Applied Mechanics and Materials Vols. 71-78

Abstract: In this paper, the form of perforated brick holes under different thermal conductivity were measured. To meet the strength required in the circumstances, as a scientific experiment to find an appropriate form of holes, porosity in order to meet the current rate of energy saving requirements. Experimental results show that the number of holes, size, shape, all affect the size of the thermal conductivity. Finally, several experiments are compared to find a suitable type.

Abstract: Utilization of industrial and agricultural waste products in the construction industry has been the focus of research for economical and environmental reasons. In this paper, Lime sludge, a paper and pulp industry waste product, has been chemically, physically and thermally characterized, in order to evaluate the possibility of its use as construction materials. X-ray Fluorescence and X-ray diffractometry studies for the determination of composition and presence of crystalline material and Thermo Gravimetric Analysis to identify the phase transition of lime sludge, as well as physical and mechanical properties and its pozzolanic activity have been conducted. It is concluded that the acceptance of this waste product by the construction industry could be decided depending on the application, keeping in view of the limitations on the mechanical strength.

Abstract: For the purpose of correct theoretical evaluation about the bearing capacity of unbounded pre-stressing composite slab. According to the construction methods and basic principles of unbounded pre-stressing composite slab, basic assumption of composite slab flexure calculation is defined; under the elastic stage, composite slab section stress-strain relationship at each stage was analyzed, as well as resolving the stress increment problem of vivo unbounded pre-stressing steel bar in the limit stage, and flexure bearing capacity of composite slab in various destroy mode in the limit stage was produced by the limit equilibrium method. The practicality of composite slab flexure bearing capacity formula was tested and verified by specific examples, provided a theoretical foundation for the practical engineering application.

Abstract: Two classification methods for coarse recycled aggregate used in asphalt concrete were investigated in this paper, respectively classifying by coarse recycled aggregate properties and asphalt concrete properties. When classifying by coarse recycled aggregate properties, coarse recycled aggregate was classified into three types by the apparent specific gravity, water absorption, crushed value, Los Angeles abrasion value and brick content of coarse recycled aggregate. When classifying by asphalt concrete properties, coarse recycled aggregate was used to prepare asphalt concrete; and coarse recycled aggregate was classified into three types by the optimum asphalt content ratio (R_OAC), theoretical maximum specific gravity ratio (R_TMSG) and indirect tensile strength ratio (R_ITS) of asphalt concrete containing coarse recycled aggregate. The proposed classification criterions of the two classification methods were respectively given.

Abstract: LEED is the most authoritative green building appraisal system in the world, which is also the green building appraisal system’s leader in the world. Researching the changes of LEED, can in favor of the development of green building appraisal system in our country. This article through the comparative analysis on the value and content between LEED 2.2 and LEED 3.0 to observe its development, and make brief contrast with Chinese green building appraisal system, the advantages of LEED can make a good reference for our green building appraisal system.

Abstract: Although many people discussed the strength and durability of concrete with natural sand in severe environment, few people investigated the mechanics performance of concrete with manufactured-sand under condition of freeze-thaw cycle, at present. Experimental studies on C30 concrete with manufactured-sand were carried out under condition of freeze-thaw cycle, which based on the testing of raw material performance and concrete mix ration, in this paper. Comparative studies on the changing laws of the mass, strength and the relative dynamic elastic modulus of concrete were developed in three cases which were freeze-thaw cycle, freeze-thaw cycle and acid corrosion and freeze-thaw cycle and alkali corrosion. The test results showed that the mass, strength and the relative dynamic elastic modulus of concrete with manufactured-sand decreased evidently with the increasing of times of freeze-thaw cycle. The durability of acid and alkali-resistant of concrete with manufactured-sand was also remarkably weakened due to the action of freeze-thaw cycle. The capability of acid and alkali-resistant of the concrete was decreased with the increasing of times of freeze-thaw cycle and the anti-acid capability was decreased more seriously.

Abstract: Silica alcogels were prepared by hydrolysis with hydrochloric acid and condensation with NH₄OH of ethanol diluted tetraethylorthosilicate (TEOS) precursor and trimethylchlorosilane and hexane as surface modifying agent. The physical properties such as density, appearance, hydrophobicity, surface area, pore size distribution and thermal stability were measured. It was found that the physical and hydrophobic properties of the silica aerogels depend on the TMCS/hexane (V) volume ratio. The density decreased with increase of V, and the aerogels are more hydrophobic as V=3%. The aerogels were thermally stable up to a temperature of 350 °C, and the aerogel prepared has a high surface area and large pore volume.

Abstract: The thermal properties of the crystal sandstone light ceramic products, nature sandstones, tiles and composite floorboards were analyzed and compared in detail by scanning electron microscope (SEM) and thermal simulation method. The results show that the different thermal properties are the main factors which lead to the different thermal comfort to these materials. It is analyzed in theory that the good thermal comforts of the crystal sandstone light ceramics are come from the low thermal conductivity and low density mainly. And the thermal simulation is a reference method on the thermal comfort research of architectural ceramics.

Abstract: A heterocyclic derivative of 3-(N-mono-n-lurylaminomethyl) quinazolin-4-one was synthesized and its tribological behavior as an ashless additve without phosphorus and sulphur in liquid paraffin was evaluated using a four-ball tester. On the basis of the experimental results, the novel additive has been found to be quite effective as a potential additive in liquid paraffin. The nature of the film on the rubbed surface was investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS).

Abstract: To investigate further the bearing capacity of flexural members of GFRP（Glass Fiber Reinforced Polymer）SR(steel-reinforced concrete) under symmetric monotonic loading, a full range nonlinear analysis is made. Flexural capacity computing program of GFRP-Reinforced structures is put out, according to structure reinforcing theory and correlative rules through the finite ribbon method based on flat section assumption. The moment-curvature relative curves and the influence curves of the fiber winding angle and pipe wall thickness to load-deformation are obtained by the computer programming. The test specimen’s flexural capacity increases obviously with the increasing of steel ribs models. The slope of curve decreasing in monotonic loading latterly showed that the ductility of component improves. The changes of concrete strength had little effect on initial stiffness and capacity of GFRP SR concrete.