Title:
Mechanical Energy Dissipation Using Cement-Based Materials with Admixtures
Author(s):
Po-Hsiu Chen and D. D. L. Chung
Publication:
Materials Journal
Volume:
110
Issue:
3
Appears on pages(s):
279-290
Keywords:
cement; compressive strength; damping; energy dissipation; flexural strength; graphite; mortar; silica fume.
DOI:
10.14359/51685661
Date:
5/1/2013
Abstract:
Silica fume and a novel graphite network (8 vol.%) cementitious admixture are effective for enhancing the mechanical energy dissipation of cement-based materials, as shown under small-strain dynamic flexure at 0.2 Hz. The fraction of energy dissipated reaches 0.26, 0.58, and 0.22 for cement paste, mortar, and concrete, respectively, as provided by silane-treated silica fume and the cementitious admixture, which cause steel-reinforced concrete to increase the dissipation, loss modulus, loss tangent, and storage modulus by 16,000%, 450,000%, 16,000%, and 170%, respectively. The highest loss tangent and loss modulus obtained are 0.14 and 3.5 GPa (20.3 and 507.5 ksi), respectively. Silane-treated silica fume alone causes steel-reinforced concrete to increase the dissipation by 9900%; untreated silica fume alone gives an 8000% increase. Without steel or admixtures, the dissipation decreases from cement paste to mortar and concrete. With steel and/or the admixtures, the dissipation increases from paste to mortar and decreases from mortar to concrete. The dissipation decreases with increasing frequency, such that the presence of silica fume reduces the frequency effect.