We're a small but mighty team of concrete consultants.

At Minnesota-based Beton Consulting Engineers, LLC, we know concrete at a
molecular level. This isn’t just a cute tagline. We approach concrete from a
chemical, materials, and structural engineering perspective and have worked on
projects all over the world.

How the Beton team works

Our team members have diverse viewpoints, knowledge and skill sets that we often combine to solve client problems. We believe our collaborative approach results in unique, productive solutions. As our client, you’ll receive thoughtful, fresh ideas based on science, intuition and years of experience. We welcome your thoughts and experience into our brainstorming process, too. Combined, our team members lead and serve on 25 American Concrete Institute (ACI) committees and subcommittees. ACI is the leading authority and resource for developing concrete specification standards. Also, we are LEED accredited as well as professionally licensed in 15 states. Let us analyze, diagnose, explain, predict, and design
your concrete.

Kevin MacDonald, President & Principal Engineer

PE in Minnesota and P.Eng. in Ontario and Alberta, Canada.

Kevin is Beton’s founder and president. He is a Fellow of the American
Concrete Institute (ACI) and a member of ASTM, ASCE, the Concrete Society
and Professional Engineers Ontario.

His commitment to ACI includes a role as the past chair of the 132-Responsibility in Concrete Construction
and chair of of subcommittee 130-0B-Production/Transport/Construction and
302 Construction of Concrete Floors. Further, he is a member of ACI
committees 211-Proportioning Concrete Mixtures, 212-Chemical Admixtures,
223-Shrinkage-Compensating Concrete, and 232-Fly Ash in Concrete and 318
sub A.

In addition to his concrete consulting work, Kevin is an assistant
professor at the University of Wisconsin-Stout in the construction
management program where he teaches courses in concrete, reinforced
concrete design and heavy construction. He brings considerable experience
in field and lab concrete, quality control and problem-solving to his
students and clients.

He earned a B.S. in Chemical Engineering as well as a Master’s and PhD in
Engineering Materials from the University of Windsor in Ontario. Quality
of concrete remains one of Kevin’s interests. He is heavily involved in
ACI certification with the Aggregate and Ready Mixed Concrete Association
of Minnesota.

Email him at

Mary Vancura, Principal Engineer

PE in California, Florida, Idaho, Iowa, Massachusetts, Michigan,
Minnesota, New Jersey, North Carolina, Ohio, Oklahoma, South Carolina,
Tennessee, Texas, Virginia, Washington, Washington, D.C. and Wisconsin.

Mary is a principal at Beton, and a civil engineer with experience in
structural engineering, municipal engineering, construction inspection,
construction project management, and concrete testing.

She has worked for more than 10 years learning how chemistry and chemical
engineering principles are essential to understanding how concrete works
and why it fails. Her expertise is in developing thermal control plans,
failure analysis, durability testing, and life cycle modeling. She is also
adept in using statistical analysis to evaluate the efficacy of
construction quality control and quality assurance testing.

Mary is involved with ACI as a voting member of committee 207-Mass Concrete,
subcommittee 117-0N-Tolerance Data, and committee 548-Polymers and Adhesives
for Concrete.

She earned a B.S. in Civil Engineering from Gonzaga University, and a
Masters and Ph.D. in Civil Engineering from the University of Minnesota.
Vancura also has an MBA from Augsburg College, Minneapolis. Email her at

Rachel Detwiler, Principal Engineer

P.E. in Minnesota

Rachel is a civil engineer and a fellow of the American Concrete Institute.
She teaches technical writing at the
University of St. Thomas in St. Paul, MN, as well as writing the blogs for our website. With more than 35 years’
experience, she is an expert in concrete testing, construction
troubleshooting, and failure analysis.

Rachel designed and directed a multi-laboratory test program that became the
basis for changing the relevant ASTM standards to allow 4 inch x 8 inch
cylinders to be used on an equal basis with 6 inch x 12 inch cylinders for
concrete acceptance testing. She has investigated numerous construction defects and concrete failures,
developing practical solutions for her clients. She has also served as
an expert witness in concrete-related lawsuits.

Rachel is a member of the following ACI committees: 201-Durability of Concrete, 214-Evaluation of
Results of Tests Used to Determine the Strength of Concrete, and 234-Silica
Fume in Concrete. She serves on the organizing committee for the University of Minnesota’s annual Concrete Conference.

Rachel holds a B.S. in Civil Engineering, an M.S. in
Structural Engineering, and a PhD in Civil Engineering Materials from the
University of California at Berkeley. She was also a postdoctoral fellow at
Institute for Building Materials at the Norwegian University of Science and Technology in
Trondheim, Norway. Email her at

Mark Lukkarila, Principle Petrographer and Materials Scientist

B.A. in Earth Science

Mark has technical expertise in the cement, concrete, masonry, and aggregate
industries. He is a fellow of the American Concrete Institute and has
extensive knowledge of cementitious systems, cement and hydration chemistry,
gained over more than 30 years of experience. He has performed petrographic
examinations of concrete, aggregates, and masonry as well as petrographic
examination of historic mortars and concrete. He also has extensive
experience with mixture proportioning of shotcrete dry pre-blended mixes.

Mark’s gone out to big projects like the Beacon Hill tunnel in Seattle, and
the San Vicente Tunnel in San Diego for troubleshooting and has worked as
a research laboratory manager and technical services director in the cement
industry, where he became adept at interpreting process conditions through
the use of clinker microscopy techniques.

Mark also has extensive experience with new product development and troubleshooting product performance as well
as process related issues. His participation in ACI includes: Chair of
E701-Materials for Concrete Construction and Chair of 524-Plastering. He is
a voting member of 221-Aggregates, 225-Hydraulic Cements, 240-Pozzolans,
506-Shotcreting, C621-Cement Tester Certification, and E710-ACI University
Programs. Mark also is very active in ASTM and is past-chair of subcommittee
C09.46 on shotcrete, and is task group chair for C294 and C295; both relate
to concrete aggregates. He’s an examiner and educator for
ACI’s shotcrete nozzleman certification program. Mark received a B.S in Earth Science from the University of Minnesota
Duluth. Email him at mlukkarila@betonconsultingeng.com.

Julie Buffenbarger

LEED AP BD+C, Senior Scientist and Sustainability Principal

Julie is a Fellow of the American Concrete Institute (ACI). She is the chair
of 130-Sustainability of Concrete, and a member of 232-Fly Ash in Concrete,
132-Responsibility in Concrete Construction, and 234-Silica Fume in
Concrete. She has more than 25 years’ experience in the concrete industry,
including 10 years doing product development with a large, international
admixture company and 12 years troubleshooting for a cementitious materials,
concrete, and aggregate manufacturer.

Julie has promoted sustainable materials and construction practices with designers, contractors, and agency
officials. She actively promotes the use of concrete products in building,
road and energy markets. Julie’s expertise is in sustainability (LCA, LCC,
and EPDs) and innovative implementation of sustainable and resilient
construction practices; admixture chemistry, cementitious materials,
concrete product development, troubleshooting concrete product performance,
and concrete durability modeling and testing. She is proficient in multiple
building and infrastructure sustainable rating systems. She earned a B.S. in
Chemistry and M.S. in Organic Chemistry from Bowling Green State University,
Bowling Green, Ohio. Email her at

Brad Ahrens

Senior Lab and Field Technician

Brad Ahrens has more than 20 years’ experience in concrete lab and field
testing, quality control, and inspection. Brad has worked onsite management
and troubleshooting for ready-mix concrete production on many paving,
commercial building, and residential high-rise projects as well as major
bridges including Wakota, Hastings High, Lowry Avenue, and I-35W Saint
Anthony Falls. Ahrens’ MnDOT certifications include aggregate and base,
Concrete Field Tech 1, Ready Mix Plant 1 and 2, cylinder compression
strength, grading and base, and MPCA SWPPP training.

At Beton, Ahrens manages lab equipment and durability concrete testing, assists with
cementitious product development, acts as Beton’s liaison to ready-mix companies,
and assesses concrete failures. He formerly worked for Braun Intertec,
Cemstone, Professional Engineering Services, and Kimley Horn. Email him at

Sara Shuga

Junior engineer

Sara Shuga received her B.S. in Civil Engineering from Michigan
Technological University. She began her career as a civil design engineer in
Chicago and the Twin Cities prior to moving to Denver, CO, where she was a
Development Review Engineer for Jefferson County. Upon her return to the
Twin Cities, she taught math and was the Environmental Health and Safety
Coordinator at a private university.  In 2014, she joined a ready-mix
company as a materials engineer where she reviewed project specifications,
designed concrete mixtures and analyzed data in order to improve quality and
service. Email her at

Christine Snider

Project manager

Christine has a background in education, program coordination and volunteer
management.  Her most recent career was as a program coordinator in youth
sports, where she organized over 3,000 youth athletes and 1,000 volunteers.
During her three years at the organization, she put into place systems and
efficiencies which enabled the organization to double in size and put them
on a path for future exponential growth.  In 2020 Christine won a national
award with The Aspen Institute Project Play for designing, implementing and
enforcing a system enabling recreational youth sports organizations to be in
compliance with the federal SafeSport law. She is coordinating Beton’s
effort to become CCRL certified and testing in Beton’s labs.  Email her at

Lori MacDonald

Office manager

Lori has a background in banking, education, and organizational management.
She is Beton’s primary contact for payroll, accounting, human resources,
procurement, professional liability insurance and general inquiries. Email
her at betonadmin@betonconsultingeng.com.

Photo credits: Nick Lentz, Lentz Photography
Renee McGivern, Spark Plug Consulting