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.

Background on Beton Consulting Engineers

Kevin MacDonald, Beton’s founder and president, has a PhD in Materials Engineering, 30 years of field and lab concrete experience, including 10 years as vice president of engineering and quality at a large urban ready-mix concrete plant. He has a knack for taking the most complex ideas and putting them into action. Under Kevin’s leadership, Beton makes concrete work for you.

Beton’s origins lie in two iconic bridges that cross the Mississippi River in the Minneapolis/St. Paul area. Trained in classical chemical engineering, Kevin developed a program to predict the heat development of concrete mixtures, as well as the temperature with respect to time due to the hydration reactions in a concrete member. He was reminded of the importance of quality control in mass concrete placements after the concrete plant substituted Type III cement for slag!

Following this blunder, Kevin spent three days and nights at the Wakota Bridge in St. Paul making sure the pumps worked in a post-installed cooling system in one of the piers. He did this to ensure that cold water circulated through massive concrete piers, limiting the core temperature in the curing concrete.

As a result of this experience, Kevin developed Beton’s mass concrete doctrine that each mass concrete placement is monitored and modeled individually to prevent failures due to error, and to monitor the incoming materials. Beton has successfully predicted temperatures in more than 800 mass concrete placements.

The push to quickly rebuild the I-35W bridge in Minneapolis after its disastrous collapse in 2007 allowed Kevin to design and implement concrete mixtures with as much as 80% replacement of cement with slag, fly ash, and silica fume. Not only were the mixtures place-able, they are extremely durable and have served as successful examples of high cement replacement mixtures.

Let us analyze, diagnose, explain, predict, and design your concrete.

Kevin MacDonald, President & Principal EngineerPhoto of Kevin MacDonald | Beton Consulting Engineers

PE in Minnesota and P.Eng. in Ontario, 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), a member of the ACI technical activities committee, and is the present and past chair of many ACI committees including Responsibility in Concrete Construction.

Under Kevin’s leadership, Beton makes concrete work for you.

Mary Vancura, Principal EngineerPhoto of Mary Vancura | Beton Consulting Engineers

PE in Florida, Iowa, 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.

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.


Rachel Detwiler, Principal EngineerPhoto of Rachel Detwiler | Beton Consulting Engineers

P.E. in Minnesota and Illinois

Rachel is a civil engineer, a fellow of the American Concrete Institute, and a member of the ACI committees on the durability of concrete and on silica fume in concrete.

With more than 30 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 allowing 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 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.

Mark Lukkarila, Principle Petrographer and Materials ScientistPhoto of Mark Lukkarila | Beton Consulting Engineers

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 nearly 30 years of experience.

He has performed petrographic examinations of concrete, aggregates, and masonry as well as petrographic examination of historic mortars and concrete.

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.

Mark received a B.S in Earth Science from the University of Minnesota Duluth and is now very active in the American Concrete Institute; he is past-chair of the ACI 221 Committee on aggregates. Mark also is very active in ASTM and is past-chair of the subcommittee C09.46 on shotcrete, and is currently the Task Group Chairman for ASTM C294 and C295; both relate to concrete aggregates.

Julie BuffenbargerPhoto of Julie Buffenbarger | Beton Consulting Engineers

LEED AP BD+C, Senior Scientist and Sustainability Principal

Julie is a Fellow of the American Concrete Institute (ACI). She is the chair of Committee 130-Sustainability of Concrete, and a member of 232- Fly Ash, 132-Responsibility in Concrete Construction, and 234-Silica Fume.

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 now 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.

Brad AhrensPhoto of Brad Ahrens | Beton Consulting Engineers

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.


Samantha PrincePhoto of Samantha Prince | Beton Consulting Engineers

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 Content 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.


Leah Cohen

Engineering intern

Leah worked as our intern in 2019 assisting with concrete batching and on-site field testing. She serves in the Minnesota Army National Guard in the nearly 700-member 34th Expeditionary Combat Aviation Brigade, which was activated on Friday, Sept. 21. The unit will be deployed in October. Cohen will eventually serve nine months in Kuwait and Iraq after some additional training in the U.S. She is studying civil engineering and plans to finish her education at Minnesota State University-Mankato upon her return.



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.





Photo credits: Nick Lentz, Lentz Photography