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Analysis of microstresses in cement paste by fluorescence piezospectroscopy
Sven M F Asmus1, Giuseppe Pezzotti
1Degussa Construction Chemicals Asia Pacific, NMB Central Research Labs, Chigasaki 253-0071, Japan. Sven.Asmus@mbt.com
Summary
Researchers developed a new method to measure microstresses in cement paste using fluorescence microprobe spectroscopy. This technique reveals stress chains and high microforces within the granular material, aiding in developing stronger cementitious systems.
Area of Science:
- Materials Science
- Solid Mechanics
- Spectroscopy
Background:
- Cement paste exhibits complex granular behavior under stress.
- Understanding microstress distribution is crucial for material performance.
- Existing methods for stress measurement in cementitious materials are limited.
Purpose of the Study:
- To develop and present an experimental method for measuring microstresses in cement paste.
- To investigate the granular character of cement paste through stress distribution analysis.
- To establish a general tool for stress analysis in cementitious systems.
Main Methods:
- Utilized fluorescence microprobe spectroscopy.
- Employed Raman spectrometry with alumina (Cr3+ fluorescence lines) as a piezospectroscopic stress sensor.
- Generated two-dimensional stress maps to visualize stress distribution.
Main Results:
- Identified stress chains, confirming the granular nature of cement paste.
- Observed significant fluctuations in stress distribution.
- Detected microforces substantially exceeding the macroscopic strength of the material.
Conclusions:
- The developed fluorescence microprobe spectroscopy method is effective for analyzing microstresses in cement paste.
- The technique highlights the presence of localized high stresses within granular materials.
- This method can support the development of advanced cementitious materials with enhanced toughness.