Title: Strengthening Mechanisms of High-Performance Concrete

Author(s): W. Jiang and D. M. Roy

Publication: Symposium Paper

Volume: 149

Issue:

Appears on pages(s): 753-768

Keywords: admixtures; compressive strength; high-performance concrete; modulus of elasticity; porosity; shrinkage; strengthening; stresses; water-cement ratio; Structural Research

DOI: 10.14359/4184

Date: 10/1/1994

Abstract:
The main topic focuses on a materials science approach to evaluating three major strengthening mechanisms of high-performance concretes: reduced porosity by low water-cement ratio, absence of macro-defects, and synthetic composition mechanism. The substantially improved cement matrix materials can be obtained by deliberately using one or more of the preceding mechanisms. The preliminary experiments were carried out by two computer coupled techniques, one utilizing an electromechanical linear variable differential transformer (LVDT), while the toughening experimental technique was based on determining the J-integral to obtain K 1 c and G 1 c in an indirect way suing small-size specimens. An acoustic emission system was also used. At different concrete maturity stages, the acoustic emission signal generated from the microstructure is transformed due to wave propagation and the transducer response. The data are analyzed numerically. The results obtained through this study are expected to contribute to the establishment of a new strengthening concept of high-performance concrete. The objective of this paper is to sketch a new approach to a group of strengthening phenomena that are as important from a theoretical viewpoint as they are useful for technology.