> Qaammat Pavillion
Photo credit: Julien Lanoo
Photo credit: Julien Lanoo
Photo credit: Julien Lanoo
Cast glass, Glass bricks, Adhesive bonding, Glass blocks, Arctic architecture, Glass structure.
November 2020 - October 2021
Konstantin Arkitekter, appointed by Qeqqata Kommunia
Research Team (at TU Delft)
Telesilla Bristogianni, dr. Faidra Oikonomopoulou, Mariska van der Velden
Konstantin Ikonomidis (Konstantin Arkitekter), Valérie Hayez and Burak Akin Aksoy (DOW)
Beginning of November 2020, the Glass Research Group of the Faculty of Architecture and the Built Environment of the Technical University of Delft was contacted by architect Konstantin Ikonomidis with the request to provide glass expertise for a small -yet challenging- project: An adhesively-bonded glass brick pavilion that would serve as a landmark within the Aasivissuit – Nipisat UNESCO heritage site in Greenland, the Qaammat Pavilion.
The pavilion is intended to create a landmark in the village of Sarfannguit, a cultural landscape in West Greenland and a UNESCO World Heritage site since 2019. The landmark will help identify this unique location for hikers on the nearby passing trails. The location contains the remains of several thousand years of human history. It is a cultural landscape with a rich and well-preserved tangible and intangible cultural heritage linked to climate, navigation and medicine. Characterized by the two fjords that meet on Sarfannguit’s eastern tip on the hills, the pavilion’s location has been carefully chosen by the local community, site manager Paninnguaq Fleischer-Lyberth and Konstantin Ikonomidis for its impressive view over the Sarfannguit municipality.
The vision of the architect, Konstantin Ikonomidis, was to create a small pyramidal pavilion constructed from solid cast glass bricks, which were manufactured and subsidized by Wonderglass (https://wonderglass.com/). The Qaammat Pavilion, following roughly a conical frustum in shape and comprising 2 semi-circular perforated glass wall units, and total dimensions of circa 3.2 m in diameter and 2 m in height, faces a diverse set of engineering challenges compared to existing adhesively bonded glass brick structures, such as the Crystal Houses and the Atocha Memorial. In our case, the structure should be built under a limited budget and with the aid of the local population, commanding a simple bonding system. The pavilion’s location on top of a rocky hill, further supported this demand, as it implied a complicated access, an absence of electricity and of other commodities conventionally available in construction sites. Adding to this, the location is just north of the arctic circle, implying that the adhesively-bonded pavilion should be able to withstand temperatures as low as -35˚ C. Hence, key for the successful construction of the Qaammat Pavilion is finding an adhesive that satisfies the structural and aesthetic requirements of the project, can withstand the extreme winter temperatures of the polar climate and can offer a simple, fast assembly process that spares the need of a specialized building crew and equipment.
Based on the above, the TU Delft researchers conducted research on adhesives that satisfy, among others, the following key performance criteria: a shear and tensile strength of ≥1 MPa and an operating temperature as low as -40oC in terms of structural performance; a clear or light in colour adhesive in terms of visual result; and a fast fixing (<30 min) and curing time (< 24hr) and a 1-3mm gap filling ability in terms of buildability.
Contrary to the existing realized examples, here two-component adhesives from the silicone and polyurethane families were considered the most suitable candidates. Up until now, in adhesively-bonded glass brick structures, such as the Crystal Houses, the Atocha Memorial and the LightVault, acrylates and epoxies have been preferred as they can yield high-strength and high transparency; yet they call for a high-precision construction and a highly-specialized crew (or robotic assembly). Here, ease-of-assembly and a demanding range of operating temperatures proved to be the most critical aspects, rendering two-component adhesives from the silicone and polyurethane families as the most suitable candidates for this application as they typically present tensile and shear strength above 1 MPa, excellent stability of mechanical properties over a broad temperature range and equally importantly an increased gap-filling capacity that allows for an easy construction.
Accordingly, a few selected adhesives were experimentally evaluated via applicability and shear tests. The applicability tests involved bonding two glass bricks, in order to further understand and evaluate the speed of reaction and strength development, evaluate the ease-of-assembly and get acquainted with the necessary equipment to dispense each adhesive. For the shear tests, triplets of specimens, each consisting of two cast soda-lime silica glass bricks bonded together, were prepared per adhesive candidate and tested at (i) lab temperature conditions and (ii) -5oC.
Based on the tests, an Experimental Fast Curing Adhesive, formulated specifically for this project by Dow, with a shear strength of circa 1 MPa, 3 mm gap filling capacity and white colour, was selected for bonding most of the pavilion; owing to its considerably larger gap filling capacity it facilitates the ease of assembly. Based on the prerequisites set by the TU Delft team, DOW has removed the colouring pigment of the reacting component in order to achieve a final white colour instead of dark grey, and changed the mixing ratio from 100:14 weight to 4:1 Vol, to reduce the snap time down to 4 - 6min and the time to handle strength to approx. 24 hrs. Only the bottom rows of the pavilion were bonded by another adhesive of a higher shear strength, necessary in this location, due to the reduced overlapping of the bricks (and thus smaller bonding surface). Tolerances in the first rows of the pavilion are minimal and can be absorbed within that adhesive’s limited (1mm) gap filling capacity.
Following the construction of a small visual-mock up at the TU Delft cast glass lab facilities, the bonding on site of the pavilion started in August 2021. The construction site was covered with a tent and a heater was installed in the middle. All materials were shipped to Sisimiut, the closest city, and then transported on site first by a small fisherman’s boat and then by ATV bikes. Researchers Telesilla Bristogianni and Faidra Oikonomopoulou from TU Delft travelled to Greenland in order to train the architect and the locals on the developed bonding process and assist in bonding the first 15 rows of the pavilion. The construction concluded at the end of September 2021, just before the harsh winter temperatures would start and the pavilion opened to the public in early October 2021.
The construction of the Qaammat Pavillion highlights the practical challenges linked to the assembly of an adhesively-bonded glass brick structure in a location characterized by remoteness and extreme winter conditions. It further exemplifies the importance of the adhesive selection at an early design stage, in order to realize a structure as close as possible to the envisioned design by the architects given the logistical limitations involved. The adhesive selection can further prevent or add to manufacturing delays, challenges and construction complications interwoven to the properties of the bonding media. The research and development of the adhesively bonded system for the Qaammat pavilion further confirms the need of experimental validation of structural systems made of adhesively-bonded cast glass components, in order to derive the desired engineering data and ensure their safe structural application, as there is a lack of relevant guidelines, building regulations and standardized data.
It also revealed that logistical challenges do not only evolve around ordering the main materials on time, such as glass blocks and adhesive; the availability of supporting technical equipment, which was a real challenge to obtain on time in Greenland, is equally critical for the successful construction of the bonded glass structure. Finally, it shows that a close-collaboration between the architect and researchers is crucial for the success of novel glass structures.
The Qaammat Pavilion is the 2021 Popular Choice Winner of the Architizer A+Awards in the Pavilion Category.
F. Oikonomopoulou, T. Bristogianni, M. van der Velden, K. Ikonomidis, 2021. The adhesively-bonded glass brick system of the Qaammat Pavilion in Greenland: From research to realization. Journal Architecture, Structures and Construction
V. Hayez, B. A, Aksoy, T. Bristogianni, F. Oikonomopoulou, K. Ikonomidis, 2021. The Qaammat Pavilion: A story of innovation, collaboration and inclusion. Intelligent Glass Solutions.
Funded by: Qeqqata Municipality, NAPA, The Nordic Institute in Greenland, Dreyers Foundation
Material sponsorship: Dow (adhesive), Wonderglass (glass bricks)
Contact (at TU Delft)