bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Gradation of Sand on the Mechanical Properties of Engineered Cementitious Composites
Authors: Yang Ying Zi , Yao Yan , Zhu Yu
Published: May 2011

Four-point bending test was employed to investigate the effects of gradation of sand on the mechanical properties of Engineered Cementitious Composites (ECC). The characteristics of ECC such as mid-span deflection, first cracking load, peak load and fracture toughness were obtained from the load-deflection curve. Effects of gradation of sand on fresh properties, compressive strength, flexural strength and drying shrinkage of ECC were also discussed in this paper. Test results shown that when the fineness modulus of sand in ECC was 1.0, the mid-span deflection and fracture toughness of ECC increased nearly 1.5 times and 2 times that of ECC with the sand fineness modulus of 2.97, respectively. With the sand getting finer, the more superplascitizer is needed and the crack width of ECC becomes smaller. The drying shrinkage of ECC with 2.97 and 1.0 fineness modulus of sand at 24 days was 8×10-4 and 15.6×10-4, respectively.
Effect of the Interfacial Transition Zone on the Migration Behavior of Cations under the Accelerated Lithium Migration Technique
Authors: Liu Chih Chien , Wang Wei Chien
Published: May 2011

This paper researches the effect of the interfacial transition zone (ITZ) on the migration behavior of cations under the Accelerated Lithium Migration Technique (ALMT). Cylindrical mortars with different aggregate volume fractions (Vf) and w/c=0.5 were used. The result shows that when Vf≤ 20 %, the Li+steady state migration coefficient (Ds) is influenced by the dilution and tortuosity effects of the aggregate. The combined effect of ITZ and percolation occurs at Vf= 30 %, and the effects increase with the increase in Vf. Based on the experimental and regression analysis results, when the assumed thickness of ITZ = 20 μm, the approximate Dsof ITZ and percolated ITZ are 46.4 and 52.6 times the matrix migration coefficient.
Study on the Engineering Characteristic of California Bearing Ratio (CBR) of Expressway Subgrade Material
Authors: Yang Guang Qing , Xiong Bao Lin , Zhang Bao Jian
Published: May 2011

The California Bearing Ratio(CBR) denotes the potential strength of subgrade material and is the important index of evaluating its using performance in expressway. In order to study the main influence factors of the CBR value of clay, The physics and chemistry tests of fifteen groups subgrade materials, coming from the Qing(Dao)-Yin(Chuan) expressway in hebei province, are done. Based on the result of tests, which there are obvious difference between CBR value with the same plastic index clay under the same test method and condition, the influence factors of California Bearing Ratio of expressway subgrade materials are distribution of particle sizes in soils, mineral component and clay mineral component. The profitable conclusions are gained: the main influence factors of California Bearing Ratio of expressway subgrade material are the type of mineral component and the content of each mineral, the distribution curve shape of particle sizes in soils and the clay ratio silt secondly. The CBR value minishs with the clay ratio silt increasing.
Model Reliability Assessment: A Hydrodynamic Modeling Approach for Flood Simulation in Damansara Catchment Using InfoWorks RS
Authors: Awang Ali Awang Nasrizal , Ariffin Junaidah
Published: May 2011

This paper presents the flood inundation model using a hydrodynamic approach for flood simulation. A Digital Elevation Model (DEM) for Damansara Catchment was developed and integrated into the InfoWorks River Simulation (RS) program. Hydrographic surveying activity was carried out to collect existing Damansara River cross-section. The 3D flood model was calibrated using the 26th February 2006 and 15th October 2008 flooding event data. The model was validated using the flooding event on 21st March 2007. This computer simulation results produced hydrograph that indicates the capability of the model in dealing with regional flood analysis for future usage in designing structural flood measures.
A Study on the Development Trend of Sustainable and Healthy Residence
Authors: Wang Pei , Cao Yue Jun
Published: May 2011

Firstly, this paper gives a brief review of the nature and characteristics of sustainable and healthy residence. Secondly, with an analysis to the current situation and problems of urban residence in China, it makes a tentative study on the development trend of healthy residence based on the concepts of opening urban space and new auto culture. Finally, it initiates some proposals for healthy residence with energy-saving and environmental protection.
Numerical Simulated Method on Wind Environmental of Outdoor
Authors: Li Can , Deng Tian Fu
Published: May 2011

Outdoor wind environment play an important role at planning an estate. The method of simulating the wind environment of the district was conducted by two cases that had been tested and verified. The steady-state three-dimensional turbulent airflow fields were analyzed by computational fluid dynamic (CFD) method for the two cases. The distribution of velocity, pressure and turbulivity were presented. The detailed schemes on simplified physical model, mesh division, solving and boundary conditions defining were presented. Results shows that numerical simulation helps predict the details of the outdoor wind environment of estate, and it helps evaluate outdoor air quality in all its aspects or improve planning.
Field Estimates of Hydraulic Resistance of Ice-Covered Rivers
Authors: Li Samuel
Published: May 2011

A large volume of velocity profiles measured from ice-covered rivers is used to estimate the composite Manning’s coefficient no associated with the ice and riverbed. Estimates are obtained using four methods, based on (I) depth-averaged and maximum velocities, (II) logarithmic velocity distributions fitted to field data, (III) energy slope combined with the logarithmic velocity distributions, and (IV) the Manning’s equation. Estimates of the composite coefficient range from 0.012 to 0.040. The coefficient can increase up to seven-fold through the winter. Method (II) has shown advantages. The energy slope appears to be between 25% and 50% of the water slope.
The Research of Developing and Constructing Tourist Attactions in Dong Jiahe
Authors: Hu Rui Bo , Xu Ren Ping , Wang Kun Qian , Mao Xing Ran
Published: May 2011

In the modern times,development and construction of eco-tourism area with different directions are popular in the nationwide.We should direct by the new design concept, using bionic design as specific guidance.DongJia river is located in very special geographical conditions and environment of carst.,its unique natural landscape formed the exotic landscape that "trees grown in the water, and the water flows across the trees; you can see cherry blossoms in spring, avoid the summer heat, and view hongye in the autumn,enjoy snow in the winter." The thesis described DongJia River tourist attractions by the nature, history, and economic, analyzed the factors of pros and cons in its development,and at last put forward constructive ideas of DongJia River tourism: a prominent feature, historical showing, concerning about red culture, and using these cultural factors skillfuly.
Study on Cognizing Disaster Prevention Signs in Public Buildings
Authors: Song Bo , Ma Kun
Published: May 2011

The public buildings and facilities investigated in this paper have disaster prevention signs, but they have the defects such as non-uniform, having gaps and unsystematic. The human subjective initiative of disaster prevention signs lays in the sign cognition which is influenced by many factors. In this paper, comprehensive investigation has been taken, and the relevance between disaster and sign cognition has been analyzed. A new perspective that cognizance regions are classified as risk, transitional and safe is proposed. Besides, the ways of setting up signs according to different regions have been researched. These contributes to the cognition of disaster prevention signs.
Dynamic Responses of Arch Dams Considering Different Reservoir Models
Authors: Hu Shao Qing , Sun Bai Tao
Published: May 2011

In this paper, the dynamic responses of an arch dam in the case of normal water level and operating low water level were simulated by using additional mass model and incompressible finite element model for reservoir respectively. The results showed that the reservoir models have a great impact on dynamic response of arch dams. The maximum principle tensile stress using incompressible finite element model of fluid is less than that using additional mass model. With the depth of the reservoir water increasing, the hydrodynamic pressure acting ton the dam surface caused by earthquake force increased and the dynamic responses of dam also increased.
Reliability Analysis on Yuwangbian Slop Based on Monte-Carlo Simulation
Authors: Feng Yi Fang , Zhang Hua Zhi , Wang Yu , Zuo Qing Jun
Published: May 2011

Based on the Yuwangbian high loess slope, which is located in Xi'an Yanta District, the basic principle of Monte-Carlo method is presented. By means of geotechnical engineering and geotechnical environment emulation software Geostudio-slope/w and based on Morgenstern-Price slope stability analysis method, the reliability and stability of the slope are analyzed under different kinds of working condition. The stability factor, reliability index and failure probability under the corresponding working conditions has been obtained. The results coincide with the actual condition, which makes the Geostudio software combine with the Monte-Carlo method and provides reference for the reliability analysis of loess slope.
Applied AVSWAT 2000 for Assessment of Pollutant Load in Brantas River Basin, Indonesia
Authors: Sholichin Mohammad , Othman Faridah , Shirazi S.M , Akib Shatirah , Harisuseno Donny , Sisinggih Dian
Published: May 2011

This paper presented the results of assessment pollutant load such as nutrient and phosphorus on Brantas River basin Indonesia. A Soil and Water Assessment Tool (SWAT) was choose to applied in this study due to successful for simulate the effect land used management from large watershed in many countries. Stream flow and sediment yield were calibrated for the 1991-2003 period and validated for the 2004-2006 period. The resulting statistical goodness-of-fit was evaluated with the Nash-Sutcliffe coefficient NS = 0.38 and R2 of the one-to-one line for monthly stream flow was 0.725. Results showed that annual average nutrient loads such as organic N, organic P, nitrate, sediment P increased in trend from 1991 to 2006.Simulated results showed that average annual nutrient load was 60.88 kg N/ha/yr for organic N, 11.64 kg N/ha/yr for Nitrate, 0.08 kg P/ha/yr for organic P and 0.25 kg P/ha/yr for soluble P, respectively. The most dominant type of land use contributing to increased nutrient load in rivers was the rice field. The water quality of Brantas River did not meet class II in term of nutrient parameters based on local water quality standard.
Critical Flow Theory on Nonlinear Penetrating Mechanism of High Energy Beam Drilling
Authors: Ho Je Ee , Chen Da Chih
Published: May 2011

For most of previous study on electron beam drilling (E.B) or laser beam drilling (L.B), the evaporating phenomena was assumed to be a minor parameter and could be neglected. In fact, the assumption usually leads to the overestimation of drilling efficiency and causes a significant deviation from experiment result. To improve this defect, a critical flow theory, based on the reacting pressure downward into the melting layer, is first introduced in this study; which not only successfully separates the evaporating model to convective model, but the critical transition of drilling characteristic will be also accessed. Examine the melting cavity of copper drilling conducted in E.B process, the evaporating phenomena responsible for drilled cavity had been verified to be as a prior parameter as the incident energy density is below 6×1010 w/m2. When compared with the experiment data made by Allmen [1], proposed theory shows an excellent agreement for copper drilling and their relative errors are no more than 30%.
An Algorithm for Force-Closure Grasping of Three-Fingered Hand
Authors: Liu Qing Yun , Jiang Bo , Yu Xiao Liu
Published: May 2011

On the assumption of FCWF model, the conditions of three-fingered robot hand force-closure grasping are equivalent to grasp matrix be full rank and exist rigorous internal forces. Based on the analysis to the geometrical characteristics of contact points, the existence condition of the frictional sectors is established. By means of studying the relative location relationships between the frictional sector borderlines and their intersections, the existence condition of the concurrent polygon of three internal forces is presented. Taking the equilibrium relation of internal forces into consideration, a general algorithm using vector calculation for force-closure grasping is established. An example is given to illustrate the validity of the algorithm.
Study on the Impact of the Construction Industry by the Development of Globalization Low-Carbon Economy and the Changing Pattern of International Competition
Authors: Jia Hong Jun
Published: May 2011

Low-carbon economic development strategy of globalization on the construction of deep-seated changes in production methods proposed new requirements. Requiring the construction industry to enhance output level, to improve the output value of profits, and strengthen the quality of the industry, expand the international market, and enhance core competitiveness. In this paper, an in-depth analysis on the challenges posed by low-carbon economy to the construction industry and the issues caused by international financial market volatility was made. And recommendations on strengthening the construction industry production relations, promoting the progress and improvement of the construction industry production methods and leading the sustainable development of the construction industry were proposed.
Vibration Characteristics of Composite Thin-Wall Beams
Authors: Ma Jing Min , Ren Yong Sheng , Tan Tao
Published: May 2011

The equations of motion for the free vibration of composite thin-walled closed-section beams are derived based on Lagrange’s equation of the second kind. Two stiffness configuration box beams are considered and corresponding closed solutions formula of natural frequency presented. The finite element analysis software, ANSYS is used to calculate the natural frequency and vibration mode shape of composite thin-walled cantilever beams. And the results are compared with closed solutions. The influence of composite elastic coupling and ply angle to thin-walled beams’ free vibration is investigated.
Effectiveness and Mechanism of Fly Ash in Inhibiting Alkali-Silica Reaction of Sandstone
Authors: Li Bei Xing , Zhang Jian Feng , Ke Da
Published: May 2011

The effectiveness of fly ash in suppressing expansion due to alkali-silica reaction (ASR) of sandstone are studied respectively based on accelerated mortar bar test and concrete prism test. The mechanism of fly ash in inhibiting the ASR of sandstone is examined by scanning electron microscope (SEM) and energy dispersive analysis of x-ray (EDAX). Moreover, the reliability of fly ash in inhibiting ASR of sandstone was discussed through concrete strength and frost resistance tests. Results indicate that the replacement amount of fly ash is 20%, the expansion due to ASR can be decreased to the critical value of a non-reactive aggregate. The reason why fly ash can inhibit the alkali reactivity for the sandstone is that the strong reaction between alkali and fly ash dissipates the alkali, and the products of alkali-silica-aluminate gels are non-expansible. For the concrete specimens suffered from accelerated ASR tests, their strength and frost resistance are decreased with the increment of fly ash replacement.
Study on the Effect of Fly Ash or Silica Fume to Hydration Heat of Cement
Authors: Ma Li Guo , Zhang Yun Sheng
Published: May 2011

The hydration heat evolution process is studied on the pure cement paste, the cement- fly ash binary system and the cement- silica fume binary system with water binder ratio(w/b) of 0.53, 0.35 and 0.23 by using isothermal calorimeter(TAM Air). The fly ash replacement in the cement-fly ash binary system is 10%, 30% and 50% respectively. The silica fume replacement in cement-silica fume binary system is 4%, 8% and 12% respectively. The experiments results indicate that w/b had great impact on the hydration heat evolution and the hydration heat decrease with the decrease in w/b. The addition of fly ash greatly decrease the exothermic rate and total hydration heat. The addition of silica fume shortens dormant period and increases the peak exothermic rate, but reduces the total hydration heat.
The Civic Apartment for the Aged in the Background of Chinese Population Ageing
Authors: Shi Qian Fei
Published: May 2011

At the end of 20th century, our country has already entered population aging stage. Along with the aggravation of the population ageing, the change of people’s viewpoint, it makes residential elderly-living mode turned into social elderly-living mode and the apartment for aged also springs up gradually. The paper introduce the development of the foreign representative apartment for the aged and the welfare history of policies and present conditions, analysis the problems of our country’s apartment for the aged and the future development directions of it.
Synthesis and Dispersibility of Polycarboxylate Copolymers with Poly(ethylene oxide) Side Chain
Authors: Li Shun , Yu Qi Jun , Wei Jiang Xiong , Wen Zi Yun
Published: May 2011

Polycarboxylate copolymers (PCs) with poly(ethylene oxide) (PEO) side chain were synthesized using first an esterification reaction technique and second a free radical polymerization in aqueous solution. The resultant PCs have been characterized by Fourier transform infrared (FTIR) spectrum and gel permeation chromatography (GPC). The molecular structural parameters of PCs were determined from GPC and ion chromatography (IC). The dispersibility of PCs having different degree of polymerization (DP) of PEO side chain was investigated in cementitious system. Also, the mechanism of dispersion was discussed via the respect of electrostatic repulsion and steric hindrance effect. The results show that the PCs possessing an appropriate DP of PEO side chain can exhibit a higher dispersibility.
Research on the Electrochemical Behaviour of H05MnNiMo and H06H1 Submerged Arc Welded Seam in the S2- Medium
Authors: Bi Zong Yue , Feng La Jun , Lei A Li
Published: May 2011

Welding sticks H05MnNiMo and H06H1 are developed to improve the corrosion resisting property of the X80 pipeline in submerged arc welding. Influence of the concentration of sulfur-bearing medium and the temperature on the corrosion of welding seam from X80 pipeline steel was investigated with the Electrochemical Polarization Method and Weight loss Method. And the characteristic and mechanical of the welding seam was discussed. The results show that the welding seam prepared in H05MnNiMo is of high corrosion potential, both of the welding seams have a maximum of corrosion rate 1.0×10-7 mm/a, in the S2- bearing solution with a S2- concentration from 1.0% to 2.5%, at the temperature from 20 OC to 60 OC, thus they can be classified as anti-corrosive material.
The Evolution of Architectonic Aesthetics in the Context of Globalization
Authors: Zhou Bai Ling
Published: May 2011

Research the evolution of architectonic aesthetics by concentrating on politics and economics in the background of Globalization. The accelerative modernization forces the individual aesthetic needs into the opposite, from which point out the evolution of the post-modern architecture can also be traced into the process from the deviation from astriction to sensibility then to the reflection on basic rationalism and at last to the aesthetic individualism. In conclusion, the trend of individualism, personalization and pure “experience” in architectonic aesthetics will continue its evolution and exert its influence on the development of Chinese architecture.
Estimation and Stochastic Convergence Test of China's Transportation Technical Efficiency
Authors: Zhu Jia Xiang , Tan Qing Mei
Published: May 2011

Applying super-efficiency DEA model and co integration test method, this paper estimates the transportation technical efficiencies and tests their convergences during 1986 to 2008 in China; the main results are as follows. Average transportation technical efficiency of Chinese provinces takes on a decreasing trend since 1986.There are regional disparities of transportation technical efficiency in China, namely coastal and northeast regions have high-level technical efficiencies, while those of the central and western regions are low. The study also finds that the convergences of transportation technical efficiency exist in coastal and northeast regions in the long run, which do not exist in the middle and west parts and nation-wide. Finally, the corresponding policy suggestions are given.
A 4-Order Polynomial Movement Law of the Cam Mechanism without Shock
Authors: Li Chun Ming , Chen Jing , Zhang Chun Ling
Published: May 2011

In order to seek a simple follower part movement law of the cam mechanism, based on the discipline of defining inverse hour as the positive direction, the cosine, sine acceleration and 5-order polynomial law are analyzed and the characteristic of rigidity and flexibility attack are studied. The forming of movement law with 4-order polynomial is proposed. Cutting the raise course into two parts, the five undetermined coefficients can be defined by 5 boundary condition of the first part. The velocity drawing of the two parts is mirror symmetry around the cut point. The acceleration drawing of the two parts are center symmetry around the cut point. There is neither rigidity nor flexibility attack under the new movement law. Its velocity and acceleration drawing are smooth and its sensitive coefficient on the cam acceleration is more perfect. So the new movement law has a perfect dynamic property. Contrasting to the other law with the same characteristic, the new law is more simple and practical.
Experimental Research and Numerical Analysis on Fiber Reinforced Plasterboard-Reinforced Concrete Composite Floor Slabs
Authors: Huan Xiao Lin , Li Chang Liang
Published: May 2011

Fiber-reinforced plasterboard is patent product which was developed by Rapid Build Structure Ltd. of Australia. Fiber reinforced plasterboard can be used as baseboard , and after casting, it integrate with reinforced concrete to make up fiber reinforced plasterboard-reinforced concrete composite floor slabs. In this paper, numerical analysis method is accepted to analyze the process of bearing the loads of fiber reinforced plasterboard-reinforced concrete composite floor slabs. The calculated results, such as load- section strain curve and bearing capacity are compared with experimental data. Based on the results analysis, a mechanical analysis model is built, which provides some reference basis for computer simulation experiment of this type of structure.
Lime Brust of Sintering Bricks of Purple Sandy Shale: the Effect of Limestone Particle Size
Authors: Feng Zhi Gang , Tang Zhen Ping , Li Hui Juan
Published: May 2011

Simulating current sintering process in local brickkilns, Hengyang region, Hunan Province, China, at 800°C, througt indoor sintering experiment on a series of brick samples of purple sandy shale, in which particle sizes of limestone are >-1Φ, >0Φ, >1Φ, >2Φ, >3Φ and >4Φ, respectively, it is concluded that the following: (1) Limestone granularity is a crucial factor affecting the quality of sintering bricks of purple sandy shale. Under different particle sizes, the critical content of limestone causing lime brust of sintering bricks is distinct, and lowers with the increasing in limestone granularity. (2) When limestone granularity is different, its impact way on the quality of sintering bricks is also distinct. The more coarse limestone granularity is, the more concentrative the swelling stress produced by the hydration of free CaO is, the more easily lime brust occurs. On the contrary, the more fine limestone granularity is, the more dispersive the swelling stress is, there is the more help to reduce or eliminate the occurrence of lime brust. (3) In view of the relationship between limestone granularity and the critical content of limestone giving rise to lime brust of sintering bricks, the production practice can be effectively guided.
Effect of Mineral Admixtures and Chemical Activators on the Strength of FGD Gypsum-Fly Ash Complex Cementing Material
Authors: Wang Xin Tang , Zhou Ming , Zhang Yi
Published: May 2011

A kind of FGD gypsum from Ningbo Beilun Power Plant of China and fly ash were used as the raw materials with which a complex cementing material was made. Effect of the related factors such as paste material, water proportion, mineral admixtures (Cement, CaO) and chemical activators (NaOH, CaCl2, Na2SiO3, K2SO4) on characteristics of FGD gypsum-fly ash complex cementing material (noted as FGD-GFCM) is studied through a large number of single factor experiments. The additives with significant effect were chosen and the optimal mix proportion was determined. The experimental results show that an appropriate amount of admixtures can effectively improve the strength of the FGD gypsum–fly ash complex cementing material presented here. It is concluded that the strength of FGD-GFCB for 28d is best as the ratio of gypsum and fly ash is between 2:3 and 1:1 and water aggregate proportion is inversely proportional to the cementing material strength and apparent density of it.
Research on Shrinkage and Cracking of Cement Paste Based on Environmental Scanning Electron Microscope
Authors: Li Yue , Sui Chun E , Li Xue Hui
Published: May 2011

In order to study the shrinkage characteristics of cement paste, environmental scanning electron microscope was used to observe the microstructure shrinkage of cement paste and cement mortar under different humidity. The results showed that : with the relative humidity decreased from 80% to 10%, the shrinkage cracking of paste microstructure appeared in different degree and increased continuously,also the regression analysis showed the relative humidity and shrinkage was conical relationship.
The Strain-Energy Criterion of Iso-σθεθ Line for Mixed Mode Crack in Concrete
Authors: Chen Si Li , Qu Kun , Shi Jian Jun , Lu Li Hua
Published: May 2011

The fracture process of concrete structures is a very complex process, which includes the crack initiation, cracking, expansion and unstable failure. Based on the analysis of existing fracture criterion theories and some experimental data, this paper proposed the strain-energy criterion of I so-line for mixed mode crack in concrete. This formula is easy to be deduced, clear in physical concept; besides, it predicts the crack initiation angleθ0and determines propagation of the crack. The guidelines of the theoretical predictions are consistent with the measured results, which show that the guidelines can be applied to analysis crack problems of concrete I-II mixed mode fracture.
A New Binding Agent of Na2O-B2O3-SiO2 Syetem Sol for Expanded Perlite Thermal Insulation Board
Authors: Gao Jin Xiu , Wang Xiao Shan , Li Lu Bao , Ruan Hua , Tu Hao Chi , Wang Zi Sheng , Wang Zhi Yu
Published: May 2011

In recent years, many buildings went up in flames one after another. It is thought-provoking. So the fire-proof property should be considered into one of the most important performance of the building thermal insulation materials. As a result, the study on the expanded perlite lightweight porous inorganic material heated up fast although its application still has some problems to be solved. In this paper, we take the expanded perlite as raw material to make thermal insulation board, and then study on the effect of volume weight on the coefficient of thermal conductivity and tensile strength. What is more important, we find that a new binding agent of Na2O-B2O3-SiO2 syetem sol contributes to improving its water resistance.
High Performance and Low Cost Compound Admixture of Expanded Perlite Powder/Redispersible Polymer Powder for Dry-Mixed Mortar
Authors: Tu Hao Chi , Wang Xiao Shan , Li Lu Bao , Ruan Hua , Gao Jin Xiu , Wang Zi Sheng , Wang Zhi Yu
Published: May 2011

Since modern architectural technology has set a new standard for toughness of mortar, expensive polymer admixture has been used to modify dry-mixed mortar currently. But high cost critically restricted popularization of dry-mixed mortar. A new expanded Perlite powder- redispersible Polymer powder Compound dry-mixed mortar Admixture (PPCA) was researched in this paper. The research has indicated that PPCA showed synergistically optimized effect. There was the best modification effect when expanded perlite powder/redispersible polymer powder rate was 2 and admixture/cement rate was 0.15. The Ratio of Compressive strength to Flexural strength (RCF) declined to less than 3 when compressive strength of mortar staying above 10MPa. Moreover, cost of this compound admixture only was 1/3 of redispersible polymer powder admixture of the same performance. Meanwhile, this PPCA can improve water retention and increase softening coefficient of mortar to above 1.
The Influence of Formaldehyde/Phenol Ratio on Properties of Foamable Phenolic Resin and Phenolic Foam
Authors: Zhang Wei , Ma Yu Feng , Chu Fu Xiang , Wang Chun Peng
Published: May 2011

The foamable phenolic resin was prepared by gradual copolymerization of formaldehyde, paraformaldehyde and phenol using sodium hydroxide (NaOH) as catalyst, by way of adding NaOH, paraformaldehyde in different steps. The environmental protection vesicant, foam stabilizer and mixed acid curing agent were mixed with the foamable phenolic resin to prepare flame-retardant insulation phenolic foam. The influence of the formaldehyde/phenol molar ratio on the activity, toxic residue of foamable phenolic resin was investigated. Besides, the foam cell structure, insulation and flame-retardant properties of the phenolic foam were also studied. The results showed that as the molar ratio of formaldehyde to phenol was 2.0, the free phenol content was 2.3% and hydroxymethyl content was 34.83%, the thermal conductivity was 0.046w/mk, oxygen index was 54.3% and carbon monoxide (CO) peak production was as high as 1.8584 kg/kg, which was suitable to be used as insulation and flame-retardant materials in buildings.
High Performance Thin-Bed Dry-Mix Mortar for Autoclaved Aerated Concrete Blocks
Authors: Huang Zhao Ming , Yuan Yu Fei , Wen Zi Yun
Published: May 2011

At present, masonry and plaster of AAC blocks are still carried out by traditional construction methods which often lead to some quality defects such as cracking and leaking in the wall and hollowing and spalling in the plaster layer, etc. and hinder greatly the popularization and application of AAC blocks. On the basis of the characteristics of AAC blocks and the dry masonry thin-bed mortar, a kind of high performance dry-mixed Mortar for dry masonry process of AAC blocks was developed. The mortar has excellent workability, high water-retention, property, good mechanical properties and good construction properties. It solves the problems caused by traditional construction methods. The mechanism for these is discussed.
Defects in ZrO2-Reinforced Aluminum Foam Prepared by Infiltration Process
Authors: Wang Fang , Wu Jian Guo , Wang Lu Cai
Published: May 2011

The aluminium foam is reinforced by compositing ZrO2ceramic balls with high hardness. The production process includes preparing precursor using NaCl particles and ZrO2ceramic balls, infiltrating molten aluminium into precursor and cleaning NaCl particles. The defects presented during the process make the structure inhomogeneous and influence the performance of aluminium foam composite. The defects consist of inner and surface shrinkage caused by insufficient infiltration and inhomogeneous distribution of ZrO2ceramic balls in the composite. By analyzing the forming mechanism, offering right control of process and choosing correct parameters, the sound aluminium foam composite was prepared. The optimum value of pouring temperature, preheating temperature of die and particles and the suction was determined as 740°C-760°C, 480°C-500°C and -0.04Mpa, respectively. The composite has the structure with 0.8-1.2mm pore size, 60-70% porosity and ZrO2ceramic balls of 40 percent by volume. The research makes a basis for the application of the new aluminium foam composite.
Study on High-Efficiency Complexed Foaming Agent for Lightweight Foamed Concrete
Authors: Liu Xian Ming , Wang Li Ya , Li Sen Lan , Wang Jian Ping
Published: May 2011

The introduction of foam into concrete, made the concrete have a small internal, closed independent uniform bubbles, which can form light weight, good insulation properties of foamed concrete, mainly used for roofing, non-load-bearing walls and thermal insulation layer pipeline. The purpose of this study is to obtain basic data on the properties of the development of lightweight foamed concrete containing a novel and high-efficiency foaming agent for various applications. The results show that this novel complex foaming agent have high foam expansion and stable foam. Lightweight foamed concrete based on LC foaming agent exhibits high compressive strength, low thermal conductivity and low water absorption after 28-day curing. Furthermore, it can be found that micropores is homogenously distributed into the LC foamed concrete with density of 400kg/m3.
The Roles of B2O3 and P2O5 in the Formation of Cement Clinker
Authors: Ma Xian Wei , Niu Ji Shou , Wang Pei Ming , Chen Hu Xing
Published: May 2011

The roles of B2O3and P2O5in the formation of clinker which stand on the each side of the IV main group are discussed. The results show that the role of B2O3and P2O5in the formation of clinker are different: B2O3has evident effect, which is lost at higher temperature, on the consumption of CaO at 1300°C while the effect of P2O5is mainly reflected at higher temperature, especially at 1400°C; Suitable B2O3makes C3S transform form R to M3, but P2O5induces C3S change into M1. What they have in common is that more B2O3and P2O5will decrease the content of C3S.
Optimizing Performance of Magnesia-Spinel Brick Used at Cement Rotary Kiln
Authors: Wang Dong , Li Yong , Li Yang , Li Rui , Li Yue
Published: May 2011

Using high pure magnesia and magnesia-spinel as the main raw material, keeping the same quantity of spinel, specimens were made with different spinel size distribution (≤0.044mm, 1-0mm, 2-1mm, 3-2mm and 3-1mm). Dextrin and brine are the binder. Specimens were dried at the temperature of 110°C for 24 hours, sintered at the temperature of 1680°C holding 8 hours in a tunnel kiln. The properties and microstructure of the specimens were analyzed. The results are shown that the addition of spinel with grain size of 3-1mm improves sintering of magnesia-spinel brick, with the thermal shock resistance reaching 18 cycles, the cold crushing strength reaching 54 MPa, improving the comprehensive performance of the magnesia-spinel brick.
Application of Capillary Absorption on Characterization of Structure of Cement Compacts Containing Micro Silica Fume
Authors: Shen Ye Qing , Deng Min
Published: May 2011

Effect of packed structure on behavior of capillary absorption was briefly reviewed. Silica fume blended cement was pressed at pressure of 18MPa in a special mould to prepare packed structure. Structure of blended cement compacts was characterized by method of capillary ethanol absorption. Results show that linear correlation coefficient between absorption weight and square root of absorption time for each compact is more than 0.999. Micro silica fume is randomly filled into the skeleton of the compact. With increase of silica fume addition, porosity of the compacts and total length of average capillary pore in the compacts increase, whereas diameter of average capillary pore decreases. Quantified characterization of structure of the blended cement compacts will benefit to research of design and control of cement materials.
Bonding Force Investigation between C-S-H Clusters in the C3S Pastes and AFM Tip
Authors: Sun Hai Yan , Gong Ai Min , Peng Yu Lin
Published: May 2011

With the experimental objects of the C3S pastes curing at 60 days with water-solid ratio of 0.5, the micro mechanical characteristic between C-S-H clusters and tip has been investigated in the low scale. The results show that the experimental method is feasible for bonding force between C-S-H clusters and tip using atomic force microscopy (AFM) in the real atmospheric conditions. Though bonding force values are discrete in view of the anisotropy character of the cement-based material, the normal distribution can be fitted for the variation of bonding force between C-S-H blusters in the C3S pastes and AFM tip with a mean of 6.2nN. Even if bonding force values is somewhat higher due to the roughness and the measuring conditions in the paper, the experimental method using AFM could still be effective for the lateral correlation for bonding force of the different systems. The research on bonding force between C-S-H clusters would play the important role in establishing the new microscopic structural model.
Research Progress on the Mechanical Property of High Strength Structural Steels
Authors: Ban Hui Yong , Shi Gang , Shi Yong Jiu , Wang Yuan Qing
Published: May 2011

High strength and high performance steels used in structural engineering have been developed, but the application is constrained and the design work changes as a result of the different material property. In order to study high strength steel material property features, the production process, steel grade and code limit requirement were reviewed and discussed. Some important mechanical property indexes including the stress-strain relationship, yield-tensile strength ratio (i.e. Y/T ratio), ductility and toughness, were analyzed based on a large amount of tension coupon test data reported in the available literature. The stress-strain relationship model used for finite element analysis was proposed. It is concluded that high strength structural steels have excellent toughness but lager Y/T ratio and lower elongation compared with those of traditional steels, some of which even exceed the code limit values. It is necessary to do deep research on the relationship between the steel mechanical property indexes and structure safety and to make further development of high strength steels. This research work is helpful to comprehend the material property of high strength structural steels and relevant code limit requirements.
Application and Analysis on Polypropylene Fibrous Concrete
Authors: Wang Ying Hao , Liu Xu Dong
Published: May 2011

In fuel gas project, the foundation of carburetor is in circumstance which concrete occurred freeze-thaw circulation. To meet durability of structure, polypropylene fibrous concrete was used in design to solve concrete freeze-thaw. By means of a project, this paper talks about its crack control mechanism, impermeability, frost resistance and wear-resisting strength. Furthermore, some attention is listed to use polypropylene fibrous concrete successfully.
Research on Durability Performance of Novel Double Solution Grouting Material with Metakaolin
Authors: Yan Chao , Ding Qing Jun , Xu Jian Ping , Wang Hong Xi
Published: May 2011

At the present, Portland cement-water glass double solution grouting materials have many problems, such as the instability of gelation time and of products, and poor groundwater-corrosion resistance performance, etc. A way to improve the performances of double solution grouting materials was studied by adding metakaolin into the systems. Based on the rapid gelation performance of Portland cement-water glass and the durability of alkali-activated salic cementitious materials, an ideal structural model of the novel anti-aqueous dispersion and anti-aqueous dissolution grouting material (AAGM) was established. Series of experiments were prepared to verify the Na+ solidification and water-corrosion resistance performance of the metakaolin-water glass double solution grouting materials which combined with cement. The results indicated that the compact structure of AAGM was composed of a dominant ingredient of (Na,Ca)-Si-Al-H zeolite gel and a minor part of C-S-H. Moreover, it was shown that the AAGM had hydrated product of low solubility and compact microstructure tested by Fourier transform infrared spectra (FTIR) and transmission electron microscopy (SEM), which proved the well anti-aqueous dispersion and anti-aqueous dissolution performance.
Performance Study on Alumina Red Mud-Cement Stabilized Macadam Base
Authors: Qin Min , Liang Nai Xing , Lu Zhao Feng
Published: May 2011

Based on the analysis of chemical constituents and mineral composition, a new disposal method of alumina red mud added in cement stabilized macadam base was put forward. Through experiments of compressive strength, dynamic elastic modulus, splitting intensity and resilient modulus, mechanical properties of alumina red mud- cement stabilized macadam base and base performance affected by alumina red mud dosage were studied. Also, the strength formation micro-mechanism of alumina red mud-cement stabilized macadam mixture was explored by scanning electron microscopy (SEM). The results indicate that alumina red mud-cement stabilized macadam mixture has good mechanical properties; its early compressive strength, early splitting intensity, dynamic elastic modulus, resilient modulus are improved obviously with alumina red mud mixing; the mixing amounts of alumina red mud and cement are significantly affected mixture strength and the optimum mixing amount is respectively 10~12% and 5~6%; alumina red mud can promote cement hydration and hydrates generation. it not only is used as interstitial material among aggregates，also as binder closely linked aggregates through the spatial reticular structure formed by red mud and cement hydrates, which enhance mixture strength.
Effects of Nickel on Structure and Properties of Ferro Superalloy
Authors: Wang Hai Tao , Chen Chang Lu , Kang Dian Cai
Published: May 2011

The affecting law of nickel on structure and properties of ferro superalloy, which was cast by intermediate frequency induction furnace, were studied by orthogonal experimental method. The tensile strength and oxidation weight gain rate at 1000°C were tested. The matrix microstructure and scale morphologies and composition were studied using scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. It was found that the high temperature tensile strength went up with the increase of nickel by the forming of high temperature strengthening phase of γ’. After 100 hours aging at 1000°C, γ’ phase separated in blocks. Certain content of nickel improved the high temperature oxidation resistance of test alloys, but excess of it caused the higher oxidation weight gain rate and loose structure oxide scales with holes and exfoliating. In considering of high temperature tensile strength and oxidation resistance, the ideal content of nickel in ferro superalloy should be 9wt.%, with which at 1000°C the tensile strength of test alloys mostly exceeded 70MPa, and the average oxidation weight gain rate was only 0.55g.m-2.h-1, reaching the strong oxidation resistance. Such scale was compounded by Cr2O3 and Fe(Ni)Cr2O4 with compact structure, fine and even oxide grains.
Defects of Conventional Concrete and Developments of Self Compacting Concrete along with its Applications
Authors: Wang Zan Zhi , Supartono Franciscus Xaverius
Published: May 2011

The obstacles met during the production and construction of High Strength Concrete (HSC) and High Performance Concrete (HPC) are analyzed, then the poly-carboxylate based admixture is studied in detail. After that, presents the trend of using Self Compacting Concrete (SCC) to improve the performance of concrete structures, i.e. its durability and reliability, because its highly flowing nature makes it suitable for placing concrete in difficult conditions and sections, especially with crowded steel reinforcement. Utilization of SCC can also reduce the time required for placing large sections in concrete structures, e.g. in the basement or substructure’s concrete pouring. SCC may also minimize the noises on the construction site that are induced by concrete vibrators. Accompanying the presentation of the performance of SCC, its applications in the recently completed Grand Wisata Cable Stayed Bridge designed by the Authors are also introduced.
Study on the Flexural Property of PVA-High Toughness Cementitious Composites
Authors: Tian Wen Ling , Xu Lei , Wang Xiao Wei
Published: May 2011

For the compressive strength of the normal concrete is high and the tensile strength is low, it is typically brittle material. The ultimate tensile elongation of it is insufficiently 1/1000. Zhongwei Wu, an academician of Chinese Academy of Engineering pointed out that compounding cementitious composites was the way to make it high-performance, and fiber reinforced was the key[1]. Polyvinyl Alcohol Engineered Cementitious Composites has super flexural performance[2] and stretching ability[3],and its ultimate deflection is approximately 40 times larger than that of normal concrete when bended, similar to the multiple cracking and super toughness of uniaxial tensile test, it shows significant bending hardening behavior in the process of the test. This paper studied its flexural property by four point bending test .
Carbonation Behavior of Recycled Aggregate Concrete under Loading
Authors: Zhu Ping Hua , Wang Xin Jie , Feng Jin Cai
Published: May 2011

A study on carbonation resistance of recycled aggregate concrete (RAC) subjected to different loading level was carried out. Three series of concrete mixtures were prepared with loading level of 0.5, 0.8, and 1.2 of ultimately tensive strength of concrete. The coarse recycled aggregate was used as 30%, 60% and 90% replacements of coarse natural aggregate and fine recycled aggregate as 10%, 20%, and 30% replacements of fine natural aggregate. Moreover, the fly ash and slag were employed as 15%, 25%, and 35% addition of cement. Although the action of the tensile stress had a negative effect on the carbonation resistance of RAC, it was found that the addition of fly ash and slag was able to mitigate this detrimental effect. The carbonation depth would increase with an increasing loading level and reduce when increasing the sand ratio.
Fuzzy Synthesis Method for Evaluating Quality Class of Coarse Recycled Concrete Aggregate
Authors: Zhu Ping Hua , Feng Jin Cai , Wang Xin Jie
Published: May 2011

It’s necessary evaluating for quality of coarse recycled concrete aggregate (CRA) before it is used as feasible alternative of natural coarse aggregate (NCA). The factors affecting the quality of CRA, however, being multitudinous and complicated so much, associated to regional characteristic of CRA, led to a research on evaluating quality of CRA from China. First, the CRA was partitioned into three fuzzy quality classes corresponded to high, middle, and poor, respectively, whose applicable environment action grades and projects in terms of quality classes were suggested. Second, a fuzzy synthesis method how to evaluate quality classes was proposed. The present method used six indices, i.e., attached mortar content, bulk specific density, water absorption, Los Angeles abrasion loss, chlorid content and sulfate content. The weights for six indices were obtained based on credibility matrix and frequency statistic and the memberships based on optimum-intervel-style membership function. Using fuzzy weighted average operator, judgment matrix was calculated and synthetic membership score was considered as quality class judgment standard. Last, large numbers of engineering examples were computed using a program compiled in Matlab language. Computing results show that the present method is objective and reliable.