Silica fume admixture effect on the dynamic properties of concrete

The construction of concrete structures using silica fume (SF) additions is a common practice because it is well known that this pozzolanic material improves the compressive strength of concrete, among many other mechanical and physical properties. The response of a structure under dynamic actions is highly determined by the dynamic mechanical properties of its building material. In this work, it has been studied the influence of SF additions in quantities ranging from 0% to 15% of cement mass on the dynamic and static mechanical properties of concrete, such as: resonant frequencies, dynamic and static modulus of elasticity, damping ratio, compressive strength and flexural strength. The results prove that SF additions or replacements reduce both the dynamic modulus of elasticity and damping ratio of concrete. The dynamic elastic properties of concrete, with and without SF, present higher values than their static counterparts. These differences are smaller in concretes containing SF.

Research highlights
► Dynamic and static mechanical properties of concrete with SF have been studied.
► Different concrete types with variations in the SF proportioning have been tested.
► Resonant frequencies of concrete specimens have been determined.
► The influence of SF admixtures on the concrete damping ratio has been determined.
► The evolution of dynamic properties was analyzed for 28 and 90 days.