The modification of matrix is an important method to improve the mechanical properties of strain hardening cementitious composite (SHCC) . The influence of the properties of the matrix water binder ratio (W/B) and fre...
详细信息
In this study, data envelopment analysis(DEA) was used to evaluate the management performance of 26 apartment projects in Taiwan. DEA evaluates the relative efficiency of each project based on eight inputs and five ou...
详细信息
In this study, data envelopment analysis(DEA) was used to evaluate the management performance of 26 apartment projects in Taiwan. DEA evaluates the relative efficiency of each project based on eight inputs and five output items. This approach provides an active mechanism for promoting an objective assessment of property management in Taiwan. The empirical results provide insight into the performance of the apartment building projects.
To study the shear capacity increase in RC beams afforded by mixing polyvinyl alcohol (PVA) short fiber into the concrete of the beams, uniaxial tensile tests on concrete with five different mix ratios of short fiber ...
详细信息
ISBN:
(纸本)9810555636
To study the shear capacity increase in RC beams afforded by mixing polyvinyl alcohol (PVA) short fiber into the concrete of the beams, uniaxial tensile tests on concrete with five different mix ratios of short fiber and static loading tests on RC beams with the same mix ratios were performed. The increases in shear capacities of the beams were also estimated according to residual tensile strength of concrete obtained from uniaxial tensile tests. This study found the following: 1) the higher is the mix ratio of short fiber, the greater is the increase in the shear capacity of the RC beam, and 2) the proposed formula allows the shear capacity increase to be estimated from the residual tensile strength of concrete.
The roles of the construction process participants may vary in different countries – depending on legal regulations, tradition, the accepted practice. In this article the basic acts defining and regulating the roles ...
The roles of the construction process participants may vary in different countries – depending on legal regulations, tradition, the accepted practice. In this article the basic acts defining and regulating the roles of the construction process participants in Russia, Poland and Slovakia are presented. Based on these, the basic duties of the parties are discussed together with pointing the differences in these national systems. As there are some possible organizational schemes widely applied for construction processes their influence on the quality of the structures erected is described and discussed.
The authors aim to provide a set of tools to facilitate the main stages of the competitive bidding process for construction contractors. These involve 1) deciding whether to bid, 2) calculating the total price, and 3)...
详细信息
The problem of water inrush is commonplace in underground constructions. This paper using the thin plate model studied the critical thickness of tunnel aquifuge. According to the extreme equilibrium principle, the for...
详细信息
The problem of water inrush is commonplace in underground constructions. This paper using the thin plate model studied the critical thickness of tunnel aquifuge. According to the extreme equilibrium principle, the formula for calculating the minimum safe thickness of aquifuge was deduced. It further argued that the calculated plate thickness is just the minimum safe thickness of aquifuge, where the stress from underground water pressure is equal to the extreme stress supported by the extreme stress of the aquifuge. Through applying the formula to the practical cases, the authors concluded that the derived formula relatively conforms to the real constructions and can be applied into real tunnel engineering. Then after analysis and summary, the conditions and ranges of formula application were also obtained.
The structural performance of steel frames with novel lightweight composite infilled wallboard is experimentally and numerically investigated under the curvature surface deformation. This study compares the mechanical...
The structural performance of steel frames with novel lightweight composite infilled wallboard is experimentally and numerically investigated under the curvature surface deformation. This study compares the mechanical behavior for the open-frame, the closed-frame with mudsill and the closed-frame with infilled wallboard, through experiment and finite element analysis, under the positive and negative curvature surface deformations respectively. The structural responses such as basement counterforce, additional strains at different key locations and the effects of mudsill and infilled wallboard are evaluated. It has been found that the steel frames with the new composite infilled wallboard can considerably increase the stiffness of the structures in resisting surface deformation and re-distribute the loads amongst the beam and column members in the frame. The force transmission effect of the mudsill accelerated the changes in the additional strain at column bottom. Frame beam is the main component that bears the curvature surface deformation. Mudsill has a consistent stress pattern with the frame beam and can significantly influence additional strain of the frame beam due to its stress sharing effect. The infilled wallboard is connected with the column-beam members and thereby influences the additional strain of the frame column significantly.
The use of low-processed materials is a requirement for building in accordance with sustainable development. The examples of such materials are the components of plant origin – cellulose fibers, cereal straw and hemp...
The use of low-processed materials is a requirement for building in accordance with sustainable development. The examples of such materials are the components of plant origin – cellulose fibers, cereal straw and hemp/flax shives. Their carbon footprint is often negative since they absorb large amounts of carbon dioxide from the atmosphere during the plant growth. These materials are employed for thermal insulation or as a material for walls. Recently, hemp shives have enjoyed growing popularity in the production of lime-based composite, used for filling walls in timber frames. Owing to high porosity, the shives improve the thermal insulation properties characterizing the composite. By changing certain parameters, for instance the hemp shives to binder ratio, it is possible to modify the physico-mechanical properties of a composite; in contrast, the properties characterizing the hydrated lime binder can be altered using additives. The paper presents mechanical properties (compressive strength) as well as physical properties (density, porosity, thermal conductivity coefficient, absorptivity) of composites with various proportions of hemp shives of the Bialobrzeskie variety to the lime binder modified with gypsum and metakaolinite.
Energy demand rises significantly correlated to human activities in recent years. In contrary, energy supply from unrenewable resource decreases gradually from year to year. OMW as one of the renewable resources has n...
Energy demand rises significantly correlated to human activities in recent years. In contrary, energy supply from unrenewable resource decreases gradually from year to year. OMW as one of the renewable resources has not been expanded well in Indonesia. Therefore, SMFC will answer the alternative technology to generate electricity from OMW. The objectives of this study are conducted to compare of waste volumes on power generation and COD removal in SMFC and determine the optimum waste volume for SMFC application affected by river sediment microorganism source and mixed waste type. SMFC reactor as MFC single chamber was designed by 2.5-liter volume of plastic houseware utilized with single graphene anode and cathode to increase the power generation. The waste volume as the independent variable was adjusted 1/3; 1/2; 2/3 of the 2.5- liter volume of SMFC reactor, whereas river sediment microorganism source and mixed waste were dependent variables. The power density and COD removal percentage in 1/3VR, 1/2VR, and 2/3VR were compared on days 21 which was the typical day of the optimum performance of SMFC. The result shows that power density and COD removal of waste volume 2/3VR was higher than 1/3VR and 1/2VR. Power density of waste volume 2/3VR increased 1.5 - 3 times of power density of waste volume 1/3VR and 1/2VR, respectively. COD removal of waste volume 1/3, 1/2, and 2/3 remained stable. The optimum waste volume, the higher power density and COD removal, in addition to the result that 2/3 of the waste volume was the optimum result.
In this study, microstructural investigation was carried out to analyse the internal sulphate damage in the nano-Al2O3 (nAl) reinforced white cement pastes. As white cement is generally used in the production of archi...
In this study, microstructural investigation was carried out to analyse the internal sulphate damage in the nano-Al2O3 (nAl) reinforced white cement pastes. As white cement is generally used in the production of architectural concrete, 52.5 R type white cement was preferred in the scope of the study. Nano Al2O3 was substituted into the cement paste at 0% and 5% ratios. Three different methods were used for microwave curing. Different microwave curing techniques were performed as 120 minutes of 100 Watt application, 75 minutes of 100 Watt-30 minutes of 150 Watt-15 minutes of 200 Watt application, and 90 minutes of 100 Watt-15 minutes of 150 Watt-15 minutes of 200 Watt. In order to accelerate the formation of DEF damage, Na2SO4 was added to the cement paste at 2%, and 5% ratios. Three different microwave curing methods were used to investigate the occurrence of DEF damage in nano Al2O3 reinforced concrete concretes. In the pastes produced for this purpose, dense ettringite structure was observed. In cement pastes without nAl, the ettringite structure had a low S / Ca ratio (<0.20). More ettringite was formed in methods 2 and 3 used as microwave curing. The heat treatment applied in the microwave curing was the same as in other thermal curing applications, and in case the inner sulphate source was present it led to the formation of ettringite. This process became more evident in the presence of NA by increasing power application
暂无评论