SLOPING THE GRADE?
SLOPING THE GRADE?
(OP)
Slab on Ground - 46'x134', 4 interior drain points (not at evenly spaced intervals) with the slab elevation level around perimeter & at intermediate joints. 4 inch difference between drain elev. and perimeter, slab sloping to drain points.
Does the concrete thickness vary in order to create the slope or should the base be graded to give a constant 6" slab thickness? I have 6" slab, 6" compacted aggr. base, 1 ft. select fill. It seems like it would be difficult to accurately grade the base considering the contours. My boss says to vary the concrete thickness, with 6" being the minimum at the drain points, but 4" seems like a big difference in thickness. Any sage advice out there?
Does the concrete thickness vary in order to create the slope or should the base be graded to give a constant 6" slab thickness? I have 6" slab, 6" compacted aggr. base, 1 ft. select fill. It seems like it would be difficult to accurately grade the base considering the contours. My boss says to vary the concrete thickness, with 6" being the minimum at the drain points, but 4" seems like a big difference in thickness. Any sage advice out there?





RE: SLOPING THE GRADE?
RE: SLOPING THE GRADE?
RE: SLOPING THE GRADE?
From your posts I'm feeling better about standing firm with my design, but I'll need to convince the bossman. He's been on the site for quite a few of these jobs and claims this is the way to do it (he's a mechanical but has seen alot of construction). I don't see the added grading labor being worth the extra concrete bucks as boo1 points out.
RE: SLOPING THE GRADE?
RE: SLOPING THE GRADE?
I had 2" clr. cover on top originally, I guess it will stay and will end up as 6 at the 10" thk. areas. I've been calling out the "soff-cut" method for joints recently but haven't seen it performed yet. Maybe that will help.
RE: SLOPING THE GRADE?
The varying thickness of the slab creates varying restraint, thus a greater tendency to cause "random" cracking.
For the voting, I would keep the concrete thickness uniform and slope the subgrade.
RE: SLOPING THE GRADE?
THERE IS NO TECKNICAL PROBLEM IN PROVIDING SLOPE IN CONCRETE.BUT YOU SHOULD ALSO LOOK FOR ECONOMICAL SOLUTION .
RAGHAV