Applied Mechanics and Materials Vols. 174-177

Abstract: This text used double fast cement, and fly ash, and high performance polymer and fiber for main material and plus agent for has high performance spray material of preparation and research, by distribution out of material has following advantages: condensation time fast, and short-term and late strength high, and dry shrink volume minimal, and stick poly sexual strong, and waterproof, and back bomb rate small, and seal performance very good, and has must of flexible, and using range wide.

Abstract: Because of its durability and strength, more and more porous concrete has been used for riverbank protection or foundations of greenery. This study described a new type of green roof system without a soil layer on the porous concrete. This paper also discussed reuse of waste (fly ash generated from thermal power stations and aggregate made of ALC panel waste) to configure a newly proposed thin-type green roof system. As a result, the pilot model of lightweight thin type porous planting foundation satisfied the dynamic strength and ensured 30% void ratio needed for viability of vegetation.

Abstract: This paper analyzes the necessity of the research on recycled concrete, origins and properties of the recycled aggregate, the research status of material properties of recycled concrete, such as recycled concrete workability and mix design, mechanical properties, drying shrinkage and concrete creep of recycled concrete, durability etc, and the research status of structural members of recycled concrete, including columns of recycled concrete, beam-column joint of recycled concrete, frame structure seismic performance and so on, thus proves the research significance is great, moreover points out the future direction of the research on recycled concrete.

Abstract: Using desulfurized gypsum and steel slag as raw material make desulfurized gypsum-steel slag composite gelled material, by adding cement, triethanolamine, aluminium sulfate, compound activator improve gelled material mechanics performance of materials. The experimental results show that when the proportion of desulfurized gypsum and steel slag for 85:15, mixing the compound activator that aluminum sulfate mixed quantity is 1%, cement mixed quantity is 3%, triethanolamine mixed quantity is 0.8%, sample’s 14d flexural strength can reach 5.83 MPa and compressive strength can reach 16.14 MPa. SEM analysis shows that a lot of C-S-H gel structure in hydration products is conducive to improve desulfurized gypsum-the strength of steel slag gelled material, reach the purpose of improving gelled material mechanics performance.

Abstract: Cold bonded lightweight aggregate (LWA) was produced by adding 0%, 25% and 50% granulated blast furnace slag (GGBS) or rice husk ash (RHA) to fly ash (FA) by the pelletization process with cement additives. The results show that GGBS addition significantly improved the crushing strength of LWA, whereas there was no effective on crushing strength of LWA when RHA was used. GGBS addition significantly reduced the water absorption of LWA; on the contrary, effect of RHA was to increase the water absorption. Unit weight of LWA added RHA was in range of 719-903 kg/m3, while that of LWA added GGBS was in range of 918-1082 kg/m3. High performance lightweight concrete (LWC) made with the selected LWA (60% FA + 40% Cement and 30% FA + 40%Cement + 30%RHA) had unit weight lower than 2000 kg/m3. The 28-day compressive strength of the LWC was in range of 49 to 57 MPa. The results of the electrical resistivity and ultrasonic pulse velocity tests indicate that the LWCs might be considered to be durable concrete.

Abstract: Starch microsphere is artificial starch derivative, can be synthesized by cross-linking reaction from crude starch and modified starch. In this study, a new type of crosslinked starch microspheres with degradability was prepared by crosslinking reaction of soluble starch with N, N'-methylenebisacrylamide (MBAA) in inverse suspension using K2S2O8-Na2SO3 as initiator. The microsphere size and size distribution of the starch microsphere were determined, and the structures were studied by SEM and FT-IR. And then, the starch microsphere was expected to been used in nasal drug delivery system, artery embolization, radiotherapy, immunoassay and so on.

Abstract: This thesis analyzes the current situation of the heat insulation system of composite wall in China. Through comparison, it points out that heat insulation system is the trend of the development for heat preservation and energy saving, and meanwhile, it gives direction for further research to several different new type heat insulation systems.

Abstract: Through the pull-out test methods, the concrete strength、reinforcement diameter Basalt Fiber Reinforced Plastics Bars、the anchorage length、 stirrup rate and other factors on the bonding properties of the BFRP reinforced concrete is analyzed. The BFRP bars and reinforcing steel bars bonding properties is compared. BFRP reinforced concrete bond failure mode has two types .As the concrete strength increases, the bond strength of the BFRP reinforced concrete increased. With the increase BFRP bars diameter and shear lag relationship, the cohesive force of the BFRP reinforced concrete decrease accordingly. And the failure modes of the shape of the BFRP reinforcement concrete in BFRP bonding properties with a big impact for the specimens’ configuration stirrups on the ductility. When BFRP bars loading under the same load level, the end of the slip is greater than the free end slip.

Abstract: To improve the ecological performance of pervious concrete, single-factor test method was adopted to study the correlation between compressive strength, flexural strength and splitting strength, the effect of porosity to the strength was analyzed as well. The shrinkage characteristics were compared through experiments between ecological pervious concrete and no-fines pervious concrete, ecological pervious concrete and common concrete.

Abstract: Abstract: In view of the seismic design requirement for ductility, a group of the cyclic loading experiment is carried out on seven concrete-filled square steel tubular with different axial load ratio, slenderness ratio and concrete grade. After that, the load-displacement curves and the skeleton curves of these frame columns are attained, together with the load-displacement value of each step. Based on these data, an analysis on various factors that affect the ductility of concrete filled steel tubular columns is conducted. The results show that the decline of the bearing capacity in the end-column is mainly due to the germination and expansion of the plastic hinge of pillar. Furthermore, increasing the axial compression ratio will lead to the earlier emergence of plastic hinges, which correspondingly reduces the ductility and horizontal anti-shearing capacity of the frame column. In addition, increasing slenderness ratio can contribute to delay the emergence of plastic hinges, which improves the ductility and energy dissipation capacity of columns, but decreases the horizontal anti-shearing capacity. As a result, adopting the higher grade concrete can effectively reduce the negative effects from the large values of axial compression ratio and slenderness ratio. The experimental results perfectly support the data from the finite element calculations.