Title:
Viscoelastic Behavior of Silica Fume in Absence of Binder
Author(s):
Shuang Lu and D. D. L. Chung
Publication:
Materials Journal
Volume:
112
Issue:
1
Appears on pages(s):
137-146
Keywords:
bulk density; cement; compaction; dynamic loading; modulus; silica fume; vibration
DOI:
10.14359/51686983
Date:
1/1/2015
Abstract:
The viscoelastic behavior of silica fume (with and without silane treatment) without a binder is evaluated under dynamic smallstrain compression. The loss-tangent/solid-content, storagemodulus/solid-content, and loss-modulus/solid-content describe the solid part of the compact; they increase with silane treatment, and decrease with increasing frequency. The viscous character stems from the interparticle movement. The highest loss-tangent/solid-content is 0.57 and 0.41 for treated and untreated silica fume, respectively; the highest storage-modulus/solid-content is 24 and 12 psi (165 and 82 kPa) for treated and untreated silica fume, respectively. The treatment results in increased aggregation, ≤40% increase in the loss-tangent/solid-content (due to the viscous character of silane), ≤90% increase in the storage-modulus/solidcontent(due to the increased cohesion), and ≤180% increase in the loss-modulus/solid-content. An increase in the solid content of the silane-treated silica fume results in a decrease in the loss-tangent/solid-content (due to the decreasing ease of interparticle movement), but an increase in the storage-modulus/solid-content (due to increased cohesion).