Concrete Moisture Migration Flashcards Preview

BD_Ballast > Concrete Moisture Migration > Flashcards

Flashcards in Concrete Moisture Migration Deck (11)
1

forces of adhesion, surface tension, cohesion

capillary action:

2

moves from areas of high pressure to area of low pressure by diffusion

water vapor

3

diffusion

water changes from a liquid to a vapor as it evaporates

4

water not used in curing process

free water

5

scheduling construction so full cure time, before sealing/floor finishes.
ideally min:

6 weeks

6

vapor barrier placement:

directly below slab, top of sand/subbase

7

max recommended water-cement (w/c) ratio

0.45-.50

8

vapor barrier material

thin sheet material, typ. plastic
> 10 mils thick

9

vapor barrier permeance

not > 0.04 perm

10

*perm =

passage 1 grain
water vapor per hour
through 1sqft of material
@ pressure differential of
1” mercury between the
2 sides of material.

11

only SLOWS rate of vapor transmission

Vapor retarder