& UHPC DESIGN
& UHPC DESIGN
A team of designers, material scientists, industrial chemists, master craftsmen, digital fabricators, and innovative explorers.
A design-based fabrication company, specializing in concrete and ultra high performance concrete (UHP C), with over 25 years of complex casting experience and architectural design. Fine Concrete is one of a select group of firms in the United States holding a sub-license to design and fabricate with Ductal®.
This innovative material produces concrete elements that are up to 10 times stronger than conventional concrete. The UHP C possesses unprecedented flexural strength, allowing for finer, thinner, lighter and more elegant designs. The chemistry is cutting edge while still embracing the natural qualities of concrete.
The studio is focused on landscape elements, furniture and architectural spaces through the design and fabrication of custom commissions. The design practice is engaged in construction and fabrication projects for residential, institutional and commercial applications – from urban site furniture to surfaces and screen walls - from bathtubs and sinks to fireplaces to tables - from corporate and institutional interiors to exterior building elements.
Fine Concrete is a visionary design studio harnessing the potential of Ductal®, a patented Ultra High Performance Concrete, exploring new technologies in fabrication for production oriented architectural elements and urban furniture.
Bloomingdale Trail - A 3-mile urban intervention on a previously abandoned elevated railway line in Chicago connects through diverse cultural neighborhoods. Designed by Michael Van Valkenburgh and Associates and working with Landscape Forms, Fine Concrete fabricated a series of ultra high performance concrete benches whose differing types combined to create spaces for inhabitation - vibrant gathering places and contemplative retreats from the city.
Designed in collaboration with the Office of the Vice President for Research, at the University of Virginia, we fabricated a series of interlocking and rolling tables and bases that could programmatically adapt to a wide variety of uses. combining metal as formwork, and revealing the formwork as surface we produced a new material where process and product are indistinguishable.
Ultra High Performance Concrete building elements were selected as the solution for unprecedented spans in a high rise mixed-use development in Washington D.C. Thin elements with long structural spans were achieved using no internal structural support. This resulted in durability never before achieved in similar building elements, as the freeze-thaw process is not a concern of UHPC. With a custom integral color and design matrix, we cast sills and lintels using the technologies best adapted for repetitive casting.
Designed as a three dimensional puzzle with Studio Twenty Seven Architecture, concrete surfaces were imaged as a ribbon wrapping and revealing custom bamboo cabinets. The resulting elements were modern sculptural pieces complementing the overall aesthetic of the renovated townhouse.
Working with the high profile design firm, Bushman Dreyfus, we designed a floating stair for an avant garde and creative theater lobby. The elegant simplicity of the design took advantage of the performance characteristics of Ultra High Performance Concrete. The combination of high traffic needs dictating superior durability and the floating quality of the stairways was only possible with this proprietary concrete formulation.
The landscape of Virginia is populated with Vineyards and Tasting rooms. Working from a master plan by Francois Goffinet and a design by Pete O’Shea, O'Shea + Wilson Siteworks, the water troughs and transverse connections were envisioned as soothing elements encountered in the landscape. Large molds were fabricated then the precast troughs were moved to the site, connecting existing hydraulic systems and inventing new possibilities for interaction.
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We are collaborators
We are a group of designers, trained as architects with over 25 years of experience in the field. We approach every project as a creative endeavor.
Our reverse-funnel thinking allows us to explore perspectives and influences before detailing the best design and process for a specific project.
Our focus is on site-specific and user-oriented products and systems.
We have an award winning portfolio and international recognition as insightful, sensitive and tactile designers of unique forms and spaces.
We are research oriented
As material experts, working exclusively in precast concrete and Ultra High Performance Concrete, we begin our design thinking with the material, and design to its inherent characteristics.
We have developed several mix designs over our many years of casting and have proprietary formulas tested and engineered for differing applications. This approach produces the most efficient and aesthetically coherent designs.
We encourage early collaboration on a client’s design to fully tap this insight. We can start with a client’s initial concept, or fully developed drawings and specifications.
We are visionary
Experienced in design, construction, fabrication and installation. One of our primary assets is our knowledge of complex forms and unique design strategies.
We have the ability to think through a design from concept to occupation. We do this with a real-world approach and emphasis on efficiency, sustainability, and durability.
We have a team of structural engineers with a hands-on knowledge of the latest concrete material advances to take best advantage of material performance capabilities. We engineer each piece for the project requirements and for an unprecedented life expectancy.
We are experienced
Scheduling and budget are important dimensions of each project. We deliver high quality elements on time and within budget.
• estimating with 60 day quote commitments
• analysis of weights and dimensions
• strategizing on options of fabrication technologies
• collaboration with structural engineer team
• production of detailed shop drawings for fabrication
• coordination of assembly of all components
• scheduling of shop fabrication to meet deadlines
• work with subcontractors to ensure smooth delivery
• install or coordinate install logistics
We are complex mold makers, fabricating wood or fiberglass molds by hand or with a CNC router. For high production line pieces, we fabricate welded steel molds or cast high-density rubber master molds. We are artists and craftsman in the shop or on the computer. For prototyping designs, we can produce 3-D prints of 3 dimensional pieces or one-to-one scale models in steel, wood or high-density foam.
We have a specialized palette of integral pigments that are cast within the concrete. We have an extensive library of custom color samples keyed to formulas for repetitive and precise fabrication. All pigments are color-fast to withstand environmental conditions.
Our proprietary casting method is precisely followed during the mixing and pouring sequence. Depending on the mix design and integral color, we batch and test to assure consistency and performance capabilities.
We have a craftsman’s eye for fine finish. The degree of polish depends on the application or needs of the project. Diamond-impregnated wet polishing systems achieve a super smooth finish and sandblasting yields differing surface textures. Glass or other aggregates are honed, metals or other materials are inlaid, or we emboss the surface of the concrete with intricate detail. Sealers are formulated for durability.
The studio, Fine Concrete, is focused on landscape elements, furniture and architectural spaces through the design and fabrication of custom commissions. The design practice is engaged in construction and fabrication projects for residential, institutional and commercial applications – from urban site furniture to surfaces and screen walls - from bathtubs and sinks to fireplaces to tables - from corporate and institutional interiors to exterior building elements. Fine Concrete is a leader in the cutting edge design and material science aspects of concrete exploring the new technologies available to fabrication for production oriented architectural elements and urban furniture. Whatever the scale, the studio designs objects that are sensuous and seductive, transforming raw materials in unexpected ways, combining the uniqueness of the handmade with the precision of new technologies.
Alexander Kitchin: A leading designer in fine concrete with over 20 years of research and fabrication in the material, Alexander Kitchin received his undergraduate degree from the University of Virginia and his master’s degree from Southern California Institute of Architecture (SCI-Arc). While practicing in architecture firms in Charlottesville and teaching at the University of Virginia in the late 90’s, Alexander won the prestigious Rome Prize and spent a year in Italy as a Fellow in Architecture at the American Academy in Rome. He also received a Graham Foundation grant for his investigation into design and research in concrete. After returning to Charlottesville, he founded a design studio, translating his research into the investigation of the timeless and intimate relationships between materials, spaces and people. Alexander has taught design studios at the University of Michigan and the University of Pennsylvania focusing on community design and build projects and fabrication and design of urban spaces. He has also taught photography at the University of Virginia and his photographic work on intuitive spaces, elbwrm, is part of a larger body of work, "Apparitons". Currently adjunct faculty at the University of Virginia School of Architecture, Alexander teaches a design process that investigates the character inherent in materials and how the process of making informs the spaces we design. His studios are part of the Design Thinking Concentration with an emphasis on community engagement and on the skills inherent in the architect's critical thinking approach. His research includes a hands-on approach to architecture through the active fabrication shop. He has taught, visited and lectured at schools across the country and abroad in architectural design, fabrication, theory, and photography. As the design partner interested in all aspects of the process, Alexander brings to the firm years of experience in architecture and design as well as the fabrication knowledge that translates the intentions into the realities of the way we create with material.
Nicole Sherman: Nicole brings a diverse background to her design work. She graduated from the Elliott School of International Affairs at George Washington University with a degree in Russian and Eastern European Studies and an intensive focus on the Russian Language at Columbia University’s Language Institute. After a legislative appointment with Save the Children in Washington, Nicole joined the Clyde's Corporation as Catering Director for the 1789 Restaurants which followed with a position in Texas as Catering and Marketing Manager at the newly opened Hotel Crescent Court. After the successful launch of that property, Nicole returned to her intention of law school and international law and was hired by Fulbright and Jaworski as Senior Litigation Assistant. Law school at University of Houston was put on hold with a family move to Charlottesville in 1994 – where she shifted her emphasis to her creative passions. A daughter of an award-winning architect, she and her husband, Bill Sherman, founded William Sherman and Associates. While he was a full time faculty at the University of Virginia School of Architecture, Nicole assisted with the operation and financial dealings of the ten-person architecture firm. During this time, she also founded Softhardwear, a jewelry design company focusing on found and recycled hardware. Nicole added another line of jewelry a few years later, NicoleNoelle; it was this jewelry that formed the basis of her first internationally marketed book on jewelry design. Two years later, her second book on design returned back to the company’s origins and her love of hardware. Her jewelry has exhibited and is shown in numerous galleries and stores on the eastern seaboard. In 2008, Nicole joined Alexander and established a partnership, Fine Concrete, specializing in custom casting and production lines for the urban landscape. An expert in UHPC fabrication and experienced in design, project management and implementation, she brings a unique mix of talents to the provenance of concepts, their development and their realization.
Fine Concrete, LLC is one of a select group of firms in the United States holding a sub-license to design and fabricate with Ductal®, an ULTRA HIGH PERFORMANCE CONCRETE.
This innovative material produces concrete elements that are up to 10 times stronger than conventional concrete. The UHPC possesses unprecedented flexural strength, allowing for finer, thinner, lighter and more elegant designs. The chemistry is cutting edge while still embracing the natural qualities of concrete.
DUCTAL® is fiber-reinforced and has tensile strength, unlike conventional concrete. It achieves this engineering feat by progressively absorbing the energy applied and efficiently dispersing it throughout the matrix. These mechanical properties make it possible to create very slender structures with little or no passive steel reinforcement.
DUCTAL® is self-consolidating with microfine aggregates that make it extremely dense with less porosity, offering resistance to scratching and staining. This super fine design matrix also produces a surface capable of intricate detail with unlimited surface textures, finishes and colors.
DUCTAL® is a sustainable material that uses less energy to manufacture and substantially less water in the fabrication of the elements. There is no off-gassing. Ductal® offers many LEED certification credits.
DUCTAL® owes its innovative character to its exceptional mechanical performance, in particular its resistance to compression and bending, its creep and shrinkage behavior, and its fire-resistance.
The table below indicates the material’s general performance values which are obtained in the test procedures specified in the UHPC recommendations.
Ductal® exhibits excellent performance in compressions: It is 4 to 8 times higher than conventional concretes. Compression behavior is almost linear elastic up to the maximum stress and exhibits no damage to the material during this phase. Stress curve – deformation for a sample of Ductal® with metallic fibers.
Shrinkage and creep are probably the most remarkable properties of Ductal®. Creep tests have been carried out in France at the Ecole Centrale de Nantes and at the Laboratoire Central des Ponts et Chaussées (LCPC) and in the United States at the Federal Highway Administration (FHWA) Research Center in McLean, Virginia, USA.
For ordinary concrete, the creep coefficient can reach 3-4; for high-performance concrete, this is reduced but the recorded deformation remains higher than the elastic deformation. The creep coefficient of Ductal® is less than 0.8, and if a heat treatment is applied, the creep factor is less than 0.2, as shown in the figure below. As a rule, a value of 0.3 is considered for calculations.
Since the water to cement ratio is very low, Ductal® does not exhibit drying shrinkage. An endogenous shrinkage is observed (300 to 400 μm/m), but when heat treatment is applied, shrinkage is complete by the end of the treatment and there is no subsequent residual shrinkage, as shown in the figure below.
Ductal® with metallic fibers contains 2% by volume of metallic fibers, or more than 50 million metallic fibers per cubic meter. The fibers give the material a ductile behavior during bending (i.e., when loaded in flexure behond the elastic limit, micro-cracks occur and the fibers hold the cracks tightly closed, providing a ductile performance rather than a sudden or brittle failure) as shown in the following graph.
The ductility behavior observed during bending is characterized by a multiple cracks before the stress peaks, without localization and without the presence of any major cracks.
Fatigue tests on pre-loaded test samples were carried out at the CSTB. The loading applied was between 10 and 90% of the elastic limit. The figure below shows a crack opening displacement curve in relation to the number of cycles. Note: There is no increase in the crack opening, i.e. no crack propagation, at 1.2 million cycles.
Analysis of the rate of increase of the deflection in relation to the number of cycles shows that the loading applied is below the material’s threshold of endurance. When calculating the design of structures subjected to fatigue action-effects, the service stress is limited to the material’s resistance to direct tension. The results presented above verify that the application of the UHPC rule is particularly reliable in the case of Ductal® products with metallic fibers.
Ductal® materials are classed as “M0” (non-flammable). A specific formulation, Ductal®-AF has been developed for improved fire resistance. This formulation uses metallic fibers, to which organic fibers are added. ISO 834 fire-resistance tests on loaded and non-loaded columns and beams have been carried out at the Centre Scientifique et Technique du Bâtiment (CSTB – Marne-La-Vallée) and at VTT in Finland. These tests have demonstrated the material’s excellent resistance and near total absence of spalling. The photo below shows a column before and after the ISO fire test.
Material properties at high temperatures
The characterization of Ductal® at high temperatures was carried out at CSTB in Grenoble, at SFC in France, at the University of Braunschweig in Germany, at the Politecnico di Milano in Italy, and at Imperial College London in the UK. A summary of the results is given below.
Evolution of the resistance under compression according to temperature
Compressive tests at high temperatures were carried out on test samples of Ductal®. Some of the tests were carried out on samples after cooling having been maintained at a given temperature T: so-called ‘residual’ tests. Some of the test samples were tested at the constant temperature T: so-called ‘hot’ tests.The figure below shows all the results. We can see that the results obtained are almost all higher than the “DTU Feu” (French fire safety standard) curve specified for HPCs (extension of the “DTU Feu” for HPCs between 60 and 80 MPa).This standard DTU curve can therefore be used for calculating the fire resistance of structures in Ductal®.