Jon Belkowitz experiments with nanoscale additives to concrete. |
Every
day, concrete structures crack and erode prematurely due to Alkali
Silica Reactivity (ASR), a chemical reaction that causes fissures in the
material as it sets. Jon Belkowitz, a doctoral student at Stevens
Institute of Technology, plans to put an end to this problem through his
study of chemical reactions within concrete at the nanoscale. Taking
advantage of Stevens nanostructure characterization tools and materials,
his research into the optimal use of nano silica will create a new
concrete mixture that will result in longer-lasting buildings, roadways,
sidewalks, stairs, sewers, and dams.
“With
the advent of nanotechnology, the material properties of concrete,
including ASR mitigation, allows engineers and architects the ability to
use concrete in applications that were once impossible,” John says.
Optimizing concrete
On
the most basic level, concrete is a mixture of finely-powdered cement,
rock aggregate, and water. A reaction between the cement and water
yields calcium silicate hydrate, which gives concrete its strength, as
well as ASR gel. The ASR gel forms at the interface of the alkaline
cement and the non-crystalline silica found in the aggregate. As the
concrete hardens, the ASR gel expands, causing residual stresses that
weaken the concrete and cause it to deteriorate. As pressure builds at
the interface, the concrete starts to crack and crumble from within,
over a period spanning days to years.
“Using
nanostructure characterization tools, we are now able to understand the
many mysteries of concrete, for example, that there are three types of
water in hydrated concrete, and those three different types of water
have three different types of molecular movements, which means three
different forces,” John says. The more you know about concrete, he
notes, the more complex it becomes. He hopes his research will uncover
new methods of increasing the mechanical properties of concrete.
Jon’s
research takes a three-tiered approach: “I’m using this new
nanotechnology to not only stop ASR from being produced, but I’m also
using nano silica to strengthen the hydrated cement matrix of concrete
to resist the expansive nature of the ASR gel,” Jon explains. “I’m also
trying to change the properties of the excess water within the concrete
so that it can’t react with soluble alkalines in silica to cause ASR
gel.”
Despite
the material’s ubiquity, the reactions within concrete as it dries and
strengthens are difficult to control. “This is an ongoing problem in the
concrete industry,” Jon says. “In the past we really had no way to
understand the development of the crystallgraphic grains of the concrete
matrix. We could set up models, or use other minerals to compare to
Calcium Silica Hydrate. We don’t create the same structure every single
time. Through the use of nanostructure characterization tools, we now
have the ability to gain a better understanding of the hydrated cement
matrix that makes up concrete.”
Jon’s research is being conducted in the Nanomechanics and Nanomaterials Laboratory
under the guidance of Dr. Frank Fisher, Associate Professor of
Mechanical Engineering and Co-Director of the Nanotechnology Graduate
Program. Though Jon hopes to apply his research in civil engineering
applications, his work is multidisciplinary, combining solid-state
physics, mechanical engineering, polymer synthesis, and chemical
engineering.
Jon’s
research is funded by New Jersey Alliance for Engineering Education
(NJAEE), through the National Science Foundation (NSF) Graduate Teaching
Fellows in K-12 (GK-12) Program. He works in a local high school in
Bayonne, New Jersey ten hours a week as part of the program, and says he
enjoys the opportunity to share his passion with students. “It’s
exciting to open up their minds to new possibilities,” Jon says. “They
eat it up.”
A “concrete geek”
Jon
comes to Stevens with 15 years of concrete experience: 10 years in the
United States Air Force placing concrete on civil engineering projects
around the world, and 5 years at concrete manufacturing giant LaFarge,
where he designed new types of concrete in a lab and translated these
into products with real-world applications. Jon graduated with
distinction from Colorado School of Mines with a Bachelor of Science
degree in Civil Engineering and the University of Denver with a Master
of Science degree in Materials Science. Currently he owns Intelligent Concrete, LLC, which is dedicated to concrete research, development, and education.
This
wide-ranging experience allows him to converse equally well with
scientists, business, and laypeople. It also gives him a realistic
approach. “One of the hardest things to do in the concrete industry — or
in any industry — is to take lab data and translate it into commercial
industry,” Jon says. “In the lab you have nearly perfect conditions. In
the real world, it’s messy.” His concrete knowledge has already yielded
results. In 2008, his Chronolia Road Patch Design received the
“Innovation of the Year Award” from the American Concrete Institute –
Rocky Mountain Chapter.
Jon
has made a life for himself out of concrete, but would not have it any
other way. “I’m a concrete geek at heart,” he says. In fact, it is
something of a “family business,” Jon quips. Jon’s father works in
marketing for a concrete company, and his wife is pursuing her
undergraduate degree in Engineering at Stevens, looking to specialize in
concrete.
As
he looks to the future, Jon is confident that his work at Stevens
studying the smallest reactions within concrete will yield big rewards
in the future.
