Title:
A Review of ACI Recommendations for Prevention of Plastic Cracking
Author(s):
Peter H. Morris and Peter F. Dux
Publication:
Materials Journal
Volume:
102
Issue:
5
Appears on pages(s):
307-314
Keywords:
concrete; crack; shrinkage; temperature; vapor pressure
DOI:
10.14359/14709
Date:
9/1/2005
Abstract:
The ACI recommendations for the prevention of cracking of plastic concrete attempt to eliminate such cracking by ensuring that the rate of evaporation from unprotected concrete surfaces does not exceed the estimated rate of bleed water production. The current recommendations, however, do not account for the large scatter of the underlying experimental evaporation data nor the effect of altitude on evaporation rate. Ignoring the scatter of the evaporation data frequently leads to an unacceptably high probability that the evaporation rate will exceed the bleed rate. Ignoring the effect of altitude leads to similar high probabilities, but in only a comparatively small number of cases. Simple modifications of the ACI recommendations are suggested that can account for both effects. However, insufficient data on the variability of bleed rates are currently available to allow the scatter of the evaporation data to be accounted for completely.