Pouring concrete over carport concret pad
#1
09-22-14, 01:49 PM
Pouring concrete over carport concret pad
I enclising my garage and adding anothe bedroom. I will be pouring a 6 inch fiber reinfored slab (will be 8 inches in areas due to how carport slab is made). I am using a bonding agent and cutting expansion joints.
The carport has two brick walls and two opens walls supported by pillars.
My question is will the bonding agent, walls, and pillars be enough to stop any lateral movement, or should I have some drilled into the existing slab.
The carport has two brick walls and two opens walls supported by pillars.
My question is will the bonding agent, walls, and pillars be enough to stop any lateral movement, or should I have some drilled into the existing slab.
#2
09-22-14, 07:29 PM
The footings or lack thereof, under the slab will determine how well it holds, in the future. That's where the structure starts. What year was the house built?
#3
09-22-14, 07:50 PM
why fiber ? its generally only good for fiber-factory owners who want bigger boats impo 
6" of conc won't move unless you're placing it on a slope & subjecting it to vibratory force,,, better you should drill the existing pad & insert some 4" exposed vert bar,,, a bonded overlay is much more than JUST adding a bonding agent,,, for best results, we scarify the existing slab, dempen the surface to meet ' surface saturated dry ' conditions, scrub in wet grout, & IMMEDIATELY place the new mud 
any contraction jnts you install should be in accordance w/ACI jointing practices yet you're also bound to honor ( reference ) existing jnts as they will likely reflect up thru the new slab,,, a proper jointing pattern is more important than fiber
6" of conc won't move unless you're placing it on a slope & subjecting it to vibratory force,,, better you should drill the existing pad & insert some 4" exposed vert bar,,, a bonded overlay is much more than JUST adding a bonding agent,,, for best results, we scarify the existing slab, dempen the surface to meet ' surface saturated dry ' conditions, scrub in wet grout, & IMMEDIATELY place the new mud 
any contraction jnts you install should be in accordance w/ACI jointing practices yet you're also bound to honor ( reference ) existing jnts as they will likely reflect up thru the new slab,,, a proper jointing pattern is more important than fiber
#4
09-23-14, 09:44 AM
Member
My DOT concrete overlay experiences (first one done in 1971, many thereafter) have consistently shown that the most effective bonding agent available is to use a neat Portland cement slurry, vigorously broomed into the surface just prior to placing concrete. No other methods of anchorage are needed. And I wouldn't waste my money on fiber reinforcement, either--the few experiences I had using it were not particularly successful, with the fiber mixes developing more cracks than the control mixes did.
#5
09-24-14, 03:23 AM
my dot experience is similar to bdge's - fiber's not worth the addl exp impo altho, when it was 1st introduced, it sounded as if someone invented a silver bullet,,, nothing yet is a substitute for a properly install'd jnt pattern,,, it seems bdge & i often arrive at the same conclusions albeit from different directions
