Applied Mechanics and Materials Vols. 166-169

Abstract: In order to reveal the flexural behavior of normal section of steel reinforced recycled coarse aggregate concrete beams，6 steel reinforced recycled concrete beams were designed for flexural test，the study mainly considered the impact of coarse aggregate replacement rates and concrete strength grade two changing parameters on the flexural behavior of steel reinforced recycled coarse aggregate concrete beams. Through this test, the whole mechanical process、crack distribution and failure behavior of this kind of specimens were observed, and obtained the stress-strain distribution curves、the ultimate bearing capacity and load-displacement curves parameters. Based on the study measurement data, deeply analyzed the impact of coarse aggregate replacement rates and concrete strength grade on the flexural behavior of steel reinforced recycled coarse aggregate concrete beams. The result shows that: steel reinforced recycled coarse aggregate concrete beams’ failure pattern was similar to normal SRC beams, during loading process the section strain agreed with the plane-section assumption, and the beams have good bearing capacity and deformation performance.

Abstract: Microbe technology is introduced for improving silt The metabolic outcomes and precipitation of microbes can glue the soil granule,plug mineral lattice crystal,simultaneously strengthen their shear resistance.Characteristics of silt before and after modification are compared by CU triaxial compression test. By Scanning Electron Microscope(ESEM) and Energy Dispersive X-ray(EDX),the modification mechanism of silt has been investigated.The results show that the values φ of silt is increased larger modified by carbonate mineralization microbes, while the value of cohesion increases larger by polysaccharides viscose microbes.

Abstract: The basic principle of arch bridge design is high level concord of 5 points between arch axial line and the pressure line. Taking lightweight aggregate concrete as arch crown filler, the casting area is divided into arch spandrel area and arch crown area. Through adjusting filler weight density, the arch axial line and pressure line can be adjusted to decrease the difference between them. The force condition of main arch bridge gets improved. The method can reinforce double-curved arch bridge together with increasing section method. It is seen that the property of arch ring masonry material got a full play. Bridge durability and comfort degree improved significantly.

Abstract: soils and their related behavior has always been the subject of many studies. Recent researches show some interests in investigation of inclusion of randomly distributed fiber in soil. Reinforcing subgarde in pavement systems has always been an issue. This study focuses on effect of fiber inclusion on the strength of subgrade material. Natural fiber and plastic fibre were used for this investigation. Fiber contents and length have been changed during these tests. The fiber percentage varied from 0 % (for unreinforced samples) to 2% and fiber length varied from 10mm to 30mm. UCS tests and compaction tests were carried out to investigate behavior of the composite under different condition. The fiber length and fiber content found to play important rule on the strength of fiber reinforced composite. Furthermore it was observed that ductility of sample increased by fiber inclusion.

Abstract: Slope protection is to ensure the security of levee foundation engineering. This article take the actual project--the Bird Island Park of Shenyang City hinge joint concrete block slope,as an example, use of FLAC software and strengthen reduction method, calculated by 29°slope angle, 45kg block the effect slope stability factor of safety. In view of the different parameters (slope, block quality, bulk density, cohesion force, internal friction angle), discussion of various parameters on slope stability of safety coefficient, and obtained the best slope and block quality combination, so as to the slope protection design and application reference.

Abstract: Lean duplex stainless steel tubular members are relatively new grade of material. An experimental investigation of lean duplex stainless steel tubular members subjected to web crippling is presented in this paper. The test specimens were strengthened with adhesive bonded carbon fibre-reinforced polymer (CFRP). The web crippling tests were conducted under End-Two-Flange, Interior-Two-Flange, End-One-Flange and Interior-One-Flange loading conditions. A total of 38 web crippling tests was conducted. The investigation was mainly focused on the effects of web slenderness of lean duplex stainless steel tubular sections on CFRP strengthening against web crippling. The lean duplex stainless steel type EN 1.4162 was used in the investigation. The tests were performed on five different sizes of square and rectangular hollow sections that covered a wide range of web slenderness ratio from 8.1 to 57.0. Three different failure modes were observed in the tests of the strengthened specimens, namely the adhesion, interlaminar failure of CFRP plate and combination of adhesion and interlaminar failure of CFRP plate. It is shown that the web crippling strength of lean duplex stainless steel tubular members may increase up to 76% due to the strengthening of CFRP.

Abstract: Based on the fatigue test for flexural performance of five reinforced concrete beams, the variation characteristics of the crack development, concrete strain, steel strain, fiber strain with the cycle number of the fatigue load were analyzed, and the effect of hybrid fiber sheets and basalt fiber reinforced polymer(BFRP)sheets on flexural fatigue performance of the strengthened beam was studied. The results show that the accumulated damage of RC beams strengthened with hybrid fiber sheets was slowed down significantly, the anti-crack property was much improved, and the fatigue life was greatly prolonged. Compared with the ordinary RC beam and the RC beam strengthened with double BFRP sheets, the fatigue life of RC beams strengthened with hybrid CFRP/BFRP(C/BFRP) sheets and hybrid CFRP/GFRP(C/GFRP) sheets was increased by 291.26%, 298.63% and 10.73%, 13.53%.

Abstract: The anchorage force loss of the prestressed anchor rope results in reduction or loss of anchorage force, which poses an enormous threat to the project safety. In the conceptual design process, factors like the system , structure, spacing and tonnage of anchorage, and properties of rock and soil should be considered and measures should be taken to effectively control or reduce the effect of the anchorage force loss, which possesses great theoretical and practical significance on the design, construction , safety and social-economic benefits of the anchorage project. Finally, the validity and reliability of design measure was proved by an engineering example.

Abstract: The mixture ratio between host crystal and curing agent of PU resin was calculated adopting the particle reaction principle based on the same equivalent weight, the results show that the mixture ratio between host crystal and curing agent of PU resin is 100:20～26; then through the analysis of DSC cures, viscosity-temperature cures, viscosity-time cures and the gelatin time under 25°C, the best mixture ratio of 100:20 was confirmed whose curing process and viscosity can well meet the requirements of the pipeline lining rehabilitation technology; in order to test and verify its operational performance, the adhesive strength between the resin and the pipeline wall was simulated and tested, the results show that the adhesive strength of the resin whose mixture ratio is 100:20 is high, that can meet the requirements of the pipeline lining rehabilitation technology.

Abstract: The paper analyses the design practice activities of protecting, changing and reusing the domestic and overseas historic buildings in origin. It analyzes the method of changing and reusing historic buildings by using specific cases: Beijing 798 Factory, Wuxi North Door Art Center, and the National Industry and Commerce Museum. Finally, it proposes that historic buildings should be changed and reused by sustainable and reasonable ways according to the cultural values, building features of themselves, and the city demands.