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

Photo of engineer Kevin MacDonaldPE 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. He also is a member of the ASTM Committee, ASCE and Professional Engineers Ontario.

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.

In addition to his degrees, Kevin has gained considerable experience in field and lab concrete, and as the vice president of engineering and quality for a large ready mix producer. He has developed a knack of taking the most complex ideas and putting them into action.

He has been on the board of directors for the American Concrete Institute (ACI), and is the chair of 132-Responsibility in Concrete Construction and of of subcommittee 130-0B-Production/Transport/Construction. He also is a member of ACI committees 211-Proportioning Concrete Mixtures, 212-Chemical Admixtures, 223-Shrinkage-Compensating Concrete, and 232-Fly Ash in Concrete.

Kevin co-authored “Performance-Based Concrete Mixtures for Durable, Long-Life Bridges” with Julie and Mary and “Who is Watching Out for the Cylinders?” in Concrete International.

Under Kevin’s leadership, Beton makes concrete work for you. Email him at betonadmin@betonconsultingeng.com.

Mary Vancura, Principal Engineer

Photo of engineer Mary VancuraPE 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 mvancura@betonconsultingeng.com

Rachel Detwiler, Principal Engineer

Photo of engineer Rachel DetwilerP.E. in Minnesota and Illinois

Rachel is a civil engineer and a fellow of the American Concrete Institute. She also teaches technical writing and civil engineering materials at the University of St. Thomas in St. Paul, MN.

With more than 35 years’ experience, she is an expert in concrete testing, construction troubleshooting, and failure analysis. She designed and directed a multilaboratory 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 also has been called 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.

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 Institute of Technology in Trondheim, Norway. Email her at rdetwiler@betonconsultingeng.com.

Mark Lukkarila, Principle Petrographer and Materials Scientist

Photo of petrographer Mark LukkarilaB.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. He’s gone out to big projects like the Beacon Hill tunnel in Seattle, and the San Vicente Tunnel in San Diego for troubleshooting.

Mark 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

Photo of senior scientist Julie BuffenbargerLEED 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 jbuffenbarger@betonconsultingeng.com.

Photo of lab and field technician Brad AhrensBrad 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 will manage lab equipment and durability concrete testing, assist with cementitious product development, be Beton’s liaison to ready-mix companies, and assess concrete failures. He formerly worked for Braun Intertec, Cemstone, Professional Engineering Services, and Kimley Horn. Email him at bahrens@betonconsultingeng.com.

Photo of civil engineering graduate Samantha Prince.Samantha Prince

B.S. in Civil Engineering

Samantha graduated from the University of Minnesota (MN) in 2019 with a degree in civil engineering with an emphasis in structures and also graduated from Doane University (NE) with a degree in physics. At the University of Minnesota, she was an ASCE officer and Concrete Canoe team captain for two years.

Samantha interned with the US Bureau of Reclamation (Denver, CO) for five years in the Concrete, Geotechnical, and Structural Laboratory Group working in the concrete laboratory. While there, she did concrete testing, aggregate preparation, concrete mixing, and assisted in research.

Sam started with Beton as an intern in 2018 and now works with us full time. She focuses on durability testing, thermal control, and the design of shrinkage compensating concrete slabs on ground. Email her at sprince@betonconsultingeng.com.

Photo of junior engineer Sara ShugaSara 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 sshuga@betonconsultingeng.com.

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 the Beton Labs.  Email her at csnider@betonconsultingeng.com.

Lori MacDonald's photo | Beton Consulting EngineersLori 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