تأثیر نوع دانه بندی بر خواص فیزیکی و نفوذپذیری بتن متخلخل در روسازی

Abstract:
The influence of aggregate gradation on the permeability and mechanical properties of porous
concrete was investigated. A standard mix and five standard aggregate gradations were
selected. Since porous concrete contains no or little fine aggregate, its structure is formed by
the interlocking of the coarse aggregates. So the aggregate gradation is a very important
characteristic as it influences such properties of porous concrete as strength and permeability.
There was statistically significant difference between the results from the strength and water
permeability of porous concrete with different aggregate gradations. For example, the
difference between minimum and maximum compressive strength was 33%, and a 20%
difference was obtained for flexural strength. It was found that the uniformity coefficient has
influence on the flexural strength of porous concrete. In order to develop the flexural bending
strength prediction model, the two parameters of compressive and uniformity coefficient were
explained using linear regression model. The obtained Goodness of fit (R2) for this model was
0.879. The results of the current investigation showed how fine aggregate influenced the
compressive and permeability of porous concrete.