New test method for obtaining softening response of unnotched concrete specimen under uniaxial tension

摘要: A new method was developed to obtain the complete stress-deformation response of an unnotched concrete specimen. This employs a digitally controlled closed-loop testing machine and five control channels: stroke LVDT four LVDTs mounted on The test portion specimen fully spanned by these LVDTs. outputs channels load cell were monitored during computer equipped with LabTech's Notebook software. ‘C’ language program written enable quick switching mode from one another. problem uncertainty in location major crack tackled said arrangement program. It demonstrated that it is always possible stable post-peak provided ensures at any time test, feedback used exhibits, time, largest slope response-time curve. An acoustic emission (AE) measurement system six also experiments. Monitoring signals AE transducers valuable information which helped making decision switch control.