Comparison of the Silica Fume Content for High-Strength Concrete Production: Chemical Analysis of the Pozzolanic Reaction and Physical Behavior by Particle Packing

Abstract Silica fume (SF) is the most commonly mineral admixture used for the production of high-strength concrete (HSC) due to its chemical characteristics of pozzolanic reactivity and physical filling effect. The objective of the present work is to compare the SF content by the chemical analysis of the pozzolanic reaction and the physical behavior by particle packing techniques. The first step of the study was to analyze the SF content to consume the calcium hydroxide (CH) produced during the hydration of Portland cement (PC), based on stoichiometric calculations. Then, the SF content for maximum packing density was obtained using analytical particle packing models and experimental tests. The compressive strength of the pastes was also measured. The results showed that the theoretical SF content for consuming CH is 15.6%, replacing PC. According to the packing density analytical models, the ideal SF content is 15% of the total fine materials. However, the experimental results indicated the use of a smaller SF content (10%). This difference between theoretical and experimental results is probably due to the high specific surface of the SF, which results in important surface forces between the grains, particle agglomeration and difficulty in SF densification with water.

Saved in:
Bibliographic Details
Main Authors: Campos,H.F., Klein,N.S., Marques Filho,J.
Format: Digital revista
Language:English
Published: ABM, ABC, ABPol 2020
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392020000500203
Tags: Add Tag
No Tags, Be the first to tag this record!