Title:
Simulation Studies of the Effects of Mineral Admixtures on the Cement Paste-Aggregate Interfacial Zone (SP-105)
Author(s):
D. P. Bentz and E. J. Garboczi
Publication:
Materials Journal
Volume:
88
Issue:
5
Appears on pages(s):
518-529
Keywords:
cement-aggregate reactions; cement pastes; concretes; fly ash; pozzolans; silica fume; Materials Research
DOI:
10.14359/2179
Date:
9/1/1991
Abstract:
The interfacial zone between cement paste and aggregate plays a critical role in determining concrete's mechanical performance. In recent years, high-performance concretes have been produced based on a low water-cement ratio cement paste containing a superplasticizer and silica fume. One of the key benefits of silica fume is its ability to improve the integrity of the interfacial zone in concrete. This paper presents a three-dimensional microstructural model for simulating the interfacial zone in concrete, including the incorporation of inert and pozzolanic mineral admixtures. The model is utilized to obtain the cementitious material phase distributions as a function of distance from the aggregate surface to quantitatively characterize the interfacial zone. Pozzolanic admixtures, such as silica fume and fly ash, are found to increase the homogeneity of the interfacial region, with the most important enhancement proposed to be the improved homogeneity of the calcium silicate hydrate phase.