bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Fire Resistance Performance of Pre-Stressed Suspended Steel Reticulated Shell
Authors: Yu Feng Bo , Wang Xin Tang , Zhou Ming , Wang Wan Zhen
Published: December 2010

Pre-stressed steel structures with large space are widely used in stadium, exhibition hall, theater and other buildings today. In order to study the fire-resistance behavior of suspended steel lattice shell of a stadium, the method of performance-based fire resistance design is used. First of all, the stadium physical model is established and the software FDS is used to determine the heating curves of the measuring points of the large space structure for two fire scenes. Compared with international standards heating curve, the heating curves of the large space structure obtained here has characteristic of local high-temperature. The finite element software MSC.MARC is further used to simulate the fire behavior of the pre-stressed steel structure with large space, in which the fire scene with 10MW design power of fire source and 30 minutes duration of fire are considered and two loading ways that overall non-uniform temperature field loading and the local high temperature components loading are accepted. The results show that the pre-stressed steel structure with large space has good fire resistance behavior, and the overall failure will not take place for the fire scene suggested here during 30 minutes duration of fire.
Numerical Analysis of Pre-Stressed Steel Trusses Subjected to Fire Load
Authors: Wang Xin Tang , Zhou Ming , Wang Wan Zhen
Published: December 2010

The computational model of numerical analysis of the planar pre-stressed steel trusses subjected to fire load is established according with main consideration to the response mechanism of the structure in fire. For the convenience of application, the EC3 constitutive model of the steel materials in fire is simplified with series expansion, and the suggested formula for each stage are unified. The fire behavior of the planar pre-stressed tubular steel trusses in which two cables are set is analyzed with the model presented here and the effect law of different factors on the bearing capacity of the structures in fire are discussed. It is concluded that fire response of the pre-stressed steel trusses is affected obviously by the different model of material under the same fire conditions, and critical temperature of the structure in fire increases with strength grade of steel material, which means that choice of the proper material model used for analysis of behavior of the steel structure under fire is very important and need to be studied further.
Stress Analysis of Steel Deck Pavement of Box Girder Bridge under Vehicle Wheel Loads
Authors: Xu Liang , Wu Ya Ping
Published: December 2010

This paper deals with the mechanical property of a new designed bridge pavement of box girder bridges. Our concerning is the stress change at the interface between the steel deck and the pavement due to the vehicle wheel loads, which can be considered as a kind of concentration force to the pavement. The finite element method is utilized to analyze the present problem. Several simulations are carried out by taking account of different positions of the vehicle wheels in order to simulate the interface stress change under real conditions. The present results can be a helpful reference for steel-deck pavement design.
Research on the Stability of Erecting of Pre-Cast Segmental Box Girders with SPZ1300/48 Gantry
Authors: Sun Zhi Xing , Chen Shi Tong , Xu Hong Wei
Published: December 2010

In the present paper the whole structure and the construction process of SPZ1300/48 gantry is introduced and the stability of the gantry under lifting process and transition process is also analyzed by some reliable finite element method software. By the analysis of the overall stability of the structure, taking into account the bad weather (strong winds) in the region, in the case of lifting process and after the segments placed, the optimal lifting sequence of the beam segments on account of the stability of the structure itself is obtained. By this way a useful sample for analysis of similar systems is provided, and then a technical foundation is established for bridge constructions by segmental assembling method for larger span or tonnage.
Corrosion Condition Research and Bearing Capacity Analysis of a Space Truss Base on Corrosive Environments
Authors: Yan Xu , Li Tie Ying , Yang Ning
Published: December 2010

A certain natatorium is selected as the object for the corrosion researches on common carbon steel which has been used in the corrosive environments for 20 years. Bearing and deformation capacities are calculated to simulate corrosion by elastic and elasto-plastic finite elements analysis with ANSYS. The result is shown that corrosion condition should be considerable to the space truss with thin wall thickness in the severely corrosive environments.
Calculation and Analysis of the Deflections of U-Section Steel-Encased Concrete Composite Beams
Authors: Zhou Xue Jun , Zhang Ting , Zhang Yuan Zhi
Published: December 2010

U-section steel-encased concrete composite beams is the new type composite beam.This kind of composite beam takes thick steel plate as bottom plate and thinner cold-formed thin-walled steel as web which are connected through a u-shaped section by welding, and then concrete are poured in the u-shaped. In this paper an experimental study was conducted on six full size simple supported U-section steel-encased concrete composite beams.The relationships of the load-deflection curves of the composite beams were obtained. From the experimental results,the variation laws of deflection are analysed,and three defletion formulas are analysed and compared. Based on actual code. A theoretical formula is proposed for defletion. The results of theoretical formula are proved to be in good agreement with the experimental results.
Construction Elements’ Research of Steel Box Girder Based on the 6 σ Quality Control Method
Authors: Zhang Yi Sha , Yao Yun Shi , Zhao Zhen , Yao Nan
Published: December 2010

The steel box girder is widely used benefited from the high torsional and bending rgigidity, good entirety, light weight, better appearance and good stability. Using 6 quality control method, the problem diagnosis and quality control are made to the steel box girder’s making critical process such as assembly and jointing in the New Hi-Tech Zone of Xi'an’ s Arterial road 4# bridge , so as to meet the quality requirements.
Cracking Mechanism of Long Concrete Bedding Cushion and Prevention Method
Authors: Zhu Zhen Yang , Qiang Sheng , Liu Min Zhi , Wang Hai Bo
Published: December 2010

The long concrete bedding cushions are more vulnerable to cracking than the dam concrete, even the cushion is much shorter than the dam block, especially those constructed in hot season and the off period lasts long. The cracking mechanism of such cushion is studied and presented in this paper. There are several reasons contribute to the cracks of bedding cushion, but the thermal stress is the main factor. The temperature distribution is always unevenly during the construction period of bedding cushion. During the long off period, temperature drop in local high temperature zone, temperature fluctuation and temperature difference between inside and surface are the main factors causing cracks for bedding cushion without proper thermal control measures. Some thermal control measures are always used in practical engineering, but it can not always effectively prevent bedding cushion from cracking. Reasonable water pipes cooling measure, which can prevent local high temperature at the early age of construction, and effective heat preservation measures in cold season, which can reduce temperature difference between inside and surface and temperature fluctuation, are necessary to prevent cracking. One bedding cushion of concrete dam is numerically stimulated by 3D FEM, and effective temperature control measure is proposed in this paper.
A Rapid Seismic Evaluation Method of Masonry Buildings Based on Earthquake Damage
Authors: Su Qi Wang , Zhao Shi Chun
Published: December 2010

Wall and tie column shear strength of every floor in masonry buildings as indicators of earthquake-resistant capacity, the evaluation criteria of the indicators was obtained based on the earthquake damage analysis on the 72 multi-storey masonry buildings in Dujiangyan and Hanwang areas. Based on these tests, a rapid seismic evaluation method of masonry buildings was proposed, this method can assess the degree of earthquake damage for the masonry structure under the level of seismic intensity directly. The application of the method is introduced by analyzing the earthquake damage of a masonry building in Wenchuan earthquake. The results show that the method can evaluate the aseismic performance for masonry buildings, and can assess the degree of earthquake damage additionally.
Stress-Chemistry Mechanism of Mortars Made with Steel Slag Sand
Authors: Lun Yun Xia , Liu Shao Shun , Zhou Ming Kai , Liu Xiao Fan
Published: December 2010

A stress-chemistry method was used to investigate the expansion behavior of mortars made with steel slag sand (SSM). The results indicated that periclase and free CaO were the main mineral components resulted in expansion of SSM by means of volume increment and local stress concentration after hydration. So it can be concluded that stress concentration arised from enrichment and uneven distribution of expansile mineral components was the main reason resulted in the volume expansion of SSM. Model of expansion of SSM was built according to the characteristics of crack and types of versicolor particles.
The Primary Exploring of Seismic Property of Different Type Structure House
Authors: Cao Su Qing , Xin Xiao Fei
Published: December 2010

The article makes pushover analysis for two multiplayer frames(one common frame and one abnormity columniation frame)and three small high-rise structures (shearwall, short-climbed shearwall and frame-shearwall structure)based on software ADINA. Consequently, from displacement, vibration period and storey shear force, it is shown that the abnormity columniation frame can meet the seismic requirement and the short-climbed shearwall have better seismic capacity.
Study on Concrete Filled Square Steel Tube under Lateral Impact Loading
Authors: Zheng Liang , Chen Zhi Hua
Published: December 2010

Finite element models of both the concrete filled square steel tube and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. Three stages of time history curve of the impact force of the concrete filled square steel tube including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. And with the wall thickness increased, the peak of the impact force and the platform value is also increase, with axial force increased, the peak impact force hardly changed, but the impact platform value have a certain extent lower. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of the impact of the concrete filled square steel tube based on numerical analysis, four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation. Finally, time history curve of the impact force and displacement according to the dynamic response is analyzed under the impact of the corner of the concrete filled square steel tube, the results show that the anti-impact capability of 45 degree angle is higher than that of the front impact.
Erection of Pearl Bridge by Bear Angle Vertical Swivel Method
Authors: Guo Zi Hua , Zhang Zhe
Published: December 2010

Bear Angle Vertical Swivel Method for arch bridge has been developed for many years overseas and obtained stated success such as Kobaru Valley Bridge in Japan and ArgenLobel bridge in Germany, this method is in the researching period right now in China. During the processing of construction, concrete of arch rib was casted vertically and then rotated, main arch ring was casted vertically by formwork climbing technology, main arch ring was laid to completed bridge elevation by using continues jacks, forming a set of swivel construction method for arch bridge.
The Application of Grid-Frame Structures with Specially Shaped Columns in Energy-Saving House Using Phosphorus Gypsum
Authors: Li Li , Ma Ke Jian , Zhang Hua Gang , Lu Ya Qin
Published: December 2010

The feature of the concrete grid-frame structure with specially shaped columns is the frame beams and specially shaped columns in the walls were divided by rib beams and rib columns, then the rib beams, the rib columns, the frame beams and the specially shaped columns together constitute the grid-frame structures with specially shaped columns. The rib beams and the rib columns can share parts of the vertical and horizontal loads which the structure should bear and work together with the frame beams and the specially shaped columns, so make the lateral stiffness of the structure is increased and the ultimate strength, ductility and seismic performance of the structure are improved. Moreover, Phosphorus gypsum will be poured to enclose concrete beams and columns and become the filler wall among them. At the same time, phosphorus gypsum wallboards are used as the middle filler walls to separated rooms flexibly. By doing so, the building is more energy saving. In addition, the phosphorus gypsum which is a type of industrial waste can be consumed and become useful material in construction.
Test and Finite Element Analysis of Concrete Continuous Beams Strengthened with CFRP Sheets
Authors: Cheng Dong Hui , Yi Ya Min , Wang Tian Feng
Published: December 2010

In order to study the mechanical behavior on concrete continuous beams strengthened with CFRP sheets, three two-span continuous beams strengthened with CFRP sheets in the control section at each span were fabricated and tested with two-point loading type. The test data such as load, crack distribution and deformation were obtained in different stages. Based on the test data, the finite element analysis on the continuous beams strengthened with CFRP sheets was carried out by ANSYS software. The variation of steel stress and deflection of control section in the intermediate support and the bearing capacity in different stages were obtained, moreover, the results show that the ultimate strength of continuous beams strengthened with CFRP sheets has not improved largely in elastic state while increased significantly in plastic state, and the continuous beams displayed obviously internal force redistribution.
Design and Construction of the Slab with Novel Filled Material
Authors: Wang Lu Min , Zhang Da Ying , Liang Xing Pei
Published: December 2010

A new cast-in-situ slab which is filled with novel filled material (EPS-block) consisting of disused expanded polystyrene plastic granule, cement and building cementing powder is invented. EPS-block with perfect centrosymmetric torus shape is very suitable for filling into two-way slabs. It breaks a new path to use disused expanded polystyrene foam, and reduces environment pollution greatly. Through the practical study of the slab with EPS-block, the appropriate construction method is found out, and the dependable construction technique is afforded for further development of the slab with EPS-block.
Effects of Packing Degree and Calcium-Silicon Ratio of Cementitious Material on Strength of Reactive Powder Concrete
Authors: Ji Tao , Chen Bao Chun , Zhuang Yi Zhou , Huang Zhi Bin , Liang Yong Ning
Published: December 2010

Aim & Goff model was used to predict the packing degree of cementitious materials including cement and silica fume. The mix proportions of reactive powder concrete (RPC) with different packing degree and calcium-silicon ratio of cementitious materials were designed and a strength test was carried out. The study results reveal that the flexural strength and compressive strength of RPC are related to the packing degree and calcium-silicon ratio of cementitious materials. For the mix proportion of RPC with the calcium- silicon molar ratio of 1.353 that is slightly less than the theoretical value of 1.42, where calcium hydroxide can react with silicon dioxide more fully, its strength of RPC approaches summit although its packing degree of cementitious material is not the largest one.
Numerical Analysis on Vibration Mitigation Effect of EPS Geofoam on Retaining Wall
Authors: Wang De Ling
Published: December 2010

The mitigation of earth force by placing expanded polystyrene (EPS) geofoam buffer between retaining wall and backfill soil under dynamic loading is a topic worth consideration. In this paper, the effects of EPS geofoam buffer on the reduction of thrust wall force are numerically studied to simulate three reduced-scale models of rigid walls using a large shaking table. Numerical simulation technique using the finite element program Abaqus is described. The paper shows that the numerical Abaqus models are able to capture the trend in earth forces with increasing base acceleration for all three models. The use of the EPS geofoam as a compressible buffer yields obviously reduction of the lateral seismic thrust against retaining wall. The quantitative dynamic load–time response of the numerical simulations was in good agreement with measured physical test values.
A New Method to Prepare Carbon Fiber/Carbon Black Reinforced Concrete and its Properties
Authors: Hou Zheng Tao , Sun Ming Qing , Li Bin , Zhang Xie Dong
Published: December 2010

A new method is proposed to prepare carbon fiber reinforced concrete (CFRC) and carbon fiber (CF)/carbon black (CB) reinforced concrete in this paper. First, CF is dispersed in 0.4% carboxymethylcellulose sodium (CMC) water solution. Then, resolvable carbon fiber surfacing mat (RCFCM) is manufactured and cut into small patches. Finally, these patches are mixed with cement, sand, gravel, CB and water. During mixing, RCFCM patches are broken up once they meet with water. So, CF is dispersed into concrete. Results show that this method is feasible. CF/CB reinforced concrete possesses low resistivity (<100 Ω•cm), high compressive strength (≥35 MPa) and low contents of CF (0.3 Vol.%) and CB (0.6 Vol.%), so it can be used as a kind of conductive concrete for melting snow and deicing applications on highways. Both the mixing time and the curing period can affect the electrical and mechanical properties of CF/CB reinforced concrete.
Study on the Fabrication of Compound Cold Cathode Electrode in a Field Emission Display
Authors: Wang Feng Ge , Li Yu Kui
Published: December 2010

With photolithography process and screen printing technique, the compound cold cathode electrode was developed on the cathode glass plate for improving the field emission ability and emission uniformity of CNT cathode. The compound cold cathode electrode mainly consisted of the indium tin oxide (ITO) blocks which was the divided ITO thin film, the bar silver stripes fabricated by the solidified silver slurry and the cathode insulation layer with good insulation performance. Carbon nanotubes were prepared to form the field emitters, and the diode type field emission display (FED) was fabricated. The manufacture process was also presented in detail. The vacuum sealed FED exhibited better field emission characteristic, low operating voltage and high display brightness.
Development of a Method in Evaluation and Adjustment for Consistency of Group Decision-Making Based on Grey Relational Analysis and its Application in Evaluation of New Rural Economic Building Materials
Authors: Wang Li Jiu , Li Li
Published: December 2010

In this paper, grey relational analysis (GRA) was used in consistency test of group judgment matrixes. The evaluation indicator weight was obtained through the judgment matrix calculated with expert evaluating method in analytical hierarchy process (AHP). The judgment method and the adjustment process for consistency of group judgment matrixes were studied. First, the consistency indicators were put forward, and then the definitions and the theorems of consistency indicators in the judgment method were defined based on GRA. Then the theorems were given proof. A method using GRA to judge the consistency of group judgment matrixes was proposed for the first time. Second, adjustment modeling was developed to solve the consistency of group judgment matrixes. Finally, the applications of the judgment method and the adjustment process have been illustrated by given example. It is believed that the proposed methods are applicable to test consistency of evaluation indicators of new rural economic building materials.
Numerical Analysis to Impact of Different Heights for Subgrade Connecting in High-Speed Railway
Authors: Yuan Jian Yi , Lv Ya Yu
Published: December 2010

Subgrade connecting has become an important research project in high-speed railway construction engineering. Combining the hub project of Hefei railway, numerical calculation was executed with different subgrade heights to existing line’s safety operation and subgrade stability by FLAC software. It shows that deformations in the vertical direction of the connection between the new subgrade and the old and the old subgrade surface increase following the increment of subgrade height, and the velocity of deformation increment also aggrandize. Reduction of subgrade height is beneficial to trains safety on existing line and subgrade integration property. It will be instructive to control differentia deformation for the connecting subgrade projects in high-speed railway.
Influence of Layer Interface Condition on Modulus Backcalculation Results of Semi-Rigid Asphalt Pavement
Authors: Qiu Xin , Yang Qing , Hu Yong Ju
Published: December 2010

To make appropriate rehabilitation decisions, determining structural layer moduli of the existing semi-rigid asphalt pavements is a crucial task for highway engineers. The objective of this study was to analyze the errors in layer moduli backcalculation due to modeling of layer interface condition. Firstly, according to the full bonding hypothesis, a dynamic finite element analysis model was established to generate a synthetic surface deflection database of the semi-rigid asphalt pavements. Then, the regression functions between deflections basin parameters and layer moduli were created and used to backcalculate layer moduli. Secondly, different friction coefficient values between asphalt layer and stabilized base layer were introduced into dynamic finite element model, accordingly, deflection basin parameters were calculated and layer moduli are determined based on the established regression functions. Finally, the backcalculated layer moduli and the original moduli values were compared. The analysis results demonstrate that assuming full bonding, instead of actual interface conditions of asphalt-stabilized base layer, moduli of stabilized base layers is underestimated, up to 2.5 times smaller than the original values. The improper interface condition of the binder-stabilized base layer has little influence on moduli of asphalt and subgrade layer.
Evaluation of Mechanical Properties at early Ages of Dry-Mixed Self-Compacting Concrete
Authors: He Pei Xiang , Wang Xiu Shi , Wang Jian Guo
Published: December 2010

This paper evaluates mainly the dry-mixed self-compacting concrete (DSCC) based on the experimental study. The study analyzes mechanical properties of DSCC at the hardened condition, which has been conducted as follows: compressive strength and split tensile strength with elapsed age as well as size effect of strength. Rate of gain in strength at different periods of curing such as 1day, 3days, 7days, 14days and 28days are studied for different DSCC mixes and suitable relations have been established for the gain in strength at the early ages. Relations have also been formulated for compressive strength and split tensile strength for DSCC mixes. Size effect of compressive strength and structural efficiency have been evaluated, all at cured after 28 days.
Study on a New Adhesive of Concrete Cracks Repairing
Authors: Zhou Qi , Hao Ji Ping , Lv Ping , Men Jin Jie
Published: December 2010

A new class of structural glue called permeant adhesive is introduced for repairing concrete cracks. The viscosity and strength of the permeant adhesive are tested, respectively. Then the durability of concrete such as sulphate attack, freeze-thaw resistance and impermeability of the repaired concrete are discussed. It is shown that temperature and reactive diluent are important factors in viscosity of the permeant adhesive. Curing agent and reactive diluent are important factors in strength. Hereby, the optimum proportion is A: B=1:0.5, and the amount of reactive diluent is 10% to 15%. The strength of the repaired concrete which is immersed in sulphate increases 3% to 26.2%, while the freeze-thaw resistance and impermeability of the repaired concrete are better. The above provide the theoretic and experiment foundation for simpling the pressure grouting technique of the concrete repaired and the application on the permeant adhesive.
State-of-the-Art for Experimental Studies on the Mechanical Behavior of FRP-Confined Concrete
Authors: Sun Wen Bin , Wang Jian Lin
Published: December 2010

Numerous experimental studies have proven that the confinement with FRP-wrap or tube encasement could enhance the strength, ductility and durability of concrete columns. The variation of each distinct experimental test result to its actual mean value is the general cause of modeling inaccuracy, and this appears to be a lack of consensus among the research community. This paper critically reviewed the current experimental studies with the emphasis on the revelation of the mechanical behavior of FRP-confined concrete and analytical study of its behavior.
Influence of Structural Plane in Similar Soil Surrounding Rock on Excavation Stability
Authors: Chen Qiang , Chen Wei Tao , Meng Guo Wei
Published: December 2010

Lots of primary or secondary structural planes in similar soil surrounding rock are the main difference with Quaternary soil surrounding rock, but the particularity isn’t considered in the analysis of tunnel stability. The fact, which similar soil surrounding rock has most weak structural planes, is testified by engineering examples. The influence of structural plane in similar soil surrounding rock on excavation stability was analyzed through combining theory with disintegration test and numerical calculation. The research results show that there are a lot of structural planes in similar soil surrounding rock. The angle between structural planes and tunnel axes and shearing strength of structural planes control the stability of tunnel. Disintegration time of soil is shortened due to structural planes. On a certain condition, structural planes can induce local collapse in soil surrounding rock while excavating.
Durability of Lime-Fly Ash Stabilized Soil Activated by Calcined Phosphogypsum
Authors: Yang Min , Xie Yan , Pang Ying
Published: December 2010

Stabilized soil is widely used as road base and sub-base materials, and is sometimes used as covering for waste matter in China. In soil stabilization, the property of a locally available soil are usually modified though chemical stabilization[1]. Cement stabilization and lime stabilization are the two most commonly used methods. Lime-fly ash stabilized soil has been widely applied in road engineering due to its good integrity, great bearing capacity, high stiffness, and water-proofing quality[2-4]. One disadvantage of lime-fly ash stabilized soil is that without any additives, its inherent low initial strength makes it inappropriate for use under low-temperature conditions. Researchers have found that the pozzolanic reactivity among lime, fly ash, and soil contributes to the strength of lime-fly ash stabilized soil. To increase the initial strength of lime-fly ash stabilized soil, many approaches have been used to accelerate the pozzolanic reaction. Sulfate activation is one of the methods that has been widely investigated, specifically, Na2SO4 and CaSO4[5]. PG, another sulfate, has also been investigated. However, existing studies have limited to the investigation of the development of strength of the stabilized soil as road base and sub-base materials. The effect of PG on the durability of stabilized soil has rarely been implicated. This work aims to study the effect of thermally treated PG (400°C) on the properties of durability, in addition to other aspects, of lime-fly ash stabilized soil. Lime-fly ash stabilized soil with different proportions of calcined PG were prepared and cured at normal conditions for 7 d and 28 d. Mass loss and strength loss under different treatments were determined. X-ray diffraction(XRD) patterns and scanning electron microscopy(SEM) photos were examined to gauge whether improvements in the performances of the stabilized soil can be obtained by use of thermally treated PG.
Crack Resistance of Concrete with Incorporation of Light-Burnt MgO
Authors: Chen Xia , Yang Hua Quan , Zhou Shi Hua , Yan Jian Jun
Published: December 2010

The advanced Temperature and Stress Test Machine was introduced to evaluate the cracking resistance of concrete with inclusion of light-burnt MgO under full restraint by tracking thermal and deformation development. Results showed that light-burnt MgO being incorporated ranging between 4 per cent and 6 per cent by mass of cementitious materials was beneficial to increase the maximum compressive stress and cracking stress of concrete by 0.37MPa and 0.2MPa on average respectively. The maximum temperature was slightly reduced from 59.8°C to 66.2°C while cracking temperature was significantly decreased from 0.8°C to minus 5.6°C. Sensitive anti-cracking coefficient F was forwarded to assess the early cracking tendency of concrete and in general, inclusion of 4 per cent light-burnt MgO with activity of 109s was rated the best in crack resistance.
Diffusion Mechanism of Chemical Contaminator in the Environment Medium and Interaction between them
Authors: Cui Qiang , Zhang Zhen Hua
Published: December 2010

In the underground repositories, the microstructure change of surrounding rock mass under the chemical reaction will cause the porosity change in medium. Aiming at the chemical reaction effect on the environment medium, the porosity of sandstone specimens, along with Ca2+ concentration of solution were tested. Based on the analysis of test results and the theory of chemical thermodynamics, the chemical action mechanism was concluded for absorption of Ca2+. With the combination of the theories of chemical kinetics, chemical thermodynamics, and solute transportation, a reactive-transport model to describe porosity change under chemical reaction was established. Finally a simplified chemical model was advised to describe microstructure change of rock under chemical reaction. And the numerical simulation analysis was performed. The simulation result indicates that with the reaction time increasing, the porosity reduces firstly and then is driven to stabilization in the end. The study results can be used as a valuable reference to understand the mechanism of the chemical reaction effect on the microstructure change of sand rock.
Self-Expansive Behavior of Steel Fiber Reinforced Self-Stressing Concrete
Authors: Wang Bo Xin , Huang Cheng Kui , He Huan An
Published: December 2010

Steel Fiber Reinforced Self-stressing Concrete (SFRSSC for short) is a new type of high performance cementitious composite with self-expansive performance and high crack resistance. SFRSSC is actually a kind of expansive concrete which self-stresses, namely pre-compressive stresses, are induced by dint of some restrictions generally provided by steel bars and steel fibers to concrete expansion after hydration of expansive cement. As a result of chemical reaction, concrete achieved pre-stresses by itself different from mechanical pre-stressed concrete, so called steel fiber reinforced self-stressing concrete. In this paper the material experiments of 40 SFRSSC prisms are carried out to determine the rule of the self-expansive behavior. According to the theoretical model, a procedure how to determine the self-stress is supplied in order to supply references to the structural applications of steel fiber reinforced self-stressing concrete.
Discussions about the Situation and Prospects of New Building Materials Industry
Authors: Gao Ying , Zhao Ya Jun , Han Xiao Bin , Bian Jian Min
Published: December 2010

After the reform in China, our new building materials industry has developed rapidly. After 30 years of development, China's new building materials industry occurred and is developing from small to large. It has formed a new industry, become an important product of industrial materials and promoted China's economic growth. On the contrary, the rapid development of economic construction and the rising living standards provide the development of new building materials with a broad market and good opportunities. Driven by market demand, new building materials in China has formed a circulation network; Most of the foreign products can be produced in China, for example, China's production of different varieties of the color and different grades of decorative materials to improve the living conditions of urban and rural residents and make great contribution of changing the appearance of the city. China has formed a professional team for new building materials’ research, production and circulation. In this paper, we analyzed the current situation of the development of new building materials and put forward some countermeasures and suggestions to promote the development of new building materials.
Cable System Using Epoxy-Coated Prestressing Steels in China
Authors: Zhu Wan Xu , Li Li , Deng Ai Wu
Published: December 2010

Using the electrostatic spraying method to spray the epoxy coating on the surface of prestressing wire or strand. By this method, the mechanical properties can reach the same level of original prestressed steel, the anti-corrosion ability is superior to that of galvanized steel, and the epoxy coating not only does not have a negative impact on anchorage performance, but also improve the bond strength between wire and cold-cast filler. The LZM cable system using epoxy-coated wire and the OVM250 and GJ cable system using epoxy-coated strand have been developed and widely applied in China since the year of 2001.
Simulation and Experimental Study on Temperature Distribution of Mass Steel Fiber Concrete
Authors: Wang Yu Dong , Fan Xiao Chun , Xiang Chun Lin , Liu Hua
Published: December 2010

Temperature and elastic modulus of mass steel fiber concrete change as time in casting process. If not well handled, it is easy to crack in the process of construction. In order to hold the temperature distribution of mass high strength concrete in pouring process, we set up the model that meets with engineering characteristics. It is based on the partial differential equation of heat conduction and elastic modulus value from test and cement hydration heat of concrete on site. By contrast, the simulation results are in good agreement with the experimental results.
Research on Function Aggregate Prepared by Steel Wastewater Sludge
Authors: Ding Qing Jun , Huang Xiu Lin , Sun Hua , Yang Kun
Published: December 2010

Industrial wastewater sludge contains a certain amount of heavy metals, which will cause environmental pollution. In this paper high Cr, Zn content wastewater sludge from steel plant was used as the main raw material, with Kaolin and other materials as adjustment materials. Through optimization design of raw mix composition and firing system, a kind of function aggregate was got, which had an apparent relative density of about 3.0 g/cm3, a vacuum water absorption between 16%~23%, and a linear attenuation coefficient more than 0.15cm-1. Use XRD and SEM to analyze the existence state of heavy metals in aggregates. The novel method for making function aggregates provides a technical support for resource utilization of steel wastewater sludge, which could be applied in the field of high strength concrete and radiation shielding concrete.
Experimental Study on Molding Technology and Mechanical Properties of Cotton Stalk Block
Authors: Chen Guo Xin , Feng Wei Gang , Huang Wei
Published: December 2010

The work presented in this paper focuses on the molding technical and mechanical properties of cotton stalk block. Cotton stalk block is a new type of ecological filling materials. The previous test data and practical experience show that the major three factors affecting the compressive strength of the block are the glue consumption, the density of block and the sand content of block. In this paper, the method of orthogonal experiment is used to analyze the molding technology of cotton stalk blocks and the above three factors (glue consumption, density and sand content of block). The research results show that, the glue consumption and the density have significant effect on the compressive strength of the block, but the effect of sand content of block is less. In additional, an optimal combination of the three factors is obtained. Based on this combination, the compressive strength of the block can reach to1.55 MPa, which can meet the strength requirement of the filling materials.
Structure and Interfacial Property of UHMWPE Fiber Treated by Pyrrole Vapor Deposition
Authors: Zhou Cun , Jin Xin , Wang Wen Yu
Published: December 2010

UHMWPE fibers have widely application, but the poor adhesion to polymer matrix limit its development. Polymerization of vapor phase pyrrole on UHMWPE fibers was introduced in this paper for improve the adhesion between UHMWPE fibers and epoxy. The Ppy-coated UHMWPE fiber was studied by SEM, FTIR, DSC and pullout test, respectively. The result showed that there is no chemical act between UHMWPE fiber and polypyrrole. The Ppy coatings have strong effect on the morphological and adhesion property of UHMWPE fiber. The most important, the maximum pullout force was improved after pyrrole polymerization on the surface of UHMWPE fiber.
Mechanical Properties of Hybrid Nylon-Steel- and Steel-Fibre-Reinforced High Strength Concrete at Low Fibre Volume Fraction
Authors: Yew Ming Kun , Ismail Othman
Published: December 2010

The mechanical properties of hybrid nylon-steel-fiber-reinforced concrete were investigated in comparison to that of the steel-fiber-reinforced concrete, at the same volume fraction (0.5%). The combining of fibers, often called hybridization is investigated in this paper for a very high strength concrete of an average compressive strength of 105 MPa. Test results showed that fibers when used in a hybrid nylon-steel fibers reinforced concrete form could result in superior composite performance compared to steel-fiber-reinforced concrete. The basic property of the hybridized material that was evaluated and analyzed extensively was the modulus of rupture (MOR) and splitting tensile while the compressive strength was only slightly decreased compared to single steel fiber reinforced concrete. There is a synergy effect in the hybrid fibers system.
Experimental Study on the Durability of Glass Fiber Reinforced Polymer Pole and Tower for Power Transmission
Authors: Zhang Ling Ling , Sun Qing , Zhang Ling
Published: December 2010

This paper studied the durability of Glass Fiber Reinforced Polymer (GFRP) Pole and Tower for power transmission under the UV and adverse temperature environment. The results show that both UV and adverse temperature environment influence the performance of GFRP material, with its strength significantly reduced, and its elastic modulus increased, while the Poisson's ratio changed slightly. Xenon lamp aging affects the material properties of the specimens with protective coatings more slightly than those without any protective coatings. High temperature environment affects the material properties of specimens more obviously than low temperature environment does. Therefore, when designing the GFRP Pole and Tower for power transmission exposed in UV and adverse temperature environment long-term, designers should consider the negative impacts of the external environment, and take appropriate protective treatments.
Predicting the Workability of Self-Compacting Concrete Using Artificial Neural Network
Authors: Li Fang Xian , Yu Qi Jun , Wei Jiang Xiong , Li Jian Xin
Published: December 2010

An artificial neural network (ANN) is presented to predict the workability of self compacting concrete (SCC) containing slump, slump flow and V-test. A data set of a laboratory work, in which a total of 23 concretes were produced, was utilized in the ANNs study. ANN model is constructed, trained and tested using these data. The data used in the ANN model are arranged in a format of six input parameters that cover the cement, fly ash, blast furnace slag, super plasticizer, sand ratio and water/binder, three output parameters which are slump, slump flow and V-test of SCC. ANN-1, ANN-2 and ANN-3 models which containing 15 ,11 and 5 neurons in the hidden layers, respectively are found to predict workability of concrete well within the ranges of the input parameters considered. The three models are tested by comparing to the results to actual measured data. The results showed that ANN-2 is the best suitable for predicting the workability of SCC using concrete ingredients as input parameters.
Heating and Cooling Performance of Building Integrated Solar Roof Panels
Authors: Yan Mao , Zhu Li , Wang Yi Ping , Zhu Ming Ze
Published: December 2010

With the high proportion of building energy consumption in the total energy consumption, it is of great importance to relieve the shortage of conventional energy resources and improve the building environment by incorporating solar energy into buildings. A new type solar roof panels were designed and tested in the present paper, which perfectly achieves the integration of solar equipment with building envelope. This panel can act as the construction component for building envelope and completely removes the double-skin mode for conventional solar equipment, as well as the functional equipment for heating and cooling collecting. Corrugated colored steel roof panel was tested under various climate conditions and operation conditions. The results show that in a typical sunny day the average heat collecting efficiency is 49% and the average cooling capacity is 100W/m2. In a cloudy day, the average heat collecting efficiency is 41% and the average cooling capacity is 84W/m2.
Experimental Study on the Damage of Steel Fiber Reinforced Concrete by Simulation Domestic Sewage
Authors: Zhu Hai Tang , Fan Xiang Qian , Zhang Qiming , Li Jinzhang
Published: December 2010

Through the corrosion-damaged experiment of steel fiber reinforced concrete (SFRC) in simulation domestic sewage, the corrosion resistance of SFRC placed in domestic sewage were investigated. The results show that high concentration domestic sewage would cause the properties of SFRC to deteriorate, and the corrosion coefficients of compressive and flexural strength of SFRC decrease gradually with the increase of corroding age. The steel fiber can not inhibit obviously the degradation of concrete compressive and flexural strength unless the steel fiber volume fraction is more than 1.0%. The size effect on compressive and flexural strength of SFRC after corroding in domestic sewage is existent.
Performance of Lightweight Epoxy Asphalt Mixture
Authors: Jiang Chen Long , Li Xiao Rong , Qian Zhen Dong , Lv Wen Jie , Zhang Ping , Feng Kai
Published: December 2010

The sandstone in pavement engineering is mostly obtained by mining mountain or river way, which has brought beyond-retrieve destruction for natural environment, such as mountain bareness and ecological damage. So lightweight epoxy asphalt mixture(LEAM) incorporating different replacement percentage of granulated lightweight aggregate(GLWA) and circular lightweight aggregate(CLWA) by weight were researched. Then performances of strength, rutting resistance, moisture susceptibility of epoxy asphalt mixture incorporating GLWA and CLWA and the economical efficiency were evaluated, and results presented all performances met the specification and LEAM was more economical than the mixture without GLWA or CLWA. And the shape and replacement percentage of lightweight aggregate could improve or weaken mixture performance and the change amplitude was different. The mixture incorporating 40% CLWA replacement was determined to be the most suitable mixture for steel deck pavement of long span or special construction bridge, such as moveable bridge.
Effects of Molecular Structure of Polycarboxylate Water Reducers on their Performance in Cement Paste
Authors: Li Shun , Yu Qi Jun , Wei Jiang Xiong , Ji Ya Jun
Published: December 2010

The polycarboxylate water reducers(PCs) with different molecular structure were synthesized. The effects of molecular structure on their performance in cement paste were investigated. The results show that the PCs with a medium density of PEO side chain and/or a moderate molecular weight and its distribution have a higher dispersibility and a stronger dispersion retention stability at the same time, and that those PCs with a shorter PEO side chain exhibit a stronger dispersion retention stability. The PCs with a higher molecular weight, a lower density and/or a shorter length of PEO side chain are more easy to adsorb on the surface of cement particles. The earlier induction period is shortened while the dormant period is prolonged during the process of cement hydration in the presence of PCs. The PCs with a shorter PEO side chain show a stronger retarding effct. This effect is not very obvious with the decreasing molecular weight.
Effect of Phosphate Cement and Aggregate on the Fluidity and Strength of Phosphate Concrete
Authors: Wang Hong Tao , Cao Ju Hui , Xue Ming , Li Shuang Mei
Published: December 2010

To prepare the concrete of high strength and high fluidity, some important factors were investigated, namely species of phosphate, the ratio of phosphate and magnesia, the surface area of phosphate cement, fineness of sand, particle size distribution of coarse aggregate and the ratio of phosphate cement and aggregate. Results showed that the fluidity and strength of phosphate concrete prepared by KH2PO4were lower than that prepared by NH4H2PO4and decreased as the ratio of P/M reduced. The surface area of phosphate cement increased from 210m2/kg to 400m2/kg, the fluidity and strength firstly increased, and then decreased. The fluidity and strength of phosphate prepared by medium sands were lower than that prepared by fine sands or super-fine sands. Fast harden and early strength phosphate concrete of high fluidity can be prepared by three kinds of coarse aggregate, namely 5～10mm, 5～20mm and 5～25mm. Besides the ratio of cement and aggregate had a significant effect on the fluidity and strength, and the best ratio fell between 1:1 and 1:2.
Research on the Durability of Magnesium Phosphate Cement
Authors: Wang Hong Tao , Xue Ming , Cao Ju Hui
Published: December 2010

The Magnesium phosphate cement was prepared from MgO and NH4H2PO4. The changes of the strength, appearance and hydration products of the magnesium phosphate cement were investigated, which are soaked in sulfuric acid solution, sodium hydroxide solution, sodium sulfate solution and magnesium sulfate solution. Besides, the impermeability and salt frost resistance of magnesium phosphate cement were analyzed. The results show that magnesium phosphate cement has good resistance to sulfate erosion, especially the anti-corrosion ability of magnesium sulfate. However the alkali resistance of the magnesium phosphate cement is poor. Therefore, the magnesium phosphate cements are not appropriate to be used in alkaline environment as cementitious material. The resistance of the magnesium phosphate cement to chemical attack is closely related to the stability of the hydration product MgNH4PO4• 6H2O. The magnesium phosphate cements have good impermeability and salt freezing resistance.