bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the DO Distribution and the Influencing Factors at the Downstream of Large Dam
Authors: Kong Feng Qin , Wang Yu , Cheng Yong
Published: April 2014

During the discharge of high dam, strong collision occurred along with the energy dissipation of the high velocity aerated flow. A great deal of air incorporated into the water and formed bubbles for the water was tumbling and gyration tempestuously. A large amount of air was released from the bubbles under the action of the hydrostatic pressure, and dissolved in the water, as a result, total dissolved gas (TDG) supersaturation was caused in the water. However, the supersaturation of the TDG has some important adverse effects on the surivival and reproduction of the aquatic, eapecially the fish. This paper analysised the longitudinal distribution and vertical distribution of the total dissolved oxygen (DO) saturation and the possible causing factors through using the measured data on the discharge in the Three - Gorge cascade hydropower station, combine with the theory of the water TDG supersaturation caused by the outflow from dam. The result shows that, the construction and operation of the cascade hydropower station can lead to the higher concentration of the total dissolved oxygen in the water,and even the supersaturation. Besides, total oxygen saturation decresde with the increasing of the water depth. Furthermore, the water level in front of the dam and the energy dissipating mode have some important effect on the total dissolved oxygen supersaturation.
Application Study Based on Surfer Underwater Earthwork Calculation
Authors: Chen Xu Fang , Shi Xi
Published: April 2014

This article will introduce the powerful functions of the software such as picture drawing, data analysis and modeling based on the case study, in order to show its application methods in the aspect of underwater earth volume calculation and space analysis. It will also analyze the advantages and development tendency of the software in the underwater earthwork analysis, which will be proved by engineering examples.
Modal Analysis on the Coupled Fluid-Structure Interaction of High Arch Dam
Authors: Wang Chun Tao , Wu You Ping
Published: April 2014

The dynamic analysis of arch dam need to take complex coupling action of dam-foundation-water into account, so the dam is always simplified in former research. The disadvantage of simplification is that it cannot be determined how much influence on natural frequency and dynamic response can be caused. In view of this, Xiaowan high arch dam finite element model is set up, the result shows : whether the reservior is empty or full, the natural vibration frequency of the actual body form has little change compare with the simplified body form. Therefore, it is feasible to apply the simplified body form to substitute the actual body form for the rough calculation of the frequency of dam body. However, the simplified body form is impossible to present the dynamic response and stress concentration of accessory structures. For this reason, it should apply the actual body form for calculation.
Research Progress of Protected Plunge Pool of High Arch Dam
Authors: Wang Ying Kui , Liao Ren Qiang
Published: April 2014

The security researches of energy dissipation were always the focus in the High arch dams. Statistically, the trajectory type energy dissipation is the most widely used in the built high arch dams, and the protected plunge poor were always set downstream the dam body. However, the widely used protected plunge poor need large investment with the disadvantage of complicated operation and maintenance. Along with the construction of concrete high arch dam in the Southwest China, the “Reventment-Protected and Non-Bottom-Protected Plunge Pool” has been studied and proposed, which has the advantage of more simplified project design and more economy investment.
Experimental Study on the Flexural Behavior of Stone Slabs with near Surface Mounted Steel Bar
Authors: Dong Er Xiang , Chen Zhong Fan , Xu Ming
Published: April 2014

Six stone slabs with near surface mounted steel bar were tested to study the flexural behavior of stone slab. The test parameters included the slotting dimension and steel reinforcement ratio. The test results show that the measure of near surface mounted steel bar can significantly increase the flexural capacity and ultimate deflection. The flexural behavior of stone slabs with near surface mounted steel bar is less affected by the slotting dimension; steel reinforcement ratio is the important factor influencing flexural behavior. With higher steel reinforcement ratio, the failure mode has transformed from brittle fracture into ductile failure; cracking load, ultimate load and displacement are largely increased by 10.2%131.9%617%. The mid-span section strain distribution complies with the plane-section assumption. Stone slabs with near surface mounted steel bar can fully exert the strength of stone and steel bar.
An Algorithm for Computing Logarithms of R-Sum of First and Last Circulant Matrices
Authors: Mei Ying
Published: April 2014

In this paper, an algorithm for computing logarithms of r-sum of first and last circulant matrices is given.
Mixed Finite Element for Geometrically Nonlinear Orthotropic Shallow Shells of Revolution
Authors: Stupishin Leonid , Nikitin Konstantin E.
Published: April 2014

A numerical method for mixed finite-element formulation shallow shells of revolution is developed. Orthotropic material model is considered. Final equations are derived by the Galerkin’s method. Results of solution of test task are represented. Results precision and convergence are analyzed.
Numerical Simulation for the Effects of Ice Thickness on the Overhead Transmission Cable Tension
Authors: Wang Zha , Yao Ji , Peng Sun
Published: April 2014

A model of single span overhead transmission cable was established in this paper, based on nonlinear finite element theory, combined with supports displacement method and node equilibrium method, form-finding analysis was carried out for the model of single span overhead transmission cable, the cable tension of model was compared with the theoretical calculation value, and the correctness of the model was verified. Then update cable model was analyzed, the sag, tension and ends tilt of cable under different ice thickness was discussed. This paper provided a reliable method for on-line monitoring the safety of overhead transmission cable in icing conditions.
Numerical Simulation of Non-Contoured Aerial Cable Tension
Authors: Wang Zha , Yao Ji , Peng Sun
Published: April 2014

Since the cable structure has the characteristics that its initial form and initial prestressing are interacted unknown values, the FEM software ANSYS was used in this paper, based on the nonlinear finite element theory, the form-finding analysis steps for aerial cable was established. Then based on these steps, the form-finding analysis for non-contoured aerial cable was carried out, and the safety of the form-finding model under icing conditions was evaluated.
The Calculation of the Dynamic Problem for the Beam with Arbitrary Boundary Condition by Method of Convolution-Type Point Collocation
Authors: Li Yong Li , Zhao Zhi Gang , Yang Hua
Published: April 2014

The method of convolution-type point collocation to calculate the beam with arbitrary boundary conditions was presented by using series function in time domain and the mode shape function of the beam in space domain. And this method is applied to solve dynamic problems of beam with arbitray boundary condition. The calculation example showed this method was very simple, highly accurate and effective.
An Improved Method of Determining the Disturbed State Concept Model Parameters
Authors: Lu Wei , Pan Jia Jun
Published: April 2014

The method of postulate of relatively intact model in the disturbed concept model is reached. Because it is more difficult to assume relatively intact curve by observed experimental data, a method which could automatically calculate the stress strain relation curve of relative intact by triaxial compression test data is raised, so that the determination of material parameters becomes easier, and the improved method is verified by numerical calculation. The results show that this method can effectively determine the stress strain relation curve of relative intact.
Numerical Simulation of Air Distribution and Particle Movement in a Displacement Ventilated Room
Authors: Wang Ze Bei , Wang Bao Qing , Chen Rong Hui , Yao Shu
Published: April 2014

As people spend more time indoors, indoor air quality becomes more and more important. Displacement ventilation, as a new type of air-conditioning strategy, has showed remarkable advantages on many occasions. In this paper, the air movement and particle distribution in a displacement ventilation room is studied and analyzed through CFD numerical simulation method. The results show that the airflow field and the temperature field all have obvious hierarchical structure, and the coarse particles have more obvious settling character.
Study General Peak-Pressure Formula on Flat-Structure Slamming into Water
Authors: Yu Long Fei , Zhang Ya Qun , Zhu Liang Sheng
Published: April 2014

Aimed at those accidents such as bridge collapsed, lifting containers fall off etc., based on slamming theory, combined with such practical engineering problems, simplified slamming model rationally, and carried out corresponding physical model experiment, thus obtained universal peak-pressure formula on this type slamming issues. Then take further research to validate the formula through others data, the results show that the formula has a good reference for actual engineering problems.
Design Method for the Normal Section of Carbon Textile Reinforced Concrete Beam
Authors: Chen Lei
Published: April 2014

The purpose of the present study is to propose a design method for the normal section of carbon textile reinforced concrete (TRC) beam according to the Code for Design of Concrete Structures and failure modes. It has been suggested that the normal section may fail in case of fiber fracture in the lower portion of the beam, concrete crushing in the upper surface of the beam, or both. Beam is preferably designed to make full use of the compressive strength of concrete. Then we proposed the basic equations for the normal section of carbon TRC beam and their application conditions. At last, the proposed method is illustrated by a real example.
Numerical Simulation Method of Tensile Behavior of Glass Fiber Laminates
Authors: Yang Shao Chong , Zhang Jian Hui
Published: April 2014

Based on the structural characteristics of glass fiber laminates, a novel finite element numerical model of the laminates was proposed and established with ANSYS software. The results from the FE analysis are compared with available test data in the literature [1], which indicate the numerical model is reasonable and reliable. At same time, tensile behavior and shear behavior of the glass fiber laminates was analyzed. This study can provide reference for glass fiber laminates design and calculation, and has important practical value.
Research on the Calculation Method for Bending Rigidity of Recycled Concrete Beams
Authors: Lei Bin , Wu Hui , Yan Yu Song , Rao Chun Hua
Published: April 2014

The comparison between the experimental results of bending rigidity of recycled concrete collected from the bending test carried out by domestic and overseas researchers and the calculated results by formulas from available codes is done. The results show that formulations of from available codes are not suitable for recycled concrete beams. Then, based on the factors that influence the bending rigidity of recycled concrete beams, the formulation of bending rigidity for recycled concrete beams is proposed by theory. The experimental results by this the formulation and the test results is very close, the mean value and variation coefficient of the ratio of experimental value and calculated value for recycled concrete beams is respectively 1.01 and 0.16.Keywords: recycled concrete beams;bending rigidity; deflection; formulation
Construction Technology for Ultra-High Baseboard and Hopper of Silo
Authors: Zhu Zhang Feng , Qu Qi Zhong , Dong Jun , Ding Hai Feng
Published: April 2014

Silo structure has been widely used in the industries in China, such as chemical engineering, coal industry, light industry, fodder industry and grain industry. Nowadays, reinforced concrete silo structures have been the most general form. Due to the special features of silo structure, there have been some particular part such as baseboard and hopper. Meanwhile, the level of the baseboard is always high and the configuration of the hopper is complex. Therefore, a lot of construction difficulties and problems have been generated in the progress of silo construction. Based on practical engineering, a series of construction technologies for ultra-high baseboard and hopper of silo were proposed in this paper. With a review to the structure features of the ultra-high baseboard and hopper, an applicative formwork scheme was designed and carried out in the construction. By means of the proposed formwork scheme, some key problems were well solved and the whole engineering quality were ensured. And it has certain reference significance to the construction of this engineering.
Design of Retaining and Protecting for a Deep Foundation Excavation
Authors: Jin Hui Wu
Published: April 2014

Urban development often requires the construction of deep excavations. There are some difficulties during design and construction of foundation excavation, such as large engineering quantity, poor geological conditions, as well as challenges to design and construction of retaining and protecting structure. To solve these difficulties, supporting system of steel circle beam, steel pipe support and stiffened support compounding with steel pipe pile cofferdam is designed. Soil resistance calculating method is used for support structure design in all possible conditions and the result is compared with that using the classical method. With reasonable supporting process and construction measures, monitoring results including displacement of steel pipe piles and greatest axial force can meet the norm requirements. It is proved that the retaining and protecting system designed is safe and reliable. With the benefit of small deformation and high integrity, locking steel pipe piles gave full play to its locking function of water. The design method in the paper is feasible and may offer some references for similar deep foundation excavation.
Study on Mass Concrete Construction Technology of Raft Foundation in Yantai Ocean Development Center
Authors: Zhu Jian , Zhang Yan Bin , Du Xu Feng , Jiang Yong
Published: April 2014

Mass concrete is widely being used in the construction field, especially for the foundation of super high-rise building. In the initial stage of pouring completion of mass concrete, lots of heat generated from the cement hydration will lead to a high temperature inside of concrete. When the temperature difference between the inner and outer of concrete exceeds the limited value, thermal stress will be greater than the tensile strength of concrete, which may cause hazardous penetrating cracks of the structure. To ensure the safety and durability of concrete structure, necessary measures should be taken to control the temperature rise and construction quality of concrete. Taking a super high-rise building project as an example, this paper introduces several effective solutions to resolve above problems. The technical measures such as enhancing the concrete quality, controlling temperature rise, strengthening temperature monitoring would be detailed illustrated. Meanwhile, valuable suggestions achieved from this practical project are proposed in order to guide the structural design and on-site construction of similar projects.
Analyzing the Cost of High-Rise Buildings after Second Design Based on the Bill of Quantity Valuation Mode
Authors: Wei An Xiang , Yao Jin Hua
Published: April 2014

The second design of construction drawings is an important part for building. It is not only a simple analysis and a modification of the drawings, but is the purpose to save cost using re-designed based on construction plan and techniques. For this purpose and other advantages of second design, the current large-scale projects, especially high-rise buildings, are required for secondary design. This article mainly introduces the second design, and uses the value engineering and the weighted average method to analyze the problem of cost savings and allocation. It proposes the approaches and methods of cost savings through the second design, obtains a reasonable method of allocation ratio calculation and general distribution ratio, as well as provides a strong reference to improving the economics of high-rise buildings.
Research on Construction Engineering Quality Supervision Based on Artificial Neural Network
Authors: Han Guo Bo , Zhang Li Ning
Published: April 2014

There is a nonlinear relationship between the size and quality of objective risk factors in the construction process, this relationship is quite complex to describe specific model. According to the characteristics, introduces artificial neural network control system that is a quality supervision method for quantitative. The effective supervision on construction quality is realized in the case of the full approximation nonlinear complex system by establishing the index system of construction engineering quality supervision, and it is verified by engineering examples. The research has practical operation and guiding significance to enrich methods of quality supervision in the process of construction work and to improve the quality of building engineering.
Interfacial Slip Calculation of RC Beams Strengthened with FRP Plate under Mid-Span Concentrated Loads
Authors: Liu Ai Xia , Yang Jia
Published: April 2014

The collaborative work between fiber reinforced polymer (FRP) and concrete is achieved through the binder, so the interface of them is the weak links. The interfacial slip between FRP and concrete beam is one of the key factors to affect the behaviors of RC beams strengthened with FRP plate. According to elasticity theory, this study analyzes the theoretical analysis of interfacial slip of RC beams strengthened with FRP plate under mid-span concentrated loads. The analytical model is established, and the differential equation of interfacial slip of RC beams strengthened with FRP plate is established. Using the boundary conditions, the calculated formula of interfacial slip is deduced under mid-span concentrated loads.
The Evaluation Model of Bridge Construction Safety Management Variable Fuzzy Sets
Authors: Yang Jing , Chen Shun Liang
Published: April 2014

Basing on the index system and evaluation data of bridge construction safety management status, this paper puts forward the relative difference function of variable fuzzy set by the method of set pair analysis, and develops the fuzzy comprehensive evaluation dynamic model of bridge construction safety management status. This model was applied to assessment of a bridge construction safety management status, and achieved the desired results.
Applied Research and Development Uygur Architectural Brick Mill Mosaic and Information Technology
Authors: Li Guang
Published: April 2014

Xinjiang Uygur architectural technology has unique ethnic art forms and traditional crafts features, especially brick mill mosaic decoration techniques which make full use of local resources, with local natural conditions, the use of the building features for life and customs of the nation designed by demand. In this paper, parquet architectural technology type characterization and application of traditional brick mill Uygur, leads to the development and application of traditional Uygur architectural technology and modern information technology. By combining technology development of information technology, architectural technology makes the Uighurs have a foundation and modern design, modern construction more closely, so as to find a way in modern society, the continuation and development of national culture and national economy.
Naturalization Design of Urban Water Landscape
Authors: Ding Yi Fan , Tang De Shan , Wei Yu Hang , Sun Yi Xiang
Published: April 2014

Urban rivers have always been the foundation of urban development. In the industrial era, many countries, including China, have experienced the painful lessons of environmental pollution. From the human-water relationship study date back to ancient time, we know that there is urgent need for the reversal of this negative human impact. The naturalization design of urban water landscape requires (1) use the advanced science and technology in project planning, design, construction and management; (2) save the project investment, speed up the progress and guarantee the project quality; (3) suitable for bio-lived and multiplied and for the survival needs of the organism after river training. When conducting the urban river landscape design, we should plan and design carefully based on natural and ecological principles, and the aim is not only visually pleasing, but also ecologically sustainable.
Urban Contexts and the Shape of Urban Features
Authors: Li Gang
Published: April 2014

The shape of urban features in our country neglects the context, and goes to two extremes. These extremes damage the development of urban. This paper focuses on differentiating and analyzing the concept and culture to urban contexts and features. There is a logical affinity between the urban contexts and the urban features. That is, the urban contexts mean “truth”, the urban features means “beauty”; the urban contexts are the “cause.” of urban features, and the urban features are the “results” of the urban context.
Urban Form Conservation Strategies for Sustainable Development: An Urban Design Project of a Historic Town
Authors: Hu You Pei
Published: April 2014

During the rapid urbanization of Chinese cities, great pressure is put on the work of historic city conservation by economic development. How to achieve balance between development and conservation is a problem that must be solved urgently for urban construction. This paper explores urban form conservation strategies and approaches adapting to economic sustainable development through an overall urban design project.
Contradictions and Countermeasures of Affordable Housing Construction
Authors: Yan Lei , Zhou Wei Ran , Miao Jian Feng
Published: April 2014

The paper extends its field of research to affordable housing development, which is an important people's livelihood issue in current china. This paper begins with an outline of public rental housing construction in Chongqing so called Chongqing model, in sight of universal issues in affordable housing exploitation, analyzes main contradictions about housing policy, planning and management, and proposes countermeasures from four aspects, establishing multi-level housing guarantee system, planning comprehensively and taking measures according to local conditions, emphasizing on quality and quantity to improve performance-price ratio, and updating design concepts to advocate intensive life. In conclusion, we find evidence suggesting that China should clearly understand the contingency and stage characteristics of affordable housing development, meanwhile establish all-round and whole process support policies and measures, and strengthen renovation of science and technologies. As a typical model, the exploration on contradictions and countermeasures of Chongqing pubic rental housing construction aims to provide experience and reference to affordable housing development across China form the theoretical and practical fields.
Study on Natural Ventilation Potential for Residential Buildings in Southern China
Authors: Liu Yang
Published: April 2014

Existing methods for natural ventilation potential analysis are reviewed and discussed in this paper. Based on related research results, a simple natural ventilation potential prediction model for two-opening room is developed considering climatic conditions, local terrain conditions, building opening area and thermal comfort zone. In this model, several major cities in southern China are selected and the natural ventilation potential is analyzed by using the evaluation index of effective hours and effective air change rates. It shows that residential buildings in the south of China are suitable for natural ventilation generally, while effect differ significantly by region and season. The analysis results can help the designers to formulate the proper ventilation strategy and to make assessment of energy-saving effect.
The Fusion of Commercial Buildings and the City
Authors: Tan Wen Di , Zhu Li
Published: April 2014

The fusion of commercial buildings and city will more closely, this paper analyzes issue of fusion from three aspects, the fusion of commercial buildings and city traffic, energy, communication system, the fusion of commercial buildings and other functions building in the city, the fusion of humane geographical features of commercial buildings and city, this paper has guiding significance to design the commercial project planning and commercial building.
Commercial Space Design Research – Take Jincheng as an Example
Authors: Li Na , Liu Yuan Ping
Published: April 2014

According to the current situation of the development and characteristics of Jincheng business district, this article selects the Yihou commercial pedestrian street as a preliminary study, does deeper research of Huanghua street and Xinshi pedestrian street, etc. Their operation forms including brand shopping, electronic products, snacks and entertainments, multiple formats of mixed malls. Selected representative blocks can reflect the development characteristics and present conditions of commercial blocks in the city of Jincheng more comprehensively, with a comprehensive analysis and research on Jincheng commercial blocks, summed up their advantages and disadvantages on spatial distribution, then plays a guiding role on commercial block development in small and medium-sized cities.
A Study on Sustainable Green Ecological Landscape Design
Authors: Liu Yong Jin
Published: April 2014

Green ecological landscape design represents a sustainable design and development model, aims to build an environment which fits peoples health and living. Starting with its meanings, this paper makes a full analysis of its guiding ideology, characteristics and composition, and takes a practical application of the above analysis through elements and methods of residential landscape design. Finally, we hope this paper can play a guiding role in the process of our countrys landscape design toward to sustainable green and eco-design.
Discussing of Creating a Nostalgic Atmosphere in Landscape Planning and Design
Authors: Zhou Yun Ting , Liu Hong Min
Published: April 2014

In the rapid development of modern society, people always remember the life in the past time. Through analysing the meaning of nostalgia to find relieving stress which comes from modern society and life is the main reason for people to seek nostalgia. This paper illustrates the way to establish the nostalgic place spirit through landscape elements, material and so on based on some examples, and discuss the way to build the nostalgic atmosphere in landscape architecture.
Nonlinear Buckling Analysis of Long-Span Suspended Latticed Intersected Cylindrical Shell
Authors: Zhu Ming Liang , Sun Yan
Published: April 2014

The Suspended Latticed Intersected Cylindrical Shell (SLICS) is a new structural system, composed by the single layer Latticed Intersected Cylindrical Shell (LICS) and the prestressed cable-strut system. Mechanical properties of this structure were investigated through nonlinear buckling analysis by the consistent imperfect buckling analysis method, compared with the single layer LICS. Structure parameters including prestress level, member section, length of bar, rise-span ratio, obliquity were analyzed. And the effect of material nonlinearity on the stability was studied. Results show that the ultimate bearing capacity of the SLICS is improved as the introduction of prestress. However the prestress level has a limited impact on the ultimate bearing capacity. And the material nonlinear is very important to the stability of the SLICS.
Energy Efficiency Renovation Study of a University Library Building in Ningbo
Authors: Cang Sheng
Published: April 2014

A university library building in Ningbo is taken as an example for energy efficiency renovation analysis based on the software PBECA. Five kinds of energy efficiency reforming schemes are proposed and compared, and the best effect of energy efficiency renovation is external sunshade. Moreover, the largest energy consumption is the ground. Although all reforming schemes failed to meet the target of 65% energy efficiency, scheme five is close to 65% energy efficiency target considering the actual usage of the library building.
Principal Component Analysis in Building Energy Efficiency Rating System for Apartment Housings
Authors: Jung Ho Gun , Park Min Cho , Shin Sung Woo
Published: April 2014

This study is aimed to establish the Carbon Emission Baseline for apartment housings. The carbon emissions at the operational stage were calculated through simulation based on the physical calculation. This method was chosen because it was necessary to estimate carbon emissions before the construction of the building. In fact, the energy consumption of buildings is more influenced by social statistics than by physical factors. This study used BEER and aggregated statistics of K-apt. system with a goal of estimating carbon emissions by buildings and establishing the carbon emission baseline. For this, the reliability of the related data which determine the energy consumption and carbon emissions of apartment housings were reviewed, and components were classified. Principle Component Analysis is used to determine the main components that are comprised of BEER indicators. The variable groups which are selected by PCA would be used in multivariate analysis.
Comparison and Selection of the Durability Evaluating Parameters of Concrete in Saline Soil Region
Authors: Zhang Li , Su Xiao Ping
Published: April 2014

The mal-condition of environment directly affects the durability of concrete, and which has become a widespread problem under the complicated environment conditions. Domestic and overseas scholars have carried out many researches on the durability of concreteunder different environmental conditions. The mass and the dynamic elastic modulus loss are focused as two major criteria in the evaluation of concrete damage. The article further gives researches on the durability of concrete in the saline soil environment in the west region of Jilin province. The concrete durability tests are conducted under the actions of salt soaking, salt corrosion and freezing-thawing cycles, and salt corrosion and dry-wet cycles. Comparing the test results in the same coordinate system, it is concluded that the dynamic elastic modulus of concrete can reflect the degradation process of concrete performance more accurately and intuitively, and forecast the failure behavior of concrete under the action of various environmental factors timely and effectively. Therefore it can be used as the main index for no damage detection, while the mass loss can be acted as the auxiliary detection index during the concrete durability tests.
Constitutive Relations of Masonry under Compression — A State-of-the-Art Review
Authors: Xiong Xue Yu , Zhang Sen , Wang Li Jun , Xue Rong Jun
Published: April 2014

An in depth state-of-art review is done on the topic, constitutive relations of masonry under compression. 12 constitutive models of masonry proposed by scholars from home and abroad are presented in the paper. These models can be classified into four types. Merits and drawbacks of each constitutive relation are discussed. Ten typical constitutive relations are selected to make comparisons. Results show that the ascending branch of curves has few differences, major differences occur in the descending branch of curves. Besides, two experimental data are used to analyze the models and results are discussed. Furthermore, some suggestions on this topic in future research are presented.
Corrosion-Induced Concrete Cracking, Steel-Concrete Bond Loss, and Mechanical Degradation of Steel Bars
Authors: Tang Fu Jian , Chen Gen Da , Yi Wei Jian
Published: April 2014

This study experimentally investigated corrosion-induced deterioration in reinforced concrete (RC) structures: concrete cover cracking, steel-concrete bond loss, and mechanical degradation of corroded steel bars. Pullout and RC beam specimens were prepared, subjected to accelerated corrosion in a wet sand bath, and tested under loading. A 3D laser scan was employed to measure the surface profile of corroded steel bars and determine the corrosion effect on the distribution of residual cross section area. The crack width on the concrete surface was sampled randomly and analyzed statistically. Corrosion reduced the bond strength between steel bars and concrete, particularly in the form of corrosion-induced number and width of cracks. Both the yield and ultimate strengths depended upon the critical cross sectional area of steel bars, whereas the elongation changed with the cross section distribution over the length of the steel bars. Corrosion also changed the distribution of the cross sectional area of steel bars. The crack width on the concrete surface can be well represented by a normal distribution regardless of corrosion levels.
Durable Carbon for Structure Applications, H2-Energy Carbon Building Materials (HECBM)
Authors: Wei Wen Cheng J. , Halloran John W.
Published: April 2014

Coal and biomass are pyrolyzed to get gaseous fuels (CO, H2 and CH4), carbon aggregates, and useful Ca-species for the preparation of carbon building materials. By using hot-extrusion of carbon powder with coal-tar-pitch at temperatures above 400oC, the sample can be densified to have good strength and the potential for structure application. Two coal samples and four biomasses have been investigated and so to depict the feasibility of the application of HECBM.
Effects of Different Lithium Admixtures on Ordinary Portland Cement Paste Properties
Authors: Deng Yu Hai , Zhang Chang Qing , Shao Hai Qiang , Wu Han , Xie Nie Qiang
Published: April 2014

Lithium-based chemicals are known to their signal effect on restraining alkali-silica reaction but uncertain influence on workability and mechanical property in the concrete. The aim of this research is to analyze the effects of three lithium additiveslithium nitrate (LiNO3), lithium hydroxide (LiOH) and lithium carbonate (Li2CO3) at various dosages, with an extensive comparison on fluidities, setting times and compressive strength of cement pastes. The experimental study shows that test results vary with the type of admixture. In general, three conclusions can be made: 1) lithium nitrate and lithium hydroxide can enhance the fluidity of cement paste, but lithium carbonate has opposite effects; 2) all three lithium salts shorten setting time as well as decrease the strength at suitable dosages; 3) the variations in lithium additives dosages have different influence on the cement pastes setting time and compressive strength development.
Experiment on the Mechanical Performance of Fiber Lightweight Aggregate Concrete after Freeze-Thaw and Elevated Temperature
Authors: Cheng Bo , Huang Jing , Jiang Wen Ting , Wang Jian Min
Published: April 2014

Experiment on the compressive strength and splitting tensile strength of fiber lightweight aggregate concrete (FLWAC) after freeze-thaw cycling and high temperature was tested through blending polyvinyl alcohol fiber (PVAF) and polyacrylonitrile fiber (PANF) in aggregate concrete respectively. Five temperature levels, room temperature, 200°C, 400°C, 600°Cand 800°C were selected to heat the FLWAC test blocks after 25 times of freeze-thaw cycling. The micro-structure of FLWAC was observed through SEM. The experiment results show that, the cubic compressive strength of FLWAC is improved when the temperature is above 200°C, and the splitting tensile strength of FLWAC is obviously improved between the ranges from room temperature to 600°C. Blending fiber can weaken the brittle fracture performance of LWAC after freeze-thaw cycling at the peak loading state. However, the mass loss doesn’t have obvious improvement before and after 25 number of freeze-thaw cycling.
Meso-Structure and Transport Performance of Near-Surface Concrete
Authors: Wu Li Peng , Yang Jin Bo
Published: April 2014

Transport performance of near-surface concrete is a main factor affecting the durability of concrete structures. Meso-structure of near-surface concrete and its effect on permeability were investigated. The near-surface concrete was divided into several layers, and by considering the dilution effect, the tortuous effect, and the interfacial transition zone effect on permeability caused by aggregates, together with hardened paste permeability, a computational frame for permeability determination of near-surface concrete was established.
Research on the Comprehensive Utilization of CPFL in Concrete Moisture Curing
Authors: Chen Jian Fang , Li San Ping , Wang Lei , Dong Hui
Published: April 2014

Controlled Permeable Formwork Lining (CPFL) has particular water-storaging capacity, the mixing water remained in the CPFL can provide moisture curing for the surface layer concrete for a period time. In this paper, the water storage was tested, the appearance quality, rebound hardness and durability of the surface concrete were studied. Results shown that CPFL can significantly improved the appearance quality, early age rebound hardness, carbonation resistance, chloride ion penetration resistance and freezing-thawing resistance of the surface concrete; the coating age of anti-corrosion coating was shortened to 18 days, the cofferdam turnover rate was speeded up, the engineering cost was reduced; the coating adhesion was significantly improved and the thickness of dry coating film and adhesion of discrete were reduced. The benefit of using CPFL technology is remarkable, and it is worth promoting.
The Research of GGBS’ Influence on the Cracking Resistance of Concrete
Authors: Liu Yan , Ma Dao Xun
Published: April 2014

The aim of this paper is to study the impact of GGBS on the early age cracking resistance of concrete. To assess the volume stability of premixed concrete under different dosage of GGBS an innovative cracking test method is adopted, and the causes and effect mechanisms of that are analyzed.
The Use of Infrared Thermography in the Analysis of Engineered Cementitious Composites
Authors: do Bom Conselho Sales Rosemary , Andere Pedra Solange , Aguilar Maria Teresa Paulino , Sales Fernando Augusto , Cetlin Paulo Roberto
Published: April 2014

Non-destructive testing using infrared thermography has been used in civil construction basically in situations involving electrical conductors or mechanical wear that normally generate heat. In the specific case of materials, the application of thermography to metal stud is well documented, but there are few reports in the literature covering thermography in concrete; these are usually limited to the inspection of cracks and to the localization of water infiltration in prefabricated concrete structures. The present report evaluates the potential of the active infrared thermography method in the detection of changes in the macrostructure of engineering cementitious composite, as well as in order to estimate its thermal performance. The results show that thermography is able to detect changes in the macrostructure and is sensitive to temperature differences among the constituents of concrete.
Crack Self-Healing Properties of Concrete with Adhesive
Authors: Cao Qing Yu , Hao Ting Yu , Su Bo
Published: April 2014

An experimental program was carried out to investigate whether EVA (ethylene vinyl acetate) heat-melt adhesive can potentially act as a self-healing agent in cement-based material. The effects of incorporation of EVA and heating on the properties of mortar were studied. Experimental results show that the interface between EVA and cement matrix was well improved after heating, which allows a significant improvement in flexural strength and toughness of specimen; Pre-damaged specimens in various degrees (30%, 50% and 70%) were effectively repaired by EVA and the repair efficiency all exceeded 100%. Keywords:crack; heat-melt adhesive; self-repairing
Effect of Emulsified Waste Oil on Micro-Structure and Autogenous Shrinkage of the High Strength Concrete
Authors: Han Cheon Goo , Han Min Cheol , Huang Jin Guang , Kim Tae Cheong
Published: April 2014

This paper presents an investigation of the effect of emulsified waste cooking oil on the porosity, EDEX results and the reduction of autogenous shrinkage of the high strength concrete with W/B of 20% incorporating 20% of fly ash and 10% of silica fume. Two different types of shrinkage reducing agents, the existing glyeol based shrinkage reducing agent (SR) and the waste cooking oil (WCO) were applied and compared. The effect of emulsification of the WCO with two emulsifying speeds, 2000 rpm and 4000 rpm were also investigated. It is found that the emulsified WCO has desirable shrinkage reduction effect than un-emulsified WCO and existing SR. Test results also indicated that emulsified WCO could also reduce pore volume due to saponification reaction
Experimental Study on the Mechanical Properties of the Crumb Rubber Concrete Modified by Silane Coupling Agent
Authors: Li Wei , Huang Zhen , Wang Xiao Chu , Zang Zi Sheng
Published: April 2014

Organic molecule and Inorganic molecular could be bind by silane coupling agent,the cementitiousness between rubber particles and cement-based material could be raised because of the surface modification of rubber,thus enhance the mechanical property of crumb rubber concrete.We had researched the change regulation of Mechanical Properties,such as compressive strength,splitting tensile strength and flexural strength of the Crumb Rubber Concrete Modified by silane coupling agent with various quantity of rubber,under the condition Dosage of silane coupling agent is 0.5% of cement quality.
Parametric Sensitivity Analysis of Long-Span Arch-Truss String Structure
Authors: Bai Zheng Xian , Hou Xi Ming , Tian Shuai , Wu Jin Zhi
Published: April 2014

Parametric sensitivity to static behavior and dynamic characteristics of Long-span Arch-truss String Structures (ATSS), which is based on statistical distribution of parameter errors including elastic modulus of the material, effective area and pre-stress of cable, and thickness of steel pipe, etc., was studied by Monte Carlo simulation method of ANSYS. The error of sectional area of cable is found to be the most sensitive parameter and the natural frequencies are greatly sensitive to the errors of modulus of members. The results help to determine suitable updating parameters of ATSS, and provide valuable advices to guide the construction control.
Influence of PP Fibers on the Relative Residual Splitting Tensile Strength of HSC after Exposure to High Temperatures
Authors: Yan Rui Zhen , Ge Wei Hua , Du Hong Xiu
Published: April 2014

In order to discuss the effect of different cooling methods, dosage and length of PP fiber on the splitting tensile strength of PPHSC after high temperatures, experiments were carried out on the splitting tensile strength of C60 HSC mixed with PP fibers with different dosage ( 1.0kg/m3, 1.5 kg/m3, 2.0kg/m3, 2.5 kg/m3) and length (8mm,19mm) before and after high temperatures. The test results indicated that the relative residual splitting tensile strength of PPHSC totally declined with the increase of temperature, meanwhile, the strength value of HSC cooled in air was higher than that cooled in water on the whole. The addition of PP fiber with the length of 8mm contributed to the enhancement of the relative residual splitting tensile strength of HSC after high temperatures, whereas, only the HSC mixed with 1.0 kg/m3 PP fibers had a greater strength than plain concrete when the length of fiber was 19mm. After exposure to high temperatures, the relative residual splitting tensile strength of HSC with PP fibers 8mm in length was completely higher than those with 19mm.
Influences of Mineral Admixture on Properties of Porous Pervious Concrete Made of Recycled Aggregates
Authors: Gong Ping , Zhou Yu
Published: April 2014

In this study,silica fume and fly ash were used to replace part of cement, the 28-days compressive strength and the permeability coefficient were tested to study influences of mineral admixture on properties of porous pervious concrete made of recycled aggregates.The results show the best effect is to multiplexed mix with fly ash and silica fume, the 28-day compressive strengths of concrete is higher than those single mixed or doesn’t mix any mineral admixture.
Selection Research of Excitation Agent for Renewable Brick Powder Foam Concrete
Authors: Dong Su Fen , Long Wu Jian , Liu Xiang
Published: April 2014

Used recycled brick powder as active mineral admixture is a development prospect research direction in the new foam concrete system. Performance effects of lime and plaster as exciting agent on different gelled material system brick powder foam concrete were studied. The experimental results show that: when gelled material system is cement: brick powder=70:30, using 25% lime or 20% gypsum can obtain higher strength and lower water absorption foam concrete; when gelled material systems are cement: brick powder: fly ash=70:15:15, 60:20:20 and 50:25:25, compressive strength and water absorption are better than using lime and gypsum separately.
The Development and Application of Foam Concrete
Authors: Xia Yan
Published: April 2014

Foam concrete is a new kind of energy-saving and environmentally friendly building materials. The main features of foam concrete are lightweight,thermal insulation performance,sound proof performance,waterproof performance,environmental performance,etc;Study the principle of the preparation of foam concrete and the preparation process;Overview the research progress of application at home and abroad;The problems of the application on foam concrete and the prospect are shown.
The Effect of Admixtures on Anti-Permeability of C30 Anchor Anti-Seepage Mass Concrete
Authors: Huang Wei Rong , Tan Ming
Published: April 2014

Abstract. It was based on bridge anchor structure of three gorges reservoir area, from the perspective of enhancing the anti-permeability performance of mass concrete, taking into account the economic perspective, with the use of large dosage of fly ash and slag powder to replace cement to reduce the water-binder ratio and hydration heat, improve the anti-permeability performance of concrete, according to the characteristics of mass concrete. Through the test, the influence law of admixtures on impermeability of C30 mass concrete were obtained, and at the same time the better mix proportion of C30 anti-seepage mass concrete used in bridge anchor structure was recommended.
Experimental Study on Dynamic Mechanical Properties of HPP Hybrid Fibers Reinforced Lightweight Aggregate Concrete
Authors: Wang Dan , Guo Zhi Kun , Shao Fei , Chen Wan Xiang
Published: April 2014

The impact compression tests on HPP hybrid fibers reinforced lightweight aggregate concrete were performed with 100mm SHPB equipment. The dynamic mechanical properties and variation of HPP hybrid fibers reinforced lightweight aggregate concrete under different strain rates and loading methods were systematically studied. HPP hybrid fibers reinforced lightweight aggregate concrete is of the property of strain rate effects under impact loads as ordinary concrete. The dynamic strength and peak strain of it increased with the increase of strain rate. During multiple-impact compression tests, the specimens were able to bear multiple impacts before damage after cracks were produced. It is clear that HPP hybrid fibers reinforced lightweight aggregate concrete is an outstanding material for protective engineering to resist repetitive impacts.