bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Response of High Steep Rock Slopes Based on Wenchuan Near-Field Seismic Motion Characteristics
Authors: Xiao Shi Guo , Feng Wen Kai
Published: December 2010

Near-field seismic motion characteristics are analyzed in accordance with records of the 2008 Ms8.0 Wenchuan Earthquake measured at Wolong Station, upon which the determination of seismic load is introduced. Dynamic response features, such as acceleration, displacement and stress, of high steep rock slopes on the banks of Zipingpu Reservoir at a variety of locations resulting from horizontal seismic force are analyzed with a numerical analysis routine. The dynamic amplification factor on the slope top is determined, leading to a characterization of the mode of failure of the high steep slope. Analyses show that the dynamic amplification factor at the top of the slopes is about 1.34; however, dynamic response deformation features and stress state at different positions on the slope vary. Earthquake damage of the high steep rock slopes consists mainly of partial avalanche of the rock mass at the top of the slopes by joint cutting. Field investigations after the earthquake have partially confirmed the numerical analysis results presented in this paper.
Multiphase Constitutive Model of " Matrix-Strengthen Particle of Saturated Soil "
Authors: Ma Wen Xu , Fang Ying Guang , Li Zhe
Published: December 2010

In this article soil is treated as non-uniform material including two parts : the matrix particles and the reinforcement particles. Through soil shear strain energy and micro-crack assumptions, we establish a multiphase constitutive model connecting macro and micro scale based on classical continuum models, which includes the strain gradient, internal length scales and particle size. This model have been verified reasonable by artificial soil experiment.
Influence of Hot Leveling and Cooling Process on Residual Stresses of Steel Plates
Authors: Chen Ji Ping , Qian Jian Qing , Li Sheng Zhi
Published: December 2010

A three-dimensional thermo-mechanical coupled model of hot leveling and cooling processes of the steel plate has been conducted with MSC.Superform software. Four kinds of initial temperature distribution patterns have been determined according to literature. The effects of hot leveling and cooling processes on the transversal and longitudinal residual stresses of the steel plate have been analyzed. The results show that the initial temperature distribution patterns have significant influence on the residual stress of the plate. The more uniform temperature distribution patterns along the width of the plate, the smaller residual stress and also the smaller stress fluctuations. The cooling process has greater effect on the residual stress compared with the hot leveling process. The bigger the temperature gradient along the width of steel plate, the larger the residual stress and its fluctuation is. Through the FEM study, the value and direction of transversal and longitudinal residual stresses can be confirmed quantitatively at various positions along the width and length of plate, which can provide guidance to actual measurement of residual stress.
Field Test on Composite Foundation Incorporating Flexible and Rigid Piles
Authors: Zhang Zhong Miao , Zhang Qian Qing
Published: December 2010

This paper presents three static load tests of composite foundation incorporating flexible piles, rigid piles and different cushion materials to clarify the load-displacement behavior of composite foundation. The results of static load tests indicate that the cushion made of stone and sand is not suitable because of a large pile penetration. As far as the influence of cushion material is concerned, the cushion made of sand, gravel and rubble with the maximum particle size of less than 20 mm and grouted with cement slurry can be used to fully mobilize the bearing capacity of each part of composite foundation, and modify the load transfer mechanism of the piles. Moreover, this type of cushion can reduce the overall settlement and ensure the uniform settlement of building.
Quantitative Structure-Activity Relationship between Compound Molecular Characteristics and Nanofiltration Separation Efficiency
Authors: Yang Qing , Qiu Xin
Published: December 2010

The aim of this study is to establish a certain Quantitative Structure-Activity Relationship (QSAR) between compound molecular characteristics and nanofiltration (NF) separation efficiency. Measurements were carried out in a crossflow NF unit and using ten organic compounds (ethanol, butyl alcohol, glycerin, phenol, glucose, sorbitolum, dodecanoic acid, Imidacloprid, sucrose and Dimethomorph) in aqueous solution and two commercial NF membranes (DK and NF90). Four kind compound characteristics of Molecular weight (Mw), Octanol-Water Partition Coefficient (logP), Molar Refraction (CMR), Henry’s law (H) are selected. Through regression, F test and t test, QSAR analysis was accomplished to prove the validity of regression equation with confidence probability of equation coefficient above 85%. It could be concluded that Mw contributed most to rejection of DK and NF90 according to QSAR at constant flux (500mg/L) and feed concentration (500mg/L). The contribution of CMR is less than MW for NF90 rejection, following by logP, H.
Application of Large-Stone Asphalt Mixes in the Base Course Maintenance of Expressway
Authors: Hu Hui Min , Tong Yong Yao , Zhang Wang Li
Published: December 2010

Large stone porous asphalt mixes have well drainage ability, as well as higher modulus and durability when used as base course. Large stone porous asphalt mixes have good effect on repairing the semi-rigid base course which have longitudinal cracks. It not only can delay the reflection of cracks, but also plays the role of excluding water in structural layer owing to relatively large porosity. Deflection value of upper base's top surface decreases and deflection difference between left and right wheel track reduces after paving large-stone asphalt mixes upper base. When there are longitudinal cracks in lower base course, top surface tensile stress of upper base(large-stone asphalt mixes flexible upper base course)has significantly reduced compared with semi-rigid base course upper base. And maximum shear stress declined slightly. It can play a very well crack resistance effect when using large-stone asphalt mixes to repair broken cement stability upper base.
Internal Forces of Double-Row Pile Slope Stabilization Systems Influenced by of Pile Row Separation
Authors: Xiao Shi Guo , Yang Jing
Published: December 2010

A double-row anti-slide pile system can effectively control large landslide thrusts within a large-scale talus landslide. In such a system, the separation of the up-slope and down-slope rows of piles is a key factor that impacts the distribution of their internal forces. Common large-scale talus landslides, which are characterized by a curved slip surface that is gentle in the front and steep in the rear, are discussed in this paper. The mechanical characteristics of double piles positioned at a net separation between rows of 23.8a (where a is the length of the long side of rectangular cross section of a pile), 16.3a, 10.7a, 6a and 2a have been investigated by finite element analyses. Based on this investigation, internal forces of the pile body are found to not change with row separation monotonously. Rather, they are closely related to the pile positions (i.e. within the anti-slide or slide section of the slip surface). When the rear piles are fixed at the anti-slide section of the landslide mass, the landslide thrust on the up-slope side of the rear piles and the slope resistance on the down-slope side increase gradually as the row separation becomes larger. As a result, the comprehensive mechanical effect of double piles tends to worsen. We advise that the optimal net separation between rows of piles is 2a to 4a.
Experiment Study of Optimal Combination of Strength for Mortar and Block of Autoclaved Sand-Lime Brick Masonry
Authors: Zhang Zhong Ji
Published: December 2010

In order to write Hunan province engineering construction local standard named" Technical specification for autoclaved sand-lime brick masonry building ",the author has finished a series of fundamental mechanical properties experiments on autoclaved sand-lime brick masonry such as material character experiment, shear strength experiment , bending tensile strength experiment. By analysis on experimental data, the author found a startling regularity: there is a feature of optimal combination of strength for mortar and block of autoclaved sand-lime brick masonry.
The Effect of Polypropylene Fiber on the Mechanical Properties of Self-Compacting Concrete
Authors: Zhu Ye Ran , Cai Jun , Wang Dong , Huang Guo Hong
Published: December 2010

This paper investigates the mechanical properties (compressive strength, splitting tensile strength and flexural toughness) of polypropylene fiber reinforced self-compacting concrete (PFRSCC). The effect of the incorporation of polypropylene fiber on the mechanical properties of PFRSCC is determined. Four point bending tests on beam specimens were performed to evaluate the flexural properties of PFRSCC. Test results indicate that flexural toughness and ductility are remarkably improved by the addition of polypropylene fiber.
Experimental Study on the Compressive Behavior of Concrete Encased in CFRP Tubes
Authors: Sun Wen Bin
Published: December 2010

Fiber reinforced polymer (FRP) tube-encased concrete columns represent a formwork-free, steel-free, and corrosion-resistant alternative for a construction of a new infrastructure. In this study, a total of nine square concrete columns with cross-section of 200mm×200mm and height of 600mm including six confined concrete encased in CFRP tubes and three unconfined concrete as control specimens are prepared. The tubes with fibers oriented at 90° from axial direction are manufactured to have 3 or 5 plies of CFRP with 10mm, 20mm, or 40mm rounding corner radius. To ensure proper bond, a 100mm overlap is provided in the direction of fibers. Uniaxial compressive tests are conducted to investigate the axial strength, compressive behavior, stress-strain relationship, and ductility of them throughout the loading history until the CFRP tubes rupture. It is evident that in all cases, the CFRP tube confinement can improve the behavior of unconfined concrete, in terms of axial compressive strength or axial deformability. Test results have shown that the stress-strain behavior of confined specimens vary with different confinement parameters, such as the level of confinement (3-ply and 5-ply), corner radius at vertical edges (10, 20 and 40 mm).
Estimation of the Passive Earth Pressure with Inclined Cohesive Backfills: The Effect of Intermediate Principal Stress is Considered
Authors: Yu We Long , Zhang Jian , Sun Xiu Hua , Hu Rui Lin , Wei Xin
Published: December 2010

Estimating passive earth pressure accurately is very important when designing retaining wall. Based on the unified strength theory and plane strain assumption, an analytical solution has been developed to determine the passive lateral earth pressure distribution on a retaining structure when the backfill is cohesive and inclined considering the effect of the intermediate principal stress. The solution derived encompasses both Bell’s equation (for cohesive or cohesionless backfill with a horizontal ground surface) and Rankine’s solution (for cohesionless backfill with an inclined ground surface).
Damage Evolution Analysis of Calcareous Mudstone with Different Water Content under Uniaxial Compression
Authors: Ji Ming , Zhang Nong , Gao Feng
Published: December 2010

Uniaxial compression and acoustic emission experiments of calcareous mudstone with different water content were carried out by using microcomputer controlled electro-hydraulic servo compression testing machine control system of YAW series equipped by coal-rock acoustic and electric data acquisition system of CTA-1-type. Mchanical properties and acoustic emission law of calcareous mudstone were studied. It is concluded from experiment result that rock’s elastic modulus and compressive strength both decrease with increase water content but peak stress shows the opposite trend. It is also found that calcareous mudstone is brittleness with low water content but when water content reaches saturation, calcareous mudstone presents plastic features. Acoustic emission curve fits well with stress-strain curve: acoustic emission activity begins intensifying when stress reaches 70% of peak stress, correspondingly, acoustic emission is up to maximum at peak stress. Based on Weibull hypothesis and acoustic emission experiment, damage law of water bearing calcareous mudstone is researched and damage evolution equation with time variable is advanced.
Dynamic Mechanical Behavior of Reinforced Concrete
Authors: Liu Hai Feng , Yang Wei Wu , Ning Jian Guo
Published: December 2010

The dynamic compression experiments of reinforced concrete are carried out by one-stage light gas gun apparatus which subjects the reinforced concrete to deformation at strain rates of the order of 104/s with confining pressures of 1~1.5GPa. The stress-strain curves of reinforced concrete with different impact velocities are obtained using Lagrangian analysis method. Experimental results indicate that reinforced concrete is non-linear, rate-sensitive and pressure-dependent.
Experimental Study on the Chloride Diffusivity of Recycled Aggregate Concrete
Authors: Qin He Ying , Zhao Yan Lin , Luo Bo Guang , Chen Yi Hu
Published: December 2010

The study presented herein has been carried out in order to investigate the chloride diffusivity of recycled aggregate concrete (RAC). Meanwhile, the effect of the binder type, involving cement replacement materials such as, fly ash, slag and silica fume on the chloride diffusivity has also been investigated. For this purpose, RAC and concrete containing the different type of binders with w/b ratios of 0.35, 0.40, 0.45, 0.50, 0.55, and 0.60 were used. As a result, the chloride diffusion coefficient of RAC is higher than that of natural concrete and the partial replacement of cement with fly ash, slag and silica fume is effective in decrease in the chloride diffusion coefficient, measured by a rapid chloride conductivity test.
Study on Prestressed Laminated Strand Lumber and its Load-Carrying Capacity
Authors: Ma Jia , Yang Qing Shan
Published: December 2010

Owing to some problems in the existent plywood products such as weak shear capacity and weak wear intensity, as while as the large consumption of crude wood resources, prestressed laminated strand lumber (PLSL) is proposed in this paper, in which the multiple integration method and prestressed technology are adopted to obtain a higher strength. More significantly, used wood can be reused as the raw material of PLSL, then the crude wood will be conserved and the cost will be lowered. To study its mechanical properties, the commercial software ANSYS is adopted to establish the finite element models of PLSL. The diameter and spacing of prestressed steel wire, the magnitude of the prestress and the width of the lumber are some factors considered. Based on the nonlinear finite element buckling analysis of these lumbers, some major conclusions are summarized as follows: (1) The improvement of strength is comparatively obvious to use PLSL compared with the traditional plywood products; (2) The ultimate bearing load is rising along with the increase of the diameter of the prestressed steel wire and the width of the lumber; (3) The ultimate bearing load is descending with the increase of the spacing of the prestressed steel wire; (4) The ultimate bearing load is rising along with the increase of the magnitude of the prestress at first, but when the prestress reaches a certain level, the ultimate bearing load starts to descend.
Research Status and Prospects on the Ultra High Performance Concrete
Authors: Sun Jie
Published: December 2010

The ultra high performance concrete is a new cement-based composite material with ultra-high mechanical properties, excellent durability and excellent volume stability. In this paper, research and application of the ultra high performance concrete at home and abroad at present was introduced, existing problems of the ultra high performance concrete applied to much practical engineering were pointed out. Finally, the prospects of ultra high performance concrete were analyzed and the ultra high performance concrete is inevitable result of the sustainable development of modern concrete technology.
Dynamic Response Analysis of Deepwater Pier with Fluid-Solid Interaction
Authors: Lei Fan , Yang Ji Xin , Liu Hui
Published: December 2010

The dynamic response of underwater structures is different from those in air because of interaction between fluid and solid. The influence of water depth on dynamic effect of the pier is studied base on a cable-stayed bridge in deep water. The girder of the cable-stayed bridge is simplified as a lumped mass on the top of the pier. The three-dimensional finite element models of pier with different water levels are built to calculate the dynamic characteristics and dynamic response of the pier under the action of harmonic load. The calculated results show that with the rise of water level, the nature frequencies of the pier decrease while the displacement and stress increase.
Experimental Study of FRP Rubber Bearing
Authors: Zhang Hua , Peng Tian Bo , Li Jian Zhong , Li Wen Xiao
Published: December 2010

FRP (fiber reinforce polymer) rubber bearing is a novel isolator improved from traditional laminated rubber bearing. Several specimens were manufactured to study the mechanic properties of FRP rubber bearing. Vertical experiments are conducted to study the compression capacity and compression modulus of the bearing and horizontal experiments are conducted to study the shear modulus and damping property of the bearing. Hysteretic curve and damping ratio of each specimen are derived from the experiments. The results show that the performance of FRP rubber bearing matches that of multiplayer rubber bearing but have good damping capacity.
Improving Packing Density of Powder in Cement Paste for Production of High-Performance Concrete
Authors: Kwan Albert K.H. , Chen J. J. , Fung Wilson W. S. , Li Leo G.
Published: December 2010

The packing density of the powder in cement paste has great influence on the performance of the concrete. A higher packing density could at the same water/powder ratio increase the amount of excess water for lubricating the cement paste and thereby improve the flowability of the concrete. Alternatively, it would allow the water/powder ratio to be reduced to improve the strength of the concrete without compromising the flowability. Therefore, it is of great interest, especially for production of high-performance concrete, to maximize the packing density of the powder. This study aims to investigate the roles of superplasticizer and fillers in the packing density of the powder in cement paste. Packing density tests were carried out to determine the packing density of cement with various dosages of superplasticizer and different fillers (limestone fine, superfine cement and condensed silica fume) added using a newly developed wet packing method. The results showed that the addition of superplasticizer can significantly improve the packing density of cement while the addition of fillers can further improve the packing density of the powder.
Investigation and Countermeasures of Ship-Bridge Collision Accidents in China in Recent Years
Authors: Yan Bin , Dai Gong Lian
Published: December 2010

China is undergoing rapid economic growth and urbanization. On the one hand, in the critical period of the rapid development, the rapid expansion of high-speed railway lines makes more and more various bridges go across the river channel. On the other hand, in our country the traffic density of each river channel is ever increasing, and ships are in large-scale and rapid development stage. The conflict of shipping transport with old bridges or new bridges becomes very prominent. The causes leading to the conflict are due to the factors, such as the geological change in hydrology, bridge design defects, the deficiency of anti-collision measures, shipping mismanagement, bad weather conditions, shipping equipment failure, ship-owner’s misjudgments, and so on. By investigating the ship-bridge collision accidents occurring in the bridge construction and operation in China since 2007, this paper analyzes the natural and human factors, studying large or small influence of various factors and their solutions through typical cases. It may be helpful for the bridge design and management across the river channel in the future.
Analysis of Microstructure of Steel-Slag Ceramic Tiles
Authors: Zhao Li Hua , Liu Pu , Ai Xian Bin , Lu Xin , Bai Hao , Cang Da Qiang , Tang Qi , Zheng Shu Long
Published: December 2010

The utilization of steel slag as resource is very important in the circle economy of metallurgy industry. Because the composition of steel slag is similar to that of the raw materials of ceramic industry, the sintering process of ceramics with steel slag as one of the raw materials was studied, and the ceramic products of high performance were abstained. Based on the study above, the microstructure of slag ceramic and its effect on the performance of ceramic were studied combining the analysis methods of SEM, DTA and XRD and the software FactSage. It’s found that the diopside phase was formed in the sintering process, which has significant effects on low temperature sintering and ceramic strength improving. Simulation by software FactSage showed that the diopside phase appears when the content of the steel-slag reaches 25%, while the content of slag is higher there are more diopside phase generation.
Effect of Blast Furnace Slag and Steel Slag on Cement Strength, Pore Structure and Autoclave Expansion
Authors: Song Qiang , Shen Bao Jing , Zhou Zhi Jun
Published: December 2010

Under different content of blast furnace slag and steel slag powder, cements were mixed to investigate the effect of dosage of these two mineral admixtures on strength, autoclave expansion and the relationship between strength and volume fraction of pore. The results indicated that the ratio of clinker content to ground granulated blast furnace slag(GGBS) content is the crucial factor for compressive strength of mortars incorporated GGBS and steel slag at 28d. With different dosage of steel slag, the compressive strength of 1:1 mixes of clinker and GGBS has the maximum strength. With the steel slag mixed in cement, the porosity of cement pastes was increased. With the blast furnace slag mixed in cement, the porosity and pore size of cement pastes was decreased. Compressive strength of mortars was closely related to the content of pore in the sizes greater than 50 nm at 28d. Incorporating GGBS can significantly decrease the autoclave expansion of cement deduced by blending steel slag.
Experimental Study of Reinforced Concrete Eccentric Compression Columns with HRBF400 Steel Bars
Authors: Ge Wen Jie , Zhang Ji Wen , Dai Hang , Tu Yong Ming
Published: December 2010

Nine concrete columns reinforced with fine grain high steel bars under eccentric loading were tested to study the effects of experimental parameters, such as eccentricity distance, reinforcement ratio and concrete strength, on the failure pattern, the strain distribution and the lateral deformation. The experimental results indicate that the columns reinforced by fine grain high steel bars work harmonically with concrete, and the strength of fine grain steel bars could be utilized fully. Finally, the design value of 400MPa fine grain steel bar is 360MPa in column was proposed based on the experiment and the comprehensive theoretical analysis.
Laboratory Evaluation on Performance of Crumb Rubber SMA
Authors: Dong Yu Ming , Tan Yi Qiu
Published: December 2010

Crumb rubber modified (CRM) asphalt with crumb rubber of scrap tire has higher viscosity, better flexibility, outstanding anti-fatiguing and anti-aging properties. This paper mainly investigated material design and performance evaluation of CRM asphalt SMA mixture. Brookfield Viscosity test is used to ascertain the adoption of fiber in CR-SMA. Because of resilient volume swelling of asphalt rubber mortar, gap-coarse grade must be adopted in asphalt rubber concrete to provide enough free space. This paper amends material composition and grade proportions range of adapted CR-SMA depending on the special characteristic of CRM asphalt. After confirming best grade of CR-SMA, this paper adopted Marshall Method to design Job Mix Formula (JMF) of surface layer CR-SMA13 in Beijing airport south line expressway. The best CRM asphalt content and feasible gradation middle value were obtained by Marshall Test and volume parameter calculation. During performance evaluation phase, other two SMA usually used in Beijing region is added, including SBS modified asphalt SMA, Trinidad Lake asphalt (TLA) and SBS modified asphalt SMA. By evaluations of high temperature performance, low temperature performance, moisture sensitivity and so on. The results indicate that pavement performance of CR-SMA is excellent, and have no distinct difference compared with the other two SMA.
Analysis on Nonlinear Flowing Consolidation of Clay
Authors: Sun Qiang , Xue Xiao Hui , Zhu Shu Yun , Xue Lei
Published: December 2010

It exist non-linear flow in soft clay, which is caused by the shear flow situation of bounded-water. In this case, permeability coefficient is a nonlinear function of hydraulic gradient. With the discharge of pore water, the effective stress is increasing, and part of weakly bound-water begins flow, while the porosity and permeability are became lower. By taking into the characteristics of the pore water, it is established a model, which is explained the nonlinear flow of clay, and shown that, with the increasing of and , the consolidation time is obviously increased
Experimental Study on Mechanical Behavior of Laminated Glass’s PVB Film
Authors: Tao Zhi Xiong , Zhang Qi Lin , Chen Jun , Xie Bu Ying
Published: December 2010

The interface bond between steel fibers and concrete matrix is the key of carrying capacity of steel fiber reinforced concrete(SFRC). In marine tidal fluctuation zone and splashed area, steel fibers will be rusty, and the bending toughness of SFRC was weakened. In this study, we tried to improve corrosion resistance of steel fiber and the interface bond strength by depositing zinc phosphate coating on steel fiber. These zinc phosphate steel fiber reinforced concrete(ZSFRC) have higher anti-corrosion ability. After corrosion they still have higher bending toughness than common SFRC.
Research on Fracture-CMOD Toughness of Steel Fiber Reinforced Concrete
Authors: Wang Xiao Wei , Tian Wen Ling , Fan Ling Ling , Zhou Ming Jie , Zhao Xiao Yan
Published: December 2010

In order to study the fracture toughness of steel fiber reinforced concrete (SFRC) and the postcracking toughness evaluation method, the fracture toughness tests were done for the four types of steel fibers and three kinds of matrix strength. According to the experiment curves of the load and the crack mouth opening displacement (Load-CMOD), the fracture toughness of SFRC was studied; the formulas of the postcracking toughness coefficient and the Fracture-CMOD toughness index were established. The experiment results show that the Fracture-CMOD toughness index can reflect sensitively to the effect on concrete toughness of the type of the steel fiber, and then it is avoid that the estimation error of the initial cracking point led to the evaluation error of the toughness.Comparison with other fibers B fiber shows the best crack resistance and the toughening ability.
The Compressive and Flexural Deformation of Rubberized Concrete
Authors: Zheng Wan Hu , Li Li Juan , Liu Feng
Published: December 2010

The deformation of rubberized concrete under uniaxial compression and three-point flexure is studied in this paper by test, and the load-deflection curves and load-strain curves under three-point flexure are obtained. Three rubberized concrete, with 5%, 10% and 15% rubber contents, were tested. The test results show that rubber powder influences the compressive strength and flexural strength of concrete. The greater of the rubber dosage, the greater of the strength decreasing of concrete. The decline of compressive strength is greater than flexural strength, the ratio of flexural strength to compressive strength of rubberized concrete is 1.08, 1.16, 1.26 times of the normal concrete for three different rubber contents respectively. And the ultimate tensile strain of rubberized concrete is 1.62, 2.25, 2.80 times of the normal concrete respectively. The addition of rubber improved the toughness and deformation ability of the normal concrete.
The Spline Finite Element Method for the Analysis of the Dynamic Response of Composite Material Plate
Authors: You Feng Xiang
Published: December 2010

Based on Kirchhoff’s classical theory and adoptation the spline finite element method, three independent displacements are interpolated into the anti-symmetric angle-ply laminated plate by the spline base of the cubic spline B function, and the stiffness array and the quality array of the composite material laminated plate are derived. By using Rayleigh-Reeds method, the damping array is established; kinetic equation is derived from Lagrange equation; the response equation is expressed; the inherent frequency of the anti-symmetric angle-ply plate is found by calculation subject to the different proportions of the length to the width, the different number of the layers of the plate and different angles; and the dynamic response problems about the anti-symmetric angle-ply laminated plate are analyzed and solved. Dynamic response problems, such as the displacement, velocity and acceleration, are solved with spline collocation method, through choosing the sample strip functions as mode shape function for various boundary conditions in several numerical examples and the results are compared with Newmark’s method. And better result can be yielded. The example calculations prove the validity of the calculating ways introduced by this paper.
Action Mechanism of Sulfate Compatible Polycarboxylate Type Admixture
Authors: Jiang Ya Qing , Zhang Ji Yin , Gong Ming Zi
Published: December 2010

Interaction between cement and a kind of sulfate compatible polycarboxylate type admixture (PCA) and action mechanism of the novel water reducer were investigated. Experimental results indicate that adsorption amount of PCA on surfaces of cement particles is lower than that of polynaphthalene sulfonate condensate water reducer (PNS) because of the formation of more ettringite and calcium monosulfoaluminate, and calcium monocarboaluminate when CaCO3 presents in hydration system, even at initial period of hydration. Results from XRD analysis, derivative thermogravimetric (DTG) analysis and chemical analysis all verify the benificial effect of sulfate compatible PCA on initial and early age hydration of C3A. An establishment of electrostatic repulsion by grafting SO3- in molecule structure of PCA may result in a more negative zeta potential in the dispersion system. The improved dispersibility and fluidity retention are the result of a combination action mechanism of electrostatic repulsion cooperating with steric hindrance, and the acceleration effect of sulfate compatible PCA on initial and early age formation of ettringite and AFm phase. A combined high range water reducer mainly consisting of sulfate compatible PCA and PNS was made up based on the experimental and theoretical investigation results.
Impermeability of Sulphoaluminate Cement Mortar Modified by Redispersible Polymer Powders
Authors: Ye Zheng Mao , Chen Wen , Cheng Xin
Published: December 2010

The impermeability and other performance of sulphoaluminate cement were studied, which mixed with redispersible polymer powders. With the help of SEM and mercury intrusion apparatus, the morphology of the hydrates and the pore structure of the cement mortars were observed. The impermeability mechanism of redispersible polymer powders in sulphoaluminate cement mortar was analyzed. The results show that sulphoaluminate cement mortar could be modified by adding redispersible polymer powders. The flexural strength of sulphoaluminate cement mortar could be increased by adding redispersible polymer powders, and compressive strength of sulphoaluminate cement mortar could also be increased to a certain extent. When the mass fraction of redispersible polymer powders was 0.9%, the flexural strength and compressive strength reached 9.2 MPa and 52.5 MPa. When small amount of redispersible polymer powders was added, the impermeability of modified sulphoaluminate cement mortar was improved significantly. When the mass fraction of redispersible polymer powders exceeded 0.9%, impermeability of Sulphoaluminate cement mortar would not be improved significantly. Due to redispersible powders gap filling and film forming, the interface of cement and aggregate is more closed, total porosity decreased and unharmful porosity increased when redispersible polymer powders is added.
Mechanical Property of Pavement Concrete with Nano-Particles
Authors: Zhang Mao Hua , Wang Hong Guang , Zhang Jian Min
Published: December 2010

Mechanical properties of pavement concrete with nano-particles are experimentally studied and compared with that of plain pavement concrete. The test results indicate that the flexural, compressive and splitting tensile strengths of pavement concrete with nano-particles are all improved with different extent. Firstly, the mechanical properties of pavement concrete are enhanced with the increasing content of nano-particles, and the peak values are achieved at certain content. Subsequently, the mechanical properties of pavement concrete are reduced with the increasing content of nano-particles. The optimum amount of nano-TiO2 and nano-SiO2 added into pavement concrete are respectively 1.0% and 2.0%. There is a significant linear relationship between flexural and compressive strengths of pavement concrete with nano-particles.
Mechanical Properties and Microstructures of Cement Mortar Modified with Styrene-Butadiene Polymer Emulsion
Authors: Wang Zhen Jun , Wang Rui , Cheng Yu Bin
Published: December 2010

In this paper, styrene-butadiene polymer emulsion SD622S was adopted to modify cement mortar; mechanical properties of cement mortars were studied and microstructures was analyzed by means of Scanning Electron Microscope (SEM) and Specific Surface Area & Pore Distribution Analyzer. The results show that in contrast to ordinary cement mortar, if water to cement ratio (W/C) is constant, compressive strength of modified cement mortar can decrease, while flexural strength and toughness, ratio of compressive strength to flexural strength, increase with the increase of polymer to cement ratio in mass (P/C) at 7 and 28 curing days. With the increase of P/C, net structure made from polymer and cement hydration products is developed and pore whose size is smaller than 200Å begins to increase, which indicates pore diameters in modified cement mortar change to be finer. So microstructures of modified cement mortar become denser and display higher toughness.
Influence of Metakaolin on Mechanical Properties of High-Performance Concrete
Authors: Wang Bao Min , Liu Wei
Published: December 2010

Kaolin is a material with broad sources and a low price. Metakaolin is made from kaolin which is calcined, finely ground at an optimum temperature of 750 being kept constant for 4 hours. High strength and performance concrete can be mixed from metakaolin as a substitute for equal mass cement. The influences of 5%, 10% and 15% metakaolin in substitution of equal cement masses were studied on the mechanical properties of high-performance concrete. The test results showed that the addition of metakaolin improved the cubic compressive strength, splitting tensile strength and flexural strength of HPC, among which the improvement in compressive strength was the most siginificant, and simultaneously, there was also an improvement in concrete toughness in a certain degree. The optimum content of metakaolin is 10% resulting in an increase of the cubic compressive strength of concrete by 8.3% correspondingly.
Mechanical and Fatigue Performance Tests of Cast Aluminum Alloy ZL111 Adopted in Structure
Authors: Wang Yuan Qing , Yuan Huan Xin , Shi Yong Jiu
Published: December 2010

Characteristics of aluminum alloys such as light weight, high strength-to-weight ratio and favorable corrosion resistance have brought about a bright application prospect in building structures. Wrought alloys are applicable to common beams and columns, while casting alloys can be fabricated as connectors in point-supported glass curtain wall and joints in spatial latticed structures on account of easy implement of moulding. Because of high strength, outstanding castability and remarkable mechanical properties after heat treatment, ZL111 in aluminum-silicon alloys is regarded as a desirable option. However, aluminum alloys are non-linear materials and their properties vary with casting and heat treatment modes. It is the well-marked distinction between aluminum alloy and ordinary carbon steel that special study on mechanical and fatigue performance is required. ZL111 raw materials were selected, with alloying agent and fabrication processes meeting the requirement of GB/T 1173-1995 standard. After T6 heat treatment process, test coupons were obtained by machining from raw materials. By utilization of electronic universal testing machine and cryogenic box, tensile tests at room temperature and low temperatures were performed. High-circle fatigue tests were carried out to obtain the fatigue performance of the material. Scanning electron microscope (SEM) was introduced to observe morphology of tensile and fatigue fractures. The tests revealed the relationship between mechanical property index and temperature, which indicated that the ZL111-T6 would increase in strength and plasticity. The microstructure of fractures validated and explained the macroscopic results. Furthermore, material strength at room temperature or low temperatures, stiffness and fatigue performance could satisfy bearing and normal serviceability requirement. Because of non existence of ductile-brittle transition temperature, superior corrosion resistance and outstanding castability, ZL111-T6 material is prone to fabricate complicated elements and joints withstanding cryogenic environment instead of carbon steel.
Copolymerization of Organosilicone-Veova10-VAc Emulsion Modified with Protective Colloid of PAM-PEG
Authors: Jiang Bo Quan , Hu Shu Fen , Zeng Jiang Na , Wang Min Wei
Published: December 2010

The purpose of this work is to modify the organosilicone-veova10-vinyl acetate (OSVVVA) copolymer emulsion with protective colloid in order to improve the viscosity of the original emulsion. The protective colloid was first prepared with polyacrylamide and polyethylene glycol as raw materials. The effects of use levels of protective colloid, vinyl triethoxyl silicane and potassium persulfate and reaction temperature on emulsion properties were investigated by orthogonal experiment and their optimum values were determined to be:50 g, 4 g, 0.5 g and 84 °C, respectively, under which the viscosity of the modified OSVVVA emulsion was greatly increased from 120 mPa•s to 430 mPa•s and the other properties of the modified OSVVVA were also satisfactory. The infrared spectra of the modified OSVVVA emulsion proved that the protective colloid was successfully grafted onto the OSVVVA copolymer emulsion.
Analysis for the Shake Table Test of Rammed Earth Wall Panels
Authors: Hu Rong Rong , Dong Yu Jiang , Zhang Xing Hu
Published: December 2010

Traditional Rammed earth houses are still widespread in rural areas of western China. However, the seismic damage of earth houses is usually serious due to its poor seismic resistance and little research has been conducted on dynamic tests of rammed earth structure. A simple and low-cost method to reinforce the rammed earth wall is put forward in the paper. The shake table testing for both the wall panels with and without reinforcements has been carried out. The test results are analyzed from the aspects of damage phenomenon, dynamic behavior, and acceleration and displacement responses of both specimens. The results show the effectiveness of the reinforcement method on improving the seismic capacity of the rammed earth wall.
Integration Utilize Research of Building Waste in Energy Saving of Buildings
Authors: Li Chang Qi , Xiang Fan , Ping Yang
Published: December 2010

The construction reject is in the building construction, the service, the demolition process produces, mainly is the solid reject, including the waste cement block, the asphalt cement block, in the construction process scatters the waste material, each kind of packing material and other rejects which the mortar and the concrete, the broken brick dregs, the metal, the bamboo lumber, the decoration repair produces and so on. In view of the fact that the construction trash composition characteristic and it produces in the construction project scene actual situation, its recycling took the building material, is constructs the waste disposal use the effective method. This article has carried on the comprehensive investigation and the summary to the domestic and foreign construction trash government present situation and the comprehensive utilization technology, has analyzed the construction reject ingredient and the characteristic, has conducted the system analysis research to our country construction reject comprehensive utilization and the construction energy conservation question, and proposed suits our country national condition the construction reject circulation in the construction energy conservation comprehensive utilization.
Comparison of Diffusion and Chloride Ion Penetration of High-Performance Concrete
Authors: Khan Mohammad Iqbal
Published: December 2010

This paper reports the results of an investigation of chloride ion penetration and diffusion for high performance concrete. Concrete was prepared incorporating pulverised fuel ash (PFA) and silica fume (SF) with various water-binder ratios. Chloride ion penetration was measured at various ages using rapid chloride permeability test in accordance with ASTM C1202-91. Based on experimentally obtained results, isoresponse contours for chloride permeability were developed showing the interactive and optimized effect between the various parameters investigated. Diffusion coefficient of concrete was determined applying Fick’s law of diffusion. The results show that the inclusion of PFA and SF reduced both chloride permeability and chloride concentration of concrete. It was found that rapid chloride permeability values were consistent with diffusion coefficient of concrete.
Experiment of Basic Mechanical Properties of Concrete Mixed with Composite Coarse-Aggregate
Authors: Li Feng Lan , Li Jing , Chen Song , Zhao Wen Jie
Published: December 2010

The mechanical properties of concrete mixed with composite coarse-aggregate were studied by the orthogonal test method, in which the four factors such as the cement content, the percent of cement replaced by fly ash, the percent of crushed limestone with grain size of 16-25 mm replaced by lightweight aggregate with the same grain size and the water to binder (cement + fly ash) ratio were considered. The results show that the water to binder ratio is the most effective factor influencing all of the mechanical properties, the mechanical properties except the splitting tensile strength are less influenced by the cement content, the elastic modulus and axial compressive strength as well as flexural tensile strength is largely affected by the replacement of cement by fly ash. The effect of the replacement of crushed limestone by lightweight aggregate is much more obvious on the cubic compressive strength than on the axial compressive strength, and larger on the flexural tensile strength than the splitting tensile strength.
Effects of Change in Fineness of Fly Ash on Air-Entrained Concrete
Authors: Quan Hong Zhu , Kasami Hideo
Published: December 2010

In order to make clear of the effects of the change in fineness of fly ash on air-entrained concrete, 2 series of laboratory experiments were carried out using 6 kinds fly ash with the specific surface area in the range from 2500 to 4400cm2/g. The test results indicated higher slump and lower air-entraining content and higher dosage of air-entraining agent for fly ash with higher specific surface area. Compressive strength was found to increase with the increases of specific surface area of fly ash, while drying shrinkage and carbonation were found to show different tendency with change in fineness of fly ash.
Experimental Research on Mechanics of Fiber Reinforced Polymers
Authors: Jin Wen Cheng , Ye Da Wei , Zheng Wen Heng
Published: December 2010

Fiber Reinforced Polymers (FRP) is a new composite material with characteristic of high tensile strength, light weight and perfect resistance to corrosion. Therefore, it is a perfect reinforcing material. To make good use of FRP, its mechanics need to be severely studied. We study the mechanics of FRP by means of experiment. The Yong’s modulus and the ultimate tensile strength of GFRP, which will be used in a bridge, are measured.
Time-Dependent Properties of Lightweight Concrete Using Sedimentary Lightweight Aggregate
Authors: Chen How Ji , Tsai Wen Po , Yang Ming Der
Published: December 2010

A kind of lightweight aggregate (LWA) has been successfully developed in Taiwan, which was made by expanding under heat fine sediments dredged from the Shihmen Reservoir. In this study the performances of concrete made from the aforementioned LWA were tested and compared with those of the companion normal weight concrete (NC). The test results show that the so produced lightweight concrete (LWAC) exhibited a comparable time-dependent properties (i.e., compressive strength, elastic modulus, drying shrinkage, and creep) as compared with those of the companion NC. Based on the results, it can be concluded that the use of prewetted LWAs and the incorporation of pozzolan materials can effectively control the drying shrinkage of LWAC. The specific creep of the LC mixture was obviously higher than that of the NC mixture at the same curing time.
Study of Constructive Materials and Structure inside Long Highway Tunnel Based on Environment Factors
Authors: Shi Xiao Li , Yang Meng Rou
Published: December 2010

The selection of constructive materials and structure inside long highway tunnel was studied aiming at the relatively closed internal structure of long highway tunnel combined with its environmental factors such as noise,illumination,temperature and humidity. This paper put forward the selection principle of materials and structure on pavement and wall inside highway tunnel, and confirmed suitable reflecting materials of pavement and noise-reducing materials of wall. Furthermore, the thesis designed materials and structure of pavement and wall in noise-reduction optimization. The research has an important instructional function on improving driving environment and noise-reduction effect and promoting the construction of resource-conserving and environment-friendly society and realizing sustainable development.