Question

explain the formation of pumping on concrete roads

What should be the ratio of cement paste aggregate in permeable concrete by volume? What is the ratio, the strength is the best? what is this ratio in normal concrete?

Answer 1

Formation of pumping in concrete :

(1) Pumping in Concrete is seen when the mud and soil present beneath the road surface comes out through the cracks present in pavement on to the surface,this occurs because of many reasons some of them are weak design of pavement,poor drainage characteristics of pavement etc.

​​​​​​Ratio of cement paste aggregate in permeable concrete:

(I) The ratio of cement paste and aggregate by volume in case of permeable concrete varies from 1:4 to 1:7 generally and proportion of fine aggregate is negligible and only coarse aggregate exists

(II)At cement aggregate ratio of 1:4 the strength of the permeable Concrete is stronger

(III)In normal Concrete the ratio of

Cement:fine aggregate:coarse aggregate exists which is normally 1:2:4