New method for continuous monitoring of concrete E-modulus since casting using an output-only modal identification technique

A new methodology that allows the continuous measurement of concrete E- mod-ulus since casting is presented in this paper. This methodology is a variant to the classical reso-nant frequency methods, which have the downside of requiring concrete to be de-mouldable and withstand mechanical impact to s...

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Bibliographic Details
Main Author: Azenha, Miguel (author)
Other Authors: Magalhães, Filipe (author), Faria, R. (author), Cunha, Álvaro (author)
Format: conferencePaper
Language:eng
Published: 2010
Online Access:http://hdl.handle.net/1822/13567
Country:Portugal
Oai:oai:repositorium.sdum.uminho.pt:1822/13567
Description
Summary:A new methodology that allows the continuous measurement of concrete E- mod-ulus since casting is presented in this paper. This methodology is a variant to the classical reso-nant frequency methods, which have the downside of requiring concrete to be de-mouldable and withstand mechanical impact to start testing. The proposed experimental setup comprises a simply supported beam made-up with an acrylic tube, filled with the concrete to be tested, whose mid-span vertical accelerations induced just by ambient vibrations are continuously mon-itored by an accelerometer. The numerical treatment of the monitored accelerations allows iden-tification of the 1st resonant frequency of the composite beam, which is evolving as concrete hardens. The E-modulus of concrete can thus be directly obtained from the monitored frequen-cy. Besides the description of the overall setup, the results obtained in an experiment in which the concrete E-modulus was quantified also through static tests on the beam and via compres-sive tests in cylinders are presented and discussed.