A monitoring method for cracking parameters of rust-expanding cracks in reinforced concrete main beam structures

Abstract

The invention discloses a method for monitoring a cracking parameter of a rust expanding crack of a reinforced concrete main girder structure. An oval PZT intelligent aggregate is adopted for monitoring a rust expanding cracking condition of the reinforced concrete main girder structure; an intelligent aggregate sensor is embedded into concrete; the aggregate is used as a sensor and a driver; a signal propagated by a stress wave is compared with a calibration signal; a multiple delay imaging technique is utilized and a wavelet transform processing technique is combined, so that the happening time of the rust expanding crack and the width and depth of the crack expansion can be acquired. Compared with the prior art, the method provided by the invention has the advantages that the real-time monitoring can be realized, the device is embedded in a construction process, the integration of structure and device is realized and the damage of the device to the structure is avoided. The existing damage identification technique and signal processing technique are combined, so that the test precision and intelligence can be promoted.

Description

Technical field [0001] The invention relates to a method for monitoring rust expansion cracks and cracking parameters of a reinforced concrete main beam structure. Background technique [0002] For reinforced concrete bridge structures in atmospheric environments, offshore environments, and using deicing salts, corrosive media (chloride ions or carbon dioxide) will cause corrosion of the steel bars in the concrete, and the corrosion products will cause the concrete protective layer to crack or even peel off, which may further cause the steel bars The main girder of the concrete bridge structure is broken. In order to maintain the normal service function of this kind of structure, a lot of manpower and material resources need to be repaired. The main reason for the deterioration of the functional concrete structure in order to maintain the service bridge is the corrosion of steel bars and the cracks of concrete expansion. According to incomplete statistics, my country's annual c...

AI Technical Summary

Problems solved by technology

To sum up, the main reasons are as follows: 1) There are a large number of bridges in my country; 2) The initiative of bridge maintenance management is not enough; 3) The accuracy of the existing bridge service performance prediction model is not high, which is mainly due to the start time of bridge rust crack cracking, The monitoring methods of fracture width and depth need to be further improved to provide strong support for establishing a reliable prediction model

[0003] At present, there are mainly the following problems in the monitoring methods for the cracking parameters of rust swelling cracks in reinforced concrete main beam structures: 1) The monitoring of the start time of rust swelling cracks in structures is not timely, and the existing models of rust crack cracking start time are mainly based on laboratory There is still a certain gap between the experimental model data and the application of real bridges; 2) The width monitoring of rust swelling cracks is not accurate. Most of the existing rust swelling crack width models are fitted according to laboratory data. It is still difficult to fully apply to real bridges; 3) There is no report on the depth monitoring method of rust swelling cracks

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