Increasing Concrete Surface Roughness

[timbir04]

Hello all,

We are currently reviewing alternatives to increase the surface roughness of an existing concrete walkway that runs along a beach area. Being a resident of the area also, I've encountered very slick conditions along the boardwalk in question when wet. The boardwalk is swept daily via sweeper truck, which I believe has essentially sanded the surface down to a much finer state than when originally placed. Original specs called for medium broom finish, however the current condition is much more smooth due to the daily sweeping.

What are some alternate methods for increasing a concrete walkways surface friction for pedestrian use? I'm somewhat familiar with bead blasting, but would like to see if anyone is aware of other alternatives. Thanks

 

[ACtrafficengr]

PCC highway pavements are sometimes treated with diamond-tipped grinders to restore smoothness and traction. This might be a bit intensive for a sidewalk.

 

[dik]

Can you use hydrodemolition or an epoxy with grit?

Dik

 

[Compositepro]

Saw cut groves in the pavement, as they do on highways.

 

[oldestguy]

I'd check out the paint they use for highway center line and other pavement markings. They use beads in the paint to make it reflective, but you could use sand instead. It may take repeat painting every 10 years or so. Walk behind paint sprayers do the job for parking lots, etc.. I'd also consider another method of cleaning the walks.

 

[timbir04]

Excellent responses. Thank you.

--I will certainly look into hydrodemolition and application of paint or epoxy with grit. I like the idea of simply applying a coating rather than demolishing the surface and generating dust. I failed to mention the many high-price residences adjacent to the walkway, and dust generation would certainly be an issue.

 

[Canuck65]

I would be careful in putting any paint or coating onto the surface. If the surface is not really well prepared (sandblasting is good) then debonding/flaking of a typical coating will occur and it will look terrible, become a maintenance headache and you will lose the performance of the non-slip coating. There are non slip polyurethane's that are made for balconies, pedestrian areas, etc... which are essentially 'light' versions of parking garage membrane systems. They generally cast silica sand in with the top coat for slip resistance. Again, surface preparation is key.

I have never used it myself, however, would recommend looking into a concrete sealer that has silica cast/mixed into it. While a concrete sealer is a type of coating, it differs from paint or a membrane in that when it starts to breakdown or debond, it doesn't result in flaking, etc... It is reasonably clear, so you can't really tell when it breaks down (other than the missing silica/grit). It won't be as robust as a full waterproofing type system, but will be easier to maintain. Surface prep is still required.

 

[Ron]

Use a surface scabbler

 

[dik]

I would be careful in putting any paint or coating onto the surface.

I've had pretty good luck with epoxies and grit holding up for 15+ years (installed 15+ years ago) and subject to snowblower activity and long, continuous, cold winters.

Scabbler is good and can produce a really rough surface.

Dik

 

[dik]

I like the idea of simply applying a coating rather than demolishing the surface and generating dust.

You have to make sure the surface is well cleaned and has no detrimental material attached/embedded/leached. Check with supplier for surface prep... see Canuck's caution, grit or traction is good, but shallow, except if snow or ice covered. Ron's suggestion of using a scabbler is good, and, can provide a very agressive rough surface, but, with lots of debris.

Dik

 

[epoxybot]

You might consider a pigmented MMA coating. They stink to high heaven when applied but set up and are traffic ready in 45mins to 2 hours. The transportation equivalent is HMWM but I don't know of any that have a pigment. Without the pigment anything applied will change the refractive index of the substrate and not look appealing. The coating is obviously meant to serve as a binder. One benefit of MMAs is that they bond to themselves when later re-coat maintenance is required. It is just low viscosity plexiglass. Methyl methacrylate will also yellow less under UV than an epoxy.

 

[ACtrafficengr]

Before getting too complicated, why not try an ordinary pressure washer? They can remove some of the cement and expose the aggregate, increasing the c_f. The water should keep the dust down.

They did that every year at my college campus, just before Parent's and Alumni Weekends. I don't recall debris being a problem, but you could have someone following behind with a wet vac to pick it up.

 

[epoxybot]

ACtrafficengr

That is a very good point, even a muriatic acid etch might be worth a try. I believe there are contractors now that even do stenciled sand blasting.