Advanced Materials Research Vols. 168-170

Abstract: According to experiments by comparing with normal cement concrete and other fiber reinforced concrete, they analyze the mechanical properties and features of sisal fiber reinforced concrete. Besides, they observe the fracture process of different ages and contents of sisal fiber reinforced concrete and analyze the bonding property, toughening effect and failure mechanism. The results show that sisal fiber reinforced concrete is superior to normal cement concrete on mechanical properties, and has a feature of multi-cracking, while compared with other fiber reinforced concrete, it is more economical.

Abstract: Mechanics properties of lime-steel slag stabilized soil for pavement structures are investigated. Firstly, the chemical composition of the fine grain steel slag is analyzed by spectral analysis test. In view of the materials compositions, 5 kinds of mix proportion projects are defined. Compaction tests of all mix proportion projects are carried out in different water conditions to obtain the optimum moisture contents. Then the optimum mix proportion project is demarcated by the unconfined compressive strength test and the compression rebound modulus test. Finally, the pavement structures design for a highway of lime-steel slag stabilized soil road sub-base is made. As comparisons, the pavement structures of other types of lime industrial wastes stabilized soil road sub-base are computed. It is shown that lime- steel slag stabilized soil is suitable for flexible pavement or semi-rigid pavement because of its good strength and rigidity which can effectively reduce thickness of the lower pavement and basic deflection.

Abstract: The optical performance of the heat mirror for warm climates was proposed, and a parameter Dx which equals the ratio of solar transmission to visible transmission was defined. To make the Dx as low as possible, the thicknesses of the films for TiO₂/Ag/TiO₂ multilayers were optimized through computer simulation. A TiO₂ (140 nm)/Ag (16 nm)/TiO₂ (140 nm) structure optimized for 16-nm Ag has a maximum decrease in Dx value (from 0.75 to 0.51), which possesses excellent building energy efficiency.

Abstract: Depending on the desulfurization reaction temperature，it can be divided into fly ash generated at high-temperature furnace zone and at low-temperature flue gas zone. For simulating those two kinds of desulfurization ash, the ordinary fly ash mixed with different weight percentage of CaSO4•2H2O is divided into 2 groups, the first group is followed by calcining at 900 , another drying at 100 . And then by the experiment of workability, strength and steel rebar protection, the effect of morphology and amount of gypsum on material properties and the pretreatment method are studied. The results show that: compared with ordinary fly ash, those two kinds of desulfurization ash can improve workability, but the improving ability of desulfurization ash at high-temperature furnace zone weaker than another’s, in addition, amount of gypsum in desulfurization ash on fluidity has a threshold; Secondly, desulfurization ash can decrease strength, and the early strength of desulfurization ash at high-temperature furnace zone higher than another’s, but the development trend of later strength is in the opposite direction. Thirdly, those two kinds of desulfurization ash are harmless for steel rebar, and the steel rebar’s passive film compactness is followed desulfurization ash formed at low-temperature flue gas zone＞desulfurization ash formed at high-temperature furnace zone＞ordinary fly ash.

Abstract: The properties of inorganic cohesive glue and its appliance to repairing ordinary and high strength concrete were studied in this paper. Inorganic cohesive glue not only has high strength, but also has equivalent coefficient of expansion with that of concrete and steel. The mechanical performance of inorganic cohesive glue is better than that of concrete, and other performances are similar to those of concrete. In the concrete repair work, it can mend the ruinate concrete well, and the strength of the repaired concrete is as high as or higher than that of original specimen.

Abstract: studied types and amount of hydration products in cement paste in waste concretes and effect of the cement paste in waste concrete for compressive strength of autoclaved waste concrete samples simulated by hydrated cement with X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Infrared Spectroscopy (IR). The results showed, compressive strength of autoclaved waste concrete products increased with cement paste in waste concrete increasing, and the effect reduced obviously when amount of cement paste exceed 12.5% in waste concrete. Cement paste calculated amount exceeds 12.5% according to present national specification for mix proportion design of ordinary concrete. And it shows that effect of cement paste in waste concrete is weakly for compressive strength of autoclaved waste concrete sample. And compressive strength of autoclaved waste concrete samples is unrelated to mix and age of waste concretes. Hydrated products such as hydrated calcium silicate (C-S-H), α-C₂SH and hydrated calcium aluminate sulfate (AFm or AFt) in cement paste forming during normal temperature curing play a role of crystal seed in autoclaved waste concrete samples.

Abstract: Different solid waste and their autoclaved waste samples were studied with the methods of infrared spectra (IR), X-ray diffraction (XRD) and chemical analysis. The results indicate that there is significant difference for strong absorbance Si-O bonds stretching vibration band of solid wastes infrared spectrum. The silicates have reacted and formed new hydrates which correspond to the strong absorbance Si-O bonds stretching vibration band. For containing activity crystal or amorphous which have ever been high-temperature heat such as fly ash, slag, waste glass and steel-slag, bound water amount of their autoclaved samples are related to strong absorbance Si-O bonds stretching vibration band, but there are no unity rules between the compressive strength of the autoclaved samples and strong absorbance Si-O bonds stretching vibration band because their type of hydrates products are significant differences. The IR characteristic peaks of waste concretes are almost same, and there are similar hydrate products (tobermorite and C-S-H (I) gel) and maximum compressive strength for different samples.

Abstract: Plastic profile produced by extrusion die should be cooled down and calibrated by calibrator ,so the proper design of the cooling system in calibrator was very important to the profile quality .The cooling channels in calibrator were preliminarily designed according to target function, and peculiar heterotype optimum designs of the local cooling channels were carried out by means of numerical simulation , the cooling effect was improved obviously ,Based on enterprise resource planning ERP system and parallel project computer aided design/computer aided Engineering CAD/CAE intellectualized data-base network, design for the cooling system was more reasonable, and could meet the demands of customers much better.

Abstract: Uniaxial tensile tests of PVC membrane are carried out at seven kinds of temperature. The change law of tensile strength, strain at break and the Young’s modulus at different temperature are obtained from the tests. The results indicate with the increase of the test temperature, the tensile strength decreases while the tensile strain at break increase, but the load-deformation curve trends are similar. By using molecular break theory, the fitting formulas are proposed to predict the effect of temperature on tensile strength. In addition, the cycle loading tests were carried out in three different phases. This paper studies the residual strain and the elasticity change of the PVC membrane during the test. The results indicate PVC membrane is typical elasto-plasticity material. With the increase of cycle loading the residual strain increases.

Abstract: The application of vanadium-nitrogen alloy to develop a certain low carbon high strength H-beam steel was determined through the combination of theoretical study, product requirements and existing practical conditions. The specific rolling process was further defined through laboratory experiments. The developed low carbon high strength H-beam steel was trial produced and its properties were also analyzed. The results showed that the newly developed low carbon high strength H-beam steel had excellent mechanical properties and good weldability.