Advanced Materials Research Vol. 1094

Abstract: The first aim of asphalt mixture gradation design is moisture resistance and uniformity. In such a case, the high temperature stability and durability is to be improved. In order to improve the moisture resistance level of asphalt mixture ATB-25, and reduce the possibility of moisture damage, the experiment will use the orthogonal method. On this condition, chose 9 group of mixture gradation with two factors and three levels. With marshall experiment and the results analysis we find the relationship in VV, asphalt content and gradation. The maximal and minimum value of VV will be found. The range of moisture damage will be obtained. This research will provide a meaningful reference for ATB-25 gradation design.

Abstract: In view of three kinds of polymer modified asphalt, Compound rubber powder modified asphalt, rubber powder modified asphalt and SBS modified asphalt, were commonly used in the Inner Mongolia region, scanning electron microscope (SEM) were used to observe the macroscopic structure morphology of asphalt before and after aging , getting the influence of aging effect on modifier’s distribution state in asphalt and interface combination properties between the asphalt, that is, after aging, three kinds of modifier and asphalt interface characteristic deterioration. By using bending beam rheometer (BBR) three kinds of asphalt after aging were conducted trabecular bending creep experiments under different temperature, through analyzing the changing rules of bending creep stiffness modulus S and the value of m, it can be get that: composite rubber powder modified asphalt has the best low temperature performance , followed by the crumb rubber modified asphalt.

Abstract: Exploring strength curve and the corrosion mechanism of polypropylene fiber reinforced cement in chloride environment by the ultrasonic-rebound method and wet-dry cycle method in the laboratory. And fitting actual strength with rebound value and ultrasonic velocity, the result indicates that compressive strength of polypropylene fiber reinforced cement has a good regression relationship with rebound value and supersonic velocity

Abstract: Using ultrasonic method for various corrosion instars of clear water, sodium sulfate solution corrosion respectively after block of NDT, polypropylene mortar test results calculated according to the theory of strength. Through the press again the compressive strength test, it is concluded that polypropylene mortar test block intensity of real value^[4]. Through the press again the compressive strength test, it is concluded that polypropylene mortar test block intensity of real value.

Abstract: Modified organosilicon waterproofing agent was synthetized. It was painted on concrete surface and then the influence of durability on concrete was studied. Results indicate if it is painted on the surface of concrete, it has excellent hydrophobicity and can greatly improve the concrete quality. It can reduce the penetrability coefficient of chloride 6~10 times lower than the one without coating .The agent can prolong reinforced concrete’s life and reduce the carbonization depth of concrete.

Abstract: The autoclaved-curing high strength concrete was prepared with quartz powder (QP). The deterioration behavior of concrete specimens partially exposed to Na₂SO₄ solutions was analyzed by using scanning electron microscopy, energy dispersive spectrometer and X-ray diffraction as well. The results show that the interfacial transition zone cause the autoclaved-curing concrete damage. Sulfate chemical erosion is the main cause the damage of cement concrete. Hydration products of decomposition are the main cause of concrete crack mixing with QP. QP concrete is more susceptible to sulphate attack.

Abstract: The flexural capacity formula of reinforced concrete structure strengthened with FRP in Code for Design of strengthening concrete structure(GB 50367—2013) was introduced, and the rationality of the formula was analyzed. The results showed that the concrete compression height is independent of the tension strength of Fiber Reinforced Plastic (FRP), and the concrete compression height decreases with the increase of the tension strain of FRP, which is contrary to fact. The flexural capacity formula of reinforced concrete structure strengthened with FRP in Code for Design of strengthening concrete structure (GB 50367—2013) is worth discussing.

Abstract: The effect of nickel contents and milling parameters on the preparation procession of TiB₂-Al₂O₃ composite powders during the mechanical alloying (MA) was studied in this paper. Milling parameters have certain influence on the phase transformation of Ni-Al-TiO₂-B₂O₃ system during mechanical processing. With the same milling parameters, the proper content of Ni can promote the reaction route and influence the microtopography of the products.

Abstract: National standard high chromium cast iron contains 26% chromium by weight (Cr26). A new type of Super High Chromium Cast Iron (SHCCI) has been developed with chromium content of about 37% by weight. This paper examines the microstructure of SHCCI using SEM and XRD. The hardness and toughness of SHCCI was studied and the corrosive wear properties of SHCCI were also examined using an MCF-30 type erosion abrasion tester under H3PO4 media. The results show that, the microstructure of SHCCI is composed of M7C3 and M23C6 carbides, martensite matrix and residual austenite matrix. With proportionately greater carbon content, the hardness of SHCCI will first increase and then decrease, while the toughness and corrosive wear properties will decrease gradually SHCCI’s corrosive wear performance was significantly better than that of Cr26 cast iron. The maximum wear capacity of SHCCI is three times higher than that of Cr26 cast iron.

Abstract: The effect of rare earth element yttrium on cyclic oxidation behavior of Co-10Cr-10Al alloys in ambient atmosphere of 1 atm at 1073K was investigated. The results indicated that the addition of 0.05 at.% Y in the alloy enhanced the formation of protective oxide scales with compact smooth surface, and improved cyclic oxidation resistance of the alloy. On the contrary, the addition of 0.1-0.3 at.%Y greatly increased the oxidation rate of the alloy, with formation of a rapidly growing Co oxides layer with the porous and rough surface appearance.