Shredded Tires Make Great Concrete
Engineers from the University of British Columbia are using recycled tires to create stronger concrete. The new concrete could be used to prevent cracking in everything from buildings to bridges, and it will also help further reduces the number of tires that make it into landfills.
Of the 290 million tires thrown out each year just in the U.S., more than 80 percent are reused and recycled in some way. Still, that leaves about 57 million or so tires to do many other things with, like make a new concrete.
The new concrete is a mix of cement, sand and water and .35 percent tire fibers. Now, recycled-rubber roads are not new, some asphalt roads in the U.S. have rubber crumbs from shredded tires.
Most of you will be familiar with the crumbs that replaced pea gravel on playgrounds, and cover sweaty diving athletes on athletic fields. You can even find them in mulch.
This new process uses the tire fiber, not the crumbs. Every tire, when it’s recycled, can produce 1 kg of fiber. In initial tests, the concrete has reduced cracks by more than 90 percent.
The concrete industry produces six billion cubic feet of concrete each year and the world throws away about three billion tires. If their tests check out, we could soon see concrete that is more resistant to loading, more durable, and helps keep tires out of landfills.
Facial Recognition for Pet Doors
A new DIY project was posted to Hackster by Windows. It's a Windows 10 IoT Core doggy door with pet recognition. The door includes a webcam, MinnowBoard Max (but you can use a Raspberry Pi), passive IR sensors, servo motors and open CV, or open source computer vision.
When the pet walks up to the door, it triggers the motion sensor which turns on the webcam and captures a few pictures of the animal and runs it through a classifier. So it knows which animal it is, and whether or not it belongs on the other side of that door.
You can even set up a user interface that lets you see what else has tried using the door, and if you're the micromanaging type, you can see just how frequently your animals come and go. You can even set it up to send you text-messages with photos of blocked animals with an option to override the system with a reply text.
Pipeline Pushed to Breaking Point
Last week, researchers headed to the Cornell Geotechnical Lifelines Large-Scale Testing Facility to test advanced infrastructure sensors. Developed by UC-Berkeley and the University of Cambridge, the sensors are designed to measure strain, temperature, movement and leakage. For the test, they installed the sensors along a 40-foot section of a new type of earthquake-proof pipeline designed by IPEX, and then they buried it with 80 tons of soil.
Engineers watched as the pipe experienced a simulated fault rupture while buried inside a hydraulically powered "split basin" that they filled with the soil. While testing the sensors, they also wanted to test the pipe for earthquake fault-rupture performance.
The test was the first time that the sensors had been used to monitor buried infrastructure, and gave an unprecedented look at the pipe's ability to elongate and bend while being subject to ground failure. The sensors drew interest from the municipal engineers in attendance, who need new ways to monitor underground infrastructure.
IPEX’s pipeline itself is innovative. The company uses a molecularly-oriented polyvinylchloride material that is engineered to stretch, bend and compress as it withstands extreme ground deformation.
In a separate four-joint bending test, attendees had a chance to see the pipe's ability to bend, and it is a suspenseful, if not impressive, 26 seconds.
Next, the research team will dig out the pipeline and analyze the data collected by the sensors.
This is Engineering By Design with David Mantey.