When it comes to 3D printing, the sky is the limit. As 3D printing technology continues to advance, applications can be as far reaching as airplane and automobile parts to medical devices and even anatomically correct, biocompatible models. Although 3D printing technology is developing at a rapid pace, the technology itself is not new. It emerged in the 1980s as a means of creating rapid prototypes. In recent years the applications for 3D printed models have evolved with the available hardware, software, and printable materials. Evolving technology, paired with the creative and innovative minds of scientists, engineers, and physicians, has been the launching pad for developments within 3D printing technology specific to healthcare. One way 3D printing technology is poised to create better patient outcomes is in creating an anatomically and patient-specific models to aid in surgery and medical procedures. With the capability to 3D ...
Can polymers increase road safety by improving road pavement?
Apparently yes, as was observed over the course of a year on Interstate 380 in Iowa. A .3-mile-long 6-lane S-curve in Cedar Rapids was coated with High Friction Surface Treatment, a type of Polyester Polymer Concrete resin. Erin Jordan reports in The Gazette:
The High-Friction Surface Treatment applied in May and June 2012 added a layer of polymer concrete topped with sharp aggregate to increase friction between cars’ tires and the road. That friction helps cars avoid slipping on the curvy stretch. From June 13, 2012, to June 12, 2013, there were four crashes and one injury on the .3-mile stretch of I-380, compared to an average 10.8 crashes and 5.6 injuries in each of the previous five years, the Iowa Department of Transportation (DOT) reported.
The High Friction Surface Treatment resin, produced by KwikBond Polymers of California, has impressive physical characteristics: 900-1,400 cps viscosity, 2,500 psi tensile strength, 5,000 psi compressive strength, >30% tensile elongation, and high UV stability, and it can be cured in temperatures below freezing and is durable through extreme temperature cycles. It has been in use since 1983, along with the original Polyester Polymer Concrete.
Traditional concrete is of mix of cement, coarse aggregate, sand, and water. Polyester Polymer Concrete is a mixture of polyester resin and aggregate. It was developed due to interest among Caltrans (California Department of Transportation) engineers, as described by Kwikbond Polymers:
The Department first became interested in polymer resins in 1979 due to the superior adhesion properties and rapid return to service. The first full scale overlays of Polyester Polymer Concrete (PPC) were demonstrated in 1983 in Northern California. Those bridges are still performing and Caltrans inspection reports from 2010 rate them as ‘element level one,’ the highest rating available – a nearly 30 year proven system! Today, PPC is specified by cities, counties and states all over the United States with increasing interest overseas.
Polyester Polymer Concrete is used in 26 states already. It has compressive strength of 7,000 psi (the compressive strength required for opening to traffic is 2,500 psi) and tensile strength of 800 psi, and it exceeds the abrasive resistance of concrete 8 to 10 times. PPC is often used in conjunction with High Molecular Weight Methacrylate (HMWM) Healer Sealer, which can cure in 2 hours, even in cold or humid conditions. The sealer penetrates into concrete surfaces through very low viscosity, then polymerizes in concrete to form a tough plastic seal. Designed to fill and rebond cracks, it is also used as a primer to promote adhesion of the overlay of PPC to the existing concrete.
Polymer concrete products are most popular for bridges and have been used in the construction of Route 35 over Shark River Bridge, Belmar, N.J.; Eagle Creek Viaduct, Cascade Locks, Ore.; U.S. 101 Conde McCullough Memorial Bridge in Coos Bay, Ore.; and the I-205 George Abernethy Bridge in Portland, Ore. Most recently polymer concrete was used in the Skyway segment of San Francisco Oakland Bay Bridge in California, which carries 300,000 vehicles per day. The safer the pavement, the better!
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