Advanced Materials Research Vols. 450-451

Abstract: The principle of rotated airflow transmission of friction spinning is reported in this article. The transmission experiments use six different samples of fibers and yarns, in order to study the fiber adaptability of the flats-delivered device and to draw practical conclusions.

Abstract: The degradation process of xylose and arabinose in a binary compositions system at temperatures from 210 to 250°C was studied to clarify the reaction mechanism and to examine the effect of the degradation products of a substrate on the disappearance of another substrate. The activation energy and frequency factor for the degradation of each substrate were estimated from the temperature dependence of the rate constant. The molar yield of a pentose to furfural was ca. 0.3 at any temperature, Acidic compounds were also formed from the pentoses in proportion to the amount of consumed substrates. The formation of acidic compounds resulted in a rapid decrease in pH

Abstract: The High-density polyethylene (HDPE) / the ethylene acrylic acid (EAA) - layered double hydroxide (LDH) nanocomposites were prepared by melt blending with EAA)/ LDH master batch; and the structure and properties of this nanocomposite were studied. The results showed that the EAA acted as an effective compatibilizer for the nanocomposites can enhance the interfacial adhesion between LDH and HDPE obviously, promote the dispersion of LDH in the matrix, increase both the tensile strength and toughness of nanocomposites, and improve the thermal stability and delay the onset decomposition temperature of nanocomposites.

Abstract: Composites containing gypsum-free cement features quick strength rise at the age between 1 and 3 days. Such property predestine gypsum-free cement concrete for repair of building constructions that are to be put into service as soon as possible. Repair of concrete-cement pavements and surfaces of similar character belongs to one of field of gypsum-free cement concrete application. Materials of these constructions shall comply not only with required strength characteristics but also with needed durability. That is why resistance to alternate frost, thawing and chemical deicing substances is the principal property of GFC concrete surface. Properties of gypsum-free cement concrete – whether fresh or hardened – are mainly affected by following factors: properties of gypsum-free cement (fineness of grinding, quantity of admixtures controlling initial setting time, clinker chemical composition) as well as mineralogical and chemical composition of natural compact aggregates, and water-cement ratio. Factors listed above are to be taken into account also during design of gypsum-free cement concrete composition. This article deals with design procedure concerning composition of concrete containing gypsum-free cement considering its specificities.

Abstract: This study presents the impact of rice straw as additive material on physical properties of hollow block as compressive, flexural strength and water absorption, Softening coefficient. Through testing the hollow block physical properties, the of rice straw additive was studied. When the rice straw amount portion was 0~15%, with rice straw amount portion increased, compressive, flexural strength and water resistance effect of adding one kind of early strength agent and mixing Al2(SO4)3, CaCl2 early strength agent hollow block decreased gradually. When the rice straw amount portion was 10%, adding early strength agent Al2(SO4)3, CaCl2 ，the 28d compressive strength of hollow block was minimum, 3.5MPa; while mixing CaCl2, Al2(SO4)3 early strength agent, the hollow block softening coefficient was 0.76, water absorption rate was 3.9%, meet the requirements of national standard of common concrete hollow block. Through the experiment, the conclusion is mixing early strength agent Al2(SO4)3, CaCl2, Obviously superior to adding one kind of —early strength agent—Al2(SO4)3 or CaCl2 on the physical properties of hollow block.

Abstract: Based on the test results of composed-wall-specimens made of fiber-reinforced gypsum panel and concrete core columns, ADINA finite element models of composite walls were established in this paper. Parametric studies were conducted on this basis, which would investigate the effects of fiber-reinforced gypsum panel, concrete core rate, height-width ratio and concrete strength on the load-carrying capacity of the composite walls.

Abstract: Influence of compounded mineral admixtures on shrinkage and early-age cracking behaviors of concrete was studied, based on the fellow factors: fly ash to blast furnace slag(denoted as BSF) ratio, fly ash-metakaolin ratio, BSF-silica fume ratio. Research shows that the Pozzolanic admixtures compounded with cementitious admixtures have complementary and synergistic effect for hydration progress of concrete, which can enhance the volume stability and cracking behaviors of concrete. However, the pozzolanic admixture compounded with other pozzolanic admixture, two pozzolanic admixtures will grab Ca(OH)2 resource. And then if the dosage of mineral admixture is higher, the compounding will result to decrease the volume stability and cracking behaviors of concrete.

Abstract: Through the analysis of the chemical and physical properties of the silt in Nantong, which were compared with the clay, the needs of silt raw material for sintered brick were discussed in the paper. The results showed that, the moisture content of the sail in Nantong were lower than that of the clay, the plasticity indexes of silt of Yangtze River in Nantong section concentrated around 12 which was ideal, the chemical constituents of the silt was similar to clay, part of the mineral contents were different. The silt can be used for replacing clay to produce wall materials. It would provide theoretical foundation of materials selection and usage for sludge products companies in Nantong, as well as the reference for the merging recombination and management in the industry.

Abstract: The sleeve-bolt connection and the groove-plate connection are two major forms of bamboo’s joints under tension and compression load, and the strength of these two connections is normally governed by the brittle failure mode of shearing-split. A new configuration of sleeve-cement bamboo joint is designed. Comparative loading tests were carried out to study the static tensile and compressive performances of the bamboo joints. It is found that the joint with sleeve-cement connection behaves more ductile under tension and possesses higher strength under compression than those with the sleeve-bolt and groove-plate connections. The sleeve-cement connection ensures effective transition of the axial load in the bamboo joint, and there are more to be optimized in its design.

Abstract: As the traditional material commonly used, cement has its own limitation such as limited solidifying objects, bad stability in water, high cost and uneasy adjustment in coagulation time, not good for solidifying the waste etc.. The succeed in developing a hydroceramic-concrete for soil stabilization can take place of traditional cementing material such as conventional concrete applying and avoid the shortage of them. Here we show that a mixture of Class F fly ash, metakaolin and 8M NaOH (hydroceramic) will harden at room temperature, attaining 9.2 MPa compressive strength at 90 days, It is suggested that a hydroceramic-concrete may be used as a project material of soil stabilization as it has similar or even better compressive strength than conventional concrete.