Applied Mechanics and Materials Vols. 193-194

Abstract: The objective of this study is to improve the stiffness and control the failure mode of the pultruded glass fiber reinforced polymers (GFRP) deck members to meet the design requirements. In this study, the authors proposed that the GFRP member was affixed by another GFRP deck inside it to form a combined GFRP deck member; an epoxy mortar was filled into some of the hollow sections of the GFRP member; and the basalt/carbon fiber sheets was wrapped around the GFRP member in order to improve the ultimate strength and stiffness and also to change its original failure mode of the GFRP member. Eight GFRP deck specimens where investigated in the three-point bending test results for their ultimate strength, stiffness, and corresponding failure modes. Finally, the Euler beam theory was used to obtain the force-displacement relationships of the GFRP members and then to compare the experimental results.

Abstract: Prestressed high strength concrete pipe pile (PHC pile), a new type of pile, due to outstanding performance, widely used in various aspects of national construction, this paper introduces the development situation of prestress high strength concrete pile in our country, aiming at proposing own opinion in existence question in the construction process of high strength prestressed concrete pipe pile.

Abstract: Vacuum glazing is a new building material with excellent energy conservation and sound insulation properties. Usually, the edge sealing layer between two sheets of glass substrates are prepared by spraying the seal glass paste and then sintering. In the present research, a more effective preparation method is reported. The edge sealing layer is prepared with a glass paste by screen printing, and then sintering. The glass paste for the preparation of edge sealing layer of vacuum glazing was prepared by using low melting glass powder, ZrW2O8 powder with negative coefficient of thermal expansion and ethyl cellulose terpineol solution. The test result of the shear strength of the sealing layer indicated that the sealing is reliable.

Abstract: At present, waste rubber tires cause a significant environmental and human health problem. An innovative way to recycle used tires is that the waste tire rubber is used in Portland cement concrete as a portion of aggregates. In this paper, the crumbed tire rubber particles were used to replace fine aggregates, which includes two grain sizes, from 3 to 4 mm and 50-mesh.. The replacement levels were 0, 5, 10, 15, and 20 % by volume of the fine aggregates. Rubber concrete mixtures were produced according to mixture proportions design. The slump of fresh concrete and the unit weight of the nine mixes were examined. The mechanical properties investigation of harden concrete included determining the 28 days compressive strength and dynamic modulus of elasticity. The study demonstrated that 5 and 15 vol% replacements with rubber powder can meet fundamental engineering demands, although substituting part of fine aggregate with fine rubber powder deteriorated mechanical properties of concrete.

Abstract: This paper conducts analysis on beam-column extended end-plate semi-rigid connection joint concerning monotonic loading and cyclic loading of finite element through ANSYS program, mainly discussed the influence of parameters such as the form of end plate stiffening rib on anti-seismic performance of joint.

Abstract: According to mixture proportions design, rubber concrete specimens were produced, which were used for test of resistance to frost. In this study, different grain size and different content rubber were mixed in Portland cement concrete. Quick freeze-thaw test was carried to rubberized concrete. The research shows that appropriate proportional fine aggregate replaced by the discarded tires powder and grain can improve concrete resistance to frost, although concrete compressive strength, flexural strength and dynamic elasticity modulus decrease with increasing of rubber content. The improving effect of rubber powder is better than rubber grain. Furthermore, it is demonstrated that the dynamic elasticity modulus obtained by Non-destructive testing can commendably evaluate the frost resistance of rubberized concrete.

Abstract: The eccentric ultimate load calculation formula of square steel tube columns filled with steel-reinforced concrete was derived based on the Unified Strength Theory in this paper. The influence of intermediate principal stress and the restriction effect and the decrease of longitudinal stress were considered in the formula. Based on the axial compression load and the effect of consider the eccentricity ratio and slenderness ratio on the hearing capacity was considered, by introducing the reduction factor of concrete strength and the equivalent restriction reduction factor, the confinement of square steel tube towards concrete was equivalent to the confinement of circular steel tube towards it, based on unified strength theory solutions of thick tube, the calculation formula of eccentric compression bearing capacity of square steel tube columns filled with steel-reinforced concrete was deduced and analysed the influence complication. The results indicate unified strength theory has the good applicability and the solution has an important practical value for engineering application.

Abstract: Abstract: Analysis of infilled frames is one of the most complicated problems in the structural engineering field. This complication is mainly attributed to the existence of the variety and complex of the infills and the difficulty in modeling the infill-frames interaction. In the present paper, with the aim to study the integral behavior of the single-story single-bay steel frames with sandwich composite panel infills, a proper computational model (the panel is simplified into an equivalent pin-jointed diagonal strut) is proposed. In the theoretical study, both of the panels and steel frames are assumed to be in the linear elastic state for simplicity’s sake, and then the cross-section area of the equivalent strut is obtained by imposing the initial lateral stiffness of actual structure equal to that of simplified model. As a support of the discussion, several numerical models under monotonic lateral loadings are performed by software ABAQUS, in order to verify the theoretical analysis. Finally, results from theoretical study and numerical modeling are compared, which give a satisfactory correlation between them.

Abstract: The mechanical properties of fire-damaged reinforced concrete columns rehabilitated by carbon fiber-reinforced polymer (CFRP) rods were studied. This study aims at the effectiveness of CFRP through the contrast test. Nine specimens were tested, including three normal temperature control specimens, and six specimens heated under ISO834 standard fire. After the specimens were exposed to fire, three of them were rehabilitated by CFRP. All specimens were loaded monotonically to failure in the same way. The results showed that the failure of reinforced concrete columns rehabilitated by CFRP was due to losing stabilization, whereas the others were material broken. Furthermore, because of the fire, the load-bearing capacity of specimens was all declined sharply compared with these at normal temperature. From this research, comparing with these normal temperature control specimens, the load-bearing capacity of specimens exposed to fire firstly was ranged from 0.25 to 0.37 times. But the ratio of the loading capacity of specimens rehabilitated by CFRP and normal temperature control ones was ranged from 0.54 to 0.67.

Abstract: The welded steel structure is used as the research object in this paper. On the basis of numerical analysis of welded steel structure in 3-D residual stress field, the predicted method of the fatigue strength and S-N curve for welded steel structure is set using the volume method of the critical distance theory. The fatigue strength and S-N curve of the typical the welded steel structure including butt, misaligned welded and T-shape joints are got through theory prediction. The predicted value coincides with the experimental value. This method can be reduced fatigue test, saved funds and provided reference for engineering application.