bluuebunny/crossref_metadata_2025 huggingface dataset:
Cluster Health Monitoring System of Major Urban Bridges Based on Digital City VPN Network
Authors: Pan Yong Qing , Li Yi , He Guo Liang
Published: October 2012

With the development of bridge Structural Health Monitoring (SHM) technique and digital city concept in recent years, the Cluster Health Monitoring (CHM) system for urban bridges, simultaneously real-time monitoring many important bridges in the city has been come into engineering practice. This paper introduces a CHM system of urban bridges using Digital City VPN Network at the city of Hangzhou, China, which is composed of three parts: remote monitoring center, digital city VPN network, and bridge monitoring stations, seven bridges of different types (1 viaduct, 1 overpass, 3 tied arch bridges, 1 PC cable-stayed bridge, and 1 continuous beam bridge) are being monitored. One-year monitoring data have been collected through this CHM system, it indicates that using VPN (Virtual Private Network) technology to achieve online urban bridges cluster monitoring is a safe, reliable and practical methods.
Shear Capacity of Concrete Beams Reinforced with Continuous FRP Rectangular Spirals
Authors: Li Bing Hong , Jiang Shi Yong , Shi Qian Hua , Hu Xian Qi
Published: October 2012

The failure modes and the shear capacity of concrete beams reinforced with FRP reinforcement were discussed through an experimental investigation, in which continuous FRP rectangular spirals were used for shear reinforcement, while ordinary deformed steel bars are used for longitudinal reinforcement. Six concrete beams reinforced with FRP spirals were tested, the main variables considered were the shear reinforcement ratios, the shear span to depth ratios and the longitudinal reinforcement ratios. Two concrete beams of equal shear capacity which reinforced with continuous steel rectangular spirals were also tested to compare the behavior of concrete beams reinforced with different materials of spirals. All beams were tested as simply supported members subjected to a three-point load, the span of the beams varied in terms of different shear span to depth ratios. The test results show that the shear capacity and shear failure modes are greatly influenced by the shear reinforcement ratios and the shear span to depth ratios, the shear resistance provided by steel spirals is higher than that provided by FRP spirals in the case of equal shear capacity of beams, which is attributed to the differences in material properties and may result in different shear failure types. Based on the experimental program, four mechanical models are derived to give more accurate predictions of the shear capacity of test beams, the calculation results of these models are compared with that of the existing shear formulas or equations for concrete beams reinforced with FRP stirrups or spirals. The rotating-angle softened truss model, the strut-and-tie model, the shear formulas derived from the truss-arch model and Zsutty equations are suggested through comparison.
Experimental Study on Deposition Promotion and Erosion Control for Pit Collapse
Authors: Ying Qiang , Yuan Sheng Ying
Published: October 2012

Based on the actual measured topographic data of the pit collapse occurred at Sanjiangkou in Nanjing, a generalized model of pit collapse is established. With this model, the experimental study of flow pattern changes is made with the schemes of crow of a tree and tetrahedron-like penetrating frames. The study shows that the scheme with crow of tree play greater effect in pit velocity reduction, so it can be used in emergency rescue project. Although tetrahedron-like penetrating frames can also reduce velocity, but too crowded arrangement make limited effect in reducing velocity, therefore tetrahedron-like penetrating frames should keep proper distance while dumping into the pit collapse. Moreover, a comparative experiment is made on the effects between the singe project (only arranging the project in the slide pit) and the combined project (contains collapse entrance project and inside project). The study experiment shows that the combined project has no obvious better effect than the single project.
The Specific Properties Research of RC Beams Multiple Strengthened with Near-Surface Mounted Carbon Fiber Reinforced Plastic Bar and Pre-Stressed Helical Rib Bar
Authors: Ren Zhen Hua , Zeng Xian Tao
Published: October 2012

Seven concrete beams were constructed with normal reinforcement bars. Grooves were opened on the concrete cover of the tensile region in the concrete beams using different combinations of carbon fiber reinforced plastic (CFRP) and pre-stressed helical rib bar (HRB), CFRP and HRB pre-stressed at different levels were inserted into the grooves and filled with resin. Flexural experimental results indicated that the limit bearing capacity, rigidity, and crack resistance of the beams were strengthened significantly with near-surface mounted two pre-stressed HRB and one CFRP (BF1P2) bar, or near-surface mounted one pre-stressed HRB and two CFRP (BF2P1) bars, in which HRB was pre-stressed at 30%, 45%, and 60% of its limit strength, respectively. Compared with an un-strengthened beam, the crack loads of the BF1P2 beams increased by 86.70% and 133.33%, the yield loads by 32.25% and 72.04%, and the limit bearing capacities by 72.73% and 90%. The crack loads of the BF2P1 beams increased by 50% and 133.33%, the yield loads by 50.54% and 136.56%, and the limit bearing capacities by 72.20% and 173.60%. The BF1P2 beams had better reinforcing results compared to those of the BF2P1 beams. The beam strengthened with HRB pre-stressed at 45% of its limit strength was the best concrete beam.
Research on Impact Response and Failure Modes of H Section Steel Frame Columns Subject to Blast Loads
Authors: Liu Yun Fei , Lei Hong Gang
Published: October 2012

Using finite software ANSYS LS/DYNA for simulating the impact response and failure modes of H section steel frame columns subject to blast loads，and loading different load conditions, changing column boundary conditions and web plate thickness. Conclusion: the failure model of steel columns changes with the change of load form,steel columns will be easy to occur shear failure in the end by the dynamic load, and the flange will be easy to occur bucking failure in local by impulse load; In the case of same size and web thickness, increase the web thickness can reduce the deformation of column effectively, improve the capability of H section steel column resist the blast load.
Evaluation of the Fire Resistance of H-Section Steel Columns and Beams
Authors: Kwon In Kyu , Kwon Young Bong
Published: October 2012

Building fires can cause severe damages to not only human life but also building structures. Therefore, every nation requires a building regulation related to fire in aspect of safety of human and structural stability. The structural stability under fire condition can be evaluated by the fire test defined in each nation’s standard. However, the results from the test don’t satisfy the real situations of the building such as fire loads, opening size, loading and boundary condition of structural members, and etc. Meanwhile, performance based fire engineering design is regarded as an alternative evaluation method of fire. The fire engineering method has been regarded as a more rational method than the prescriptive method in terms of accuracy and cost efficiency. Recently, the limit temperature method is regarded as the easiest fire engineering method to evaluate the structural stability under fire. To make the backbone of a specification of limiting temperature method, limiting temperatures of various structural members are required. In this paper, in order to make a database of the limiting temperatures of H-section columns and beams, fire test programs with loading were conducted and the limiting temperatures and fire resistance were derived.
Experimental Research on Shear Property of Steel Bar/Wire Mesh Mortar Strengthening Concrete Beams
Authors: Sun Yan Hua , Chen Qiu Dong , Liu Jin Wei , Xiong Guang Jing
Published: October 2012

In order to enhance the shear capacity of reinforced concrete (RC) beams more efficiently, a thought to strengthen concrete beams by using steel bar/wire mesh mortar was proposed. A comparison experiment study on shear behavior of two kinds of strengthening RC beams(namely steel bar mat(S)mortar strengthening, and steel bar / wire mesh(SW) mortar strengthening) was carried out. The experimental results show that SW strengthening can keep the advantages of a better dispersion of reinforcement due to the addition of wire mesh, leading to a much higher initial diagonal crack load, and a better control to the crack propagation of the strengthened beams. The initial diagonal cracking load and the shear capacity of SW strengthened beams are 83% and more than 30% higher than those of S strengthened beams respectively, while the reinforcement ratio of the formers is only 22% higher than that of the laters. The working mechanism of SM mortar strengthening was discussed.
Quick Start Study on Bioleaching Method
Authors: Fu Jin Xiang , Zhang Xiang Nan , Zhang Rong Xin
Published: October 2012

The experiment uses the Shenyang northern sewage treatment plant two sink the pond sludge was the indigenous Thiobacillus enrichment culture, through the matrix of different proportion, to find the most suitable matrix proportion, so as to shorten the bioleaching process start time, improve the bioleaching process for heavy metal removal efficiency. By usihng the method developed by mixing S bacteria predominantly mixed bacteria liquid, will raise the mixed strain cycle was shortened to 11 days, the best ratio of S, Fe2+ matrix is determined as 3 : 1, the matrix culture mixed Thiobacillus is faster, and can greatly improve the bioleaching boot efficiency. Fe2+ dosing is able to activate the bacterial Fe2+ enzyme synthesis, be helpful for accelerating thiobacilli on s oxidation using elemental sulfur, while also promoting microorganism to use Fe2+. Using the technology of biological leaching experiment on heavy metal removal rate is higher, compared with a single strain has more engineering application and popularization value.
The Application of Artificial BP Neural Networks and Monte-Carlo Method for the Reliability Analysis on Frame Structure
Authors: Xue Zhi Cheng , Wang Hai Jun
Published: October 2012

In order to conduct the reliability analysis of frame structure, the limit state function was first fitted by artificial BP neural network. Then considering the orthogonal array method, sample data was arranged. After that an improved network modes was trained for the probabilistic analysis on a wide range data with the Monte-Carlo method. The mean and standard deviation for the limit state function was easily obtained and the reliability index on the structure can be also calculated. Finally, the example indicated that this method used in the reliability analysis for frame structure was feasible.
Bio-Mediated Soil Improvement under Various Concentrations of Cementation Reagent
Authors: Lee Lee Min , Ng Wei Soon , Tan Chew Khun , Hii Siew Ling
Published: October 2012

Bio-mediated soil improvement is a relatively young technology in geotechnical engineering. The practical applications of the technique are still exposed to some uncertainties. This paper investigated the effect of the concentration of the cementation reagent on the performance of bio-mediated soil improvement. The shear strength, calcite content, pH, and ammonium content of the bio-mediated soil were measured under three concentrations of a cementation reagent, i.e. 0.25 M, 0.5 M, and 1 M. The results showed that the calcite precipitation and shear strength improved with the increased concentration of the cementation reagent up to 0.5 M. However, the improvement was retarded at higher concentration (i.e. 1.0 M). This is likely due to the inhibitory effect and halophilic characteristic of the bacteria used for the biocementation
Countermeasures on Prevention and Treatment of Structural Cracks for Premixed Pump Concrete
Authors: Zhang Chang You , Zhou Zhao Yin
Published: October 2012

For premixed pump concrete, this thesis analyzed the causes of cracks according to the relevant construction features; meanwhile, it proposed the countermeasures on structural cracks in terms of raw materials and construction technologies, thus this thesis gave certain guidance on prediction and control of such cracks.
Xingtai City Coal the Mine Environment Geological Problems and Countermeasures
Authors: Li Lei , Wang Sheng Li , Wang Feng Yuan , Ren Jing Ke , Jia Xiao Peng
Published: October 2012

This article describes the Xingtai City, a typical large-scale modern coal mine, mine environmental geological problems arising due to the exploitation of coal resources, and the corresponding countermeasures and suggestions for different problems. Mainly introductions are the destruction of water resources, mine water hazard, mining subsidence and destruction of land resources, and guiding role in the safe production of coal and the surrounding environmental governance.
Research on Supervision System of Hazardous Chemical of Small & Medium-Scaled Cities in China Based on WEBGIS
Authors: Wan Xiang Yun , Yang Hao
Published: October 2012

The supervision system of hazardous chemical based on the WEBGIS technology is constructed, which displays the reality of the situation and simulates the accident consequence of security risks ( including major risk sources ) to the user in the form of map, realizes the registration of hazardous chemicals, enterprise qualification examination, administrative licensing of hazardous chemical construction projects, and investigation and rectification of the potential safety hazard in hazardous chemicals enterprise as well as management and supervision in other related business process through information means, and improves the ability of supervision and emergency rescue in chemical safety production. It has an important significance to prevent and control the major hazard. This paper introduces the supervision system of hazardous chemicals and the structure, database design, and system application of the supervision system.
Study on China’s Debris Flow Distribution and Occurrence Trend
Authors: He Na , Chen N.Sh
Published: October 2012

Debris flow disaster occurred frequently, at the same time it covered a wide area in China. Through statistics analyzing debris flow disaster data from 1914 to 1999, obtain that debris flow hazards mainly distributed in the east longitude 100-110°, 25-30°north latitude and 30-35°north latitude in China. This region is mainly affected by subtropical climate and central Asia humid tropical monsoon climate, such climate have little rainfall in winter but intense rainfall in summer, due to the complex topography and different monsoon circulation, the frequency of debris flow occurrence in this area is much higher than other areas. After the earthquake in May 12, 2008, the slope material structure are destroyed which in turn provide adequate loose clastic-sediment for debris flow to initiate, several years later the loose clastic-sediment may reconsolidate again and reach new balance. Compare the frequency and scale of debris flow before and after the earthquake, know that after earthquake the frequency and scale of debris flow are much serious than the events occurred before earthquake, then gradually tend to stable. Based on these phenomena could predict the scale and trend in the future, at the same time it could provide reference for debris flow prevention and reduction, and then reduce the loss that caused by debris flow hazards.
Time-Dependent Effect for Reinforced Concrete T-Shaped Section Beam Exposed to Fire
Authors: Zhang Gang , Wang Cui Juan , He Shuan Hai
Published: October 2012

The time-dependent effect for reinforced concrete T-shaped section beam exposed to fire was analyzed in this paper. Based on fire test of building structure home and abroad, combining crack criteria and nonlinear constitutive relationship, finite element analysis method was put forward. Analyses were performed to study the influence of several parameters on the fire resistance of reinforced concrete T-shaped section beam exposed to the IS0834 standard fire，which it included fire time and ratio of reinforcement．The studied results indicate that: section distribution gradient width has a gradual expanse from outside to inside with extension of fire time, time-dependent curve of deflection for reinforcement concrete T-shaped section beam fundamentally decreased linearly with extension of fire time; deflection is nonlinearly increased with load ratio; oblique crack is liable to occur relative to vertical crack.
Human Factor Risk Analysis and Prevention Based on the Gas Storage and Transmission Facility Accident
Authors: Cai Liang Jun , Su Li Na , Sun Ke Chun
Published: October 2012

The accident occurred on two points, one is thing’s insecure state, and the other is human's insecure behavior, the majority accidents cause of gas storage and transmission facilities are initiated by person's behavior factor in China. Furthermore, learning from the knowledge of psychology, and explore the artificially induced factors, from conduct of practice, occupational structure and cultural level, relationships, social pressure, managers own behavior. The paper put forward the measures and countermeasures which is accord with China's gas storage and transmission actual, and superintendents would promote humanities concern, and pay great attention person's life value.
Application and Research of Slope Flexible Protection System in Engineering
Authors: Ou Xiang Ping , Zhou Si Quan , Wang Ze Hua , Ruan Kun , Li Bo
Published: October 2012

According to the project, this paper discusses the constitution and site construction plan of the slope flexible protection system, and analyzes its design mechanism. Under different geological conditions and different environment, it compares slop flexible protection system with other slope treatment methods in design, construction, and economic effect. This paper concludes when it can achieve the best practicality, applicability, and economic effect.
Research on the Dam-Break Hazard Vulnerability Assessment Index System and Methods of Tailings Pond
Authors: Mei Guo Dong , Wu Zong Zhi
Published: October 2012

The method, using slope buckling safety factor to measure the degree of dam-break hazard, results in the unscientific conclusions of identical dam-break risk with respect to the desolate & uninhabited gobi desert and densely populated & highly economic-developed city. On the basis of vulnerability theory, a dam-break hazard vulnerability assessment index system, which comprehensively considering the inherent risks of dam-break and the intrinsic vulnerability of hazard-affected bodies, was established. The production of dam-break hazard-causing factor intensity, including the current dam height, reservoir capacity & downstream main ditch longitudinal, and accident probability by the Monte Carlo method is the inherent risk level of dam-break. The result by the multiplying physical exposure and the intrinsic vulnerability, including household fitness index & the emergency self-help index, as well as the disaster relief capacity is the hazard-affected body vulnerability. Results are contributable to further consummate the vulnerability risk assessment technology and the reliability of dam-break hazard.
GIS Based Large Scale Modeling and Archiving of Buildings in Historic Conservation Area: Take Luojia Hill Historic Conservation Area for Example
Authors: Niu Qiang
Published: October 2012

Based on the Geo-Model of GIS, the article researches the large scale modeling method for buildings in historic conservation area. Based on this model and the hotlink function of GIS, the method can efficiently manage and store the historic building attributes such as building name, age, historical value, multimedia information such as photographs and videos, and archive documents about historical events, drawings, protection issues, etc. The method support convenient and visual information utilization, including information analysis, 3D scene browse, thematic map, animation of historical evolution, etc. The application in Luojia Hill historic conservation area proves that the method has the character of high efficiency in modeling, good effect in information management, low workload, and convenience in use.
Reinforcement Scheme and Numerical Simulation for Sequential Excavation of the Deep Foundation Pit
Authors: Lu Rui Li , Jiang Qing Hui
Published: October 2012

The deep foundation pit engineering of Wanda Plaza in Yinchuan city is taken as a case study and the corresponding numerical model has been built. The deformation and stability of the foundation pit during sequential excavation has been analyzed by using of the FLAC3D software. The weak positions which may lose the stability are predicted by the results from the numerical simulation. A soil-nailing reinforcing scheme has been proposed to maintain the stability of the foundation pit. To analyze the support effects of the soil-nailing, the Cable structure elements have been adopted to simulate the interaction between soil and soil-nailing. The calculation results show that the maximum horizontal displacement occurs in the middle part of the pit wall and the minimum occurs in corner part of the pit wall. The soil nailing support significantly decreases the deformation of foundation pit by dispersing internal stress of soil. The reliability of the simulation results has been verified by the comparative analysis between the numerical simulation results and the deformation monitoring data of foundation pit. The proposed reinforcement scheme is not only helpful to ensure the safety of Wanda Plaza foundation pit，but also provides valuable experiences for the reinforcement of similar foundation pit engineering.
Research on Absorption of Special Impregnated Paper for Plywood Formwork
Authors: Sun Xian Qi , Zhao Chuan Shan , Yang Xin Qiang , Xu Wen Yang
Published: October 2012

Impregnated paper for plywood formwork is an important material for the production of plywood formwork. It was developing with plywood formwork and the market had been expanding. Absorption and wet strength are main factors which can effects on the property of impregnated paper. In this paper, mechanical chemical pulp and waste paper were used to make special impregnated paper for formwork. The ratio of EMP, dosage of aid, and operation conditions were discussed. The result showed that the absorption was improved by increasing ratio of EMP, adding agent, drying quickly, and lighter pressure. A certain ratio of AOCC is necessary to ensure strength. The paper also discussed the difference of white spot between bamboo plywood formwork and plywood formwork which indicated that white spot caused by waste paper .However, it wasn’t damage the quality of structures.
Application of Spent Bleaching Clay for Producing Environmental Brick
Authors: Wu Su Xi , Huang Shan Shan , Tan Chuan Bo , Cai Hui
Published: October 2012

Spent bleaching clay(SBC) is a kind of discarded by-products from edible vegetable oil factory, often resulting in environment pollution. This study aimed to explore a feasible approach to comprehensively utilize the SBC for replacing coal ash to produce unburned and environmental brick(UEB). Through a series of experiments, and considering the cost and acceptability of bricks, the optimal conditions for producing UEB was obtained. The defatted SBC is added 25 %, fine fine sand 25 %, small pebble 30 %, cement 12 %, lime 8 %, the molding pressure is 20 MPa, and the molding moisture was 10 %. Under this condition, the average compressive strength of the UEB with 28-day storage can reach up to 18.11 MPa, higher than the value of 15 MPa in the unburned brick produced from standard coal ash.
The Method Analysis of Using Finite Element Method to Determine the Bemding Moment Formula of Precast Reinforced Concrete Composite Thermal Insulation of External Wall
Authors: Wang Ying , Sui Yan E
Published: October 2012

This paper describes the calculation method and steps of compound insulation external wall panels who's whole board with openings. Using Finite Element Method to simulate and analysis the result,For in the engineering application of the sandwich type wall panel provides the basis.
Mechanics Performance Test Study on High Performance Concrete with High Content of Fly Ash
Authors: Guo Xiao Yan , Hao Run Xia
Published: October 2012

High performance concrete was disposed under Portland cement dosage 270-310kg/m3 , fly ash blend percentage 40-50 and composite admixture. Workability of the concrete satisfy pumping requirement.28 day compression strength reach 31-44MPa, 90 day compression strength reach 40-56MPa.
Statistic Damage Constitutive Model of Loessial Soil Considering Damage Threshold
Authors: Xie Xing , Wang Dong Hong , Zhao Fa Suo
Published: October 2012

The damage mechanism of loessial soils was studied by the statistical theory.Based on the characteristics strength of loessial soils micro-unit with Weibull distribution, and parameters that described by distribution variable of Drucker-Prager creterion are used, loessial soils damage constitutive model considering damage threshold is established to reflect the full process of loessial soils failure. Conventional triaxial consolidation undrained shear test results of loessial soils are taken as example to verify the model. By comparing theoretical calculation results with test results, it is showed that the statistical damage constitutive model considering damage threshold is reasonable.
Research on the Application of Slipform Concrete of Well Tower in winter
Authors: Zong Xiang
Published: October 2012

To meet the demand of performance of slipform concrete in a well tower in winter, different blend ratios of early strength water reducing agents were added to the concrete. Compared with reference concrete, their setting time test analyses, workability analyses and tests of mechanical performance and removal of forms were conducted in the laboratory. The results show that concrete with FS-A early strength water reducing agent can greatly improve early strength of concrete and meet the demand of relevant performance of slipform. This research may provide reference for design of mix proportion and construction in similar slipform project.
Application Study on the Steel Fiber Reinforced Concrete
Authors: Cui Wen , Luo Qin
Published: October 2012

Mix design of the steel fiber reinforced concrete was analyzed based on the engineering conditions. It was indicated by comparing with the strength values of steel fiber reinforced concrete (CF40) and ordinary concrete (C40) that the tensile strength of the steel fiber reinforced concrete increased about 70%, the compressive strength increased about 10%, the initial cracking strength increased about 150%.The reasonable construction technologies were used in mixing, transportation, pouring, vibrating and curing of the steel fiber reinforced concrete in order to ensure quality of the construction.
Experimental Research about the Effect on Bond Properties between Ceramsite Concrete and Reinforcement with Age
Authors: Yang Wei Jun , Li Li Shan , Wang Yan
Published: October 2012

After the pilot study about different-aged ceramsite concrete specimens, the curve and the formula about the ceramsite concrete splitting strength with age developing are obtained, the curve and the formula about the relative bond strength with age are analyzed, it provides a theoretical basis for the project production of ceramsite concrete practice.
Research on the Capability of Basal Layer Stabilized Gravel by Cement and Fly-Ash
Authors: Han Yu Min , Shi Xiao Xing , Wang Li , Zhang Dao Ming
Published: October 2012

Aiming at the basal layer demand on pavement performance in Tu – Wu Highway of Baicheng diversion road, based on the theory of gradution in mixture, experimental studies have been done in grade of gravel and road performance of stabilized gravel by cement and fly-ash. The right amount of cement and fly-ash in mixture can improve spatial structural components of mixture and its mechanical properties. Base on these measured datas, the mixture of cement and fly-ash mixed in the gravel is reasonable and feasible，and the results show its mechanical properties rely on mix proportion of the basal layer.
The Relationship between Mechanical Properties and Shrinkage of the Concretes Used in Florida
Authors: Liu Yan Jun , Tia Mang
Published: October 2012

This paper investigated the mechanical strength and shrinkage properties of the concrete mixtures frequently used in Florida. The concrete mixtures were proportioned with three different types of coarse aggregates, such as Miami Oolite limestone, Georgia granite and Stalite lightweight aggregate, and two mineral additives, including fly ash and slag. And fourteen concrete mixtures were evaluated on their characteristics of compressive strength, elastic modulus and shrinkage for 91 days. The empirical relationship between the mechanical properties of concretes and shrinkage strain was analyzed mathematically. The results indicate that the compressive strength and elastic modulus of concrete are exponentially related the shrinkage strain of concrete. The finding from this study is agreeable with that by Troxell et al [5]. Also, the effectiveness of ACI 209 and CEB-FIP models on predicting the shrinkage behavior of concretes used frequently in Florida was evaluated. The result indicates that CEB-FIP model gives more reliable prediction than ACI 209 model does.
Mechanical Properties of Reinforcing Bar HRB335 after Corrosion
Authors: Wang Ying , Ping Li
Published: October 2012

The corrosion behavior of reinforcing bar HRB335 in 3.5 wt.% NaCl solution was investigated, and the tensile mechanical properties after corrosion were tested. The results showed that, with the increase of corrosion time, the corrosion rate of reinforcing bar HRB335 increases and the corrosion becomes heavier. Meanwhile, the yield strength and tensile strength decrease, but the elongation decreases at first and then increases.
Research on Performance Concrete Made with Slay-Fly Ash and Ground Limestone
Authors: Sun Li , Zhang Hou Tian
Published: October 2012

Base on experimental studying, early strength and work performance of portland cement, slay cement and fly ash cement improves and enhances when added ground limestone into and the adding content is beyond 8% .The strength of concrete is better than ordinary concrete, early strength increases by 16.9% when added ground limestone into and the adding content is beyond 10%. By studying on experiment, the strength of concrete which has been added slay and fly ash into when added ground limestone into and the adding content is 10% improves more than strength of concrete that has only adds slay or fly ash into. The fluidity of concrete that has added slay and fly ash into when added ground limestone into and the adding content is 10% lose small, this character is good at concrete construction. This experiment provides help for us to select concrete additive admixture and make good use of industrial waste.
Experimental Study on Reinforced Concrete Beam with Embed in Basalt FRP Bars
Authors: Zhu Bai Ru , Song Yang
Published: October 2012

Many tests were carried out to study flexural failure characteristics, ultimate bearing capacity, and stiffness etc of reinforced concrete beams which are embed in basalt FRP bar. The results show that:（1）Basalt FRP bars greatly enhance load bearing capacity. (2) Beam failure characteristic is interfacial bond failure mode. (3) Reinforced beams’ integrity and stiffness are greatly improved, the beam crack resistance significantly improved.
Effects of Sample Preparation Methods on Tensile Strength of Red Clay
Authors: Zeng Zhao Tian , Lu Hai Bo , Zhang Jin Jin , Zhao Yan Lin
Published: October 2012

Effects of two sample preparation methods on tensile strength of red clay are studied. The first method adopts standard layered-bumping to make sample whose layer interfaces are vertical to tensile force. The second method uses compaction apparatus to prepare big sample and the big sample is cut to prepare triaxial sample whose layer interface is parallel to tensile force. Test results indicate that the layer interfaces of soil sample have large influence on the single axle tension test, because the results of the sample prepared by 1st method have large dispersion and low strength, while the results of the sample prepared by 2nd method are just the opposite.Moreover,the layer interfaces of soil sample have little influence on the unconfined compressive strength test, and the results of the tensile test and unconfined compressive strength test of the samples prepared by 2nd method meet with the Griffith Criterion, so the samples of uniaxial tension test should be prepared by 2nd method.
Study on Low-Temperature Performance of Asphalt Mixture Impacted by Modified Asphalt and Polyester Fibers
Authors: Yu Xun , Huang Jing Bo
Published: October 2012

Low temperature crack plays an important role on the road safety and comfort. Indoor experiments were carried out to study the crack resistance of asphalt mixture. The results show that: fiber and SBS modified asphalt can increase the failure strain energy, the failure stress and the failure strain and reduce stiffness, thus can significantly improve the anti-cracking ability at low temperature; at a critical temperature of about -10°C, the splitting strength achieve a peak value correspondingly, and the asphalt mixture transforms from the viscoelastic status to the brittle status; the failure load and the failure strain of the three kinds of mixtures are in the sequence of modified asphalt mixture> fiber mixture> common asphalt mixture; the results of the J-integral strain energy test show that fiber asphalt mixture has the maximum resistance curve slope, which means it may have better anti-cracking ability than the SBS modified asphalt mixture; the fracture stiffness can be introduced to effectively evaluate the crack resistance of asphalt mixture.
Deterioration of Laterite Engineering by Chloride Ion
Authors: Chen Gang , Yang Hua Shu , Li Jin Yu , Yan Yi Zhi , Shao Luo
Published: October 2012

Water of reservoirs shows acidity in laterite regions, and laterite engineering is chronically demolished by chloride ions in water. Ground on mechanism analysis, accelerated life tests were implemented. After permeability test, changes of grain-size-gradation were analysed at laterite remainder, microstructures of soil sample were observed, and concentration changes of iron ion as well as aluminum ion were affirmed in transudatory liquid. The harvests indicated that: sesquioxides (viscous substances in laterite) are consumed by chloride ions in water, and microstructures of laterite are demolished. Products from chemical reaction are dissolved by water and are schlepped off by seepage, so wispy leakage channels are created in engineering. The eroding of chloride ions has clearly debased security of laterite engineering.
Experimental Study on the Influence of Water Cement Ratio on the Compressive Strength of Shale Ceramsite Concrete
Authors: Cao Zhen Min , He Zhi Gang , Yang Yi
Published: October 2012

Shale ceramsite concrete is a kind of light weight aggregate concrete. In this paper shale ceramsite concrete compressive strength properties are studied by experimental preparation of different water cement ratio, and made an analysis of compressive strength comparatively among 7 days, 28 days, 56 days. The result shows that the rules of compressive strength of shale ceramsite concrete are in line with the general law strength of concrete, and increases with the age increasing, decreases with water cement ratio increasing, but they are not entirely linear relationship.
A Study on the Influences of Crumb Rubber Modified Asphalt
Authors: Chen Lan Yun , You Qing Long , Qiu Xin
Published: October 2012

In order to study the effects of different factors on the performance of crumb rubber modified asphalt, on the basis of many laboratory tests, this article analyzed such factors as types of crumb rubber, fineness, content, mixing temperature and matrix asphalt. Results show that mixed with the crumb rubber, pavement performance of the asphalt has been improved to varying degree. In the engineering application of rubber asphalt, it is suggested that the 20 mesh crumb rubber modified asphalt of truck tire be adopted, with about 16% to 18% of crumb rubber content at about 175°C. As for matrix asphalt, it should be selected according to the different climatic conditions and the mechanical characteristics of the pavement.
Orthogonal Experiment and Analysis of the Concrete which Use the Shell as Aggregate
Authors: Gao Chao , Pan Zhu , Wei Xiang Zhen
Published: October 2012

In order to test the impactions on the strength of the concrete which Use the Shell as aggregate effects of the shell for the aggregate by the use of limited and comprehensive and effective consideration of multiple factors, Use of orthogonal experimental design method to test concrete strength of shells for the aggregate. And then through the systematic analysis of the test results, obtained the proportion of mixture for the best strength.
Non-Destructive Evaluation of Composite Laminates by Using Fiber Optic AE Sensor
Authors: Hao Jun Cai , Wang Jin , Yu Yue Min
Published: October 2012

Considering the damage that composite material under loading may occur, acoustic emission (AE) technique is adopted to perform non-destructive evaluation (NDE). In order to obtain the acoustic emission emitted from the composite material, a novel fiber optic AE sensor which is based on single mode fiber optical fused-tapered coupler design is developed. Futhermore, its fabrication process was described and performance was studied. Results of a pencil break test on the composite laminate show that the fiber optic AE sensor have better frequency response than the commercial piezoelectric sensor. During a tension experiment of a carbon fiber composite specimen , the fiber optic sensor which was mounted on it detected the enormous acoustic emission signals. To analyze their characteristic parameter, such as amplitude, duration, can identify the type of failure to composite materials, including Matrix cracking , Interface stripping, fiber breakage. Experimental results would offer the reference to damage identification to complicate composite structures.
On Effects of Fly Ash as a Partial Replacement of Cement on Concrete Strength
Authors: Case Reagan J. , Duan Kai , Suntharavadivel Thuraichamy G.
Published: October 2012

As a part of a large research program aiming at the cementitious materials containing recycled materials at Central Queensland University – Australia, the current paper presents the preliminary results of a study on the effects of fly ash, which is used to replace cement in concrete, on the concrete compressive strength. For this purpose, systematic experiments have been carried out to investigate the influences of fly ash ratio and age. The compressive strength of concrete specimens with replacement ratios of 15%, 30% and 45%, and aged 7 and 28 days are measured and are compared with those of the concrete specimens without fly ash at the same ages. The results demonstrate that the strength of fly ash containing concrete improves more slowly but more strongly with aging, than their fly ash free counterparts, and an optimum fly ash replacement ratio exists where the maximum compressive strength of fly ash containing concrete can be achieved, and the maximum strength for the specimens aged 28 days and above is higher that of fly ash free concrete. Furthermore, the observation strength behaviours are analysed and discussed in terms of the influences of fly ash on interface reactions and interface bonding strength.
Performance Studies of Lightweight Concrete Mixtures Made with Rigid Polyurethane Foam Wastes
Authors: Wang Ge , Liu Ye Qiu , Cui Ying
Published: October 2012

This paper describes the results of some studies on the properties of lightweight expanded concrete mixtures made with rigid polyurethane foam waste. Experimental study on the mechanical properties of polyurethane foam waste mixed with concrete shrinkage performance and the relationship between packing density and absolute density. The results showed that: Polyurethane foam plastic waste can be used in the preparation of lightweight concrete, the strength with the state standards, and packing density and concrete absolute density with reference line between sex. Drying shrinkage comply with Selih and Bremner lightweight concrete water content to evolution.
A Study on the Microstructure Characteristics and Precipitation Law of Dredger Fill
Authors: Liu Xiao Qiang , Pei Wen Bin , Zhang Yu Ting , Zuo Dian Jun
Published: October 2012

In the effect of the external environment,the characteristics of the microscopic deformation in the soil may be induced by the microstructures such as the interaction of soil particles and interaction between soil particle and void. The microstructures have great influence on the engineering properties of soil. This paper studies the microstructures characteristics of the precipitated dredger fill in port-centered industry in Tianjin by the electronic microscope test. Finally, the characteristics and the distribution of the microstructure would be analyzed.
Study on Exfoliation Resistance of Ferro Superalloy Composite Oxide Scale
Authors: Wang Hai Tao , Zhou Shen Jie , Yu Hua Shun , Chu Zhong
Published: October 2012

Based on ferro based superalloy K273 and heat resistant steel ZG40Cr24, test alloys were cast by intermediate frequency induction furnace with non-oxidation method by alloying of aluminium and silicon. The oxidation resistance at 1100°C for 500 hours of test alloys was carried out according to oxidation weight gain method. Experimental results show that the scale exfoliation resistance of K273 and ZG40Cr24 is reinforced greatly by Al2O3 and SiO2. The scale exfoliation weight gain rate at 1100°C descends from 1.2681g.m-2.h-1 to zero, reaching complete exfoliation resistance for ZG40Cr24 test alloy. Because of 1.5<PBR(Al2O3⁄Fe)<2 and the growing of Al2O3 and SiO2 from out side of scale-scale/oxygen interface, the composite scale grows intact and compact without accumulation of growing stress.
Study on Failure Characteristics of Basalt Subjected to Triaxial Cyclic Loading
Authors: Leng Xian Lun , Liu Jia Jin , Cui Zhen , Sheng Qian
Published: October 2012

As a special kind of engineering material, the mechanical properties and failure characteristics of rock directly determine the safety of the engineering works. In this paper, to estimate the indicator of rock failure under seismic loading, the axial plastic strain development of basalt under different lithology and different frequency is studied based on triaxial cyclic loading test. A magnitude of 10-3 is obtained for the critical plastic strain of basalt at failure. The mean value of critical plastic strain is 0.003. A seismic analysis of underground powerhouse complex of the Baihetan HPP is then conducted as a study case. The development of rock mass's plastic strain with seismic loading is studied, and failure zones which have the worst effects on the complex are revealed.
Study on Dry-Shrinkage Properties of Layer Hybrid Fiber Reinforced Concrete
Authors: He Dong Qing , Zhao Yan Yan
Published: October 2012

In order to study the effects of the application of layer steel fibers and polypropylene fibers on dry-shrinkage properties of concrete, the contrast experiments on the dry-shrinkage ratio and mass-loss ratio of ordinary concrete(OC), layer steel fiber reinforced concrete(LSFRC) and layer hybrid fiber reinforced concrete(LHFRC) under constant temperature (20±2°C) and constant humidity(relative humidity 60±5%) condition were carried out. The dry-shrinkage ratio of LHFRC is smaller obviously than OC’s and LSFRC’s, and achieve a reduction of 26.9%, the dry-shrinkage ratio of LHFRC after adding grinding slag and fly ash achieve a reduction of 40.2% at the age of 180 days. However, the mass-loss of LHFRC is larger than OC’s, and achieve an increment of 18.3% at the age of 180 days, LHFRC after adding grinding slag and fly ash’s is consistent with OC’s. The dry-shrinkage properties of concrete will be improved remarkably by adding layer hybrid fiber.
Preparation and Study of a New Polyurethane Curing Agent
Authors: Song He , Deng Xin Hua , Li Qian
Published: October 2012

A new environmentally friendly polyurethane curing agent was prepared by the method that cyclic carbonate reacted with isophorone diamine. Investigated the synthesis temperature of the curing agent by DSC and FT-IR, and discussed membrane mechanical properties by curing agent and thermal properties of membrane. The results showed cyclic carbonate reacted violently with isophorone diamine in 82 °C, and the carbamate group appeared on molecular chain; breaking strength of the film and given elongation modulus was greatly improved by using this curing agent.
Mechanical Properties and Volume Deformation of Steel Fiber Reinforced Micro-Expansive Concrete Filled Steel Tube
Authors: Zhou Xiao Jun , Mou Ting Min , Fan Bi Kun , Ding Qing Jun
Published: October 2012

Abstract: Steel fiber reinforced micro-expansive concrete (SREC) with excellent fluidity, high resistance to segregation and good self-compacting ability was prepared. Compressive test, splitting tensile test and flexural test were performed. Self-developed confined expansion test instrument of concrete filled steel tube (CFST) was used to evaluate the deformation behaviors of SREC confined in the steel tube. The structure behavior of steel fiber reinforced micro-expansive concrete filled steel tube (SECFST) was investigated through 12 short column specimens. Expansion agent invariant and steel fiber contents were the dominant variables. The results showed that when compared to common micro-expansive concrete, the splitting tensile and flexural strength of SREC were increased by 78.0% and 64.7%, respectively. When the expansion agent amount was 40kg and volume fraction of steel fiber was less than 1%, SECFST exhibited stable expansive deformation. The use of steel fiber combined with expansion agent moderately improved the yield load and ultimate load of CFST.
Effect of Compatibilizers on Composite Materials of Bio-Ethanol Byproduct-Poly(lacticacid)
Authors: Zhang Ming Ming , Liu Xiao Huan , Wang Chun Peng , Jin Li Wei
Published: October 2012

The blend composite materials of bio-ethanol byproduct-Poly(lactic acid) (PLA) were produced by a twin-screw extrusion process. Effects of bio-ethanol byproduct (BEB) contents and different compatibilizers on properties of composite materials were investigated. The research showed that with the increase of contents of bio-ethanol byproduct, the mechanical properties decreased. The mechanical properties of composites were improved by adding the compatibilizers, especially the polypropylene grafted maleic anhydride (PP-MAH). When the PP-MAH content was 2.5%, the mechanical properties of the composite materials were superior to others.
Pile Samples Selection Method Based on Self-Organizing Maps Neural Network
Authors: Liu Si Si , Fan Yun Lei
Published: October 2012

One-dimensional self-organizing maps neural network (SOM) is used in pile samples selection, and the outcome can improve the accuracy of back-propagation neural network (BP) is proved. Firstly, 71 pile samples are divided into 5 groups according to SOM node weights. Each group is divided into training set, testing set, validation set to build 5 independent BP networks, called BP2. Secondly, 5 groups training set are merged into a new training set, similarly, a new test set and validation set to build another BP network, called BP1. At last, comparison of the performance of BP1 and BP2 show that using SOM network to select pile samples can build a BP network with better performance.