinkage falls by 50 %, the compressive strength and flexural strength increase by 21.7 % and 37.5 %, respectively. A model is proposed to explain the mechanism of the co-action of PPF and AEA.
Progress in Magnesium-Based Hydrogen Storage Materials
Authors: Kan Hong Min , Zhang Ning , Wang Xiao Yang , Sun Hong
Published: June 2012

Hydrogen is considered a promising alternative energy carrier that can potentially facilitate the transition from fossil fuels to sources of clean energy because of its prominent advantages such as high energy density, great variety of potential sources, light weight and low environmental impact (water is the sole combustion product). Due to low price and abundance magnesium should be considered as a potential candidate for hydrogen storage. Recent progress in the application of Magnesium-based nanostructured and composite materials in hydrogen storage is presented in this review. The main focus is on the synthesis of composite material, the design of nanocomposite material, the improvement of the thermodynamical properties and kinetics of hydrogenation/dehydrogenation and the improvement of resistance towards oxygen contamination.
Effects of Ce on the Inclusions and Mechanical Properties of 2Cr13 Stainless Steel
Authors: Liu Xiao , Wang Long Mei
Published: June 2012

The effects of rare earth metals on the inclusions and the mechanical properties of 2Cr13 stainless steel were studied by metallographic examination, scanning electron microscope (SEM) and energy spectrum analysis. The results show that the morphologies and sizes of inclusions in 2Cr13 stainless steel are changed, and rare earth metals played a very good role of modifying inclusions. The fracture mode of 2Cr13 stainless steel is typical cleavage fracture, but quasi-cleavage and dimple fracture after adding Ce into the steel, and the spherical inclusions of rare earth oxysulfide in the dimple are the main factors for this transformation. The transverse impact toughness of 2Cr13 stainless steel is improved obviously by Ce. In comparison with 2Cr13 stainless steel without Ce, the transverse impact toughness of 2Cr13 stainless steel with Ce is increased 54.55% at -40°C, and the room temperature strength are improved, the elongation and reduction of area have been improved 11.90%, 16.67 respectively.
Numerical Analysis for Thermal Wave NDT of Debonding Defect of Coating on the Matrix of the Composite Materials
Authors: Zhang Wei , Li Qi Ke , Yang Zheng Wei
Published: June 2012

For the disadvantages of the traditional NDT methods for coating defects, Thermal Wave Nondestructive Testing (TWNDT) technology was used to detect coating debonding defect on composite Materials matrix. Numerical simulation method was used to simulate the heat transfer process of thermal wave in the coating material with defects. The factors influencing the testing sensitivity were in-depth studied, including the debonding defect size and coating thickness. Simulation results show that: TWNDT technology can quickly and efficiently identify the size of the coating debonding defects, while the thickness of the coating is an important factor influencing the inspection sensitivity for the thermal wave detection.
Dispersion, Microstructure and Mechanical Properties of Ground Calcium Carbonate Whisker-Reinforced Portland Cement
Authors: Cao Ming Li , Zhang Cong
Published: June 2012

Mechanical grinding method was employed in this study to disperse CaCO3 whiskers in cement matrix. Mechanical properties of the ground whisker reinforced cement were measured. It is shown that the mechanical grinding method was advantageous to the dispersion and mechanical properties of composites. But the grinding process must be proper to assure a certain length and integrality of the whiskers. Crack deflection and whisker pullout mechanisms could account for the strengthening and toughening effects caused by whiskers.
Acid Rain Erosion Resistance of Concretes Containing Super-Fine Mineral Admixtures
Authors: Li Hong Fang , Guo Li , Xia Yi
Published: June 2012

The sulphuric acid erosion resistance of high strength concretes containing limestone powder,titanium slag and silica ash were studied by accelerating cycle sulphuric acid soak tests. It indicates that the introduction of super-fine mineral powders into concrete can improve its sulphuric acid erosion resistance. With fixed 10% limestone powder, blending 10% titanium slag or 15% silica ash can remarkably enhance sulphuric acid erosion resistance of concrete. The concretes containing mineral admixtures such as limestone powder, titanium slag and silica ash can be used in acid rain abundant area.
Concrete Admixtures in the PHC Pile Production
Authors: Jiang Yuan Hai
Published: June 2012

Design concrete mix used in the PHC pile production, silica sand powder and slag powder as a concrete admixture, replace a certain percentage of Portland cement, under the premise of meeting the PHC pile production requirements. After the steam curing, determinate the demould strength of concrete and after autoclave curing, determinate the compressive strength of concrete. Test results show that it is feasible for the use of silica sand powder and slag powder instead of Portland cement, in which the proportion of concrete admixtures up to 45%. Silica sand powder and the amount of slag powder were mixed with 150 kg/m3, 50 kg/m3, the concrete demould strength up to 49.1 MPa and the compressive strength after autoclave curing up to 89.0MPa, to achieve requirements of the national standard GB13476.
Influence of Stone Dust in Manufactured Sand on Resisting Chloride Penetration in Marine Concretes
Authors: Xiong Jian Bo , Li Peng Ping , Wang Sheng Nian
Published: June 2012

In China, manufactured sand has been widely used as fine aggregate in concrete. Therefore, it is necessary to investigate the effect of manufactured sand on durability of concrete. This research studies the influence of stone dust content in manufactured sand on resisting chloride penetration in marine concrete by strength and other physical mechanical tests, XRD, TGA and pore structure analysis. Test results have shown that the chloride diffusion coefficient increased with increasing the stone dust content in manufactured sand when the stone dust content increasing from 3% to 13%. The stone dust in fine aggregate was participated in hydration procedure of cementitious, which will promote the hydration degree of cementitious and increase the chloride binding capacity of hydration product. The influence of stone dust in fine aggregate on chloride diffusion coefficient were the combined effects of concrete pore structure and cementitious hydration products, and the porosity and pore size distribution were the main factors that influence the changes of diffusion coefficient.
Mechanical Properties of Steel Wire-Continuous Basalt Fiber Composite Plate (SBFCP) Under Monotonic Tensile Loading
Authors: Zeng Yi Hua , Wu Gang , Wu Zhi Shen , Feng Wu Qiang
Published: June 2012

Steel wire-continuous basalt fiber composite plate (SBFCP) is a new type of plate whose main constituents are steel wire and basalt fiber reinforced polymer (BFRP). To investigate the mechanical properties of SBFCP, both theoretical and experimental studies were conducted. A tri-linear model was proposed to predict the stress-strain relationship of SBFCP. Considering two parameters, the volume ratio of steel wires in SBFCP and the type of composite pattern, a monotonic tensile experiment was carried out. Test results show that SBFCP has excellent properties, including high modulus, high strength, and good ductility. Results also demonstrate that the volume ratio of steel wires affects the modulus of SBFCP significantly whereas the type of composite pattern shows little effect on properties of SBFCP.