Advanced Materials Research Vols. 450-451

Abstract: The energy method was used to analysis the deformation of acrylic waterproof membrane under the uniform load and to calculate the maximum central deflection according to the clamped circular plate. Because the shape of the deformation of waterproof membrane bulge was similar to semi-ellipsoid, the curve length corresponding to the maximum central deflection was calculated by elliptic equation. According to the curve length, the deformation could be calculated under the different water pressure and membrane thickness. Comparing the deformation with the maximum elongation ratio, the water pressure and the thickness of waterproof membrane which ensure the safety could be calculated in theory. If the water pressure was known, the thickness of spray-membrane could be determined in the tunnel engineering.

Abstract: As new materials, nanomaterials have many properties that are absence in other materials and thus can be applied to various fields. A number of nanotechnology-based products have been introduced into our lives. Nanomaterials have so many advantages. If applied to interior decoration — such as nanoscale glass on interior windows, nanoscale wall paint and nanoscale carpet — nanomaterials will bring changes to interior decoration and convenience to the living environment, while promoting the development of interior decorative materials and nanotechnology.

Abstract: Graft copolymerization of chitosan and vinyl monomer (such as acryamide and acrylic acid) and application study of the copolymer used as papermaking additive were paid more and more attention in papermaking chemical industry. Chitosan and acrylamide(AM) monomer were graft copolymerizing in inverse emulsion. Several factors such as oil-water proportion, mass ratio of chitosan and AM, emulsifier types and ratio, and initiator concentration that affect the stability of inverse emulsion were elementarily studied. Stable latex can be gained when reaction condition was that the volume ratio of oil phase and water phase was 1:1, the weight ratio of chitosan and AM was 1:8, the initiator concentration was 0.8mmol/L, the dosage of emulsification agent was 8% of the oil phase weight and the weight ratio of 1227 and OP-10 was 1:1.

Abstract: Fatigue flexural fracture test is taken out in this paper, to study the fatigue crack propagation rate of ultra-high toughness cementitious composites (UHTCC), as well as the effect of fiber volume fraction on fatigue crack propagation rate. Three fiber volume fractions are adopted: 1.5%, 2.0% and 2.5%. Similar to Paris law, a fatigue crack propagation equation of UHTCC is introduced, as dA/dN=C(△J)^m, with the two parameters A and △J are defined as the covering area of multiple fatigue cracks and the fatigue amplitude of J integral. Through experiment and analysis, the fatigue crack propagation rate slows down with the increase of PVA fiber fraction. Furthermore, the influence of PVA fiber on the propagation rate was found to become obvious with the increase of J integral.

Abstract: Failure analysis of laminates is performed by progressive failure analysis method. A modified form of Hashin’s failure criterion by Shokrieh is used to detect the failure, where a sudden degradation model is proposed to reduce engineering material constants. The numerical analysis of composite laminates is implemented in ANSYS Parametric Design Language (APDL) with commercial finite element codes ANSYS. The method can predict the initiation and propagation of local damage and response of laminated composite structures from initial loading and ultimate failure. The model has been validated by comparing numerical results with existing experimental results. And then failure analysis specimen fabricated from M40J/Ag80 and investigation on influence of stacking sequences and fiber orientations have been performed by the proposed model.

Abstract: The reaction kinetics of amination of monomethoxylpoly (ethylene glycol) (mPEG) with melamine (MA) at the molar ratio of 1:1 was studied by FTIR. This amination reaction was carried out with potassium hydroxide as reaction catalyst under high-pressure conditions at different temperature (160 °C, 170 °C, 180 °C, and 190°C) for different time (2 h, 3 h, 4 h, 5 h and 6 h). A series of melamine aminated monomethoxylpoly (ethylene glycol) (MA-mPEG) were synthesized, and the long chain of polyethylene glycol ether was grafted on the amino groups of melamine by amination. The amination kinetics parameter of reaction order and the activation energy are about 1.5 and 45 KJ/mol, respectively. In addition, the grafting amination yield increased with the number average molecular weight of mPEG at the same reaction condition.

Abstract: Based on the damage and Ottosen failure criterion, a dynamic constitutive model is proposed to investigate the mechanical behavior of concrete subjected to impact loading. The model predictions fit well with experimental results. So it can be used to simulate dynamic mechanical behavior of concrete

Abstract: As the needs of fair-faced concrete structures for the ecological environment, this paper studies the mix proportion of fair-faced concrete in C30 strength grade by experiments. 13 concretes were designed and tested considering the water to cement ratio, the cement content, the percent of pulverized fly ash, the sand ratio, the water reducer and the formwork parting agent. The workability of fresh concrete, the compressive strength of hardened concrete at 7d, 28d and 56d, and the apparent quality as well as the surface brightness of concrete were got. The results show that the surface color and brightness of concrete were influenced successively by the cement content, the water to cement ratio, the sand ratio and the percent of pulverized fly ash. The use of formwork lacker may bring concrete into better brightness, while the mix oil may be a good selection considering the cost of parting agent. The suitable mix proportions of C30 concrete for urban bridge are proposed.

Abstract: Single layer PET Fabric/polyvinyl chloride (PVC) composite materials and double layers PET fabric/polyvinyl chloride (PVC) composite materials with super thin thickness, lightweight, flexible and high strength were manufactured by means of the infusion technology under normal pressure. The sound insulation performance of these novel materials was evaluated with a two-channel acoustic analyzer. The structure and mechanical properties were investigated by mechanical tests and SEM observation. The results show that for the small surface density the double layers composite has better sound insulation performance than that of the single one. But with increment of surface density, the difference between them becomes small, and for the surface density larger than 1.3kg/m2, the sound insulation performance becomes inverse on layers, i.e., the single layer composite has better sound insulation performance than that of double layers one. Therefore, difference structures of composites can be developed based on sound wave features.

Abstract: Calcination condition and mechanical performance of alite-rich Portland cement with barium calcium sulphoaluminate mineral(C2.75B1.25A3S ) were investigated by the orthogonal test method in which the influencing factors included sintering temperature, sintering time and cooling method. The composition, structure and performance of the clinker were analyzed by the means of X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy and metallographic microscope. The results show that C2.75B1.25A3S mineral and alite can coexist in one clinker system. The introduction of C2.75B1.25A3S mineral to clinker system is benefit to promote the formation of alite at lower temperature. The optimal sintering temperature, sintering time and cooling method are 1380°C, 60 min and two-stage cooling, respectively. Under these processing conditions, the compressive strength of alite-rich Portland cement with barium calcium sulphoaluminate reaches 43.4, 80.6 and 123.8 MPa at 3d, 7d and 28d curing ages, respectively, which shows excellent performance of mechanical strength.