Ultrasonic testing method for compactness of grouting sleeve with small sample size

Abstract

The invention relates to an ultrasonic testing method for the compactness of a grouting sleeve with a small sample size. The method comprises the steps of firstly demonstrating a head wave path of an ultrasonic wave; collecting sound velocity data under the condition of invariable construction technology and construction condition; arranging the sound velocities of all test points from high to low, namely X1>=X2>=...>=Xn>=Xn+1..., considering obviously small data arranged at the back to be suspicious, calculating mx and sx through the biggest one (supposing Xn) in these suspicious data together with previous data thereof and calculating a judgment value X0 of the abnormal condition according to a formula; comparing the judgment value X0 with the maximum value Xn of the suspicious data, when Xn is not greater than X0, judging the Xn and the data arranged behind the Xn to be abnormal values, removing the Xn, carrying out calculation and judgment by using X1-Xn-1 until no abnormal value is judged; and when Xn is greater than X0, adding X<n+1> for calculation and judgment again. According to the ultrasonic testing method, the test efficiency is improved.

Description

technical field [0001] The invention relates to the detection field of the compactness of a grouting sleeve, in particular to an ultrasonic detection method for the compactness of a grouting sleeve with a small sample capacity (n<30). Background technique [0002] With the development of society and economy, people pay more and more attention to building energy saving and living environment, and the promotion of prefabricated buildings has become the general trend. However, the quality of the connection still has problems such as immature technology, imperfect equipment, and insufficient theoretical basis, and the wet connection in the connection method mainly uses grouting sleeve connection. Grout-sleeve connections utilize non-shrink grout as the bonding material to connect the reinforcement to ensure continuity of load transfer. The sleeve is usually manufactured by casting process or machining process. The grouting material is cement as the basic material, together w...

AI Technical Summary

Problems solved by technology

According to the principle of statistical sampling distribution, if the sample size is large (n≥30), the normal distribution can be used to approximate the sampling distribution; but if the sample size is small (n<30), the normal distribution can be used to approximate the sampling distribution It may bring large errors, resulting in missed judgments and misjudgments during construction.

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