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Relationship Between Microstructure and Mechanical Properties of the Paste-Aggregate Interface

• ID:

  967

• ESCSI:

  4378.003

• Author:

  Mitsui, Kenro; Zongjin Li; David A. Lange, Surendra P. Shah

• Publication Name:

  ACI Materials Journal

• Type of Publication:

  Paper

• Publisher:

  American Concrete Institute

• Dated:

  1994

• Issue/Volume:

  January-February

• Other ID:

• Page(s):

  30-39

• Reference List:

  Y

• Abstract:

  An experimental study of the interfacial zone between aggregate and cement paste was undertaken. The study adapted a newly developed pushout method. A closed-loop controlled setup was used to measure force and slip-displacement continuously during loading. The experimental data were analyzed by using a recently proposed theoretical model. It was observed that the method provides a useful way of characterizing the interfacial properties of the transition zone, including the stiffness, strength, friction, and fracture energy of the interface.The transition zone was further investigated by using backscattered electron imaging and energy, dispersive analysis of x-rays (EDAX) to characterize the microstructure of the interface. The relationship between mechanical properties and microstructure of the interfacial zone was studied.
  Various factors such as type of aggregate, treatment of aggregate surface, mixing process, and incorporation of silica fume were investigated. It was found that the microstructure of the interfacial zone can be significantly improved by aggregate pretreatment and mixing methods, and thus the mechanical interfacial properties can be enhanced.