roughen concrete surface of garage ramps for traction
roughen concrete surface of garage ramps for traction
(OP)
The contractror has put a smooth trowel finish on a new parking structure ramp, nothwithstanding our spec requirement for a non-slip swirl trowel finish. How can we rectify so cars have proper traction, without doing it in a way that will be a maintenance issue? Is there equipment that can modify the concrete surface to increase traction, and if so, what is the equipment called? I was thinking of something that would cut shallow closely spaced grooves, transverse to the direction of car travel, into the concrete surface.






RE: roughen concrete surface of garage ramps for traction
BA
RE: roughen concrete surface of garage ramps for traction
It's common to grove transverse, closely spaced grooves in highways so the equipment exists.
RE: roughen concrete surface of garage ramps for traction
As BA suggests, let the contractor propose a solution. Scarification of the top surface may work, but will slightly reduce the concrete cover to the reinforcement. The end result of scarification is a series of closely spaced grooves, but it likely won't look all that great. A heavy shotblasting might also work, but I would want to test that first.
RE: roughen concrete surface of garage ramps for traction
RE: roughen concrete surface of garage ramps for traction
Yes, as per standard practice when the contractor makes a mistake, we have asked the contractor how he proposes to correct it, but he says that he is not sure.
If scarification produces a series of parallel closely spaced grooves, then thatwould do it. But I did not realaize that was what scarification did. If you are sure that it does, then that is what we should ask the contractor to do. Are you sure that "scarification" produces a neat clean regular appearance of parallel shallow (2 mm?) grooves?
RE: roughen concrete surface of garage ramps for traction
Maine EIT, Civil/Structural.
RE: roughen concrete surface of garage ramps for traction
Texturing
shall be performed by applying a longitudinal burlap drag fol lowed by longitudinal texturing using steel tines.
Tine texturing shall be performed so that the grooves produced will be uniform in spacing, depth, and width.
Texture grooves shall be 1/8 ± 1/32 inch in width and 5/32 ± 2/32 inch in depth. The center-to-center spacing of the grooves shall be 3/4 ± 1/8 inch. If necessary, hardened concrete shall be textured by any method that will produce the required grooves.
RE: roughen concrete surface of garage ramps for traction
RE: roughen concrete surface of garage ramps for traction
For my inforamtion, can you clarify the following for me:
a) On an above-grade precast parking garage with say 60 foot wide by say 150 foot long ramps, which double as parking floors and are usually at <5% slope, the cast-in-place topping has what I would describe as a swirl pattern to the finish, with the peaks of the swirls slightly above the troughs. Is that not what you would call a swirl trowel finish? Is that made with a broom (I would not have thought so)?
b) The finish that I see on most municipal sidewalks is a broom finish. This is a pattern of straight lines transverse to the direction of the sidewalk. Is that the type of finish that you say should be used on the ramps? Which type of ramp do you mean that the broom finish should be used on - parking floor rampos (slope <5%) or non-parking floor ramps (generally 10% or more slope)?
TLHS- ok, thanks.
RE: roughen concrete surface of garage ramps for traction
See attached photo of a scarified surface. I have worked with it in the past and it does create uniform grooves of small depth, however, scarification machines vary and you would want to verify with a test sample or similar.
The uniformity of the grooves is up to the care and control of the operator. If they are not careful, the grooves will be wavy.
RE: roughen concrete surface of garage ramps for traction
RE: roughen concrete surface of garage ramps for traction
rough broom
turf drag
burlap drag
tining
all provide significantly more friction for sloped surfaces and vehicles with wet tires. Anything more than 5% I would say needs a good non-slip surface.
search google for a lot of references for this, for instance here's a couple
http://roadwaystandards.dot.wi.gov/standards/cmm/c...
http://www.wsdot.wa.gov/research/reports/fullrepor...
RE: roughen concrete surface of garage ramps for traction
RE: roughen concrete surface of garage ramps for traction
The swirl trowel finishes that I have specified and seen on many garages are fairly rough in my opinion. So I wonder if we are talking about the same thing. Maybe there are picture illustrations somewhere of the what the various finishes look like. Anyway, I lived for 20 years in an apartment complex that had a fairly steep entrance ramp that had interlocking pavers and a snow melting system below. The surface of the interlocking pavers had a smooth finish, certainly smoother than a swirl trowel finish. I never slid down or had any problem. I think there are quite a few such installations. So I am wondering why a swirl trowel finish is deemed to be no good on a ramp. Perhaps it would eventually wear down. But so would a broom finish.
For the tined finish, can the depths of the grooves be regulated? Want to keep them as shallow as possible to avoid any possible damage to the snow melting system.
Should the grooves run transverse or parallel to the length of the ramp? I would think they should parallel to avoid collecting water in the grooves. Do you agree?
Thanks.
RE: roughen concrete surface of garage ramps for traction
RE: roughen concrete surface of garage ramps for traction
http://www.eng-tips.com/viewthread.cfm?qid=366315
The sawcut grooving that Canuck67's photo should work. We typically do that on bridge decks in NY for skid resistance.
RE: roughen concrete surface of garage ramps for traction
RE: roughen concrete surface of garage ramps for traction
RE: roughen concrete surface of garage ramps for traction
Shot blasting will roughen concrete by removing the cement and sand between the pieces of larger aggregate. A coarse seel shot (390) should be used. A good operator can do it with minimal patterning. The size and hardness of the aggregate will effect the possible profile produced. a scarifier is not descriminate.. it will cut aggregate and cement matrix.
Be careful that the rebar is not too close to the surface. That can open another bucket of worms if rebar is exposed.
airsmybag