Title: Effect of Mineral Admixtures on the Cement Paste-Aggregate Interface

Author(s): J. A. Larbi and J. J. M. Bijen

Publication: Symposium Paper

Volume: 132

Issue:

Appears on pages(s): 655-670

Keywords: aggregates; alkali-aggregate reactions; cement pastes; concretes; durability; interfacial zone; matrix; mineral admixtures; permeability; strength; Materials Research

DOI: 10.14359/2111

Date: 5/1/1992

Abstract:
The interface between the cement matrix and aggregate is mostly regarded as a weak link in concrete with respect to durability and strength. It is shown that the positive effects of pozzolans on the permeability of concrete are partly related to a decrease in the thickness of the weak, lime-rich, interfacial zone. Results for various mineral admixtures, such as ground granulated blast furnace slag, powder coal fly ash, silica fume, a synthetic colloidal silica, and metakaolinite are presented. It is shown that in the presence of mineral admixtures, the calcium hydroxide content in the interfacial zone is reduced substantially.