AE-SiGMA Analysis in Split-Tensile Test of Concrete
By Masayasu Ohtsu, Shota Nosaki and Yuma Kawasaki
Concrete Research and Technology,
Vol.22, No.3, Sep. 2011 (Issue 57)
- Synopsis:
- A split-tensile (Brazilian) test is well known as a test to evaluate a tensile strength of concrete. It is reported that the tensile strength of the split-tensile test is in reasonable agreement with that of a direct tensile test, although failure process and stress distribution are easily found to be quite different. According to latest research on fracture mechanics, nucleation of the fracture process zone in the direct tensile test is reported, in relation with determination of a tensile-softening relation in concrete.
The moment tensor analysis of acoustic emission (AE) waveforms detected for one AE source is available to identify cracking kinematics of a location, a crack-type and a crack orientation. The procedure has been implemented as the SiGMA (Simplified Green's functions for Moment tensor Analysis) analysis. Here, the analysis is applied to the split-tensile tests of concrete, in order to elucidate a nucleation process of the fracture process zone. Thus, theoretical basis on the agreement of the tensile strengths in two tests of the split-tensile test and the direct tensile test is discussed. As a result, it is clarified that the facture process zone is created in a cross-section under constant tensile stress in the both tests. These similar nucleation processes of the facture process zone could reasonably lead to comparable tensile strengths in the split-tensile test and the direct tensile test. - Keywords:
- concrete, split-tensile test, tensile strength, acoustic emission (AE), moment tensile analysis (SiGMA analysis)
