An initial read of the headline might sound alarm bells in neighborhoods across the country. But think about it: If you’re a safety-conscious RVer, you know that the recommended lifespan of RV tires is but five years. That could produce a lot of old tires. Where are they gonna go? How about in your driveway? No, NOT ON your driveway, but IN your driveway.
Crumb rubber
Researchers at the University of South Australia got a “gee-whiz” idea. Why not replace some of the sand in concrete used on slabs with “crumb rubber.” This stuff is the remains of ground-up tires, chopped to a fine size, about equivalent to that of sand. Steel and other reinforcing materials are removed in the production process. By mixing the crumb rubber with cement, water, and other normal concrete ingredients, scientists working with concrete plant operators were able to prepare a concrete mix. They used this to form two reinforced concrete slabs at the entrance to the civil engineering laboratory.
University folk constructed the two old tire rubber slabs in 2018. At the same time, they also installed two conventional concrete slabs for comparison. After three years of use, the slabs were compared. Results?
“Superior to conventional—in some ways”
“We found that reinforced crumb rubber concrete (with up to 20 percent sand replacement by volume) is superior to conventional concrete in some ways, with higher impact resistance, toughness and ductility, a higher damping ratio, better thermal and acoustic insulation, and a lighter weight,” said study author Dr. Osama Youssf.
But what about the installation work? How does concrete made with old tires stack up from a labor and equipment perspective? “With respect to pumping, screeding, or finishing the concrete surface using a power trowel, contractors also reported no difference between using the crumb rubber concrete and conventional concrete, saying that the crumb rubber mix actually required less physical effort across all aspects,” concluded the report. Concrete truck drivers reported that cleaning the crumb rubber concrete out of the cement truck was easier than conventional concrete.
“The results clearly show that crumb rubber cement is a viable and promising alternative to conventional concrete in the residential concrete market,” said study author Professor Yan Zhuge. “We strongly recommend that the concrete industry considers crumb rubber concrete as a sustainable alternative to conventional concrete in reinforced residential constructions in Australia.”
But then there’s the cost
More tires recycled means fewer tires taking up space in landfills, or piling up forming mosquito breeding ponds. That’s a plus! There may be some amount of resistance in terms of cost. At present, a ton of sand sells for an average of $21. Crumb rubber is a bit more expensive, selling for more than $200 a ton. But keep in mind, crumb rubber weighs nearly five times less per cubic foot than sand. With that, the cost difference works out to be about twice the cost for rubber versus sand.
##RVT1048
Thank you! Wish I had a means to chop our used tires and add the bits to our driveway. We can get 21 tons of gravel delivered and spread for $600.
I hope these tests and uses work out – imagine the incredible amount of tires laying in back lots all over the U.S. if not the world! Think plastic or flexible roads which could flex with xthr extremes rather than explode into pot holes! How great would that be? Test on please.
Texas tried using recycled tires for interstate 40 many years ago. Did not work out.
Definitely a huge difference on the type and level of wear between an interstate and a driveway.
I seem to recall that the rubber particle size was much larger in the Texas experiment. It might be worth another go at it using the Austrailian particle size. I’m curious as to the expansion and contraction qualities of the rubberized cement due to heat. It can get as hot in Texas as it does in Austrailia.
Recycling plastic rubber glass roads to the Moon
Where the rubber meets the…rubber..
The most widespread use for crumb rubber is in rubberized running tracks. It is also the black granules kicked up by football players being tackled on artificial turf fields Finally, the rubberized asphalt mentioned by Bob Weinfort is relatively common in many locations. Combined with geotextiles as underlayment, this pavement has proved to be effective in places where concrete is impractical (eg., roads built on swelling or hydrocompacting soils in arid regions).
They just redid our school track using crumb rubber and an asphalt mixture and it still looks as good as it did when it was first done
Many uses for old tires for sure. They can be heated to very high temps in a container with no oxygen and turned into crude oil, which can be made into fuel.
They used crumbled rubber mixed with asphalt on a few roads near here. It proved to work out well.
Somebody inform ******fornia, they will make it mandatory.
Hey Billy Bob, California has been using crumb rubber as an additive to asphalt known as Rubberized Hot Mix Asphalt. And use crumb rubber and stranded rubber in Weed barrier – Vegetation Control – Minor Concrete under the miles of metal beam guard rail throughout the state. Caltrans is resting the use of Recycled Plastic in asphalt to reduce landfill plastics.
Well golly gee, who woulda thunk. Guess all our problems are solved then. Wee doggie. Jed Clampit
Sign up for your all electric RV, California style. Travel 150 miles between charges.