bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, Construction and Testing of a Solar Adsorption Refrigerator Using Synthesised Zeolite A and Water as Adsorbent/Adsorbate Pair
Authors: Amber I. , Folayan C.O. , Suleiman R.B.O. , Atta A.Y.
Published: October 2011

This paper presents the design and construction of a simple Zeolite-water solar adsorption refrigeration system which has been fabricated and tested in the Department of Mechanical Engineering, Ahmadu Bello University, Zaria, Nigeria at a geographical location of latitude 11o11’’NE. The theory on which this design is based is on the use of Zeolite-water adsorbent/ adsorbate pair to produce refrigeration. The energy source is a parabolic trough solar concentrator that collects and radiates solar thermal energy onto an air tight black coated absorber (generator) charged with Zeolite and water placed at the trough’s focal point. The absorber adsorbs and desorbs the adsorbate and produces refrigeration as vapor is released through a condenser and an evaporator. Constructional details of the system show the systems height at 1.2 m, parabolic trough dimensions of 0.6m by 0.45m, the cold chamber, has a capacity of 36 liters. The system was evaluated by leaving it outside under solar radiation and monitoring temperatures at various points inside the collector, the generator, and the evaporator through the use of thermocouple sensors. The highest and lowest temperatures of the absorber were 60.1°C and 25°C respectively. The lowest refrigeration temperature of 9.8°C was attained with 179J of cooling.
Determination of the Performance of Photovoltaic Modules Using Environmental Conditions
Authors: Sikiru Tajudeen H. , Ojo Olorunfemi , Jimoh Boyi
Published: October 2011

Manufacturers usually specify photovoltaic (PV) modules at standard test conditions of and , which may not be attainable anywhere in the world. Therefore, to determine the performance of PV modules at naturally occurring irradiance and ambient temperature, this paper proposes a theoretical methodology. This method could be used to predict the performance of PV modules given the irradiance and the ambient temperature at the site of installation. A novel technique that is based on the current-voltage characteristic model is used, it accounts for the variability in the environmental parameters. The irradiance and the ambient temperature of Zaria, Nigeria were used as an illustrative example, which showed the effects of the environmental conditions on the performance of PV modules.
Evaluation of Tri-Cone Bit Performance on Limestone Formation
Authors: Adebayo B. , Akeju V.O.
Published: October 2011

This study examines the characteristics of limestone formation as well as the performance of different tri-cone bits in limestone in Ewekoro. Rock samples were collected from different layers of limestone encountered in the quarry during drilling operation. These samples were tested in the laboratory for uniaxial compressive strength and the tensile strength. Also, the chemical compositions of the samples were determined using the X-Ray Fluorescence (XRF) Spectrometer and the results were used in the determination of the Equivalent Quartz Content (EQC). The length of the insert buttons on the surface of the drill bits were measured using digital vernier calliper at regular intervals. In addition, the tooth and bearing wear rates as well as the penetration rate were determined on the field. The results of the uniaxial compressive strength varied from 86.5MPa (medium strength) to 112 MPa (high strength). The Equivalent Quartz Content (EQC) of the rock samples varied from 17.37% to 36.676% while the Rock Abrasivity Index (RAI) varied from 15.03 to 43.317. The results of the drilling variables showed that higher wear rate was experienced when milled tooth tri-cone bit was used for drilling than using insert tri-cone bit for drilling limestone formation, hence the tri-cone bits performed optimally well in all the formations except in glauconite (GLAB) where its performance was low. However, the economic analysis indicated that the insert tri-cone bit drilling cost per metre varied from N660/m to N673/m while the milled tooth tri-cone bit drilling cost per metre varied from N684/m to N710/m. This will act as a data base for selection of drill bits and drilling equipment in limestone quarries.
Evaluation of Slope Stability in Open Pit Mine and its Effects
Authors: Ifelola E.O. , Bassey E.E.
Published: October 2011

Obajana Limestone Mine is operated by Obajana Cement Plc, the largest cement company in West Africa. The mine is located in Obajana town 49km North-West of Lokoja, Kogi State, Nigeria within the Igara-Kabba-Lokoja Schist belt with coordinates N070 55l 00ll and E060 261 0011. An assessment of the mine pit slope face was carried out in order to evaluate bench slope stability conditions with a view to providing a consistently safe and effective mine pit working environment. Scanline method was used in the geologic mapping of a section of the northern pit-wall of the mine. Empirical method was used to determine rock strength parameters relevant to design and analysis. Factors of safety values - the primary indices for assessing the probability or remoteness of slopes to failure were determined by the traditional limit equilibrium analysis; a most accepted and widely used method among geotechnical engineers. Roclab and RockPack III Software were used as tools for the analyses. Results from kinematics analysis i.e stereographic projections, stereoplots and stereo-analysis identified four sets of pole concentration with three of these lying within the friction cone (Critical area). This implies that the set of discontinuities with these poles will negatively influence stability conditions of the mine pit slope face.
Blackboard as a Tool for Peer Learning and Interaction for Engineering Students
Authors: Uziak Jacek , Oladiran M.T.
Published: October 2011

The purpose of this study was to evaluate the learning experiences of mechanical engineering students who used Blackboard technology at the University of Botswana. The results presented are based on the application of the technology in two courses offered to Year 3 students. As the results of this study were encouraging it is recommended that more courses in the mechanical engineering programme should migrate to blended mode of instruction delivery.
Modeling Analysis of the Wire-Drawing Operation Using the Weighted-Residual Finite Element Method
Authors: Oladeinde M.H. , Akpobi John A.
Published: October 2011

Numerical analysis of a wire drawing operation to compute the stress distribution along the blank cross-section is presented. The governing equation describing the wire drawing equation is weakened using the Bubnov-Galerkin finite element method to obtain the finite element model. The blank is descritized into a mesh of C0 quadratic isoparametric and C0 cubic finite elements. Stiffness matrices for all elements are obtained using the finite element model which were subsequently assembled by enforcing continuity of the nodal stress. Boundary conditions are applied and the resulting condensed system of equation solved for unknown nodal stresses using Gauss Seidel method. The relative performance of the C0 quadratic and C0 cubic elements are assessed. Parametric analysis is carried out to show the influence of drawing parameters on the stresses generated and drawing load. The analysis was carried out using a Visual Basic.Net program developed by the authors.The results are presented in both graphical and tabular forms.
Transportation Cost Minimization of a Manufacturing Firm Using Linear Programming Technique
Authors: Edokpia Ralph O. , Ohikhuare K.O.
Published: October 2011

This paper utilizes a linear programming technique in solving the transportation problem of a beverage producing company in Nigeria with a view to minimizing the total transportation cost and obtaining an optimal schedule bearing in mind the present transportation policy of the company. This work became necessary because it was discovered that the transportation costing policies of the company under study were not based on results obtained from sophisticated mathematical modeling but from rule-of-thumb methods. Transportation cost data from the peak period in the year under study were analyzed and linear programming methods were employed in finding the routes that will optimize total transportation cost of the company. From the company’s data, two transportation matrices were formulated and analyzed with optimal solutions of N 8,889,000 and N 13,989,000 giving a cost reduction of N 6,363,586 and N 1,263,586 respectively when compared with the company’s present transportation cost of N 15,252,586. On the basis of this finding, this paper recommends that the company employs this model in making its policies.
Partial Root Zone Drying Application in the Propagation of Vegetable in Northern Nigeria
Authors: Abimbola Olufemi P. , Ewemoje Temitayo A.
Published: October 2011

This study compares the response of Amaranthus candatus vegetable to root-to-shoot signals of soil drying and assesses applicability of the use of partial root zone drying (PRD) technique in increasing water-use efficiency. From a completely block randomized design, seeds were grown on three plots with each having three replicates. Three treatments were compared: half of the root system watered and half droughted by delivering 50% less crop water requirement (CWR) per irrigation depicted as 50%PRD; both halves of the root system received water application of 50% less crop water requirement per irrigation (50%CWR); while in the control treatment, both halves received 100% crop water requirement (100%CWR). The wetted and dried sides of the root system of 50%PRD were alternated on a 7-day cycle throughout experimental period. Effects of the differences in water-use on growth parameters, such as plant height, stem girth; number of leaves and leaf area were examined. Weights at harvest and root-to-shoot ratios were also compared. Drying half of the root system caused marked declines in all growth parameters in 50%CWR but only slight declines in 50%PRD. Since the main effect of water stress on Amaranthus is yield reduction, achieving better yields requires an optimum water supply from planting until ripening. Average edible wet weights (yields) of the 50%PRD and 50%CWR water applications when compared with the control were 81% and 25% respectively. The higher yield in 50%PRD may be attributed to high stomata sensitivity to drought signaling, as indicated by relatively low root to shoot ratio of 0.33. This lower ratio for 50%PRD treatment, compared to 50%CWR and 100%CWR with 0.40 and 0.66 values, was an indication of healthier and more profitable plants in 50%PRD because the decrease came from a greater shoot size.
The Application of Equivalent Flow Model in Groundwater Resources Loss Estimate of Fractured Rock Tunnel
Authors: Liu Zhi Chun , Yang Qian , Sun Ming Lei
Published: October 2011

This With the deepening of sustainable development strategy, groundwater environmental problems caused by tunnel projects are becoming more and more outstanding. This paper estimate the groundwater resources loss of fractured rock tunnel adopting equivalent flow models. In order to increase the model fidelity, the author considers the nonhomogeneous and anisotropic characteristics of fractured rock. Based on Shibanshan tunnel in Shijiazhuang-Taiyuan passenger line, this paper estimated the groundwater resources loss of fractured rock tunnel in construction stage and operation stage, which provides technical support for decreasing loss of groundwater resources.
Experimental Study on Anti-Frozen Durability of Concrete in Saline Soil Region
Authors: Jin Wei Feng , Wang Yi Hong , Zhou Gang , Fan Kun
Published: October 2011

Aiming at the problem of salt corrosion of concrete used in bridge and foundation in the salted areas of Qinghai province in our country,we study the performance of the prevention of salts corrosion and anti-freeze durability of concrete itself and concrete daubed waterproof materials outside or mixed the materials inside.The high-performance concrete made in this article used waterproof materials to prevent brine penetration and set multi-channel protection. The high-performance concrete specimens for comparison,the specimens daubed waterproof material, and rhe specimens mixed waterproof material inside are made to study the changing regularity under single factor and double factors(freeze and melt + chemical attack, carbonize + freeze and melt). The research results show the high-performance concrete made in this article has good anti-freeze durability and the protective covering of waterproof material can form multi-channel protection and effectively slow frozen corrosion of the concrete.
Exploration of Height Control in Urban Historical & Culture Heritage Protection Area-Take Example of Qu Jiang New District of Xi'an
Authors: Xie Hui , Zhou Qing Hua
Published: October 2011

Height control is one of major concerns in historical and culture environment protection. The paper concerns that how to create good overall height order and proper handle relation between heritage protection and social economic development under precondition of meet demand of basic height control in historical and culture heritage protection area. The paper takes Qu Jiang New District of Xi'an as an example through comprehensive analysis of various factors such as heritage protection, visual line analysis and urban morphology, etc. It is also focuses on quantitative approach of height control in outer space of historical heritage from perspective of visual line analysis and so on. It is concluded that under the conditions of adequate focus on the value of urban space, the sudden increase of the height outside the protection areas should be avoided in order to have a more active overall environmental outlook of the city.
On Properties of Recycled Coarse Aggregate from Repeatedly Recycling Waste Concrete
Authors: Zhu Ping Hua , Wang Xin Jie , Feng Jin Cai
Published: October 2011

The properties of recycled coarsee aggregates from repeatedly recycling waste concrete were determined. In this study, five series of concrete mixtures using coarse and fine natural aggregates were prepared, which have the same objective slump value from 35mm to 50mm and different compressive strengths ranging from 25MPa to 60 MPa. These five concretes were crushed, sieved, washed with water, hot treatmented at 300°C before they were used as recycled aggregates. After that, recycled aggregate concrete (RAC) was produced with an objectively compressive strength of 30MPa, in which the recycled coarse aggregate was used as 30%, 70% and 90% replacements of natural coarse aggregate and recycled fine aggregate as 10%, 20%, and 30% replacements of natural fine aggregate. After that, these recycled concretes were used as second recycled aggregates to produce RAC with the same objectively compressive strength of 30MPa. The physical properties of coarse aggregates including apparent density, water absorption, attached mortar content and crushing value were tested and their mineral characteristics were analyzed. The results showed that the quality of recycled coarse aggregates from twicely recycling waste concrete reached the requirements from structural concrete.
Computing Method of Elastic Foundation Beam by MATLAB and its Application
Authors: Wang Qiang , Tong Li Yuan
Published: October 2011

The elastic foundation beam method is the main method of stress analysis of the supporting structure of the foundation pit, it can easily calculate the internal forces and displacement of the structure, however, the computing method of elastic foundation beam deflection equation is more complicated. So according to the computation principle and method of elastic foundation beam, a computing program has been programmed by MATLAB mathematical software. The program has been applied to compute the internal force and deformation of deep foundation pit of Suzhou subway station. The variation law of displacement and bending moment of supporting structure during excavation has been obtained. The results of the measured and calculated agree well, and the computing results have efficiently guided and optimized supporting design.
Rapid Consolidation Behavior of Dredged Clays at High Water Content
Authors: Cao Yu Peng , Ding Jian Wen , Bian Xia , Ji Feng , Xu Gui Zhong
Published: October 2011

Consolidation of dredged clays with a system of horizontal and vertical drains is considered. Horizontal drains in the system are made of sand layers, while vertical drains are plastic vertical drains (PVD). Laboratory model tests are performed to study the rapid consolidation behavior of layered clay-sand and clay with PVD. Special cares are given to settlement and the drainage rate of dredged clays with radial and vertical drain system. Numerical analysis is also used to identify the stability time of consolidation, and to verify which method is better suitable for handling large-scale dredged clays.
Safety Risk Assessment of Highway Special Maintenance Project Based on BP Neural Network
Authors: Tian Wei , Li Hui Min , Yan Rui Qi , Hu Yun Xiang
Published: October 2011

16 items of assessment indexes are selected to build up the safety risk assessment index system of special maintenance project according to the construction safety characteristics of highway special maintenance project, based on which, the safety risk assessment model of special maintenance project based on BP neural network is brought forward. The assessment model has been trained, checked and analyzed through example and it turns out that the effective safety risk assessment of highway special maintenance project can be calculated based on this model, which also supplies decision-making basis for the project safety management.
Modeling of the CFT Column under Cyclic Load Based on OpenSEES
Authors: Li Lei , Zheng Shan Suo
Published: October 2011

This paper investigates modeling approaches of circular concrete-filled steel tube (CFT) column under cyclic load based on flexibility and fiber model. The effects of model parameters on modeling results is discussed, including constitutive relationship of materials, division of the fiber section, and the number of integration points. The results show that the material constitutive relationships of concrete and steel are prime important to the accuracy of the computational results. Three to five integration points for one CFT column in the flexibility-based analysis can achieve the desired accuracy and computational efficiency. The computational result is not sensitive to the number of sectional fibers. However, the desired accuracy can not be obtained if the number of the sectional fiber is not enough.
Experimental Study on Stiffness of Dougong in Chinese Ancient Buildings
Authors: Sui Yan , Zhao Hong Tie , Xue Jian Yang , Zhang Xi Cheng
Published: October 2011

As an important structural member in Chinese timber structure system, Dougong has an excellent capability in earthquake resistance. Through low cyclic loading experiment of single Dougong, two Dougongs and four Dougongs, the degrading rule of lateral stiffness of Dougong was studied. According to that, the hysteresis curve and skeleton curve of force –displacement were researched and the formula of resilience model and mechanical model were established. The experiment data show that slippage is the main deformation of Dougong. Energy dissipation due to frictional slippage is an important reason for the excellent seismic behavior of ancient wooden structure. The shape of hysteretic loops of Dougong assumes to be parallelogram. Plump area of hysteretic loop accounts for its excellent energy dissipation performance. The mechanic model of Dougong belongs to linear strengthen elastic-plastic model. Both the fitting equation of force-displacement and resilience model reflect stiffness changes of Dougong. These basic theories provide a theoretical basis for the study on the seismic performance, repair and strengthening of ancient wooden structures.
The Modeling and Simulation of VAV System Based on BP Neural Network
Authors: Feng Zeng Xi , Ren Qing Chang , Yu Jun Qi
Published: October 2011

VAV (variable air volume) system is a kind of all-air air conditioning system that adjusts indoor temperature by adjusting the supply air volume. This paper builds the mathematical model of supply air temperature of VAV using the step response method, and simulates the model with pure time delay according to PID parameters tuning based on BP (back propagation) neural network, and compares the simulation results with that based on traditional PID, which shows the control effect is superior to traditional PID.
A Study on Indoor Temperature and Cooling Load in Night-Ventilated Building
Authors: Duan Shuang Ping
Published: October 2011

The paper presents a qualitative effect of ventilation mode at daytime, night ventilation flow and outdoor air temperature, the temperature differences between of indoor air setting and outdoor air on cooling load reduction and indoor air temperature fluctuation at nighttime using thermal mass and night ventilation. A simple residential building model is chosen to obtain the hourly variation of cooling load at daytime and indoor air temperature at nighttime. It is noted that the temperature distribution of thermal mass material governed by an one-dimensional non-steady heat conduction equation .is considered in the paper. The dependence of the cooling load and indoor air temperature at nighttime on night ventilation flow, the outdoor air temperature, the temperature differences between of indoor air setting and outdoor air is further validated. Our results show that only suitable night ventilation flow with suitable outdoor climates and the appropriate temperature differences between of indoor air setting and outdoor air will benefit most. The present work provides guidance for designing night ventilation.
Issues of Sloping Roof Design of Multi-Storied Buildings
Authors: Yan Ya Jie
Published: October 2011

According to the sloping roof engineering characteristics of multi-storied buildings, summarized from architectural design, structural design and other aspects, the roof forms, slope, structure, drainage organization, ventilation, lighting, lightning protection and other related issues were discussed in this paper. The common problems about changing the plane roof to the sloping roof in the old buildings, such as deal with the water tanks, inner courtyard and solar water heaters of the old buildings were also investigated in this paper. The design methods and ideas of dealing with the sloping roof series’ design problems were proposed. Some reasonable suggestions about structural analysis methods, key parts of the sloping roof, cornice and plinth were given as references for the future selection of sloping roof scheme, design and other aspects of treatment.
The Experimental Method Comparison of Concrete Penetration
Authors: Ge Ruo Dong , Yu Ai Ping , Wei Ke Yu
Published: October 2011

For comparing the difference between Salt ponding test and ASTMC1202 test, the same batch of specimens divided into two groups are tested, and the chloride ion diffusion coefficient was calculated with the corresponding theory. The results indicate that the concentration gradient is larger, the concentration decreased faster and the slope of figure is more steep in salt ponding test, and the chloride ion diffusion is deeper for the role of the electric field in ASTM test. Although the diffusion mechanism is different in two kinds of test, there is little difference between the two groups of test diffusion coefficient.
Influence of Stearic Acid on Portland Cement Performance as Grinding Aids
Authors: Li Hao Xin , Yang Jian Sen , Zhu Hong Bo
Published: October 2011

Different contents of stearic acid were added to mixtures, and the influences of stearic acid as grinding aids on portland cement performances, including specific surface, compressive strength, hydration heat, Ca(OH)2 (CH) content, C-S-H gel and ettringite (AFT) content were discussed in this paper. The results show that the addition of small amount of stearic acid is enough, and excessive addition of stearic acid is not a good matter to cement grinding. Adding a small amount of stearic acid, not only don’t improve the compressive strength, but also lower the compressive strength significantly. Although the specific surface of samples with 0.1% stearic acid is lower than that of the samples with 0.025% stearic acid and reference, the compressive strength appears of higher than others. Addition of stearic acid affects not only on the rate of heat liberation, but also the hydration heat significantly. The addition of stearic acid has uncommonly impact on the content of CH, C-S-H and AFT in cement paste at 3 days, 7days and 28 days hydration age, the samples with 0.1% stearic acid has higher content of CH, C-S-H and AFT than others, and lower conversion content of AFT from 3days to 7days and 7days to 28 days. This can explain why the cement with 0.1% stearic acid is provided with the higher compressive strength than others, from the perspective of hydration production composition.
Influence of Carbon Black on Storage Stability of HDPE-SBS Modified Asphalt
Authors: Wu Xiao Wei , Cao Dong Wei , Zhang Hai Yan
Published: October 2011

In order to avoid the phase separation of the high density-polyethylene modified asphalt, a composite material modifier was prepared in the melt blending process with High density-Polyethylene (HDPE) and Styrene-butadiene-styrene (SBS) and a filler of Carbon black (CB). The storage stability of composite material (HDPE-SBS) modified asphalt was investigated by hot storage stability test and optical microscopic observation. The storage-stable mechanism of HDPE-SBS modified asphalt was analyzed also. The experimental results indicated that the difference of the softening point after storing at high temperature for 48h was very small. Micrographs of HDPE-SBS modified asphalt demonstrated that HDPE-SBS composite modifier particles dispersed uniformly and compactly and there were no obvious phase separations in the modified asphalt within a certain CB content range.
Performance Analysis of Polyacrylonitrile Fiber Concrete on Airport Pavement
Authors: Ma Hai Xin , An Ran
Published: October 2011

Properties of plain concrete and polyacrylonitrile fiber concrete, including fatigue resistance performance，flexural toughness and impact resistance performance were respectively studied．Improved effect on airport pavement classification number(PCN)by the addition of polyacrylonitrile fiber in concrete was then analyzed．Experiment results showed that all property indexes of concrete increased greatly，and pavement classification number also was enhanced by the percentage of 8.4．In this way，load-carrying capacity of airport pavement was enhanced greatly．
Development of Surface Cutting Machine for Raw Building Model
Authors: Zhang Jin Wen , Wu Xiao Jun , Wei Bao Quan , Lu Chao
Published: October 2011

This paper describes the development of cutting machine with multi-axis control for raw building model in detail. The cutting machine is integrated the MACH3 numerical system to control the three axis and while temperature of wire and move rotation are controlled by wireless remote unit. The design of interface circuit, servo motor driver circuit, wireless remote circuit are given in this paper. The state instruction circuit of cutting machine’s is presented. The fact shows that the application of this cutting machine for raw building model has obtained very good effect.
Experimental Study on Mechanical Behaviors of Lime-Stabilized Soils with Small Lime Content
Authors: Liu Zhong Yu , Xue Yong Gang , Wang Xi Jun
Published: October 2011

In order to investigate the mechanical behaviors of lime-stabilized soils with small lime content, the specimens with 4%~8% lime content and 90%~95% degree of compaction are prepared, and then in use for the unconfined compression strength test, the diametral compression test and the compression resilience modulus test after they have cured in a standard curing room for 7 to 180 days respectively. These test results show that all of the unconfined compression strength, the splitting strength and the compression modulus of resilience increase with the degree of compaction and the curing time. Thereinto, the compression modulus of resilience does rapidly between 28 and 90 curing days, and the unconfined compression strength of the soil with 4% lime content does little after 28 curing days while the compression strengths and the splitting strengths of the other soils do quickly until 90 curing days. In addition, for a given degree of compaction, these strengths of the soils with the less lime content are potentially greater at the early curing time.
Experimental Research on Mechanical Performance of Self-Compacting Reinforced Concrete Beam with Recycled Coarse Aggregates
Authors: Li Jing , Qu Xian Feng , Chen Hai Yang , Li Juan , Jiang Lin
Published: October 2011

In order to study the mechanical performance of self-compacting reinforced concrete beam with recycled coarse aggregates, recycled concrete and recycled gravel were taken as coarse aggregates with the particle size from 50 to150mm, two groups of specimen of self-compacting reinforced concrete beams with recycled coarse aggregates were made. After seven days, their bending strength were tested using method of one-third point loaded of simple beam on the testing machine. The results showed that the recycled coarse aggregates are bonded closely with the self-compacting concrete, its bond performance is good; Compared to ordinary reinforced concrete beam, it shows a smaller stiffness and a bigger mid-span deflection. In addition, the different combination of recycled concrete could reduce the self-compacting reinforced concrete’s stiffness with recycled coarse aggregate and increase its deflection.
Service Performance of HPSFRC Suitable for Super-High Vertical Pumping
Authors: Jiang Jin Yang , Sun Wei , Wang Jing
Published: October 2011

A type of small-scale fibers with dumbbells on two ends and notches in the middle was first designed to improve the workability and crack resistance of fresh high performance steel fiber reinforced concrete (HPSFRC). By using the fiber, the HPSFRC was continuously pumped to 306 meter high Sutong bridge tower. To ensure crack resistance of HPSFRC, tests concerning both non-loaded crack and structural crack were systematically performed, respectively. Then, the mechanisms behind the macro-behaviors were explored. Finally, life assessment method of HPSFRC that focused on the fatigue loading coupled with chloride and carbonation environment was presented by considering the effects of different fatigue degree on concrete durability. The results demonstrate that the steel fiber has the remarkable ability to restrain shrinkage and resist structural crack. It was also shown that the small-scale steel fiber can greatly improve the fracture toughness and fatigue property. In addition, the increased degree of damage due to fatigue loading would shorten the service life of concrete and the service life of HPSFRC under the multi-damage of fatigue loading and environmental loading would be longer than that of plain concrete.
Experimental Test of Corrosion-Induced Concrete Cover Cracking Pattern
Authors: Niu Di Tao , Song Hua
Published: October 2011

The study of cover cracking pattern can provide scientific basis for the durability assessment and maintanence of concrete structures. In this paper, corrosion induced cover cracking pattern was investigated by accelerated corrosion test. The cover thickness c, bar diameter d and bar spacing s were considered in the test. Test results showed that the cracking pattern of cover concrete mainly included four typies, that is longitudinal cracks including wedge and vertical, parallel cracks, spalling and delamination. When the bar spacing was small enough, the delamination of cover concrete occurred which had nothing to do with the ratio c/d. When c/d≤1, the corrosion of side bar mainly induced the vertical cracks and the corrosion of corner bar induced both vertical and wedge cracks. While c/d>1, the corrosion of corner bar mainly induced wedge cracks.
The Topological City
Authors: Kringas Simon
Published: October 2011

The Topological City is a design concept for a three-dimensional city in China. To accommodate future populations, cities need to be dense, diverse and ecological. Minimising the physical dimension reduces the consumption of material and energy and the destruction of ecological and agricultural landscapes. Mixed-use cities reduce the time, energy and congestion of travel. The integration of natural systems improves environmental quality and supports biodiversity. Ultimately however, the quality and functionality of contemporary urban life relies on dynamics of economic, social and intellectual interaction. The design form of a city must facilitate exchange between heterogeneous and changing programs while minimising energy and maximising habitat. High-rise construction is the dominant morphology of modern cities. Generated by an extrusion from the ground toward the sky, high-rise adds significant density but results in circulatory dead ends, structural inefficiency and habitat disconnectedness. High-rise is not interactive, energy efficient, or ecological. The Topological City proposes an alternate configuration of the urban environment. Drawing on the theory of place and connection known as ‘topology’, it constructs a three-dimensional network of vertical and horizontal towers, connected and activated by circulation. The Topological City is dense, diverse, ecological and interactive, suggesting a potential new direction for sustainable urban form.
Exploration of Land Suitability Evaluation Based on the Three Angles of Ecology, Construction Suitability Evaluation and City Safety — a Case Study of “the Master Planning of Hongya County Town”
Authors: Li Ze Xin , Zhang Tian Bao , Gong Dao Xiang
Published: October 2011

The article reviews the application of GIS technology to urban planning and the research progress on construction suitability evaluation. It points out that the present evaluation method invisibly weakens high eco-sensitivity areas and unsafe areas, and therefore the evaluation process can not objectively reflect the different angles of urban land use and its contradiction and unity. Thus, the article suggests strengthening the idea of giving priority to ecology and city safety through analyzing key sensitive factors and perfecting multi-factor superposition method. It explores a new idea for land suitability evaluation from three angles, that is, eco-sensitivity evaluation, construction suitability evaluation and city safety. An empirical study is conducted on the master planning of Hongya County Town.
New Method for Characterizing Interface Fracture between Dissimilar Materials
Authors: Peng Jun Long , Tang Jiao , Ouyang Zhen Yu
Published: October 2011

The interface fracture process of most layered or bonded structures is commonly under the control of mixed mode cracking where the interface shear and normal fracture components exist simultaneously when the hybrid joints are bonded with different adherend materials. In this work, a simple and novel method is proposed to realize and characterize the pure mode I interface fracture for the hybrid joints with dissimilar substrates. The theoretical and experimental results indicate that the present method may be considered as a standard test method for the characterization of hybrid joints with dissimilar materials.
Tests and Numerical Simulation on Short Composite-Sectioned Concrete Filled Steel Tubular Columns Subjected to Axial Compressive Loading
Authors: Zhang Yang , Qian Jia Ru , Ji Xiao Dong , Cao Wan Lin
Published: October 2011

In this paper, axial compressive loading test and non-linear finite element analysis of 10 short composite-sectioned concrete filled steel tubular column specimens are introduced. The test results indicate that the failure modes of all the specimens are similar, the specimens have high axial compressive strength and large deformation capacity. The calculated axial compressive strength of the specimens, assuming that the circle steel tube provides the lateral confinement to the core concrete and the square steel tube provides compressive strength without contributing lateral confinement to the concrete, has good agreement with the measured strength. The vertical load-strain curves, the axial compressive strength and the failure mode obtained by the non-linear finite element analysis of specimens have good agreement with the test results.
A Similarity Model Design in Concrete Attacked by Sulfate Erosion
Authors: Zhang Yan , Wang Qi Cai , Jia Lei , Huo Lin
Published: October 2011

The forms of concrete attacked by sulfate include physical crystallization and chemical crystallization. That affects the durability of concrete as an important factor especially in China's coastal areas and the Northwest region. Similarity theory in concrete by sulfate corrosion can be used to build up the similar criteria, and similar to the process of model design.
The Research of Project Financing Supply and Demand Condition about Construction Based on the Coordinate Development
Authors: Chen Sheng Hui , Li Hui Min , Ma Xin
Published: October 2011

To solve the problem of the funds supply and demand disorders in the construction project, the financing coordination decision system is established; the coordination development model is Introduced, joint action is researched between each subsystem, control factors of system is found, By calculating, the influencing factors which go against supply and demand balance are found . The conclusion drawn from the study are as follows:(1) Current construction project funds supply and demand relation imbalance seriously (2) Adopt corresponding measures, the state of capital supply and demand imbalances will be better;(3) Capital persistence, profitable and liquidity are the main factors which influence the relationship between capital supply and demand.
Component-Oriented Decomposition for Collaborative Optimization in Reinforcement Concrete Bridge Design
Authors: Wang Lian Fa , Tang Ai Ping
Published: October 2011

In order to implement the bi-level optimization strategy-collaborative optimization (CO) to bridge design, bridge optimization design process is subdivided into three subsystems in terms of component-oriented decomposition: superstructure subsystem, bearing subsystem and substructure subsystem. For system level, target function is formulated with the total direct construction cost, and inequality constraints induced relaxation factors are adopted to relax the intersubsystem consistency constraints. For subsystems, target functions are formulated with discrepancy expressions and constraints are formulated according to corresponding codes demands respectively. The feasibility and validity of the proposed approach are examined with an optimization process of reinforcement concrete box girder bridge. Optimization results from proposed approach are compared with that from mono-discipline optimization. The proposed approach shows high computing efficiency than mono-discipline optimization methods when achieving same optimization results.
The Damage Identification of Bridges Based on Structural Deflection and Wavelet Transform
Authors: Xue Ying Hui , Liu Hai Qing
Published: October 2011

Wavelet transform can characterize the local features of the signal in the time domain and frequency domain, enlarges and identifies the mutation signal of the structural response at different scales as a new signal analysis tools. In this paper, based on the structural deflection curve, propose a wavelet-based method to identify the beam structural damage. Use wavelet function to decompose the deflection curve of the structure after injury. Determine the existence of damage by the change and distribution of wavelet transform coefficients, determine the damage location, and simulate a cantilever bridge to verify this method.
Damage Sensitivity Analysis for Main Design Parameters of Steel Reinforced Concrete Column
Authors: Zheng Shan Suo , Hu Yi , Tao Qing Lin , Li Zhi Qiang
Published: October 2011

As an indispensable force component to composite structure, the seismic wave energy inputted into integral structure is dissipated by damping force working and plastic hysteresis of steel reinforced concrete column which is taken as research object. According to the condition that the SRC column is mainly used to dissipate the seismic wave energy, the ultimate energy dissipation capacity of SRC column subjected to cyclic loading is taken as the damage characterization. Based on the related theoretical analysis and experimental research, the method for calculating ultimate energy dissipation capacity of SRC column is proposed and the damage sensitivity of various design parameters which contain the section dimension, concrete strength degree and steel ratio are analyzed, then the influence laws of main design parameters impacted on damage evolution of SRC column are revealed in this paper. The research shows that sectional dimension is the most sensitive factor in the damage of SRC column and the steel ratio takes the second place, and then the strength of concrete is the most insensitive design parameter. The achievements will provide theoretical support for establishing the storey damage model of SRC frame structure under seismic excitation.
The Problems in Solar Building Integrated Development
Authors: Cao Ping , Wu Nan
Published: October 2011

Energy conservation for building on the use of solar energy has been the attention all over the world. However, the process of building integrated solar energy, went through three stages: passive accept era, simple addition era and building integrated era. There are flaws on the solar energy light heat technology development and application, it reflects on the design, construction and solar energy product itself. These flaws can be compensated if the solar energy and the building integration energy-saving construction projects can be treated as the key link during the life cycle ,cooperating with the project participants , can reach the goal of the solar energy and the building integration.
Preliminary Study of High-Rise Office Building Passive Energy-Saving in Cold Areas
Authors: Luo Zhi Xing , Yang Liu , Liu Jia Ping , Han Bing
Published: October 2011

This paper summarizes characteristics of high-rise office building energy consumption in cold areas, analyzes the common problems in passive energy saving design. On this basis, as an example of Xi’an road institute in scientific research office building, this paper introduces the design scheme of high-rise office building passive energy saving in cold areas, and verified the effect of passive design, finally calculated quantitatively study design of energy saving rate passive.
On Procedural Modeling of Urban Form - a Designer’s View and a Research Practice
Authors: Xiong Lu , Bruton Dean
Published: October 2011

Procedural modeling is a term in computer graphics referring to the creation of digital models with sets of rules. With the user-defined rule sets, digital models can be generated automatically by computers rather than modeled manually. Several popular procedural modeling methods and are listed and compared in the paper. A new research framework on procedural modeling of urban and architecture form is introduced. We also choose Jørn Utzon’s “additive architecture” as a case study and show the possibilities of future urban and architecture design.
Effect of Oil Contamination on Atterberg Limits of Soil
Authors: Tong Ling , Chen Wei Sheng , Zheng Xi Lai , Li Mei
Published: October 2011

Atterberg limit tests were preformed on diesel oil contaminated soil and crude oil contaminated soil. The results show that Atterberg limits reduced with increasing of diesel oil content. When crude oil content changed from 0 to 8%, it has little effect on Atterberg limits. However, it rose from 8% to 16%, plastic limit slightly decreased, but liquid limit increased remarkably. A "pseudo-viscosity" caused by crude oil is the key factor for this phenomenon.
Building Climatic Classification in China
Authors: Liu Da Long , Liu Jia Ping , Yang Liu
Published: October 2011

Different climate bring about different buildings, Climate has very close relation with architecture. Building climatic classification has important direction mean for architecture design, building energy efficiency and building energy simulation. Ago, China classified building climate using temperature, relative humidity, etc.. Degree, relative humidity and clearness index were regarded as classification factors. Meteorological data of 165 stations from 1970 to 2000 is used to reclassify building climate in China. Six types of building climates which respectively is Warm, Warm & humid, Weak solar radiation & humid, Cold & dry, Cold and Sever Cold & dry was obtained, character of every climate zone was summarized.
Study on Ecological Design Strategy and Practice
Authors: Zhang Hua Li , Dai Xiao Ling , Zhu Hao
Published: October 2011

This paper explains and demonstrates why uses’ needs are as important as green design principle and a good design should consider a lot on human’s feeling. It suggests that future green building will be based on principles that fundamentally address many of the issues that have become to light from this research. They will offer good working environments in which people are able to work to the best of their ability, and have the added bonus of low energy consumption.
The Experiment Research about the Condensation Prevention in the Radiant Cooling Panel
Authors: Kong Xiang Lei , Zhang Dong Hui , Guo Ting , Zhou Gen Ming , Zhang Xiao Song
Published: October 2011

This paper study some types of the condensation prevention measures in the radiant cooling board. The test bench for its surface condensation's performance is designed and built. In the experiment, four different types of radiation board, which are the grooved surface, Teflon coating surface, super-hydrophobic coating surface and the grooved surface pasted by the PTFE membrane, are investigated. The visual camera is used in observing the condensation process. It is found that: though both the Teflon coating and the super-hydrophobic coating treatment all can reduce the drop fall-off diameter effectively. Further, the super-hydrophobic coating treatment also can delay the fall-off time. The radiant cooling surface, by the measure of the grooved surface pasted by the PTFE membrane, can keep dry continuously. This work may lay the foundation for the simplification of the radiation cooling air conditioning system.
Experimental Investigation on Heat Transfer Performance in an Underground Dam Tunnel of Hydropower Station
Authors: Dang Yi Rong , Li An Gui , Yin Hai Guo
Published: October 2011

This paper presents an energy efficient ventilation method—dam tunnel air handling for hydropower station ventilation. The heat transfer characteristic between supply air and the dam tunnel is studied by model experiment. Supply air velocity, air temperature and dam tunnel surface roughness are chosen as the mainly influencing factors, the air temperature distribution along airflow direction are measured and analyzed in detail. The results show that the heat transfer performance in dam tunnel is improved as the increased of supply air temperature and the dam tunnel surface roughness, or maintained the supply air velocity at a lower level. This experimental study and its results are helpful to develop alternative and efficient systems for hydropower station ventilation.
Study on Treatment of Wastewater from the Production of PolyTHF with Extraction-Adsorption Method
Authors: Bian De Jun , Wang Li Guo , Zuo Yan , Qu Hong , Ai Sheng Shu , Tian Xi
Published: October 2011

Abstract: The wastewater from the production of polytetrahydrofuran (PolyTHF) was treated with union between of the extraction method and adsorption method. The results showed that using chloroform as extraction agent, CODCr removal rate could reach as high as 75%, then the treatment of wastewater was treated by adsorption method, which meet the national level of discharging standard, CODCr removal could reach at 100mg/L.