Advanced Materials Research Vols. 884-885

Abstract: Berberine, a common drug, which is widely used in clinical medicine as inflammatory medicines, is rarely studied about its affection on non-target organisms in recent researches. To evaluate the eco-toxicity of berberine in mouse heart cells, biochemical responses including oxidative damage and changes in the activities of antioxidative enzymes catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and malondialdehyde (MDA) induced by berberine were investigated in mouse heart cells. 7.5, 15, 30, 60 and 120 mgkg^-1 berberine was added to mouse heart cells respectively. Compared to the controls, the damage, tail DNA content (%) , tail length and tail moment went up respectively in dose-effect manner following the rising berberine; As the content of berberine increased, the activities of SOD, CAT and POD were gradually decreased and the concentration of MDA was gradually increased. Compared to the controls, the change tendency showed significant differences (p<0.05 or p<0.01). In conclusion, berberine induces oxidative stress and DNA damage to heart cells, which may be the significant mechanisms for its toxicity to mice.

Abstract: As one of most widely used structure, the behavior of masonry is influenced by its composition especially the mortar. In this paper, a series of compression tests was carried on masonry both with mortar (MP_m) and without mortar (MP_ds). Based on the results, the ultimate compression strength and elastic modulus has been compared firstly; after that, the failure mode of each prism was achieved, finally a finite element model was built for the numerical analysis on MP_ds. Results showed that compared with the MP_m, the elastic modulus of MP_ds has been reduced 30% which means the erosion of mortar should be considered when research on the historic masonry structures. The finite element model can simulate the compression strength and failure mode accurately, which showed great potential for the further parametric analysis.

Abstract: Based on Winkler model and engineering example, the behavior of elastic long pile under horizontal load was analyzed in test status while pile top at solid respectively. The analysis results show that under same horizontal static load, the maximum of pile shaft bending moment in work status is higher then it in test status. The horizontal bearing capacity of pile in work status can be get based on the proportion coefficient of the horizontal resistance coefficient, m, and crack-resistant moment calculated by critical load, H_cr. While m and H_cr can be obtained by horizontal static load test.

Abstract: To solve the problem of SRHC beam strengthened with FRP(Fiber Reinforced Polymer),a new renovate SRC beam of strengthened with FRP has been brought forward in this paper.In this paper, the load-deformation process,flexural failure characteristics of SRHC beams strengthened with FRP were researched by a new practical superposition method, the damage and bearing capacity under the limitation failure of SRHC beam strengthened with FRP are studied. In addition, according to the different positions of central axis and section of steel, the compressive region height under the limitation of three destroy is put forward. Compare the relation between the compressive region height with the distance of top flange of steel to the compression flange of concrete, hence, a applied formula to the different flexural capacity under the limitation failure of beams strengthened with FRP, the concept of presented equation is convenient for use.

Abstract: To know the physical and mechanical properties of wood to be employed as structural elements in is an important factor for its use in a rational way. The connections between members of timber structures are also relevant topic once local stress concentrations can occur and safety must be seriously taken in account. Brazilian Code ABNT NBR 7190: 1997 "Design of Timber Structures" provides guidelines for connections calculation based on two alternative limit states: wood strength to embedment or bending of the bolt. The purpose of this paper is estimate the strength to embedment of Pinus sp. to bolts in three directions with respect to the grain: parallel, perpendicular and inclined at 45o. Specimens obeying requirements of Brazilian Code related to bolts diameter (10mm) were prepared and tested. The embedment strength in parallel direction to the fiber was the highest and the failure modes were more frequent crushing and cleavage.

Abstract: Expansive Soil is a kind of high plastic clay. Because it has Strong hydrophilic mineral composition, its engineering prosperities embodies that its shape contracts under dehydrating, Inflation and softening under the influence of water and the strength attenuates. This is very difficult to construct in the region of expansive soil. In the region of seasonal frozen, as capillary water rising height is larger; it is prone to phenomenon of frost boil or thawing settlement. It has important meaning to improve hydrophilic and physical and mechanical properties of expansive soil for Slope stability of embankment and cutting of highway engineering and reducing the cost of investment. The paper discusses the engineering properties of expansive soil in Detail; expound some main methods of improved expansive soil at home and abroad and compare and analysis the mechanism and characteristics of the corresponding methods. The paper introduces preliminary testing methods of Expansive soil performance and prospects improved in the future.

Abstract: With the increase of traffic volume and axle load, asphalt pavement rutting has become one of the major damage of highway. Adding anti-rutting agent in asphalt mixture is a kind of effective mean to prevent pavement rutting. In this paper, RA anti-rutting agent is selected as the admixture. Laboratory test is taken to study the pavement performance of asphalt mixture and analyze the influence of anti-rutting agent on the pavement performance of asphalt mixture.

Abstract: The aim of this research is to evaluate the influence of castor-oil based polyurethane resin formulation (particularly proportion pre-polymer/polyol) in static bending properties of particleboards produced with Pinus sp. wood specie. Results related to modulus of rupture (MOR) and modulus of elasticity were determined. Four proportions polyol/pre-polymer were evaluated: 0.75:1; 1:1; 1:1.25; 1:1.5. Results showed improvement in MOR and MOE with increase of pre-polymer component. Proportion 1:1.25 (poliol: pre-polymer) was considered the most interesting once employs the least amount of the petroleum-derived component.

Abstract: For getting the mechanics and contact explosion capability parameters, some new steel fiber concrete samples with 5% steel fiber were tested, many groups data were obtained with compress strength, shear strength and fracture toughness. The model tests were carried out on the new steel fiber concrete under contact explosion, the coefficient of explosion cavity radius of the material is obtained by above experiments and theory study. The two kinds of experiments above point out, the new steel fiber concrete with steel fiber has very high strength and rupture temper and its capability anti-explosion is about three times than general concrete.

Abstract: Taking Jin Chuan phyllite tunnel as the research object, and based on numerical simulation of surrounding rock graded III, IV and V, the paper studied the stress characteristics of initial support and four other representative locations such as two arch vault, arch spandrel, arch haunch, and arch foot during and after the process of construction. The paper focuses on the stress characteristics of secondary lining in different locations after stability and the change of stress in different locations of initial lining before and after the secondary lining construction.