bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Aging on the Low Temperature Performance of Asphalt Binder
Authors: Li Ning Li , Zhao Xin Po , Zhang Cai Li , Li Hu Hui , Xiao Qing Yi
Published: October 2013

During the service of asphalt pavement, the aging makes asphalt binder become brittle, gradually lose flexibility and adhesion. All these result in the low-temperature properties of asphalt pavement to be poor. This paper conducts the rolling thin film oven test (RTFOT) and pressure aging vessel (PAV) test on base asphalt and rubber-modified asphalt respectively. The bending beam rheometer (BBR) test was conducted on original asphalts, rolling thin film oven test (RTFOT) residuals and RTFOT + pressure aging vessel (PAV) residuals of base asphalt and rubber-modified asphalt respectively. Results indicate that the low-temperature properties of all aged asphalts were declined. The attenuation of low-temperature properties of RTFOT + PAV residuals is larger than that of the RTFOT residuals. The attenuation of different types of asphalt is different. From the overall trend, effect of aging on the low-temperature properties of asphalt binder reduced as the test temperature reduction. The rubber-modified asphalt has superior low-temperature performance than that of base asphalt, and its low-temperature performance decreases more slowly than the base asphalt.
The Performance Evaluation and Control of Recycled Asphalt Mixture in Cold Recycling Project
Authors: Wu Hong Juan , Zhang Xin Yu
Published: October 2013

The recycled asphalt mixture was analyzed by the microstructure, grading variability and agglomerate degree evaluation from the Guaxing road. The results showed that some aggregate was more in quantity and smaller in the variation for the 9.5mm to 0.6mm material of recycled aggregate; the fineness modulus ratio (FMR) was 0.89, so the agglomerate degree of recycled asphalt mixture is relatively small, which had a little effect on the strength of the cold recycled mixtures; the gradation and unconfined compressive strength test of cement stabilized wasted asphalt mixture were made at different blending ratios; the reasonable range of the cold recycled utilization was 20% to 40% for the recycled old materials in Guaxing road.
Effect of Aging on the Low-Temperature Properties of Asphalt Mixture
Authors: Li Ning Li , Zhao Xin Po , Zhang Cai Li , Xiao Qing Yi , Li Hu Hui
Published: October 2013

This article studies the low-temperature anti-cracking properties of plain asphalt mixtures and rubber-modified asphalt mixtures at different aging condition. Laboratory flexural test was conducted on the beam specimens of plain asphalt mixtures and rubber-modified asphalt mixtures. Experiment results indicate that rubber-modified asphalt mixtures have superior low-temperature anti-cracking performance than that of plain asphalt mixtures. Compared with the short term oven aging test, the long term oven aging test has more significant effect on the low-temperature anti-cracking of the mixture. In order to better represent the low-temperature anti-cracking of in-service aging asphalt pavement, the long term oven aging test should be used to appraise the low-temperature anti-cracking of asphalt pavements in china.
Study on Warm Mix Flame Retardant Asphalt Mixture
Authors: Yuan Yu Qing , Wang Xiu Shan , Guo Tao
Published: October 2013

To study the properties of warm mix flame retardant asphalt mixture, a series tests were put forward, including Marshall Combustion experiments, rut specimen combustion experiment and texture depth experiment. With less mass loss, the warm mix retardant asphalt mixture has a better Marshall Stability, residual stability and freeze-thaw splitting strength ratio after combustion. The composite flame retardant can slow down and stop the burning of asphalt, reduce asphalt aging degree during burning process. The burning amount of warm mix flame retardant asphalt mixture is less than the ordinary hot mix asphalt concrete. To sum up, the warm mix flame retardant asphalt mixture has a good comprehensive performance.
Reflection and Transmission of Longitudinal Displacement Wave through Micropolar Fluid Interlayer in Micropolar Solid
Authors: Dang Song Yang , Xu Hong Yu , Sun Qing Yong , Liang Bin
Published: October 2013

Based on micropolar fluid theory and micropolar solid elasticity theory, reflection and transmission characteristics of longitudinal displacement wave and two coupled waves are studied when incident longitudinal displacement plane wave propagates through micropolar fluid interlayer in micropolar solid. Theoretical and numerical analytical results reveal that in general the amplitude ratios of various reflected and transmitted waves are functions of the incidence angle, the frequency of the incident wave and the material properties of the medium. At normal incidence, the reflection and transmission of only longitudinal waves take place and no coupled transverse wave is found to reflect or transmit. At grazing incidence, no reflection or transmission phenomena take place and the same wave propagates along the interface. The change rules of the amplitudes varied with incident angle are also discussed.
Research on Identification of Cement Laboratory Samples Management
Authors: Jia Yan , Yang Zhi Ling , Cheng Xiao Tian , Nie Jin Rong
Published: October 2013

In allusion to the management characteristics of the cement laboratory samples, this paper conducts introduction and comparative analysis on such four kinds of identification as inspection organization, traditional cement sample identification of corporate laboratory, paper-electronic tags and wireless monitoring devices. It shows that wireless monitoring devices are superior to the traditional sample identification and paper-electronic tags, and can achieve intelligent management of cement samples ensuring objective and fair inspection data.
Study on Semi-Circular Bending Test Using Digital Image Correlation Method
Authors: Li Peng Fei , Liu Jing Hui
Published: October 2013

Fracture toughness JC is sensitive to the characteristic of the material itself, as an effective indicator to appreciate the fracture resistance of the asphalt mixtures, is adopted by more and more researchers. The Semi-Circular Bending Test (SCB) can evaluate the fracture resistance of asphalt mixtures with different kinds of molding means. But currently, the fracture toughness JC is measured by multi specimens (at least two), the experimental consumption is high, the single specimen calculation formula didnt appear. Using Digital Image Correlation Method (DICM) can compute the J-contour integral of a single specimen, compared with the results obtained from multi specimens, the repeatability is better, the accuracy is higher. Test and analytic results show that the DICM provide a new approach to study and investigate the fracture toughness JC.
Creating Innovative and Efficient Structures and Materials
Authors: Xie Yi Min , Zuo Zhi Hao , Huang Xiao Dong , Tang Ji Wu , Yang Xiao Ying , Radman Arash
Published: October 2013

Novel and efficient structural and material designs can be realized by topology optimization that is capable of maximizing the performance of structural systems under given constraints. The bi-directional evolutionary structural optimization (BESO) method has been developed into an effective tool for topology optimization of load-bearing structures and materials. The latest advances of BESO are aimed at expanding its practical applications to a wider range of structural systems on both macro and micro scales. This paper presents recent developments of BESO for optimal design problems of a variety of structural systems ranging from buildings of large scales to materials of micro scales. Selected applications are introduced to demonstrate the capability of BESO. Examples presented in this paper are based on research and industrial projects of the Centre for Innovative Structures and Materials (http://www.rmit.edu.au/research/cism) at RMIT University.
Application of Heat/Resin Injection in the Presence of Vacuum for FRP Attachments on the Concrete Substrate
Authors: Gravina R.J. , Hadigheh S.A. , Setunge Sujeeva , Kim S.J.
Published: October 2013

Advanced processing techniques for the application of Fibre Reinforced Polymer (FRP) materials to repair concrete structures include the adoption of a vacuum consolidation process coupled with heat and/or resin injection to improve the curing process, bond strength and speed of application. The vacuum can contribute to the penetration of the resin into the surface around the exposed aggregates in order to achieve higher bond in strengthened elements. Since, debonding of FRP materials from the substrate is a brittle failure, it is essential to study this phenomenon and propose significant ways to improve the behaviour of the bondline. In this article, the interfacial bond behaviour of FRP laminates attached to concrete in the presence of vacuum and heat/resin injection is studied. The results of single lap shear tests have been utilized to investigate the capability of this system in strengthening of concrete elements. In this regard, several FRP-bonded concrete prisms will be examined in a single lap shear test set-up. Further, the effects of bondline thickness on the bond performance of adhesively bonded joints are studied.
Experimental Study on Activity of Fly Ash Replacing Cement in Concrete
Authors: Li Chang Yong , Jiang Long , Liu Yang , Xu Zhi Ming
Published: October 2013

The test and contrast mortars were made by changing water-binder (water-cement) ratio from 0.4 to 0.6, fly ash replacing rate from 10% to 30% and over-mass factor of fly ash from 1.3 to 1.7 with different methods of equal-replacing and over-mass replacing cement by fly ash. The variation of compressive and flexural strengths of mortar with water-binder ratio and admixing amount of fly ash are analyzed based on the test strengths. The formulas for calculating active factor of fly ash are proposed, and the regularity of active factor with the change of water-binder ratio and admixing amount of fly ash are given out.
Nonlinear Finite Element Analysis of the Flexural Reinforced Concrete Beam Strengthened with CFRP Sheets
Authors: Zhou Jun Wen , Zhao Feng Hua , Qi Yong Sheng , Shi Wei Cheng
Published: October 2013

Based on the tested data, the ANSYS finite element analysis software was adopted to establish the finite element model for the concrete beam nonlinear analysis.The finite element models were developed using 3-D solid element for concrete and shell element for the Carbon Fiber Reinforced Ploymer (CFRP) sheet. The results obtained from the ANSYS were compared with the experimental data for two strengthened beams with different thickness CFRP sheet. The comparisons were made for the curves of load-midspan deflection, yielding load and ultimate load. Models were calculated at the same condition as the experimental beams. Two reinforced beams strengthened with CFRP sheet were calculated in four-point bending. The load-deflection curves from the finite element analysis agree well with the experimental results. The average difference in ultimate load for two cases is 5.5%.
Study on Impaired Reinforced Concrete Beams Strengthening with Externally Steel Frame
Authors: Li Feng Lan , Yu Xiong Huai , Chen Cheng , Chen Song
Published: October 2013

A large impaired reinforced concrete beam with cracks was strengthened under self-weight action by the externally bonded steel frame composed with bottom steel plate and side hoop steel belts. The normal service loading behaviors of this beam were tested to verify the effectiveness of this strengthening method specified in current Chinese design code. Based on the analyses of test results, it can be concluded that: the deformation of flexural cross section of this beam fitted the assumption of plain cross section, the steel plate could effectively enhance the flexural stiffness and decrease the deflection of this beam, no new cracks appeared under the normal service loads, the cracks at bottom of this beam were more confined by the steel frame than those at web zone. Therefore, other measure should be taken to avoid the opening of web cracks.
Development of the Calculation Methods of Structural Reliability and its Relevant Problems
Authors: Jiang Qiang Qiang , Peng Hui , Zheng Chong Yang , Yan Qin Long , Liu Shuai , Ma Guo Dong
Published: October 2013

The correct and reasonable calculation of the structural reliability is the theoretical basis of the design, construction and use of the structure. The research is focused on the development of computing methods of reliability of structural members and system, and also points out the merits and problems of the existing methods with respect to the analysis of the present researches on structural reliability. Meanwhile, the summarization of the development and the existing problems on the reliability of time dependent structure has been provided. Furthermore, it proposes that correlation is the common problem in the computing of structural system reliability, and probes into the correlation coefficient of the calculation and the effects that correlation coefficient exerts on random variables and different systems. The conclusion shows that the specification of the adaptation range of calculation methods and reducing the effects of correlation coefficient contribute to the insurance of the structural safety.
Service Life Prediction of RC Member in Chloride Environments under Different Loading Level
Authors: Feng Yun Fen , Gong Jin Xin , Yang Xiao Yan , Zhang Qin
Published: October 2013

Chloride ingress is a major factor affecting durability of reinforced concrete structures. In the present study, service life of a RC flexural member in chloride environments is predicted. First, model for service life is established considering model error and the coupling effects of loading condition and environmental factors on the chloride penetration. Then, service life is predicted in probabilistic framework of Monte Carlo simulation. The results show that the use of a lognormal distribution for the service life seems relevant; the service life shows a great scatterings.
Finite Element Analysis of Reinforced Concrete Frame Exterior Joints with T-Section Columns
Authors: Liu Gui Rong , Wang Yu Xin , Zhao Shun Bo
Published: October 2013

Nonlinear three-dimensional finite element method was used to analyze the crack pattern and stress distribution of reinforced concrete frame exterior joints with T-section columns. On the basis of the smear-crack approach, the cracking of reinforced concrete joint was predicted. And the capability of finite element model was demonstrated by comparing the predictions with test results. Further analysis was carried out to study the effect of axial load ratio and limb length on stresses of the joints. It is seen that the stresses of joint were influenced by these two factors, which should be considered in the design of reinforced concrete joint with T-section column.
Calculation on Crack Resistance of Reinforced Concrete Exterior Joints with Special-Shaped Columns
Authors: Qu Fu Lai , Bai Yu Zhu , Tian Pei Yuan , Qi Lu Yang
Published: October 2013

According to the mechanical analysis of reinforced concrete (RC) joint with special-shaped column, the formula of crack resistance considering the effect of flange length was derived on the basis of the elasticity theory, and the expressions for calculating the frame joint core effective height and width were presented. Furthermore, four RC joints with special-shaped columns were tested under low cyclic loading to investigate the mechanical behavior. At last, the calculated results predicated by the proposed formula are compared with that by experiments, and indicate that the expression has good applicability.
Bearing Capacity Analysis of the Cross-Section Steel Reinforced Concrete Column in Different Parameters
Authors: Li Ri Liang , Xu Ya Feng , Bai Shou Yan
Published: October 2013

This paper uses the large-scale finite element analysis software ABAQUS to simulate 12 cross steel reinforced concrete special-shaped columns with the control variables of axial compression ratio and rate of steel bone, and subjected to the monotonic load with 20mm horizontal displacement. 6 columns work under the different axial compression ratio of 0.0, 0.4, 0.5, 0.6, 0.7 and 0.8. Other 6 columns are made of different rates of steel bone with different steel bone thickness of 0mm, 2mm, 4mm and 6mm, 8mm and 10mm, and subject to vertical axial force in axial compression ratio of 0.3. By simulating, we obtain the load - displacement curve of different axial compression ratios and different rates of steel bone, and analyze the effect of the bearing capacity of the cross steel reinforced concrete special-shaped columns in different parameters. The results show that the bearing capacities of the columns decrease with the increasing ratio of axial compression, and increase with the increasing rate of steel bone.
The Electricity Design of Pressure Sensor
Authors: Li Tao , Ren Guo Jing , Qi Li Feng , Liu Zhi Min
Published: October 2013

The relative discussion and research of Micro-Electro-Mechanical System (MEMS) and pressure sensor is carried out in this paper. The working principle of pressure sensor is analyzed, and the cantilever piezoresistive pressure sensor is studied in details. The electricity design of pressure sensor is researched. The open loop Wheatstone-bridge design is adopted in this paper, which adds the freedom of disposing circuit.
Study on Application of Concrete Admixture Technology
Authors: Cui Wen
Published: October 2013

Mix design of high performance concrete was determined based on the pumping simulation test. It was indicated by test and field application that the trimixture technique and the double mixture technique can improve the pump of concrete, reduce the dosage of cement and the hydration heat; adding expansion agent can prevent harmful cracks in the concrete due to shrinkage stress, improve the compactness and impermeability. The reasonable construction technologies were used in mixing, transportation, pouring, vibrating and curing of the concrete in order to ensure quality of the construction.
Key Construction Techniques of 4000m2 Hyperbolic Cooling Tower
Authors: Wang Hui
Published: October 2013

Combined with a 2×350MW gas power station project, the main construction process and specific technology of each subentry project for a large hyperbolic cooling tower were described in details. The customized steel templates were used and positioned by accurate calculation. The mass concrete was poured by alternative bay construction which replaced deformation joint and after-pouring belt. The measures such as controlling temperature, avoiding leakage and monitoring geometric size were taken actively. These methods greatly improve the quality of the structure and are strong guarantee for achieving high-quality project.
Optimal Design of the Stiffener Penstock Structure in a Hydropower Station
Authors: Bai Xin Li , Jia Qi Pei , Su Hai Li
Published: October 2013

In order to optimize the stiffener penstock structure in hydropower stations, the simple genetic algorithm and the direct search method in traditional optimization methods were integrated, and a new hybrid genetic algorithm was obtained. A mathematical model of the stiffener penstock structure was established, and the constraint expressions were presented for global stability of the penstock under external pressure as well as the local stability of the stiffening ring. The corresponding program was developed and applied to a hydropower station. Results show that compared with the original design, the optimized design of rectangular stiffener rings reduces the penstock wall thickness by 8%, saving steel products 12.9%. The economic benefit of optimization is very considerable.
Effect of Water Pipe Cooling on Thermal Stress of FuYang River Aqueduct Structure
Authors: Bai Xin Li , Li Jiang Yan , Pan Qian
Published: October 2013

In order to analyze the influence rule of water pipe cooling on the temperature field and thermal stress of large aqueduct structure, the finite element analysis model for FuYang River Aqueduct structure was established. The temperature field and thermal stress of the aqueduct structure were calculated. The following two cases were considered: structure with or without water pipe cooling, as well as the different beginning pouring months (May, June and July). The hydration-degree-based calculation methods of temperature and stress of concrete were adopted, and the high precision discrete simulation method of water pipe was used. The calculation results show that embedding the cooling pipe in concrete can effectively reduce the temperature difference between inside and outside of the early concrete and thermal stress, and is therefore effective to prevent concrete cracks. High accuracy of simulation and analysis can make people basically figure out the specific mechanism of concrete cracking and main factors even before construction, and determine accurately the structure crack location and the developing tendency.
Temperature Control Simulation Study of Inverted Siphon in Construction
Authors: Yang Kai Yun , Hao Shi Ke , Li Lin Hao , Qin Yan Zhao
Published: October 2013

This paper using three-dimensional non-steady, nonlinear temperature field and creep stress field of simulation theory, establishes a FORTRAN program for simulating the temperature and stress during the construction of inverted siphon, analyzes the temperature and stress changes and distribution of siphon walls, and proposes the scientific and reasonable control measures of temperature and crack in a complex external environment. The results show that the wall tends to cracking due to tensile stress at early age within 1 day to 3 days, and insulation measures should be taken into account.
Simulation Analysis of Concrete Temperature and Stress by Inclined-Layer Placing Method
Authors: Chen Shou Kai
Published: October 2013

The water-collecting well layer of large pump station base plate is constrained by bottom and lateral, and step construction method is used. In view of the characteristics, the simulation is done to study its temperature and stress during construction. Based on a large pump station project and the structural characteristics and construction method of water-collecting well layer, the FEM model is built, and the theories of the 3D-FEM of unstable temperature field and stress field is used to carry out the numerical calculation, which can study change law and distribution of temperature and stress. The results show that the method of step construction can increase concrete cooling during construction, but the heat dissipation potential is difference in different time of day.
Durability and Mechanical Behaviors of Steel Slag Powder Concrete
Authors: Wang Hai Long , Sun Xiao Yan , Peng Qi Wen , Xue Feng
Published: October 2013

The mechanical behaviors and durability of concrete containing steel slag powder (SSP), silica fume (SF) and fly ash (FA) were presented in this study. The fresh concrete properties, compressive strength, split tensile strength, elastic modulus, stress-stain curve, chloride permeability as well as carbonation of concretes mixed with different SSP contents or concretes containing compound mineral admixture were tested. The experimental results reveal that the mechanical behaviors and durability of concrete with 10% SSP replacing cement are both improved than that of the reference concrete. Mechanical behaviors and durability of concrete with 20% SSP replacing cement are similar to the reference concrete. Concrete with compound mineral admixture of SSP and SF obtain the highest enhancement in both strength and chloride resistance.
Simulation Analysis of Plain Sluice Concrete Temperature and Stress
Authors: Yang Kai Yun , Guo Fei , Li Lin Hao
Published: October 2013

For sluice concrete structure is more complex due to constrained by the base effect and upper structures, with the purpose of temperature control, we carry out the simulation analysis of temperature and stress during the construction of pier concrete structure. Taking a sluice project as an example, use the method developed by Thermo finite subspace model simulation procedures, the finite element model of pier structure is built with high precision. The results show that the cracking risk is relatively small and prone to surface cracks for baseplate; during construction period, much more attention should be payed to the high temperature difference between day and night, and to the insulation work at cold and windy weather; the key problem is that the middle pier which faces relatively great cracking risk, and necessary temperature control measures should be adopted.
The Australian Approach to Residential Footing Design on Expansive Soils
Authors: Li Jie , Zhou An Nan
Published: October 2013

Expansive soils in semi-arid regions are of great concern to design and geotechnical engineers. Damage to residential buildings resulting from expansive soil movements has been widely reported in Australia. This paper describes the current practice in Australia, which includes the site classification, laboratory tests and residential footing design. A case study of a residential house damaged by expansive soils is also presented.
Study on Microstructure of Remolded Loess Using Computerized Tomography
Authors: Gao Hong Ling , Chang Lian Yuan , Sun Le , Li Xiao Jun
Published: October 2013

The change of micro-structure of the remolded loess is analyzed from the CT numbers and CT images during the uniaxial creep process. It is found that there are quite complex cracks distributed on each layer in the loess during that process. The cracks are not distributed along the radial direction regularly, and the lateral deformation is not obvious.
Analysis of Influences of Weak Joints and Confining Pressure on Rock Mass Strength by Numerical Simulation
Authors: Wang Da Hai , Guo Hao Ran , Zhao Hui , Guo Yan Wei
Published: October 2013

Principal influencing factors of the strength of rock mass with weak joints were studied in this paper. Dip angles of weak joints in addition with the confining pressure is studied based on strain-softening/hardening plasticity model. The broken mechanism from the perspective of plastic zone was analyzed. The strength of rock mass with weak joints is mainly under control of the joints occurrence, the joints dip and the rock strength, and great influenced by the confining pressure. A higher strength is obtained with a higher confining pressure, the broken mechanisms varies with different joints dips.
Study on Effect of Step Height and Load for Large Wind Turbine Spreading Foundation
Authors: Luo Quan Sheng , Zhang Di , Tian Jing
Published: October 2013

Aiming at the defects and potential safety hazard in design of wind turbine generator foundation, taking the wind power project in Huitengxile as an example and based on ANSYS platform, 3-D numerical model is established by introducing the nonlinear contact between the stub of tower structure and the foundation concrete, and the contact between the concrete foundation and subgrade, the effect of step height and load on the stress status of spreading foundation for large wind turbine are studied. The research results provide reference for optimization and design of wind turbine generator foundation.
Study on the Influence of Limestone Dust on Performance of Cement Mortar
Authors: Hang Mei Yan , Zhang Jin Xia , Gao Meng , Lan Ying Jing
Published: October 2013

This paper uses dust, with particle size less than 0.08mm, produced by crushing limestone to replace the same amount of cement in different proportions and studies the performance of cement mortar. The result shows that limestone dust has water reducing effect and does not reduce strength of the mortar when its dosage is less than 12%, meanwhile, it can improve the shrinkage property and the durability resisting sulfate, which explains that limestone dust is not the inert material, but has a certain activity,.
Nonlinear Finite Element Analysis of FQQB
Authors: Zhao Feng Hua , Qi Yong Sheng , Zhou Y.Y.
Published: October 2013

The mechanical properties of the whole wall and the wall with openings under vertical loads are analyzed by nonlinearity finite element method (NFEM). The results show that the stress of steel wire has a direct relationship with the load form. The inclined plug wire mainly carries the stress caused by load differences between the two sides of concrete, it makes both sides of concrete work together better. As the diameter of the inclined plug wire increased, the effects on the FQQB mechanical properties become greater, wire mesh stress on both sides decrease, and the vertical displacement of FQQB decrease. Cracks appear above the openings of FQQB which has been cut holes. Steel wire tends to be tension stress concentrated, and there are obvious stress concentration belts on both sides of the opening. However, the size of the opening has little effects on the ultimate bearing capacity of wall panel.
Study of Strong Interlocked Skeleton Dense Gradation for Cement-Stabilized Macadam
Authors: Chen Zhe Jiang , Xue Jin Shun , Cao Fan , Jiang Ying Jun
Published: October 2013

In order to improving the performance of Cement-stabilized Macadam (CSM), analyzing the influences of its composition structure on performance, and then putting forward the gradation design principles and strong interlocked framework dense gradation (SISDG), laboratory test was adopted to verify its road performance. Result shows that CSM has the feature of the amount of aggregate above 9.5 mm, below 4.75 mm and 0.075 mm are more, while the amount of aggregate 4.75-9.5 mm is less, and the California Bearing Ratio (CBR) value of mineral aggregate with SISDG is increased by 8~14% comparing with mineral aggregate with the framework dense-graded (DSDG) presented in Design Specifications of Highway Asphalt Pavement (JTG D50-2006) gradation. Compared with CSM with DSDG, 28d unconfined compressive strength (UCS), ultimate UCS and splitting strength of CSM with SISDG are respectively increased by 6~12%, 8~20% and 8~15%.
Experimental Research on Torsional Performance of Prestressed Composite Box Beam with Partial Shear Connection
Authors: Hu Shao Wei , Zhao Ke Yu
Published: October 2013

In order to research torsional performance of prestressed steel-concrete composite box beam with different shear connection, this paper designed three prestressed steel-concrete composite box beams with different degree of shear connection, and studied the stress characteristics of prestressed composite beam under static torsion process load. The torsion behaviors of prestressed composite beam such as the steel strain, concrete flange strain, rebar strain, angle of torsion, deformation and failure patterns are analyzed on the base of the experimental results. It comes to a result that shear connectors have little impact on beams cracking torque, but ultimate torque of composite beams decreases along with the reduction of shear connection degree. When the shear connection degree is 0.5, the ultimate torque is reduced by about 15%.
Research of Punching Performance of Reinforced SFRLAC Superposed Two-Way Slabs
Authors: Pei Song Wei , Du Zhong Hua , Li Chang Yong , Shi Feng Jun
Published: October 2013

This paper introduces the test results of eight steel fiber reinforced lightweight aggregate concrete (SFRLAC) superposed two-way slabs under punching load. The tensile and compressive zones of the slabs were cast with the SFRLAC and the ordinary concrete respectively. The slab was simply supported along the four edges under central concentrated load on the short column. The main parameter of SFRLAC was the fraction of steel fiber by volume of 0.8%, 1.2% and 1.6%. The measurements were made such as the deflection, the strains of steel bar and concrete, the crack distribution, the loads corresponding to the yielding of steel bar and the ultimate state. It proved that the punching resistance of SFRLAC superposed two-way slab increased about 51%~78% with the increasing fraction of steel fiber by volume, the ability to resist punching deformation was enhanced remarkably, many fine cracks distributed on the tensile surface, and the ductility at failure state increased to a certain degree.
Influence of Ground Slag on the Rheology of Mortar
Authors: Zhang Qian Qian , Liu Jian Zhong , Liu Jia Ping
Published: October 2013

The effects of ground slag with different specific surface area on the rheology of mortar at water-binder ratio of 0.25, 0.28 and 0.30 were investigated, and the combined effects of packing density and solid surface area on the rheology of mortar were evaluated in terms of the water film thickness. The results show that with the increasing of specific surface area of slag (220 m2/kg-784 m2/kg), plastic viscosity and yield stress decrease. The correlations of yield stress and plastic viscosity to the water film thickness are basically linear with high correlation R2 values. The action of the ground slag on the rheology of mortar can be characterized by water film thickness, and with the increasing of water film thickness the rheological parameters decrease.
Study on Improving Thermal Performance of External Wall of Rural Residence in Cold Region
Authors: Zheng Zhi Feng , Lu Mei Jun
Published: October 2013

In order to improve thermal performance of external wall of rural residence in cold region, combining with construction situation, this paper selects the typical building model to analyze the corresponding construction and energy consumption. According to the climate features and resource condition of the region, some suitable constructions of external wall in rural residence are put forward and the energy efficiency effect is analyzed. It is hoped to provide some valuably theoretical foundations for energy saving studies on rural residence in cold region.
Analysis of the Impact of Concrete Compressive Strength Reduction in Joint Core Area on Super High-Rise Structures
Authors: Yu Xiao , Wu Na , Yang Zhao , Xu Kai
Published: October 2013

t is focused on a super high-rise building structure, of which the concrete compressive strength is reduced in joint core. The whole structure is calculated with program SATWE. Based on this calculation, integral stress analysis by MIDAS when concrete strength is reduced in joint core area and nonlinear finite element analysis by ANSYS on the joints of the worst cross-sections in the whole structure are developed. Thus the adverse effect of reduced concrete strength in joint core area on super high-rise structures is found out.
Influence of Inner Steel Tube Properties on Compressive Behavior of FRP-HSC-Steel Double-Skin Tubular Columns
Authors: Fanggi Butje Alfonsius Louk , Ozbakkaloglu Togay
Published: October 2013

This paper reports on part of an ongoing experimental program at The University of Adelaide on FRP-concrete-steel composite columns. A total of eight high-strength concrete double-skin tubular columns (DSTCs) were tested under axial compression. The column parameters examined included the diameter, thickness, and shape of inner steel tube. The results of the experimental study show that increasing the inner steel tube diameter leads to an increase in the ultimate axial stress and strain of concrete in DSTCs. The results also show that increasing inner steel tube thickness leads to an increase in the ultimate axial stress and strain of DSTCs. Furthermore, it is observed that concrete inside DSTCs with square inner steel tubes is not confined as effectively as concrete inside DSTCs with circular inner steel tubes.
Load Carrying Capacity Calculation of Shear Wall with Concrete Filled Steel Tube Columns and Concealed Trusses
Authors: Yang Ya Bin , Cao Wan Lin
Published: October 2013

Shear wall with concrete filled steel tube columns and concealed trusses is a new kind of shear wall. In order to further the seismic performance of the new shear wall, experiment was carried on three 1/5 scale models, which included one traditional RC shear wall, one shear wall with concrete filled steel tube columns, one shear wall with concrete filled steel tube columns and concealed trusses. Based on the experimental study, load-carrying capacity and hysteretic property of each model were analyzed. The study show that the seismic performance of shear wall with concrete filled round steel tube columns and concealed steel trusses has high bearing capacity and good hysteretic property. Load carrying capacity calculation of shear wall with concrete filled steel tube columns and concealed steel trusses were carried out, the calculate results were in good agreement with the measured results.
Study on the Compression Capacity of the Wall of Recycled Aggregates Self-Compacting Rock-Filled Concrete
Authors: Wang Hai Chao , Gao Yi Long , An Xue Hui
Published: October 2013

The goal of the paper is to make good use of solid wastes. The aggregates of ordinary self-compacting concrete are changed for the large size of recycled aggregate, which are randomly put into the mold before self-compacting concrete are poured into to form the new type of concrete specimens, and a freestone aggregate specimen is also made for a comparison. 500 tons of electro-hydraulic servo testing machine is used for the test, to measure the strength of this new wall material, bearing capacity, deformation properties and damage form, etc. Test results show that the average compressive strength of the wall of recycled aggregate rock-filled concrete is 6.42MPa, which is far greater than 2.03MPa specified in standard under same mortar strength. Therefore, the recycled aggregate concrete wall of self-compacting has higher bearing capacity, and can meet the requirment of the project.
On Overloading Design Method for the Slope of Deep Foundation Pit with Layered Soil Braced by Soil Nail
Authors: Li Li Hua
Published: October 2013

Based on plastic limit equilibrium theory of soil, the suitable values of energy safety factor are discussed here from energy work rate, the new design method for vertical slope of deep foundation pit with layered soil braced by soil nail with even overloading on slope top is proposed and engineering example is given out.
Asymptotic Approach for Finding Joint Design Point and Reliability Index in Parallel Structural System
Authors: Zhao Na , Gong Jin Xin
Published: October 2013

Joint design point is an important concept in reliability analysis for parallel structural system. The paper proposes an asymptotic approach specialized for finding joint design point, and gives the examples to illustrate the application of this approach.
Research on the Selection of Space Truss Structure
Authors: Liu Yun , Li Xiang Yu , Xia Bing
Published: October 2013

Space truss structure is widely used in various engineering fields. The key technical problems are mechanical analysis of its structure and optimization of the design of truss structure. In this paper, comparison of the four different designs of the concrete transport truss structure system based on ANSYS, and the FORTRAN procedure were programmed. Finally both practical and economical factor was chosen to meet the engineering truss structure. These results should be of guiding significance to design and construct retaining engineering in space truss structural.
Study on the Basic Mechanical Properties of Recycled Concrete Hollow Block Masonry
Authors: Hao Tong , Li Dong
Published: October 2013

By the experimental studying on the basic mechanical properties of recycled concrete hollow block masonry, the compressive and shear behavior of recycled aggregate concrete hollow block masonry under different mortar strength were analyzed. Research indicated that the compressive and shear behavior of recycled aggregate concrete hollow block masonry was similar to that of ordinary concrete hollow block masonry. The normal formula was recommended to calculate the compressive strength of the masonry. The shear strength of the masonry was affected by the mortar strength. The shear strength calculation formula of recycled concrete hollow block masonry was proposed according to the formula of masonry design code. The calculating results were in good agreement with the test results.
Correlation Test between Resistivity and Microcosmic Pore Structure of Mineral Admixture Concrete
Authors: Zhao Zhuo , Du Chao Wei , Shen Lei
Published: October 2013

Cube crushing strength, resistivity and gas adsorption analysis of mineral admixture concrete are tested to analysis the effect of raw material on resistivity and its regression relationship with concrete microcosmic pore structure index. Test results show that concrete resistivity at different age increases with the increase of cementitious material and cement dosage, and both has a good nonlinear regression relationship. Concrete resistivity at different age decreases with the increase of 56d HK method cumulative pore volume, 7d and 14d resistivity has a good linear correlation relationship with 56d HK method cumulative pore volume. 28d and 56d resistivity has a good nonlinear regression relationship with 56d HK method cumulative pore volume. Concrete resistivity at different age decreases with the increase of 56d BJH method cumulative adsorption pore radius, and both has a good nonlinear regression relationship.
Comparison on Dynamic Parameters of Structures with Different Additional Steel Frame Stories Constructed on the Prototype Reinforced Concrete Frame
Authors: Song Jian Xue , Wu Hong Tuan , Cheng He Shan
Published: October 2013

Based on a practical project, the dynamic parameters for a 4-story reinforced concrete frame, with additional different stories of steel frame constructed on its top, are investigated, including vibration period, frequency, and seismic response under minor shock, such as inter-story maximum horizontal displacement, inter-story maximum horizontal displacement angle, inter-story shear force and so on. It reveals that the maximum number of additional stories may be determined by the inter-story maximum horizontal displacement angle. With the additional steal frame adding on the top of the original structure, the maximum horizontal displacement angle often comes into being as the second story from the top of the structure, at the same time, a certain story in the prototype structure may evolve into a weak story which has to be reinforced. However, with the increasing of additional stories, the total shear force in the bottom story decreases, which leads to a new anti-seismic design concept.
Research on the Mode Classification and Application
Authors: Wu Ze Yu , Wang Bing , Lu Yong Jun , Li Chen Jing , Gu Suai Fu , Li Wen Yuan
Published: October 2013

Mode is the inherent property of structure, and any action response can be decomposed by mode matrix. Through the mode expansion, each mode direction parameter can be clarified, and the designer can elevate the good response and cut down the bad one. So the designer has capacity that assesses the whole structure property by the mode analysis, and guides the concept design and mechanical design.
Structure Mode Geometrical Identification and Application
Authors: Wu Ze Yu , Wang Bing , Lu Yong Jun , Li Chen Jing , Gu Suai Fu , Li Wen Yuan
Published: October 2013

Frequency and mode are character parameters of structure, and mode is also self-contained coordinate basis vector of displacement, so mode can be used for concept design and mechanical design. Through depth-width ratio from one to seven, results indicate the whole deformation of structure varies from shear mode to bend mode gradually; except for vertical mode, general mode is not one deformation, it is coupled by several deformations and one deformation ratio is dominant. During three of depth-width ratio, structure deforms in shear mode, so masonry structure should be in that range. In order to exerting reinforced concrete and steel material property and energy consumption capacity, the depth-width ratio should be from three to seven. For depth-width ratio between five and seven, the first eight modes is the same, manifesting mode has convergence property.
Optimal Design of Damper with Stiffness for Damping of Stay Cable under Bridge Deck Motion
Authors: Luo Shuai , Yan Quan Sheng , Liu Hong Jun
Published: October 2013

This paper studies cable-damper mitigation model due to indirect excitation caused by bridge deck vibration. In the new mitigation model, as a rule of thumb, we considered a parallel association of idealize damper with a spring to simulate the inherent stiffness of the damper. The result shows that the interaction between the stiffness of the viscous damper could deeply impact the damper effectiveness, and the external damping should be increased deeply to provide the same non-dimensional modal damping when the inclined angle of cable decreases. The optimum damping coefficient of the non-idealized damper decreases when the stiffness of the damper increases.
Study on Dynamic Responses of Human-Structure Interaction System
Authors: Wang Yi He , Yang Na
Published: October 2013

t has previously been shown that human-structure dynamic system received much attention as a major topic in the serviceability performance and safety problems. In this study, the structure occupied by human are considered as a two degrees-of-freedom system. The dynamic characteristics of human-structure system are investigated by deriving the eigenvalue equation of the system. The response of structure to a person walking across it at various rates of walking is also researched. The results show that the pair natural frequencies of coupled system have a contrary trend when the crowd densities increase. It also demonstrates that the resonant situation occurs when structural fundamental frequency is equal to or an integer multiple of the pacing frequency.
Shear-Crack Behaviors of Reinforced Full-Recycled Aggregate Concrete Beams
Authors: Li Chang Yong , Li Guang Xin , Shao Wen Jing , Guo Qi , Liu Rui
Published: October 2013

On the basis of experimental results, this paper discusses the shear-crack behaviors such as shear-cracking force and shear-crack width of reinforced full-recycled aggregate concrete beams. The full-recycled aggregate concrete was developed for the sustainable development in civil engineering, in which the coarse aggregate was the recycled aggregate made of abandoned concrete, and the fine aggregate was the machine-made sand. Sixteen beams, six of them without stirrups, were tested with the shear-span ratio varying as 1.5, 2.0 and 3.0, and the ratio of stirrups varying from 0.19% to 0.35%. The results showed that the shear-cracking force of the beam was mainly affected by the shear-span ratio, the width of shear-cracks intersecting stirrups decreased with the increasing ratio of stirrups, but the maximum crack width almost exceeded the limit 0.3mm in the first class environmental condition specified in Chinese code GB50010-2010. Comparing the calculation results by substituting the test parameters of full-recycled aggregate concrete beams into the formula of ordinary reinforced concrete beams, the lower resistance of reinforced recycled concrete beam to shear-cracking, and the larger crack width intersecting stirrups should be noted in the structural design. Based on the test data, the formula for calculating the shear-cracking force and the shear-crack width of reinforced full-recycled aggregate concrete beams are suggested.
Experimental Research on Bending Performance of Concrete Beams Reinforced with CFRP-PCPs Composite Rebars
Authors: Liang Jiong Feng , Wang Jian Bao , Li Jian Ping
Published: October 2013

The flexural behavior of concrete beams reinforced with CFRP-PCPs composite rebars was studied. Experimental results showed that the deflection of beams reinforced with highly prestressed prisms is at service loads coMParable to deflection of steel reinforced beam. Flexural cracks of CFRP-PCPs composite rebars reinforced beams are hairline before prism cracking, and widened after the prism cracking. When the concrete beam was reinforced with the prestressed concrete prisms, the crack width decreased as the prestress in the prism increased.