Applied Mechanics and Materials Vols. 584-586

Abstract: Compared with natural aggregate, recycled aggregate apparent density, bulk density, porosity, water absorption, large crushing index value, which corresponds to aggregate different sources have different indicators, which largely of recycled concrete limits on the application.. In order to more efficiently improve the utilization of recycled aggregate, ensure the stability production quality of recycled concrete, source unknown and difficult to directly measure its intensity of waste concrete materials, at the time of the preparation of recycled aggregate, it is recommended to repeat loading, using different pressures from different standard strength of recycled concrete coarse aggregate crushed curve to use as a criterion to determine the source of their overall strength. Different in different sources of strength recycled aggregate crushing value mainly reflected on the bond strength.

Abstract: The work presents the results of development of the composite gypsum binder (GB) with nanostructured binder on the basis of silica component (NBC). Introduction of NBC changes the kinetics of hardening, as well as improves physical and mechanical properties of gypsum system. Analysis of the microstructure of the GB has demonstrated in the presence of the NB the size and morphology of crystals are changed, promoting the formation of fine-crystalline structure and increase the contact area between new formations, compared to NBC – free gypsum system. Experimental studies have shown that the mechanical properties of the composite gypsum application of NBC increased, reduced water absorption, density increases, and increases the setting time.

Abstract: According to the feature of the second oil layer in the west block of Beierxi, this paper investigated the relationship between the permeability contrast and the recovery efficiency, and the relationship between the permeability contrast and the descent range of water cut of polymer flooding, using the numerical simulation. From the comparative analysis of the development effect with different methods of polymer-injection, it got the boundary of the interlayer permeability contrast of the positive and inverted rhythm layer in the second oil layer with the separated zone and separated quality polymer-injection respectively. That provided certain theoretical foundation for carrying on the polymer flooding in the region of interest.

Abstract: Used in a variety of civil engineering materials referred to civil engineering materials, it is the material basis of all traditional civil engineering civil engineering construction materials, such as: brick, stone, wood, etc., in the construction market has a large proportion But as the size of the material to expand and human population growth caused a global environmental crisis, while construction activity is one of the major activities of human life, natural resources and energy consumption and environmental pollution also have a great impact. therefore , green building materials, environmental protection applications thus born.

Abstract: The effect of steel surface conditions on the macro-cell polarization behavior of reinforcing steels embedded in cement mortar was investigated by comparing and analyzing the macro-cell current density and macro-cell polarization ratio of steels. The results indicated that steel surface conditions played an important role in controlling the macro-cell corrosion and polarization. The polished or pre-rusted surface had a better corrosion resistance to inhibit the flow of macro-cell current than the scaled surface that formed in the production process. Compared to the polished surface, the presence of mill scale or rust oxides on the surface of anodic steel could reduce the macro-cell polarization ratio of anode.

Abstract: Concerning on the modelling of quasi-brittle fracture process zone at interface crack of quasi-brittle materials and structures, typical constitutive models of mixed mode interface cracks were compared. Numerical calculations of the constitutive behaviours of selected models were carried out at local level. Aiming at the simulation of quasi-brittle fracture of concrete-like materials and structures, the emphases of the qualitative comparisons of selected cohesive models are focused on: (1) the fundamental mixed mode fracture behaviours of selected interface crack models; (2) dilatancy properties of the selected models under mixed mode fracture loading conditions.

Abstract: The deformation characteristic of granular material is important. It is important factor to analysis the bearing capacity and the thickness of granular material footings. There are many factors influence the deformation of granular material, such as material characteristic, content of water, degree of compaction, test method, etc. For analyzing size effect on the deformation characteristic of granular material, hypoplastic constitutive model considering void ratio is introduced. The influence of an initial void ratio, pressure and a mean grain diameter on the deformation is investigated by polar quantities: rotations, curvatures, couple stresses and a characteristic length. Thus, the influence of density and pressure on the initiation of shear bands can be investigated with a single set of constitutive constants.

Abstract: In order to produce required high strength steel bars for the building industry, it is necessary to provide steel with correct compositions. Effective, controlled micro-alloying is very important in the production of high strength steel bar of consistent microstructure and hence mechanical properties and weldability. Through adopting a series of measures such as molten iron pretreatment, converter final control, argon, calcium treatment, vanadium nitride and so on, a proper way to make high strength steel bar was given. The results show that the strength of the steel bars for the building industry can be increased by micro alloying with vanadium nitride. Favorable metallurgical achievements and economical benefits were gained.

Abstract: Reflective thermal insulation coatings (RTIc) are applied widely in Hot Summer and Cold Winter Zone and in Hot Summer and Warm Winter Zone. A feasible evaluation method for energy saving effect is very important for acceptance of energy efficient building construction. Combining with the research on RTIc at home and aboard, series of evaluation indicators of thermal insulation performance and energy saving effect of RTIc such as solar reflectance, hemispherical emittance, temperature, thermal resistance, energy efficiency and thermal inertia were summarized and the existing problems and several suggestions were also proposed.

Abstract: Now more power electromagnetic equipments are used. The radiation of them affects the human health and the environment. According to the mechanism of electromagnetic radiation and the influencing factor of electromagnetic pollution, the paper has researched electromagnetic radiation shielding measures. It was analyzed that the feasibility and application methods and results of steel fiber reinforced concrete (SFRC) building constructs. The application prospect and value of SFRC were brought out.