Concrete, the world’s most widely used construction material, has a giant target on its back and plenty of people want to take a piece of its pie. It’s cheap and strong, which has, so far held off many would-be competitors from getting popular. One of concrete’s major drawbacks and one of its most vulnerable areas is the fact that it’s extremely time consuming and difficult to demolish.
Researchers working with ETH Zurich and MIT believe they may have come up with a solution for our constantly evolving world, with a process they call “Rock Print.” The idea is simple, yet hard to believe: A 3D printer precisely places string in layers in between stone, which packs the stone into a strong and stable structure that is able to be formed into irregular shapes. When you’re done with the structure, simply wind up the string and the rocks fall to the ground. Both the string and stones can then be used elsewhere.
So, how in the world does this work? The researchers were inspired by Dr. Heinrich Jaeger, professor at Chicago University, and his principle he called the “jamming phenomenon.” In short, the phenomenon is the product of stuffing a bunch of material together, which we learned last week is kind of how concrete actually works on a molecular level.
In the video below, you’ll see members of the Rock Print team, with the help of a string placing robot, assemble a freestanding, 13 foot tall structure for an exhibit, followed by the demolition, which only involves winding up the string.
This is clearly just a start, but it’s an extremely interesting one. There’s no evidence yet that any strength testing has been completed on the process and we’re also not sure how secure a structure can be if it can be disassembled by pulling on a string, like an old wool sweater.
Full Story: "Reversible Concrete" Is Ready to Revolutionize Temporary Architecture | The Creator's Project
[Guest post] A Review of Top Wired and Wireless Temperature and Strength Concrete Sensors
The only thing slower than watching paint dry is, well, watching concrete dry. Proper curing of concrete is extremely important, though, for quality and safety reasons. Perhaps equally important is proper testing and documentation of the concrete’s strength over time. In a move to help bolster their digital portfolio, power tool giant Hilti has acquired Concrete Sensors, an internet connected concrete testing startup.
Times are weird, guys. While there are a lot of jobsites still open, there are many that have been temporarily shut down during the coronavirus pandemic. If you need some resources for how your construction company should handle the pandemic, you can check out my resource guide by clicking or tapping here, but if you want to take your mind off of that and use some of your newly found free time, you can learn about concrete on YouTube from a college professor.
Tying rebar is an extremely repetitive and strenuous job, but it’s an essential part of most concrete roads, bridges, and buildings. Typically, rodbusters use hand tools for this work on the jobsite, but my recent visit to the World of Concrete in Las Vegas made me realize how much innovation there has been in the space in the past few years.
Over the past few years, there have been many companies offering different ways of tying rebar, which can be a very strenuous and tedious task. It’s also extremely repeatable, which makes it a strong target for innovation. MAX USA has had a rebar tying gun out for a little while now, but they just showed off a new version at the World of Concrete.
As lithium-ion battery technology continues to get better and better, we can start to expect larger tools to hit the market – and that’s been the case over the past few years. Those advancements eventually lead to opening to door for tools that the world has never even seen before, like a battery powered roller screed for concrete.
The gigantic marathon of a construction trade show, the World of Concrete, has sadly come and gone already, but the winners of the annual contest for the show’s Most Innovative Products has just been announced!
While placing concrete on the 7th floor of a new hotel in Houston, TX, 16 construction workers were suddenly sent falling to the 6th floor below, sending 9 of them to the hospital, according to local news reports.
In September of 2017, OSHA’s new standard on exposure to respirable crystalline silica went into effect in the construction industry. The rule lowered the allowable exposure to the harmful substance to 50 micrograms per cubic meter, a measurement that we’re all familiar with [/sarcasm]. After a full year of enforcement, OSHA is considering making a change to the rule.
[guest post] a in-depth comparison between laboratory and field cured concrete maturity testing