Advanced Materials Research Vols. 535-537

Abstract: A study is presented to reveal the rule of temperature descent of large stone asphalt mixtures with different design thickness at different ambient temperature through the laboratory simulation test of large stone asphalt mixtures. The results show that the surface temperature dropped rapidly when the surface of large stone asphalt mixtures was in contact with air, then the cooling rate gradually decreased and the temperature difference between the surface and the middle of large stone asphalt mixtures maintained between 15°C and 40°C until the surface temperature dropped to the rolling end temperature. Ambient temperature and design thickness of large stone asphalt mixtures have great influences on its cooling rate.

Abstract: As high-grade refractories raw material，kyanite is widely used and the market demand is increasingly greater. The kyanite in Hebei is complicated，main chemical composition is SiO₂ 52.87％、A1₂0₃ 21.14％. The result of investigation on mineral processing technology show that desliming has a great influence on kyanite, especially acid process, the suitable lower limit particle size for desliming is 20μm. Magnetic separation process may remove iron-bearing minerals，and the iron removal rate is 87.78％．The optimum condition for magnetic separation is magnetic field conditions 1.0T. Base on the research, we can get concentrate with a grade of A1₂0₃ 58.37% and a recovery of A1₂0₃ 56.02% if we adopt magnetic separation and flotation technology.

Abstract: Based on the construction application of C50 anti-cracking pumping concrete, the influence of the polypropylene fiber and expansive agent on the concrete was studied. The workability, mechanical property, drying shrinkage and crack resistance of the pumping concrete and their mechanisms were tested. The results indicated that the workability achieve the standard of pumping concrete through increasing the dosage of polycarboxylic superplasticizers. The incorporation of polypropylene fiber and expansive agents has little influence on the compressive strength and elastic modulus, but will significantly enhance split tensile strength and decrease the drying shrinkage and cracking.

Abstract: Through experimental study of six steel reinforced high strength concrete columns under low cyclic horizontal loads, the influence on anti-seismic behavior of the columns under different axial load coefficient, stirrup ratio and steel reinforced form is analyzed.The study found in addition to the fact that the anti-seismic performance of high strength concrete columns is sensitive to axial load coefficient, steel reinforced form is also an important influencing factor. For high strength concrete columns with different steel reinforced forms, appropriate adjustment of its axial load coefficient may be carried out, however the influence of stirrup ratio is very little on anti-seismic performance of columns.

Abstract: The safe current carrying capacity of iron wire is far less than copper wires. In the simulation experiments, use iron wire replace copper wire and use welding machine as electric equipment, even the flaming. Normal operating electric homework, the whole iron wire overheat and cause carbonization of insulation layer and even set on fire because of line’s overload, and lead to short circuit between wire. Extract fire material evidence, observe and analysis. Summed up the microstructure characteristics of the sample. Apparent characteristics of short circuit melting mark organization is:wire matrix is widmanstatten structure and ferrite, the transition region is mainly widmanstatten structure; overload melted mark organization is mainly cast structure, there was more casting .

Abstract: The stability of the slurry wall in the process of slurry supporting into slot directly affects the stability of the pit. This paper analyzes the key factors for deformation control, researches the influencing factors on slurry wall stability during slurry trenching and concreting for diaphragm wall, and proposes control measures to control the stability of slurry wall and matters need attention, which is of great significance to guide the foundation construction.

Abstract: The most effective method to quickly produce large quantities of corroded reinforced concrete component is electrochemical corrosion. In this study, what effects corrosion rate as well as the process of accelerated corrosion was experimentally investigated.

Abstract: Stress mechanism and failure forms of coupling beams in high-rise buildings are analyzed. Meanwhile, general principles and conceptual design methods of coupling beam design are put forward, along with some solutions on the over reinforced in the coupling beams that frequently occur in practical projects.

Abstract: This article introduces the method of the building enclosure construction of energy saving residential buildings based on the FHP-Vc inorganic composite silicate heat-insulating board and its practical effect in projects.

Abstract: This paper proposes a method for evaluating the linear stress-strain curve and bilinear stress-COD curve, suggested by Petersson, which can describe the tensile fracture behaviour of ordinary concrete satisfactorily. The two curves can be evaluated once modulus of elasticity (E), tensile strength (f_t) and fracture energy (G_F) are determined. It is proposed that the same fracture energy test suggested in the RILEM Recommendation be used to evaluate E, f_t and G_F. Firstly, the fracture energy was as usual evaluated from the area under the load-deflection curve. Secondly, the modulus of elasticity was calculated from the initial compliance in the same curve. Finally, the tensile strength was derived from the peak load. The proposed method was verified using some experimental data available in literature. The calculated values of the modulus of elasticity and the tensile strength were in good agreement with the corresponding experimental data. The method seems to provide a simple and practical way of evaluating the stress-strain and strain-softening curves of ordinary concrete, though further assessment is needed.