Composite-section simply supported beam and manufacturing method thereof

Abstract

The invention discloses a composite-section simply supported beam and a manufacturing method thereof, which solve the problems of corrosion of internal reinforcing steel bars and influence on bearingcapacity of structure by the bending and cracking of the reinforced concrete simply supported beam in the prior art. The composite-section simply supported beam combines ECC (engineered cementitious composite) and common concrete, so as to improve the ductility of the member and overall durability. The composite-section simply supported beam adopts the technical scheme that the composite-section simply supported beam comprises a common concrete layer and an ECC layer, wherein the ECC layer is arranged at the outer side of the common concrete layer; the ECC layer and the common concrete layer are combined into a simply supported beam with a rectangular section by side crossing surfaces, and a debonding layer is arranged at the bottom crossing surface of the ECC layer and the common concretelayer; a reinforcement skeleton is arranged in the common concrete layer and is used as support.

Description

Technical field [0001] The invention relates to the field of civil engineering and construction, in particular to a simple-supported beam with a composite section and a manufacturing method thereof. Background technique [0002] At present, reinforced concrete simply supported beams are widely used in the civil construction industry, but because concrete has good compressive properties, low bending and tensile strength, poor toughness, high brittleness, small ultimate tensile strain, and difficult to control cracks, the steel Concrete simply-supported beams are working with cracks during normal use, which is difficult for some structures that do not allow cracks or have strict requirements for crack width. At the same time, the existence of cracks allows harmful substances to penetrate into the concrete, causing damage to the durability of the concrete, which in turn causes the steel bars in the simply supported beam to directly connect with the harmful medium, especially for som...

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Problems solved by technology

[0002] At present, reinforced concrete simply supported beams are widely used in the civil construction industry, but because concrete has good compressive properties, low bending and tensile strength, poor toughness, high brittleness, small ultimate tensile strain, and difficult to control cracks, making steel bars Concrete simply supported beams are in the state of working with cracks in normal use, which is difficult for some structures that do not allow cracks or have strict requirements on crack width.

At the same time, the existence of cracks allows harmful substances to penetrate into the concrete, causing durability damage to the concrete, and then makes the steel bars in the simply supported beams directly connected with harmful media, especially for some open-air structures and structures in humid environments Under the action of harmful substances such as acid and chloride ions, the surface of steel bars will gradually corrode due to oxidation, and gradually develop to the inside. During the process of steel bar corrosion, the volume expansion will easily crack the surrounding concrete protective layer, forming longitudinal cracks and even causing corrosion. The surface concrete falls off, which further accelerates the corrosion of internal steel bars

[0003] Under the influence of oxidation and corrosion, the stress-bearing area of ​​the internal stressed steel bar is also gradually reduced, and due to the existence of longitudinal cracks, the bonding surface between the concrete and the longitudinally stressed steel bar will be damaged, reducing the cohesive force. The bearing capacity of the component is reduced, and the overall stiffness of the structure will also be greatly reduced, which greatly affects the normal performance and safety performance of the structure.

On the other hand, due to the huge difference in the modulus of elasticity of steel and concrete, this also makes the deformation of the two different when they are stressed. When the stress level is low, it will crack. At this time, the tensile stress of the cracked part will be borne by the longitudinal tensile steel bar alone, and part of the tensile stress needs to be transmitted to the concrete part through the interface bonding force. In this process, it is easy to cause the steel bar and Relative slippage occurs between concrete, causing longitudinal splitting cracks and concrete spalling, affecting the overall performance of simply supported beams

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