Applied Mechanics and Materials Vols. 193-194

Abstract: In order to use the construction generated soil to replace high quality sand for consolidation pile as filling material partially. Clay soil specimens with different plasticity index were prepared. Moreover, the permeability tests were carried out for studying the permeability property. Experiments show that permeability coefficient can be guaranteed over 10-4cm/s in loosening status when plasticity index is smaller than 30, but that becomes very small in consolidation status. Therefore, some auxiliary methods must be adopted to improve the permeability of sand piles for drainage efficiently.

Abstract: There were three key factors including glue quantity of veneer, hot-pressing time, hot-pressing temperature to be researched on the effect of plywood performance, which gave a effective conclusion about technology parameter. The results indicated that the three factors obviously were related to the bonding strength and ranked as hot-pressing time > glue quantity of veneer > hot-pressing temperature in sequence. The best groups for production technology were that glue quantity of veneer was 320 g/m2 with hot-pressing time and temperature of 1.2 mm/min and 135 °C respectively.

Abstract: The article is based on the rubber crumb modified asphalt’s fundamental characteristics, paving a practical road surface, doing rubber crumb modified asphalt concrete road surface in the Northern cold regions’ practical application and testing, summarizing relevant experience, providing reference for similar engineering application .

Abstract: The synthesis of polymer materials from renewable biomass resources has attracted lots of attention. In this study, lignin based polyurethane heat insulating building materials were prepared from isocyanate and lignin polyol. Lignin was modified by polyethylene glycol and glycerol with 0.6% acid at 120°C to obtain lignin polyol containing reactive hydroxyl groups, and then polyurethane foams were prepared by the reaction between the above lignin polyol and isocyanate. Hydroxyl value of lignin polyol, gel time, apparent activation energy for polymerization, impact strength and thermal conductivity of lignin based polyurethane were investigated. The results showed that: (1) hydroxyl value achieved 397.0 mgKOH/g at temperature 120°C; (2) the apparent activation energy for lignin based polyurethane polymerization was 34.12 kJ/mol; (3) compressive strength reached 291 kPa with lignin polyol content 30%; (4) thermal conductivity was 0.02517 W/mK when lignin polyol dosage was 30%. It was detected that lignin could be used to prepare polyurethane heat insulating building materials in replacement of petroleum polyols.

Abstract: Hydration dynamics of Portland cement was investigated by low field NMR, a technique with advantage of continuous and nondestructure monitor. The transverse relaxation time, T₂, and signals intensity arising from the physically bound water in paste were measured. Their evolution with the hydration time could be used well to describe the hydration dynamics. Three successive periods, comprising of initial period, accelerated period and steady period, were defined according the different rate of change. The reactions and mechanism for individual stage were disscussed based on the cement chemistry theory.

Abstract: End-of-life CRTs are classified as hazardous waste since the funnel glass component has a high Pb content. Alternative management of the glass is required due to the cessation of closed-loop recycling of CRT glass. This study aims to compare the feasibility of using CRT funnel glass as fine aggregates in a self-compacting mortar by addition of limestone to enhance the Pb immobilization. Sample mixtures of self-compacting mortar were prepared from Ordinary Portland cement Type 1 (OPC) with water/cementitious (W/C) ratio of 0.38 by weight, which contained 0, 20 and 40 wt% of Samsung CRT funnel glass ground to sizes smaller than 595 µm as a sand replacement. The sample with glass mixtures contained additions of 5, 10 and 15 wt% of limestone, ground to sizes smaller than 297 µm as a viscosity modifying agent (VMA). The samples’ flow ability was tested by V-funnel and Marsh cone. Pb-fixation in the samples was analysed by TCLP at 7 days and 14 days. The addition of limestone as a viscosity modifying agent improved flow ability in mixtures with CRT funnel glass, with the addition of 10 wt% limestone showing the highest flow improvement in V-funnel tests for both glass mixtures. CRT funnel glass utilized as sand replacement at 20 and 40 wt% showed Pb leaching results within the US EPA allowable limits. However, the addition of limestone reduced the Pb immobilization ability in mortars. A silica based VMA such as fly ash and rice husk ash should be used for these applications.

Abstract: In this research, two buildings were constructed using phenolic insulation along with considerations of various experimental elements and condition. These environmental factors include natural ventilation, forced ventilation, the mist system, and shading. The results show that when the building is well insulated, the heat transported across the well is effectively prevented indicating that the phenolic resin is effective in insulating the building. Under full sunshine, the room temperature is 10 °C lower than the ambient temperature under full sunshine with the best insulation effect observed at 10:00 am. Shading will provide additional insulation effect to lower the room temperature by 3 °Cmore; the insulation efficiency can also be improved by ventilating the room. Results at 12:00 noon show that shading can effectively reduce solar radiation on the wall whereas force ventilation will carry away heat to reduce the room temperature. Shading will always be effective in reducing the room temperature by about 4 °C, and at 14:00, forced ventilation is the most effective in lowering the room temperature.

Abstract: The molten carbonate fuel cell (MCFC) is an important research field of the new energy generation equipment. To aim at the problem that MCFC electrical characteristics reflect the generating performance, the electrochemical process mechanism of MCFC electrochemical reaction was analyzed firstly, then an electrical model of MCFC electrical characteristics based on the electrochemical process was advanced. Thirdly, the hot start process, and the output test of MCFC generation applied the experiment were particularly presented. Finally, the experimental results proved that it was fast and accurate.

Abstract: This paper aims to figure out whether or not the new sustainable building material mineral wool could save energy consumption from commercial office building. Professional software such as EnergyPlus, Google SketchUp was used to simulate the thermal and energy-saving effect of this new material. The final results show that after the application of mineral wool, 28.05% (114.23GJ) energy consumption is able to be saved by the large commercial office building located in Beijing, within which 88%(139.27GJ) heating could be reduced

Abstract: An optimal air-entraining agent was selected through a systematically experimental and theoretical study on air-entraining and full-light-aggregate concrete (AEFLC) for structural and thermal insulating wall. Among the three air-entraining agents: rosin acid sodium, Polycarboxylate-type agent, Lauric acid-based agent, Lauric acid-based (Huntsman) air entraining agent was considered the best for the air-entraining quantity and quality. As the result, a AEFLC with the apparent density of 1110kg/m3, compressive strength of 18.8MPa in 28 days, and thermal conductivity of 0.38w/(m.K) was obtained.