鋼絲網(wǎng)增強(qiáng)超高性能混凝土-混凝土組合柱軸壓性能.pdf

1、Construction of concrete filled UHPFRC tubes (Ultra High Performance Fiber Reinforced Concrete) results in systems with ductile characteristics, high stiffness and strength. It also makes optimum use of materials based o

2、n their mechanical properties and resistance to corrosive environments. One such application is demonstrated in concrete-filled hybrid UHPFRC tubes. It is named Hybrid Composite Column (HCC) for the fact that it contains

3、 an additional wire-mesh layer into the tube. The hybrid UHPFRC tube provides the necessary additional longitudinal and transverse reinforcement, as well as a permanent formwork for the concrete core. The concrete core c

4、ontributes to the overall stability and stiffness of the composite system. Compared to a conventional RC column, construction time is reduced because there are no formworks in sites, and compared to a segmental PC column

5、, lifting load is significantly reduced because of a void section (or empty core). The present study is an experimental investigation of HCC as structural column. The main focus of this research is on the uniaxial compre

6、ssion behavior of concrete confined with hybrid UHPFRC with 1.5％ and 2% fiber volume (Vf) along with 1.26% and 2.52% transverse steel ratio (ρsv %) for core concrete. For the better confinement effect, the bond between t

7、he concrete core and the tube is necessary throughout the length of the column. To achieve this, the threaded bars were embeded through the columns as shear connectors.
　　Size effect on strength of quasi-brittle mater

8、ials like concrete, ice and rock, in the literature often referred as geo-materials, has been an issue of discussion over the last three decades. Size effect investigations have been carried out either by experiments or

9、through numerical simulations. Usually mechanical properties of specimens of different sizes are investigated.
　　The second part of this research has focused on the influences of specimen size on tensile behavior of a

10、n ultra-high-performance fiber-reinforced concrete (UHPFRC). In this study, the Size Effect phenomenon was investigated under uniaxial tension for both wire-meshed and non-wire-meshed notched dog-bone specimens. This stu

11、dy was conducted by performing four uniaxial loading tests on four different specimens.
　　It was found that under given experimental conditions, the nominal strength strongly depended on the specimen size. The test re

12、sults indicate that, there is a strong influence in mechanical properties due to variation of the testing specimens. For wire-meshed dog-bone, it was found that the mechanical behaviour of UHPFRC was improved by the pres