Title:
Relationship Between Microstructure and Mechanical Properties of Paste-Aggregate Interface
Author(s):
Kenro Mitsui, Zongjin Li, David A. Lange, and Surendra P. Shah
Publication:
Materials Journal
Volume:
91
Issue:
1
Appears on pages(s):
30-39
Keywords:
aggregates; bond (paste to aggregate); mixing; shear strength; silica fume; Materials Research
DOI:
10.14359/4447
Date:
1/1/1994
Abstract:
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 continuously measure force and slip-displacement 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 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.