White in-situ concrete as an ode to rich Chinese paper tradition

China Xuan Paper Town is a groundbreaking project in China's Anhui Province. This new "paper town" pays homage to China's centuries-old paper tradition, was designed by the China Academy of Art and built by the Xuancheng Municipal Construction Group. At the heart of the project is the China Red Star Xuan Paper Plant. The construction made full use of on-site poured white fair-faced concrete based on Aalborg white cement.

What makes this location unique is the combination of various functions such as production, exhibition space, sales, accommodation, research, tourism and more, all centered around Xuan paper culture.

The architecture and landscape on the banks of the Wuxi River are seamlessly integrated into the design, which in turn is dominated by white concrete in the form of giant paper sheets. This creates a painter-like "paper" mountain landscape that exudes the unique charm of Red Star Xuan Paper. The design elements emphasize the texture of Xuan paper: large white areas in a spatial and minimalist artistic concept. Numerous paths and the continuous slope design enhance the unique charm of the Paper Mountain journey, allowing visitors to enjoy an authentic touring experience while moving among the white concrete slabs.

It is situated on the water, surrounded by mountains and often shrouded in mist, which adds to its ethereal atmosphere. On a sunny day, the reflection of the main structure in the water is simply stunning. The use of closely spaced façade panels, combined with the reflection of sunlight on the concrete surface, creates an ever-changing play of light and shadow that brings the building to life.

The project and the main structure build on the centuries-old Chinese paper tradition in a contemporary manner. The concrete surfaces reference the unique texture of handmade Xuan paper and the skill and dedication of the artisans. The beauty and durability of the concrete allude to the charm of Xuan paper, with a lifespan of more than a thousand years. The use of white concrete perfectly represents the white and non-fading characteristics of Xuan paper.

Four different experience zones were worked around, each with a unique theme. The first zone, the "Cave," invites visitors to step inside a mountain cave, which leads to a series of interlocking paper "cavities. The second zone, the 'Sheet of Paper,' showcases the paper-making process on a large, curved ramp that integrates the various stages of production into an open space. The third zone, 'One Field,' combines the typical terraced landscape with traditional handmade paper-making techniques into an immersive experience. Visitors here can not only observe the production process but also actively participate in it. Finally, there is the "One Hall" zone, dedicated to the sale of the famous, handmade Xuan paper. Together, these four zones offer a comprehensive and immersive journey through the region's rich cultural heritage.

The design is quite complex, with numerous variations in floor plan, heights and volumes to optimize land use while maintaining the original topography. Three interconnected buildings with a total area of nearly 11,000 m2 were constructed of huge frames of thin walls and slender concrete beams, with large spans forming the roof. The roof structure has a maximum span of 36 m and consists of a continuous curved surface, where no two concrete beams are identical. The main structure is made of on-site poured white exposed concrete, with approximately 70,000 m2 of visible concrete surface, meeting the most stringent standards for material storage, production and transportation. Dimensioning had to be very precise, with allowable tolerances of only 3 mm for verticality, 2 mm for flatness and 2 mm for formwork joints. Due to its many architectural and constructional highlights, the project was awarded the "Da Vinci" Gold Award at the Florence Art Biennale in Italy. 

Modern architecture used on-site poured white concrete based on white cement from Aalborg. In this technology, freshly mixed concrete is poured into the formwork on site to create the final shape. The formwork is removed after a few days, after which the concrete structure is essentially finished. This one-time pouring and shuttering process results in a smooth and bright white decorative surface. The textured surface mimics the formwork with its grain, joints and clamping holes, creating a surface that shows off the essential beauty of concrete. White exposed concrete is considered one of the most sophisticated and honest expressions of concrete, with a highly tactile appearance. It also gives a natural feeling of robustness and elegance that cannot be achieved with other building materials.

The construction process required a unique formwork system because of the complex structure. The construction team devised innovative ways to prevent leaks or uneven formwork joints. They used high-quality materials such as surface-impregnated formwork sheets, resistant wood to stiffen the formwork, steel tubes as back ribs and patented bolts and plugs. A special spacer for the white mortar was also developed to ensure that the reinforcing steel is correctly fixed in the formwork without discoloring the white concrete surface. To prevent corrosion of the rebar, the twisted wire nodes were pointed inward. After stripping, the team made every effort to protect the surface from damage or contamination, preserving the quality of the concrete and reducing the need for post-processing.

5D BIM technology was applied to preventively detect possible errors and optimize construction processes. Diagrams were created for all formwork and clamping holes so that construction progress was orderly and extra work was avoided afterwards. Structures with thin beams and large spans were monitored and controlled in real time to ensure safety. This was done by monitoring the deformation of the concrete. Twelve measuring points were set up at selected locations and monitored 24/7 for six months.

Construction of the "Paper Mountain" project was a huge challenge because of its complicated structure and many constraints on scale, appearance and style. During the construction process, the construction team did not overlook the intended essence of the building. The perseverance of the construction team members embodies a spirit of unsurpassed craftsmanship with unwavering focus on quality and respect. After three years of hard and painstaking work, the designers, construction teams, owners and suppliers succeeded in shaping the initial design intent, with scrolls stacked into mountains, suspended surfaces like fog and a floating platform like water.