Expertise Facility Types

Research tagged "slab-on-grade"

Dynamic Stiffness and Subgrade Modulus of a Slab-on-Ground

“Conventional wisdom” amongst users of cutting-edge electron microscopes and other sensitive research instruments is that their instrument will perform better if supported on a “thick” concrete slab-on-ground.  Typically, their choice of a slab thickness is based on what worked well for someone else, without any thought given to an analytical justification.  The paper presents the […]...
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Voids Beneath Slabs-on-Ground: Using the impulse response test to verify adequate slab support

Introduction A concrete slab-on-ground is one of the most common of all floor types.  Slabs-on-ground are popular for many applications, especially in research facilities, where they usually provide the highest-quality vibration environment.  This is because they are stiff and uniformly supported, such that they do not exhibit the resonance characteristics of a suspended slab. As […]...
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An experimental study of vibration attenuation performance of several on-grade slab configurations

There are several instances in the literature in which particular positions are taken regarding the nature of the floor supporting sensitive equipment such as advanced electron microscopes. Assertions are made that one methodology is better than another at reducing vibrations. However, very little experimental evidence has been provided to support those positions. This paper presents […]...
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Design of Stiff, Low-Vibration Floor Structures

Dynamic loading of a floor can excite vibrations that may adversely affect production or research activities using equipment supported on that floor. These loads may be caused by mechanical systems or personnel activities. One way to minimize vibrations is with a slab-on-grade floor, but often this is not possible due to constraints such as lot […]...
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News tagged "slab-on-grade"

Amick to Address Concrete Professionals

Hal Amick will speak on October 28, 2014 at a session on vibration-sensitive structures at the Fall Conference of the American Concrete Institute in Washington, DC.  The rather lighthearted title, “Silk Purses out of Sows’ Ears: Concrete Structures for High Technology Research and Manufacturing,” refers to the role concrete is often expected to play when […]
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Voids beneath concrete slabs

CGA has seen an upturn in work related to non-destructive hammer testing of concrete slabs-on-grade, which documents the presence or absence of voids beneath the slab.  (This can be due to either localized settlement or slab curling.)  An article on this was published by several staff members in the July 2009 issue of Concrete International, […]
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