bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study of Wet-Screened Aggregate Concrete under Biaxial Compression after Freeze-Thaw Cycles
Authors: Song Yu Pu , Xu Xiu Juan
Published: May 2011

Using the static and dynamic triaxial experimental machine, experimental study of the strength of wet-screened aggregate concrete are carried out under biaxial compression stress ratios, 0.25, 0.5, 0.75 and 1 after 0, 50, 100, 150, 200, 250, 300 cycles of freeze-thaw. The change of surface of wet-screened aggregate concrete specimens after different cycles of freeze-thaw are observed and described. The failure characteristic of specimens and the direction of the cracks are also observed. Based on the test data, the influence of freeze-thaw cycles and compressive stress ratio on the ultimate compressive strength and corresponding stress-strain relationship is analyzed respectively. The relationships between the ultimate compressive strength and freeze-thaw cycles, the stress ratios are given, respectively. On this basis, the unified failure criterion with consideration of the influence of freeze-thaw cycles and stress ratio is proposed. It can serve as a reference for the maintenance, design and the life prediction of ocean structures, hydraulic structures, marine structures and offshore platform in cold regions.
Analysis on Low Amplitude Loading Fatigue Life Strengthening of the Rear-Axle Housing in a Farm Transport Vehicle
Authors: Wang Yan Sheng , Zhang Yi Hua , Hu Ke Jun
Published: May 2011

Experimental studies were carried out on real rear-axle housing in a farm transport vehicle to investigate the influence of low amplitude preloading on structure life，in order to explore increase potential of rear-axle housing in a farm transport vehicle fatigue life. It is proved that a strengthening area exists in low amplitude loading area. Fatigue lives of rear-axle housings have been increased in some extent with preloading within this area. It can make fatigue life double at most. Based on physical tests, the best strengthening load region of rear-axle housing in a farm transport vehicle was estimated. It provides some technical supports for increasing fatigue life of real rear-axle housing.
Identification of Building Envelope Overall Coefficient of Heat Transfer Using Recursive Least Squares Algorithm
Authors: Yu Guo Qing , Gao Gang Feng , Lin Xin Feng
Published: May 2011

This paper introduces the methodology and procedures of identification of overall coefficient of heat transfer (U-factor) of building envelopes using recursive least squares algorithm and dynamic heat transfer data. Application this method to three types of typical to examine the correctness and feasibility of this method. The following conclusions can be obtained: 1) Identification of U-factor of building envelopes using recursive least squares algorithm is feasible for engineering purpose, the identified U-factor can be near to its real value; 2)The testing periods can be much shorter than the steady testing; 3)The identification error is associated with the thermal inertia. The error is larger as the thermal inertia of building envelope is large within the same testing circumstances.
Stiffness Analysis and Determination of the Most Reasonable Height for Flat Vierendeel Structures
Authors: Wei Cui Xia , Du Shou Jun , Sun Zhong Qiang , Ma Kun Ru
Published: May 2011

In order to improve the stiffness and reduce the cost, the stiffness analysis of the flat vierendeel structure was taken in to account with the analytical method and FEM. The structural main geometrical parameters’ influences on stiffness were studied, such as the height of the structure and the area of the upper and lower chords. The study showed that there was a most reasonable height for any flat vierendeel structure, which could make the stiffness best and the deformation least, and the formula for the reasonable height was deduced. Furthermore the area of the chord’s influence on the most reasonable height was discussed. At last, case study by FEM proved the validity of the proposed method, and several measurements for stiffness optimization were also put forward, which could be a reference for the design of relevant projects.
Experimental Research on Constitute Relation of Concrete under Uniaxial Tension and Compression with Different Strain Rate
Authors: Chen Hai Bin , Su You Po , Xing Jun Wei , Zhang Yu Min
Published: May 2011

The constitutive relation of concrete under uniaxial tension and compression is an essential theoretical basis for structural analysis of concrete. Because of the lack of sufficient stiffness for ordinary test device, a stable decline branch of stress-strain curve could not be obtained. The condition of realizing the stress-strain complete curve for concrete uniaxial tension and compression is derived. The experiment device for uniaxial tension and compression was designed and fabricated with increasing stiffness method. Experiments were carried out for concrete with grade C30~C60 and strain rate 10-5/s~10-2/s. The equation for stress-strain curve in the rising branch were obtained and so were the complete stress-strain curve of uniaxial tension and compression under different strain ratio, which provide the theoretical basis for concrete structural analysis.
Technology and Application of Landscape Ecological Replacement and Repair of Urban River
Authors: Zhang Shi Xia , Zhang Ji Ming , Zhang Shi Min
Published: May 2011

Based on the theory of the landscape ecology , this paper puts forward the ways of the landscape ecological protection, repair and replacement of the urban river system and emphasizes adopting the holistic and systemic view, which integrates river with its catchment area and combines stormwater infiltration, storage and usage with these in the process of river harness.
Mechanical Characteristics of Concrete Exposed to External Flexural Load, De-Icing Salt and Freeze-Thaw Cycles
Authors: Yuan Xiao Lu , Li Bei Xing , Zhao Shang Chuan , Zhou Shi Hua
Published: May 2011

This paper investigates mechanical characteristics of concrete exposed to external flexural load, de-icing salt and freeze-thaw cycles. Concrete specimens made with ordinary Portland cement or ordinary Portland cement incorporating fly ash with the replacement of 10% or 20%, or 0.7/10000 air-entraining agent and 20% fly ash, or ground blast furnace slag with the replacement of 15% or 30%, were made and exposed to flexural load, freeze-thaw and de-icing salt environment. Mechanical properties of concrete including compressive strength and flexural strength were measured. Phase composition of samples was determined by means of x-ray diffraction (XRD). Results indicate that increasing flexural stress ratios reduced compressive strength and flexural strength of concrete, and presented higher improvement of mineral admixtures in concrete strength. Incorporation of mineral admixtures and air-entraining agent decreased the loss of concrete strength. X-ray diffraction analysis showed the presence of abundant calcium chloroaluminate and ettringite in paste samples.
The Analysis of Influencing Factors of Multi-Ribbed Composite Wall’s Skeleton Curve
Authors: Chang Peng , Zeng Hang
Published: May 2011

Based on the numerical simulation of the basic behavior of multi-ribbed composite wall under low frequency cyclic load, the skeleton curve is consistent with the experimental results. Also, the factors such as axial compression ratio, the intensity of filling blocks and the shear span ratio which may influence the shape of the skeleton curves are analyzed. The results shows that the yield load of multi-ribbed composite wall as well as the limit load are positively related to the block strength, while are negatively related to shear span ratio. Besides, by the method of finite element model, 9 groups of skeleton curve data of multi-ribbed composite wall in different axial compression ratio, shear span ratio and the intensity of filling blocks were simulated. On the basis of multiple linear regression analysis of the numerical results, the equations for calculating the feature points in the skeleton curve are given.
Research on the Jing-Wei River System's Ecological Corridor in Metropolitan Area of Xi'an
Authors: Wang Fei , Wang Chun Mei , Wang Qi
Published: May 2011

As we all know, Jing-wei river system provides the ecological support for the development of Great Xi’an Metropolitan Area. However, the town’s random development, unreasonable planning and destructive construction causes bad effects on the Jing-wei river, like the area’s decreasing, and function’s degradation, which greatly limits the sustainable development. According to the conflict between development of Great Xi’an Metropolitan and ecological construction, the thesis comes up with idea of building up the ecological corridor, which gives a detail analysis about environmental characteristics of the Jing-wei river system, the spatial relation between the Jing-wei river system and construction zone of the town, the important function, characteristics of structure, and width of the ecological corridor, and its landscape evaluation system.
Effect of Curing System on Mechanical Property of Slag-Based Geopolymer
Authors: Wang Qing , Tu Xin , Ding Zhao Yang , Sui Zhi Tong
Published: May 2011

Geopolymer has been gradually attracting world attention as a potentially revolutionary material that is one of the ideal substitutes of Portland cement, and fundamental studies on geopolymer are increased rapidly because of its potential commercial applications. However, little work has been done in the field of curing system of geopolymer. In this paper, influence of curing temperature, curing time and curing humidity on the mechanical properties of slag-based geopolymer was studied by using the compressive strength as benchmark parameter. Results have shown that the early age compressive strength of geopolymer increased and the long-term compressive strength decreased at first and then increased as the curing temperature increased, 80°C was the best curing temperature. With prolonging the curing time, it was found that the compressive strength of early age of geopolymer reached the maximum ( 116.3 MPa for 1d, 97.5 MPa for 3d) as the curing time was 12h, and that of 28d geopolymer was 91.3 MPa as the curing time was 10h. It was also found that the compressive strength of geopolymer reduced evidently as the humidity increased.
Characteristics of University Landscape Planning and Design
Authors: Wang Shi Ying
Published: May 2011

The impact of the campus environment is an important factor in the quality of college campus, it is closely related to the school's image, brand, honor, and quality. Therefore, building high-quality, high-quality university campus landscape has drawn attention of colleges and universities increasingly. In order to build a campus environment with good ecological environment, beautiful landscape, vibrant and rich cultural atmosphere, we need to understand the nature of university landscape planning design. With the purpose of in promoting and exemplifying the university landscape planning and design, the thesis will illustrate from the following aspects: the design of campus landscape is to build an organic growth, carrying the material carriers the school even the human spirit the cities, and with the responsibility of integrational function.
Planning and Design Concept of ‘Diversion Enter City’ and ‘Landscaping by the Water’ in Wujiaqu City in Xinjiang
Authors: Hu Xiang Hong , Chen Ying Jie , Zhao Heng , Mu Jun Jing , Wang Yu Xiang
Published: May 2011

‘Diversion enter city’ is a fundament in constructing ‘Waterfront City’. It plays an important role in enriching the urban landscape level and improving the quality of the environment and urban quality. Associated with the planning project of Mengjin channel passing through Wujiaqu city, the present paper suggested a planning idea of ‘landscaping by the water’ by means of ‘Diversion enter city’, on satisfying the requirement of flood control. Choosing history and culture as landscape design elements, the landscape units became the carriers of urban culture. The idea provides a theoretical guidance and technical support for planning landscape ecology, constructing eco-city garden, building civilized city, improving the quality of life, speeding up the economic development of this city.
Performance Improvement of Soft Rock as Filling Material for Subgrade
Authors: Mao Xue Song , Zhou Lei Gang , Zheng Xiao Zhong , Ma Biao , Liang Jie
Published: May 2011

A soft rock is generally prohibited to be used as filling material for highway subgrade. A novel method for improving the performance of subgrade is proposed. Aiming at the large amount of highly weathered soft rock along Shiyan-Tianshui superhighway, the physical and mechanical properties of the natural soft rock is analyzed. Then the cement is mixed into the soft rock as filling material to better the subgrade performance.The field and indoor experiments showed that the maximum dry density and optimum water content increases when the cement content increases. By mixing the cement, the subgrade performance can be significantly improved.
Laboratory Study on Cold Recycling with Foamed Asphalt
Authors: Yang Li Ying , Tan Yi Qiu , Liu Hao , Li En Guang
Published: May 2011

With the rapid development of highway construction and rehabilitation, more and more waste asphalt mixture is produced. The waste is under great environment pressure. The reuse of the waste is urgent. Foamed asphalt cold recycling is a solution. In this paper, the foaming abilities of different kinds of asphalts are tested and the best foaming asphalt is found out. Then, the RAP is evaluated. Finally, the properties of the cold recycling mixture are studied. As a comparison, two different gradations with different amount of RAP are designed and their performances are evaluated. By all these tests, it is illustrated that the cold recycled asphalt mixture with foamed asphalt can fulfill all the technical requirements. The foamed asphalt mixture began its first use in Beijing and exhibits well.
Assessment of Government Contractor Classification System in Saudi Arabia
Authors: Alsugair Abdullah M. , Abuthnain Mansour M.
Published: May 2011

This paper presents results of a study to assess the Government Contractor Classification System in Saudi Arabia. Contract award procedures in public projects of Saudi Arabia are accomplished in two steps. The first one involves qualifying contractors to insure that their technical, financial, and managerial capabilities are suitable for the project to be awarded. This qualification is accomplished by the Contractor Classification Agency- Ministry of Municipal and Rural Affairs- in which the contractor is classified according to his specialty and capabilities. In the second step, bids of the contractors who satisfy the required classification are evaluated to select the best bid. Since the contractor classification is the only screening method to disqualify incompetent contractors and the difficulty of dismissing a qualified contractor who submits the lowest bid, the contractor classification must be an actual measure for the contractor's capabilities. To assess the contractor classification system a questionnaire has been prepared and distributed to the project mangers in different public ministries and agencies. The number of distributed questionnaire was 250 and 198 were collected and used in this study. In order to conduct an objective evaluation, a comparison has been conducted between performance of contractors who are awarded projects based on the contractor classification only with performance of contractors who are awarded projects based on the contractor classification and an additional prequalification by the project owner. Also, Chi-squared test was used to verify the cause of the difference in results of using these two types of prequalification. Results of the study reveal that the contractor classification system does not properly reflect the contractors’ capabilities.
Improvement of High Algae-Laden Water Treatment by Coagulation Aid of Chitosan
Authors: Wang Yu Heng , Wang Yu Heng , Zhou Xiu Yan , Li Na
Published: May 2011

Using aluminium sulphate (AS) and chitosan as the main coagulant and coagulant-aid respectively, the high algae-laden water was treated by coagulation /flocculation/sedimentation (C/F/S). When the dosage ranges of AS and chitosan were 35~45 mg/L and 0.4~0.7 mg/L respectively, the removal rates of turbidity, algae cells and TOC were all enhanced apparently compared with adding AS alone. Especially the effective removal of organic matters has a significant sense. The compound action of AS and chitosan can reduce dosage of aluminum salt coagulant for meeting the treatment requirements, which means reduction of residual aluminium in treated water. The algae flocs generated by coagulation aid of chitosan were larger and more compact and had a faster settling velocity. So the application of chitosan can bring better environmental and economic benefits in water treatment.
Recycled Technology of Urban Road Construction Waste and Miscellaneous Fill Used as Subgrade Fillings
Authors: Liu Bing Kang , Fan Jin Song , Hu Hui Min , Fu Li Hui
Published: May 2011

Continuously increasing municipal renovation and roadbed excavation produced a considerable quantity of solid waste each year such us miscellaneous fill mixed with broken pavement fragments and brickbats, which resulted in a series of urban environment and soil resource issues. Comprehensive recycling technology for soil modification to attain the strength requirements of subgrade fillings from the related road construction codes is necessary and even urgent, since the usual soil replacement is not the economic and environment-friendly method. The field investigation and laboratorial tests hereby had been completed to confirm the application potentials of typical soil specimens selected from different locations. The experimental results indicate some of specimens can be reused as subgrade fillings in road construction immediately and others should be treated by soil amelioration. To further certify the practicality of this recycled technology and broaden its range of application, three typical reutilization and treatment techniques, cold recycling, soil solidification and dynamic consolidation are introduced into engineering projects.
Experimental Study on Properties of a Kind of New Concrete
Authors: Xiong Mei
Published: May 2011

Dry-mixing self-compacting concrete (DSCC) is a kind of new concrete composite materialswhich based on self-compacting concrete vibration. DSCC was prepared with the cement, the coarse aggregate and sand of high strength and some cement replacement materials that had the better crack resistance. And it has the characteristics of filling performance, gap trafficability and anti- segregating like self-compacting concrete. The paper study on the basic mechanical properties and anti-carbonization ability of DSCC through concrete performance test, the results indicate that the basic mechanical properties and durability of DSCC better significantly than common concrete materials.
Experimental Study of Recycled Concrete Aggregate for Cement-Stabilized Macadam
Authors: Wang Hui Fen , Liu Hai Yan , Xiao Zhao Ran
Published: May 2011

The merits of recycled concrete aggregate used in cement-stabilized macadam have been demonstrated, and the influence of recycled concrete aggregate on strength and deformability of cement-stabilized macadam was studied, while the recycled aggregate was used as a replacement of equal gradation for original aggregate. The results show that the optimum moisture content of mixture was increased with the increment of recycled aggregate content within a certain range, but maximum dry density and drying shrinkage strain were decreased. The unconfined compressive strength was first increased and then decreased, and the splitting tensile strength was first increased and then gradually stabilized. Recycled aggregate with a reasonable content is beneficial for improving the pavement performance of cement-stabilized macadam.
Studies on the Evolution of Use Patten of Lakeshores in Wuhan
Authors: Wu Jing
Published: May 2011

There are more than 100 lakes in the central districts of Wuhan, which can be listed as the top one in China. Although Wuhan is gifted with such natural resources, it is still ruined by some personal factors such as soil and water losses and urban expansion in lakeshore areas. In recent years, lake areas decreases, wild species are driven away because of the damage and solidification of lands, and lakes in Wuhan are facing unexpected great challenges. The thesis will employ ecological grid analysis and mathematics statistics analysis to make a research on the pattern of lakeshore land use in different years, and summarize principles for its evolution.
Design Consideration of the Nonuniform Stress Distribution of Pultruded Structural Member under Compression
Authors: Choi Jin Woo , Lee Seong Sik , Joo Hyung Joong , Kim Chang Won , Ok Dong Min , Yoon Soon Jong
Published: May 2011

As a new construction material, fiber reinforced polymeric plastic structural shapes are readily available. Therefore, new construction and existing structure rehabilitation using FRP materials are ever increasing trend because of FRP material’s chemical and mechanical properties compared with those of conventional construction materials such as steel and concrete. Among the structural composites, pultruded fiber reinforced polymeric plastic structural members are the most popular for the civil engineering applications because of the cost effectiveness. However, they are made of fiber reinforced polymer resin system, they have relatively low modulus of elasticity and also cross-sections of structural shapes are composed of thin plate components such as flange and web. Therefore, structural stability is an important issue in the design of pultruded structural members. For the design of pultruded structural member under compression, buckling and post-buckling strengths of plate components may be taken into account. In the structural steel design following AISC/LRFD, in addition to the buckling strength, the nonuniform stress distribution in the section is incorporated with a form factor. In this paper, the form factor for the design of pultruded structural member under compression is investigated by experiment. Based on the experimental results, the form factor for the design of pultruded structural shapes have been suggested.
Loading Rate Effect on FRP-to-Concrete Bond Behaviour
Authors: Li Xiao Qin , Yang Zhen Jun , Chen Jian Fei , Lu Yong
Published: May 2011

This paper presents a preliminary finite element study on the effects of strain rate on the FRP-to-concrete bond behaviour using the K&C concrete damage model in LS-DYNA Explicit. The developed FE model uses the first-order eight-node hexahedron 3D solid element with one integration point and a sub-millimetre mesh. Results show that the model can simulate the static FRP-to-concrete bond behaviour with good accuracy and mesh objectivity. It also shows that the loading rate has significant effects on the bond behaviour.
Quantitative Comparisons of Construction Productivity of Curtain Wall Operations in High-Rise Buildings by Means of Simulation Techniques
Authors: Lee Tae Hee , Kim Hyun Mi , Ko Yong Ho , Han Seung Woo
Published: May 2011

The paper presents construction performance comparison of curtain wall operations. It is well known that curtain wall operations are major parts of high-rise construction projects. Literature reviews of high-rise buildings and curtain wall operations lead the study to focus on a unit system which has been widely applied in the domestic high-rise curtain wall construction. Data was collected by recording in actual curtain wall construction sites and simulation model was implemented for the quantitative comparison between the simulation value and the value of actual curtain wall construction sites. It is expected that this proposed study contributes to the further studies of developing an optimized assembling process model for engineers and site personnel in construction.
Illumination Design for Shaping Lighting Culture in the Room
Authors: Zhang Jin Hong
Published: May 2011

Interior design in modern room pursues culture taste. The illumination design is an indispensable part in shaping the culture of room. Because of the importance of artifical light in modern life, excellent illumination design plays a very significant role on shaping the lighting culture in room and improving people's quality of life.
Mechanical Properties of Concrete with Recycled Clay-Brick-Powder
Authors: Ge Zhi , Sun Ren Juan , Zheng Li
Published: May 2011

This paper studied the mechanical properties of concrete with cement partially replaced by recycled clay-brick-powder. Four variables (water/cement ratio, sand ratio, replacement level and average particle size of clay-brick-powder) were considered. Each variable had four levels. By using the orthogonal experimental design method, total 17 mixes, including one normal cement concrete as reference, were tested. Experiment results showed that recycled clay-brick-powder could be used as partial replacement of cement in concrete without reducing its properties. The strength was not significantly reduced with cement replacement level up to 25%. The elastic modulus was lower compared with cement concrete.
Measuring Apparent Gravity Effect to Characterize the Magnetization of Ferro-Fluid
Authors: Ho Je Ee
Published: May 2011

Due to the reversible transformation of physical property is strongly induced for ferro-fluid, so called intelligent working medium, subjected to the magnetic flux, its effective viscosity, especially, is closely dependent on the magnetization of ferro-particle and shows a special advantage in reducing the damping effect without magnetization hysteresis. Therefore magnetized fluid as a new engineering material, used for the shock absorber of building structure, has gradually attract scientist’s interest and engineer’s attention. Instead of previous experimental measuring the magnetized degree of ferro-fluid by costly Vibration Sample Magnetometer (VSM), a designed testing mechanism, based on modified Langevin function in apparent weight loss to characterize the magnetic behavior, is introduced in this study. It not only features as an stable, economical and affordable utility for local researchers, but a safe, easy operation with fast data acquisition would be also accessed. While compared with the experimental result conducted by VSM for ferro-sample provided by Matsumoto Co., the significant deviation using classic Langevin function in saturated magnetizationMd,within the magnetic field, 0 ~ 6 mT, can be effectively lessened to 50 % as the calculation undergone by modified model proposed.
Study on the Effects of Natural Pozzolan and Limestone Powder on Mechanical Properties of Roller Compacted Concrete Pavements
Authors: Madhkhan Morteza , Hamidi Armin , Salehi Navid
Published: May 2011

Due to high maintenance and production costs of conventional asphalt pavements in recent years, substitution of concrete pavements has been taken into account. One important factor of such pavements is the long-term performance. The substitution of pozzolanic materials with existing cement in the mixture is a common choice to improve the durability factors and to increase the long term compressive strength. Owing to this change in cementitious materials, a general anticipation of the pozzolanic behavior to be observed is that the early age compressive strength gets decreased. On the other hand, this defect will be compensated in the long-term compressive strength. Furthermore, as conventional loads of road pavements are concerned, the tensile and flexural strengths have their own importance. Regarding these two factors, the related tests were also performed and the results were analyzed. The main purpose is to find the optimum material among these 2 types of pozzolanic supplements and its percentage of substitution with the preference of having the best average strength in both long and short term performances. Altogether, the natural pozzolan had better performance than limestone powder.
Evaluating on the Skid Resistance of the Aggregates Based on Mineralogy
Authors: Wang Da Wei , Yin Chao En , Chen Xian Hua , Steinauer Bernhard
Published: May 2011

Four groups of granite aggregates with different mineral structures were investigated. They were formed into test plates with a flat surface and polished with the Aachen Rafeling Tester using quartz powder and quartz sand as the polishing agent respectively. At the end of each polishing stage, the friction coefficient of these plates was measured with the skid resistance tester (SRT) and the Wehner/Schulze test apparatus (PWS), which represent different contact conditions. By comparison of the different friction development in the course of polishing, the influence of mineral composition and crystal size on the polishing resistance and friction coefficient of the aggregates is determined. This new methodology can be applied to evaluate the long-term skid resistance of the aggregates for road engineering.
Features of Water Landscape of Ancient Villages in Huizhou
Authors: Jin Nai Ling
Published: May 2011

The water landscapes of Huizhou ancient villages present evident regional features due to geographical conditions, history and culture and construction idea. Through analysis and summary for characteristics of water landscapes of Huizhou ancient village in the paper, its quintessence is studied to be aimed at providing thinking for optimizing strategy of modern village environment and construction idea of modern landscapes.
Practice Analysis of Urban Road Pavement Roughness and Detect of Destruction
Authors: Peng Jr Hung , Sung Po Hsun , Lin Jyh Dong , Wei Kuang Yi
Published: May 2011

The urban road becoming more perfect, pavement engineering is from new construction to maintenance management. The authorities, from acceptance the new construction turn into survey of the road‘s situation and control of various types of damage and road conditions on time, to maintain a good condition of the road. In this study we use the CCD with the general Global Positioning System to provide GPS coordinates and have a street shooting for each 20m of road, record of the CCD road imaging system, and with GPS coordinates, the street pavement shooting can identify the highest frequency distress type within 100m of the road, and compare with the value of IRI for statistics, considering different distress conditions associated with the International Roughness Index, and to explore the causes. This study has an Urban Road Management System, it divided into road flat index query and pavement condition index query, and user can use this system know the pavement condition every section. The road maintenance unit can be judged by this indicator status of pavement roughness to develop a conservation strategy of each section, reflecting the degree of conservation of each section, making the pavement to maintain a good quality. Urban road maintenance management system is for the each authorities built the road pavement maintenance management system for pavement managers with different levels of management authority, and to assist in the system can provide information for urban roads to do planning, query and management, it is beneficial to the authorities to implementation of urban roads and other road maintenance operations, they can immediately understand the pavement condition.
Experimental Study on the Axial Compression Behaviors of Short Rectangular Concrete Columns Encased in CFRP Tube
Authors: Sun Wen Bin
Published: May 2011

In this study, 9 short rectangular concrete columns with cross-section 150mm×300mm and height 600mm are prepared, they are 6 confined concrete columns encased in CFRP tubes and three concrete columns as control specimens. The tubes with fibers oriented at hoop direction are manufactured to have 3 or 5 plies of CFRP sheet with 10mm, 20mm, or 40mm rounding corner radius. To ensure proper bond, a 100mm overlap is provided in the direction of fibers. Axial compression tests are conducted to investigate the axial strengths, compression behaviors, stress-strain relationships, and ductility until the CFRP tubes rupture. It is evident that the CFRP tube confinement can improve the behaviors of concrete core, in terms of axial compressive strength or axial deformability. Experimental results also show that the stress-strain behaviors of confined specimens vary with different the layers of CFRP sheets and corner radius at vertical edges.
EFG Virtual Crack Closure Technique for the Determination of Stress Intensity Factor
Authors: Chang Xue Ping , Liu Jun , Li Shi Rong
Published: May 2011

The aim of this paper is to introduce a virtual crack closure technique based on EFG method for thread-shape crack. The cracked component is discretized and the displacement field is determined using a coupled FE/EFG method, by which EFG nodes are arranged in the vicinity of crack tip and FE elements in the remain part in order to improve computational efficiency. Two typical parameters, nodal force and crack opening displacement attached to crack tip are calculated by means of setting up an auxiliary FE zone around crack tip. Strain energy release rate (SERR), further stress intensity factor (SIF) are determined by the two parameters. The method to calculate SIF is named as virtual crack closure technique based on EFG method. It is showed by several numerical examples that using the method presented in this paper, SIF on the crack tip can be obtained accurately.
Seasonal Distribution of Nitrate in Kuroshio of East China Sea
Authors: Liu Chao , Kang Jian Cheng
Published: May 2011

Analyzing the nitrate seasonal distribution and nitrate high-value areas in Kuroshio of East China Sea, shows that: (1) The average concentration of nitrate in Kuroshio of East China Sea were the highest in summer and the lowest in winter, the continental shelf area was higher than the off the coast area and nitrate concentration increased with depth. (2) There were three major high-value areas of nitrate in Kuroshio of East China Sea. The first high-value area’s center was 122.5°E, 26.5°N in northeast of Taiwan island, the depth range was 0~100m. The second high-value area distributed around 124.5°~126.2°E, 25°~ 27°N, the depth range was 100~500m. The third was in southwest of Kyushu which was in north of 28.5°N, the depth range was 0~500m. These areas were potentially highly productive areas, and also were the fish resource rich areas which needed to pay more attention on exploration in Kuroshio of East China Sea in future.
Research on Flexural Behavior of Coarse Recycled Aggregate-Filled Plain Concrete Beam
Authors: Li Jing , Wang Lin Fu , Li Juan , Qu Xian Feng , Jang Lin
Published: May 2011

In order to study the flexural behavior of coarse recycled aggregate-filled plain concrete beams, two beams were made. The experiment of simply supported beam under concentrated loads is performed, which makes us get the ultimate flexural capacity, midspan deflection and the development of cracks of each beam, and the numerical simulation of the damage process of beams is also carried out using finite element software. The results indicated that the tension property of coarse recycled aggregate-filled plain concrete beam is better than ordinary concrete beam, and some failure forms of bending is similar; the strength of recycled aggregates greatly influences flexural behavior of coarse recycled aggregate-filled plain concrete beam.
Study on Design Strategies for Improving Outdoor Thermal Comfort in the Cold Regions of China
Authors: Li Jing , Liu Yu
Published: May 2011

Along with the improvement of dwelling quality, the length of time and frequency of outdoor activities in winter greatly increase in the north China area, although the outdoor thermal environments are still unsatisfactory. It is necessary for both planners and architects to improve outdoor thermal environments in the cold regions of north China. This paper firstly introduces the general winter climate features in some north China cities. Then, it takes Xi'an city as an example to show the shortage of uncomfortable outdoor environment. Thirdly, the design strategies to improve outdoors thermal comfort include wind and snow protection, sunlight usage, environmental zones and recreational facilities, etc. are discussed.
The Laboratorial Study of Fracture Energy Release Rate of the Reservoir Ice Layer
Authors: Liu Xiao Zhou , Liu Peng
Published: May 2011

The fracture energy release rate , which is the important parameter of ice pressure calculation model that is built on energy balance method, is the fracture mechanics performance of ice material. It is related with these factors such as ice material temperature T, which must be measured by experiment. It is the experimental method of fracture mechanics used in this paper. These ice specimens on the different thickness T were tested with fracture mechanics method at low-temperature testing machine, to obtain the fracture flexibility change rate of ice body which contains pre-crack and the values of under different conditions of T, which could determine fracture energy release rate of ice body during the ice pressure generated, which provide the necessary experimental data to establish ice layer pressure calculation model for the application of energy balance method.
P-Wave Onset Detection Based on the Spectrograms of the AE Signals
Authors: Xu Jie
Published: May 2011

Determining the onset of acoustic emissions (AE) signal is very time consuming if the onset is picked manually, so it is important to read the arrival times ofPphase automatically. Automatic onset detection and picking algorithm has been proposed by applying the spectro-ratio on time–frequency sub-band. Powers of frequency sub-bands are determined by spectrogram as a time–frequency representation. Adaptive thresholds are calculated for one of these sub-bands to check if there is aP-wave arrival in the segment or not. To verify this check another test is done using the spectro-ratio. The application of this algorithm on the AE signals from the pencil-breaking test shows a reasonable result.
Numerical Simulation and Wind Tunnel Studies of the Wind Load on Wind Turbine Structures
Authors: Chang Cheng Hsin , Wang Jen Mu , Cheng Chii Ming
Published: May 2011

This paper investigated the structural responses of the wind turbine due to wind loads by performing the wind tunnel test and the Computational Fluid Dynamics, (CFD). The base shear force and the base moment of the wind turbine measured by the wind tunnel test were compared with the numerical simulation results. Both the numerical dynamic mesh and sliding mesh models were selected for the numerical simulations. The results showed that the dynamic mesh model was better than the sliding model by comparing to the wind tunnel test result. In the case of the k-epsilon RNG turbulence model, the prediction of the bending moment affecting by acrossswind was more than 50%, and the prediction of the force affecting by acrosswind was less than 3%. The both simulation results of the prototype and the full scale wind turbine were obtained by CFD model. The comparisons of the result showed that the error of Fxwas about 15% and Mywas about 13.5%.
Comparison on General Track Spectrum for Chinese Main Railway Lines and Track Spectrum of American Railway Lines
Authors: Chen Xian Mai , Tao Xia Xin , Cui Gao Hang , Wang Fu Tong
Published: May 2011

The general track spectrum of Chinese main railway lines (ChinaRLS) and the track spectrum of American railway lines (AmericaRLS) are compared in terms of character of frequency domain, statistical property of time domain samples and dynamic performance. That the wavelength range of the ChinaRLS, which is characterized by the three levels according to the class of railway line, is less than AmericaRLS at common wave band of 1~50m is calculated. Simultaneously, the mean square values of two kinds of track spectra are provided at the detrimental wave bands of 5~10m, 10~20m, and so on. The time-histories of ChinaRLS and AmericaRLS are simulated according to the trigonometric method, and the digital statistical nature of simulated time samples is analyzed. With inputting the two kinds of time-histories into the vehicle-railway system, the comparative analysis of the two kinds of dynamic performances for ChinaRLS and AmericaRLS is done in terms of car body acceleration, rate of wheel load reduction, wheel/rail force, and the dynamic responses of track structure. The result shows that ChinaRLS can characterize the feature of the Chinese track irregularity better than AmericaRLS, the track irregularity with the ChinaRLS of 200km/h is superior to the AmericaRLS, and the track irregularity with the ChinaRLS of 160km/h corresponds to with the sixth of AmericaRLS.
Development and Application of Eco-Friendly Concrete
Authors: Li Zhu Guo
Published: May 2011

Concrete is the most popular construction material. In its lifetime, natural resources such as limestone and aggregate are consumed. Meanwhile, emission of air pollutants and discharge of waste concrete in large quantities are of great concern. However, in recent years, high performance concrete and new types of concretes have been developed to decrease the environmental burden in its lifespan or in production phase, to utilize a substantial amount of recycled industrial waste, and to improve local environment. These eco-friendly concretes are classified into environmental protection type such as high performance concrete and recycled concrete, and environmental creation type such as porous concrete used for planting and air-purifying concrete with TiO2coating. This paper introduces the concept of eco-friendly concrete and summarizes present technologies and application.
Research of Treating High Ammonia-N Wastewater by CASS Process
Authors: Li Ying , Guo Ai Jun , Zhou Jing
Published: May 2011

High ammonia-N wastewater is leading to serious environment consequence. Adopting CASS process (Cyclic Activated Sludge System) to treat high ammonia-N wastewater is a good select, which is proved to be a flexible, convenient and efficient treatment. Kinds of factors which effected the nitrogen removal of high ammonia-N wastewater were studied and the optimum working condition of treating high ammonia-N wastewater by CASS process was discussed.
The Research of Growth Model of the Pecan Tree Height, Trunk, Crown Diameter and DBH
Authors: Yao Wen Bin , Li Xiao Liang
Published: May 2011

500 pecans were measured in Henglu village of Linan city of Zhejiang province. Through measuring the tree height, trunk, crown diameter and DBH（diameter at breast height）and analyzing the correlation, the regression equation applicable to different range can be chosen.
The Influence on Lining Moment of Tunnel under the Local Weakening of Structural Strength of Loess
Authors: Li Rong Jian , Zheng Wen , Fang Juan , Che Gao Feng
Published: May 2011

The influence of structural strength on the lining moment of tunnel should be properly evaluated in order to meet the engineering demand in loess area. It is essential to analyze and evaluate the lining moment of tunnel by means of the finite element method under the condition of the different local weakening of structural strength in loess. Firstly, some researches on the structural strength of loess tunnel are reviewed. Then, some different cases of the local weakening of structural strength in loess are analyzed in this paper. Numerical results not only indicate that the lining moment of tunnel tends to change obviously with the different local weakening of the structural strength, but also reveal that the weakening location of structural strength has important effect on the distribution and redistribution of the lining moment of tunnel.
Design and Experimental Investigation of a New-Style Pultruded GFRP Mid-Beam
Authors: Zhang Wei , Zhang Ming Yi , Gao Li Tang
Published: May 2011

Earlier laboratory test results showed a possibility of utilizing GFRP beam as a mid-beam in foundation pit support. This paper presents the development of a new-style GFRP mid-beam with I-section and double webs. Loading tests show that the new-style GFRP middle beam can satisfy the requirements for the globe and local stabilities, and simultaneously the material strengths of the middle beam can also be fully utilized. Beam tests with bolted connections show that a combined use of steel bolts and GFRP splice plates improved the stiffness and strength of the beam by 17.9% and 45%, respectively.
A New Edge Detection Method for Seismic Fault Image
Authors: Song Yan Xing , Yao Zhen Jing , Yang Jing Song , Tong Qing Bin
Published: May 2011

A new edge detection method for seismic fault image was presented. The method decomposed an image by morphology Haar wavelet, then used morphology edge detection operator to detect edge of the low-frequency morphological wavelet level, at last, the low-frequency and high-frequency coefficient are synthesized to realize the edge detection. Extensive experiments have shown that the method proposed in this paper can detect the edge of the seismic fault accurately with simple operations, and it is very competitive compared with other methods.
Study on Antioxidative Effect of Lycopene to the Photosensitized Oxidation of Soybean Oil
Authors: Li Xi Hong , Du Jin , Liu Chang , Wan Sen , Tang Yao , Xue Ting
Published: May 2011

A research was designed to study the effect on inhibiting the photosensitized oxidation of natural (lycopene) and synthetic (tertiary butylhydroquinon, TBHQ) antioxidant in soybean oil. In the presence of light, mean value of all samples revealed that a significant increase in peroxide value, free acid value and thiobarbituric acid (TBA) assay. The addition of lycopene and TBHQ reduced the peroxide value of control sample from 12.810 to 7.378 and 9.882 meq/kg, respectively. And TBA was found to be 0.163 in control sample, while the values of lycopene and TBHQ treatments were 0.080 and 0.134. Meanwhile, the oil samples were treated with different does of lycopene under light, the rate of oxidation increased considerably with a corresponding decrease in the content of lycopene. The data showed that oils containing 300 ppm lycopene had the lowest levels of free fatty acid value.The results indicated that lycopene in soybean oil exposed to light were found to be effective in inhibiting lipid oxidation.
Study on Nonlinear Finite Element Analysis Method of Multi-Ribbed Composite Slab Structure Containing Steel Fibers
Authors: Qiu Ji Sheng
Published: May 2011

Steel fiber concrete multi-ribbed composite slab system includes material composite and structure type composite, which has good mechanical and thermal insulation properties. This paper presents an assessment of the structure investigated using three-dimensional nonlinear finite elemental analysis. The analysis firstly has focused on solving the constitutive relation of the materials and the effect of steel fiber to determine the finite element simulation. Moreover nonlinear finite element analysis for the mechanical properties of the whole process on the composite structure system has been presented in this paper, and by changing the fiber volume fractionvf(0%, 1%, 2% and 3%) the parameter has been discussed. The analysis results show that stress distributions of the structure are close for different concrete strength and steel fiber volume fraction before formation of the plastic hinge lines of the upper edges. When the structure began to crack and the plastic hinge lines of upper edge gradually formed, due to the influence of the redistribution of internal forces, the steel fiber volume fraction has significant impact for the mechanic behavior of the structure. In addition, the steel fiber volume fraction on the developing and distribution of the cracks has little effect. This analysis method and results for the steel fiber concrete multi-ribbed composite structure can provide some valuable references for the structure research and application.