Method for determining flexural capacity of light ultra-high performance concrete beam

Abstract

The invention relates to a method for calculating the flexural capacity of a light ultra-high performance concrete beam. The method is characterized by comprising the following steps that the sectionwidth and the section height of the LUHPC beam are determined, the axis compressive strength, the tensile strength, the longitudinal bar ultimate strength and the reinforcement ratio of concrete are tested, an LUHPC beam bending test is carried out, and the bending bearing capacity of the test beam is obtained; the influence rule of the reinforcement ratio on the flexural capacity of the LUHPC beam is studied, according to the strain distribution rule of the cross section in the bearing capacity limit state, a cross section stress simplification diagram for simplifying a stress graph of a pressed area into a triangle and considering concrete tensile stress contribution of a tensile area is established, and therefore the flexural capacity calculation formula of the light ultra-high performance concrete beam is obtained. By means of the method, the problem that an existing standard flexural capacity formula is not suitable for the light ultra-high performance concrete beam is solved, andtheoretical and test bases are provided for application of LUHPC new materials in bridge engineering.

Description

technical field [0001] The invention belongs to the technical field of bridge and culvert engineering in the transportation industry, and in particular relates to a method for determining the flexural bearing capacity of a lightweight ultra-high-performance concrete beam. Background technique [0002] High-strength concrete has been widely used in civil engineering structures, but its shortcomings such as heavy weight and poor crack resistance restrict the spanning capacity and durability of bridge structures. The lightweight of high-performance concrete is an important research hotspot at present. The basic mechanical properties of Lightweight Ultra-High Performance Concrete (LUHPC) developed by our research group are: compressive strength greater than 110MPa, splitting strength greater than 12MPa, elastic modulus greater than 3.8×10 4 MPa, the apparent density is less than 2100kg / m 3 . However, as a new material, LUHPC's component flexural performance is not for ultra-hi...

AI Technical Summary

Problems solved by technology

However, as a new material, LUHPC’s flexural performance is not for ultra-high performance concrete, so it cannot be directly applied to the calculation of flexural performance of lightweight ultra-high performance concrete LUHPC beams.

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