Analysis of microstresses in cement paste by fluorescence piezospectroscopy.
An experimental method to measure microstresses in cement paste, as a typical granular medium, was developed employing a fluorescence microprobe spectroscopy method. Stresses were recorded with a Raman spectrometer making use of (Cr3+ fluorescence lines of) alumina as a piezospectroscopic stress sensor. In a two-dimensional stress map, fluctuations in the stress distribution led to stress chains, indicating the granular character of cement paste. Due to these fluctuations, microforces much higher than the macroscopic strength of the material existed. The presented technique is proposed as a general tool to analyze stresses in cementitious systems. In practice, the method supports the development of toughening additives to materials like cement paste.
Asmus
Sven M F
SM
Degussa Construction Chemicals Asia Pacific, NMB Central Research Labs, Chigasaki 253-0071, Japan. Sven.Asmus@mbt.com
Pezzotti
Giuseppe
G