Advanced Materials Research Vols. 671-674

Abstract: This paper evaluated the restrain effect to cracks in the concrete members containing expansive admixture addition. An experimental study modeling the slab of the field bridge is performed. The free strain, the actual strain of specimens with or without expansive admixture and steel bars is measured. Based on the experimental results, the internal restrain effect and steel restrain effect to cracks are calculated as approximately 0.35 and 0.2~0.3 respectively.

Abstract: The thermal performance of a new regenerated glass pumice board as external wall thermal insulation material was analyzed in this paper. Considering the roles of solar radiation and air convection, and selecting Wuhan city as an example of the hot summer and cold winter zones, the temperature field distributions of the external building walls in different orientations in summer and winter seasons were numerically simulated by using the finite element software ANSYS. The thermal performance of regenerated glass pumice exterior wall external insulation system including the heat transfer coefficient and the temperature distribution was evaluated. The simulation results demonstrate the good thermal insulation performance of the regenerated glass pumice as a new kind of external wall materials, and the feasibility of the application of this environmentally friendly material to the wall insulation system in energy conservation building is also promoted.

Abstract: One of the effective ways of low carbon concrete is to reduce the cement content. It can not only reduce the greenhouse gas emission, but also improve the comprehensive utilization of industrial solid waste. In this paper, the mix design and experimental research of C15 Self-Compacting Concrete (SCC) were carried out by substituting cement with high volume fly ash. A partition coefficient of environmental burden Cm was introduced in order to assess the environmental effect of different mix proportion SCC precisely by using life cycle assessment method. Evaluation results showed that the mixing of fly ash can reduce the consumption of coal, the discharge of CO2 and the solid wastes effectively. The study provided a rational basis for the high performance and low cost fly ash concrete.

Abstract: In view of the present situation that the preparation of complex high titanium heavy slag concrete (hereinafter referred to as CHTHSC) by using all coarse aggregate, fine aggregate and ground admixture made of high titanium heavy slag, is in need of experiments and studies in detail, this paper, based on the verification and analysis of structural stability of complex high titanium heavy slag and through tests of preparing CHTHSC from C10 to C55, compares CHTHSC with ordinary concrete and high titanium heavy slag concrete (hereinafter referred to as HTHSC) from three aspects of mixture amount of coarse aggregate, fine aggregate and composite powder. Results show that the compression resistance, axial compression resistance and cleavage strength of CHTHSC are higher than those of the other two kinds of concrete. For CHTHSC, it is appropriate to have composite powder take the place of 15%-20% of cement content.

Abstract: In recent years, with the modernization of the home facilities and the rise of the renovation boom,the decorative materials which are numerous in variety and different in function also get more and more chemicalizing .As a result, the bedroom air pollution can not avoid gaining increasing atten- tion to it and greater emphasis on the problem. As non-toxic, odorless and pollution-free products,the new materials of water printing ecological wood researched and developed by Liaoning Rentian Sci- ence&Technology Co.,Ltd are environmental,healthy and safe,which not only greatly reduce the con- sumers’decorating costs, but also solve the problems of the decoration materials containing formald- ehyde and the properties of durability as well as waterproof performance.Undoubtedly,they become the most popular eco-friendly decorative materials with broad market prospects.

Abstract: Flammability of toughened phenolic (PF) foams containing ammonium polyphosphate (APP), melamine phosphate (MP) or melamine cyanurate(MCA) was studied by limiting oxygen index (LOI). The LOI values show that APP or MP is an effient flame retardant than MCA in the toughened PF foams. The thermal decomposition and mechanical properties of the phenolic foams were also investigated.

Abstract: The influence of part of fly ash replaced with lime dust on fly ash recycle concrete compressive strength and frost resistance is investigated by compression tests and rapid frost-thawing test. The experimental results show that part of fly ash replaced with lime dust will reduce the early compressive strength of the fly ash recycled concrete; the right amount of lime dust replacing fly ash can raise the latter compressive strength of fly ash recycled concrete, the best replacement proportion is 10%. The anti-frozen capacity of fly ash recycled concrete will reduce by replacing part of fly ash with lime dust, and the amplitude reduction of anti-frozen capacity of fly ash recycled concrete in seawater is greater than the amplitude reduction in sulfate solution and in freshwater.

Abstract: An experimental study on mechanical behavior of home-made super-elastic NiTi Shape Memory Alloy (SMA) bar subjected to tension was made. The SMA bar specimen was 8mm in gage diameter and 50mm in gage length. The experimental tests were carried out by applying repeated cyclic loads. The tested tension strain amplitudes were 1%-7% and material phase was austenite. The mechanical characteristic parameters, such as phase transformation stress, deformation module, residual strain, energy loss and equivalent damping were studied. The effects of strain amplitude, loading rate and loading cycles on these parameters were analyzed. The considerable super-elasticity and stable cyclic behaviors of home-made SMA bar during the test showed its great application potential in aseismic devices.

Abstract: In this paper, three fatigue models are employed and proposed for modeling the fatigue life of different fiber-reinforced composite material systems. In order to identify the unknown parameters in these models, Genetic Algorithm (GA) is used for estimating its values. This technique is a stochastic process that leads straight to different S-N curves that predicts the trend of the experimental data without the need for any assumptions. The calculation results show that these three models, especially the nonlinear regression model, whose parameters are assigned by using GA are all satisfied with the experimental data, and the average value of RMSE is below 0.1. The method of fatigue damage simulation presented should have a very good application prospect.

Abstract: Two approaches of improving the toughness of polypropylene (PP)-based composites reinforced by natural cellulose fibers were developed. The surface modification of cellulose fibrils (CMF) or fiber by either in-situ grafting polymerization of butyl acrylate (BA) on CMF surface via an atom transfer radical polymerization (ATRP) or adsorbing the cationic polymeric latex with core-shell structure on fiber surfaces was performed; and resulting fibers or CMF were used as reinforments in an attempt to enhance the toughness of the PP-based composites. The results of mechanical properties indicated that the flexure, tensile, and impact strengths of the CMF-g-PBA reinforced composites were all improved. The cellulose fibres treated by cationic latex also showed the same trend. The optimal dosage of latex for hydrophobic-modifying fibers was also identified.