Title:
Reducing Crack Risk in Industrial Concrete Floors
Author(s):
Johan L. Silfwerbrand and Ali A. Farhang
Publication:
Materials Journal
Volume:
111
Issue:
6
Appears on pages(s):
681-690
Keywords:
crack risk; creep; industrial concrete floors; material tests; restrained shrinkage; shrinkage
DOI:
10.14359/51686833
Date:
11/1/2014
Abstract:
Cracking and curling are two important problems in industrial concrete floors. In many practical cases, it is easier to design the concrete floor slab for mechanical loads than for shrinkage stresses. This paper proposes a simple equation that mirrors the major factors influencing the crack risk in concrete floor slabs. By using this equation, the industrial floor designer or contractor can make a proper material selection that leads to a substantially reduced crack risk. Tests on strength, free shrinkage, restrained shrinkage, and flexural creep support this hypothesis. Furthermore, the use of shrinkage-reducing admixtures (SRAs) seems to not only reduce the free shrinkage, but also maintains the beneficial condition of substantial creep that leads to shrinkage stress reduction.