Method for testing variation of early-age dynamic elastic modulus of concrete in time-dependent manner

Abstract

The invention discloses a device and method for testing variation of the early-age dynamic elastic modulus of concrete in a time-dependent manner. The device comprises an excitation tool and test part, a vibration response test part, a signal recording part and a signal processing part, wherein the excitation tool and test part comprise a PVC (Poly Vinyl Chloride) board and a force hammer capable of acting on the PVC board; a rubber hammer is arranged at the front end of the force hammer; a load sensor is arranged on the rubber hammer; the vibration response test part is an acceleration sensor; the acceleration sensor is arranged on the PVC board; the signal recording part is a dynamic signal test and analysis system; and the signal processing part is a computer. The device provided by the invention has the advantages of simple structure, convenience in dismounting and less needed materials and instruments, and belongs to nondestructive test. The device can perform tests repeatedly and continuously, is applicable to both scientific researches and test on the early-age dynamic elastic modulus of concrete in the early age in a construction field.

Description

technical field [0001] The invention relates to a device and a measuring method for measuring the change of the dynamic elastic modulus of concrete at an early age with time, and belongs to the field of concrete construction. Background technique [0002] In the field of civil engineering, the dynamic elastic modulus of early-age concrete is very important. [0003] At present, there are generally two methods for the concrete elastic modulus test: (1) The principle of mechanics, using the hydraulic loading method to measure the static elastic modulus of concrete after 28 days (that is, the method adopted by the specification), this method cannot measure the elasticity of early-age concrete Modulus, and often can only do corresponding research for one situation; (2) Non-destructive testing method, mainly using the principle of vibration or ultrasonic pulse, which measures the dynamic modulus of elasticity of concrete. The principle of vibration is to use simple harmonic forc...

AI Technical Summary

Problems solved by technology

For the test piece cast within 1 day, since the test piece has not been removed from the mold, it can only emit and receive ultrasonic waves on the surface of the mold, and the accuracy of the obtained signal is too poor, so the ultrasonic pulse method cannot be used to accurately measure the temperature of the test piece cast within 1 day. Dynamic modulus of elasticity

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