- Q.
Which is better
at preventing cracks in concrete slabs: fiber reinforcement or
wire mesh?
A.Robert Shuldes
responds: Neither fiber mesh nor wire mesh will guarantee
no cracks. In fact, a concrete slab will always crack as it
shrinks during curing. By placing control joints at the proper
spacing, you can limit where those cracks occur (see table of
recommended joint spacing). If, however, a crack occurs where
you did not expect it, wire mesh is better at keeping the crack
tight and preventing it from opening up further.
Robert Shuldes,
P.E., is an engineer with the Portland Cement
Association.
Maximum Spacing of Slab Control Joints
|
|
Slab
thickness
|
Slump 4 to 6
in.
|
Slump less than 4
in.
|
|
Aggregate less
than 3/4 in.
|
Aggregate 3/4 in.
and larger
| Aggregate ¾
in. and larger
|
|
4
in.
|
8
ft.
|
10
ft.
|
12
ft.
|
|
5
in.
|
10
ft.
|
13
ft.
|
15
ft.
|
|
6
in.
|
12
ft.
|
15
ft.
|
18
ft.
|
Source: Portland Cement Association