Advanced Materials Research Vols. 168-170

Abstract: This paper presents the thermal stress characteristics of polystyrene plate - thin plaster wall. Based on thermal stress analysis module of ANSYS software, a three-dimensional element solid5 is selected to mesh the wall model, which can simulate the coupling effects of thermal stress and structural stress field. The critical temperature of hot and cold cycles is taken as the critical temperature condition, which is imposed on the calculation model. Windowless Wall and window wall were modeled separately. Temperature field, thermal stress, and deformation distribution were proposed after comparing and analyzing the two simulation results. Numerical simulation results indicate that: (1) Whether in high or low temperatures, window or windowless, polystyrene plates thin plaster wall insulation system has very good thermal insulation properties；(2) Polystyrene plate - thin plaster wall insulation system is influenced by the temperature stress. Different stress fields concentrate significantly around windows and in the middle of wall especially around the windows. In fact, it is relatively same as the law of cracks around the windows.

Abstract: To tackle the annually increasing amount of municipal waste, this paper proposes a new consolidation technology to consolidate stale municipal waste, and elaborates on the consolidation effect and safety. Research results demonstrate that 28-day strength of municipal waste consolidation can be up to more than 38 MPa by this consolidation technology. Thus consolidation durability is better in terms of resistance to freezing, water, dry-wet circle and sulfate erosion. Meanwhile, its amount of leaching-out solidified heavy metal meets the requirements of national standard in China, in other words, heavy metal ions are effectively bound and stably solidified.

Abstract: Shale ceramsite concrete is a kind of materia with lightweight, heat preservation, heat insulation, fire resistance, earthquake resistance and other excellent performances as green building materials, it has very broad application prospects. Its consumption in China is second only to the density of ordinary concrete. In this paper, local shale products, by ordinary concrete slab and shale concrete slab structure comparison of performance tests and the thermal performance test, indicating shale properties of concrete.

Abstract: In this paper, Q235 steel was investigated in order to manufacturing ultra-high strength material. The process of severe cold-rolling and low temperature annealing of lath martensite effectively reduced the crystal size from about 300 nm to 20 nm, and introduced mass weak interfaces in steel, has been demonstrated a new promising technique for producing in-situ composite multi-nanolayer steel with ultra-high strength (b 2112 MPa). Cold rolling and subsequent annealing have great impact on microstructure evolution as well as material mechanical properties. In the as-rolled state, the strength is approximately four times increased than as-received material (hot-rolled state, b 515 MPa), which is attributed to work hardening and grain refining during cold rolling. As the cold-rolled sample subjected to further annealing below 500 , deformed microstructure underwent further recovery and recrystallization, finally became refined equiaxed grains, microstructure characteristics along rolling direction arrangement was decreased; In addition to ultrafine ferrite grains, nano-carbides precipitated uniformly in the specimen annealed at 500 , total elongation increased to 16%, the corresponding yield strength was 1208MPa, much higher than that of as-received samples. The phenomenon of fracture delamination was observed from the specimens, which were cold-rolled and annealed at 500 , and the delamination plane was parallel to the rolling plane. In-situ composite weak interfaces effect has great impact on the fracture surface.

Abstract: This paper addresses a simulation investigation of a fin-tube thermal storage unit involving phase change process dominated by heat conduction. The heat transfer of fin-tube thermal storage unit with phase change material (PCM) was simulated by Fluent. Graphical results including outlet temperature of heat transfer fluid (HTF), average temperature of PCM and phase front interface of solid and liquid phase of PCM versus time and fin distance were presented and discussed. According to simulation results, it was concluded that only the fin-tube thermal storage unit with fin distance of 12fin/inch could satisfied the request of heat release performance of household heat pump water heater for shower.

Abstract: 43 Φ50mm × 100mm column stress - strain curve tests are completed through RMT-201, which studied the compressive stress - strain curves of recycled aggregate concretes at distinct confining pressures under conventional triaxial stress state. This article, has analyzed the influence of different water-cement ratios, confining pressures on the curves, and raised constitutive equations of triaxial compression stress - strain curves for the different strength of recycled aggregate concretes.The brittleness indexes for recycled aggregate concrete under distinct confining pressures were analyzed contrastively. The result showed that: the failure modes of recycled aggregate concrete specimens are similar to those of ordinary concretes, but the final failure patterns of recycled aggregate and ordinary aggregate are quite different; with the increase of lateral pressure, the peak stress and peak strain of recycled aggregate concrete show linear growth; recycled aggregate concrete compressive stress - strain curves under the uniaxial and triaxial stress states are similar to ordinary aggregate concrete, yet peak strain shows signs of larger growth; with the increase of lateral pressure, the brittleness of recycled aggregate concrete reduces. The brittleness index of high-strength recycled aggregate concrete is larger wholly than that of ordinary recycled aggregate concrete and with confining pressure reaching a certain value, the brittleness index remains stable.

Abstract: pavement performance of SEBS modified asphalt mixture are analyzed. Dynamic shear rhometer(DSR) experiments were performed to evaluate the rheology properties of SEBS modified asphalt binder and performance of SEBS modified asphalt mixture was evaluated based on laboratory experiments, experiments included: wheel tracking, moisture susceptibility, low-temperature beam bending and fatigue. The results shows that the rheology properties of SEBS modified asphalt binder are more ideal than SBS modified asphalt binder on anti-fatigue effect. Tensile stress ratio(TSR) of SEBS modified asphalt mixture increases 5.0%, tensile strength increases 6.1% and tensile strain increases 19.8%, though the dynamic stability(DS) decreases 3.1%, the fatigue life-span increases significantly compared with SBS modified asphalt mixture. It means that pavement performance of SEBS modified asphalt mixture is better than SBS modified asphalt mixture, and it is more applicable to be utilized in highway engineerings and some special engineerings such as bridge deck pavement that need anti-fatigue performance.

Abstract: The PS-MMT was synthesized through intercalating styrene monomer into the layer of MMT by in-situ polymerization. Composite modified asphalts with PS-MMT and SBS were prepared by melt blending. Rolling thin film oven test (RTFOT) was carried out to study the aging property. The results demonstrate that both modified MMT and SBS homogeneously disperse in the base asphalt, which lead to an improvement in terms of toughness, strength, and thermal stability. Impact of the PS-MMT on the properties of SBS modified asphalt appears as a decreasing penetration, an increasing softening point, and a decreasing ductility. Compared with that of SBS modified asphalt, the anti-aging property of PS-MMT /SBS modified asphalt was greatly improved.

Abstract: Epoxy asphalt has fundamentally changed the thermoplastic of asphalt and endowed the asphalt with excellent physical and mechanical properties. This paper analyses the developing technical requirement of thermosetting epoxy asphalt and points out its main problems during preparation and application process. Aiming at the steel deck paving characteristics, the author has independently developed epoxy asphalt binder and tested its performances, the results have showed that this binder can meet the basic requirement of various pavings, and its further research are in process.

Abstract: The optimization of insulation material of external wall is a multi-attribute uncertainty decision-making problem. Herein based on theory of multi-attribute decision making, a novel decision-making model using generalized connection number of set pair was discussed to solve the problem. Namely, the certainty and uncertainty relationship between the evaluation plan and the optimal plan or the worst plan for the optimization of insulation material was described by means of identical-contrary analysis of set pair theory. And a generalized connection degree was introduced to evaluate comprehensively the relative membership degree of the evaluation plan to the optimal plan. The results from a practical example show that the proposed model used to select the plan of insulation material is feasible and reliable, and easy to operate.