Meanwhile, vertical stress distribution in filling and critical height of soil arch effect was studied, assumptions about the soil arch was compared with the test results. In order to research the vertical stress distribution in filling and critical height of soil arch effect, the stress of pile cap, soil between piles and fill at different height were monitored and recorded, on the basis of field test on plastic tube cast-in-place concrete pile (TC pile)-supported embankment, the load transfer during the periods of embankment filling and preloading was analyzed. The uniaxial tensile strength increased by approximately 1.5 MPa/log10 unit (2.2 × 10 2 psi/log10 unit) in the range of quasi-static loading rates. The multi-scales reinforcement, especially the microfibers, amplifies the strain rate effects in the matrix by improving stress transfer within it. Direct comparisons with ultra-high-performance cement-based matrix (without fibers) and other fiber-reinforced concretes (FRCs) studied in literature indicated that this new material is more sensitive to strain rate effects than all previously studied cement-based materials. Experimental results showed that the modulus of rupture increased by 25% in the range of quasi-static loading rates (1.25 × 10-4 to 1.25 GPa/s ), and was quadrupled for loading rate superior to 500 GPa/s (7.25 × 10 7 psi/s). To cover a large range of loading rates, two dynamic tests were carried out using four-point bending test devices on thin slabs: a hydraulic press and a block-bar. This material can be considered elastoplastic with strain hardening in tension. The synergetic behavior of fibers at different scales is the main feature of the multi-scales fiber-reinforced cement-based composite studied in this paper. ©, 2015, Editorial Office of Journal of Hohai University (Nature Sciences). The average ratio of the calculated results to the test results is 0.98, demonstrating agreement between them. The calculated results of the flexural bearing capacity of prestressed steel-reinforced concrete beams are compared with the test results in the limit state. With regard to prestressed steel-reinforced concrete frame beams in bending, and with reference to the theory of confined concrete as described in the literature, a bearing capacity calculation method for prestressed steel-reinforced concrete frame beams considering regional constraints is proposed based on the superposition principle. concrete under pressure when it is destroyed, and enhance the flexural bearing capacity of the beam. Test results show that steel can effectively restrain concrete deformation in the core area, improve the brittleness of. An experimental study on bonded prestressed steel-reinforced concrete frames at an early stage was conducted to investigate the constraint imposed by steel in the prestressed steel-reinforced concrete beam to concrete and its impact on the carrying capacity of the frame beam.
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