Shear strengthening method for reinforced concrete beam by using CFRP grid-PCM strengthening layer

Abstract

The invention belongs to the technical field of computer aided design, and discloses a shear strengthening method for a reinforced concrete beam by using a CFRP grid-PCM strengthening layer. After 28days of maintenance of the original concrete beam, dust cleaning and sand blasting are carried out on the outer surface of the original concrete beam; a rivet is used as a temporary anchor, and the CFRP grid is fixedly arranged on the side surface of the original concrete beam; polymer mortar is sprayed or applied on the original concrete beam and the outer surface of the CFRP grid; and finally, high-pressure PCM spraying is carried out on the side surface. After the original concrete beam is compositely strengthened through the CFRP grid-PCM, the shear capacity is increased by 30% to 40%, andthus, the effect of improving the shear capacity of the reinforced concrete beam strengthened by the CFRP grid-PCM is remarkable; and besides, in order to more reasonably and effectively predict theshear capacity of the reinforced concrete beam strengthened by the CFRP grid-PCM, a design calculation formula based on CFRP grid effective strain is proposed.

Description

technical field [0001] The invention belongs to the technical field of computer-aided design, and in particular relates to a shearing reinforcement method for reinforced concrete beams by using a CFRP grid-PCM reinforcement layer. Background technique [0002] At present, the existing technology commonly used in the industry is as follows: due to uneven settlement, many reinforced concrete (RC) structures designed and built with the original standard caused by the 2011 Great Japan Earthquake have collapsed or been damaged, such as sluice gates, etc. . After research, it was found that the reinforcement of the reinforced concrete structure designed according to the original standard was insufficient. However, if the traditional concrete-wrapped reinforcement method is used, it is necessary to drill holes at the corners where the steel bars are densely distributed to insert reinforcing steel bars; in addition, in order to prevent the reinforcing steel bars from corroding, the...

AI Technical Summary

Problems solved by technology

[0005] To sum up, the problems existing in the existing technology are: when traditionally pasting FRP sheets to strengthen concrete structures, epoxy resin is usually used as a binder, so that FRP and concrete can form a composite whole

At present, the design and calculation methods for the shear bearing capacity of reinforced concrete beams strengthened by FRP grids at home and abroad usually do not take into account the effective strain of FRP grids, thereby underestimating the actual shear resistance provided by them to the structure, resulting in Too conservative, causing unnecessary material waste and economic expenditure

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