Is concrete sustainable?

In the book Concrete and Culture by British architectural historian Adrian Forty that I wrote more about here, his interest in labor as a material is used to frame the subject of culture around the use of concrete. With themes spanning from sustainability and nature to art, politics and economy, and time/weathering, Forty discusses concrete as a symbol of all, or the opposite. Despite its historical nature, I really appreciate the pages that Forty invests in the crucial discussion about sustainability – is concrete a sustainable material or is it not! Cons point at the high use of energy to produce cement. Cement is made from baking its raw materials, limestone and clay, at 1450 degrees Celsius – conservatively stated, 5 % of the world’s CO2 emissions come from the production of cement. – it is hard to be precise because it is uncertain how much cement is actually produced, between 1.5 and 2.5 billion tons. A rule of thumb from traditional production is that the production of one ton of cement emits one ton of Carbon. Around 50 per cent of the carbon emissions are the result of the chemical reaction; around 40 per cent by the burning of fuel in the kilns, and about 10 per cent come from fuel to extract and transport the raw materials.

Forty discusses ways to reduce either the use of fuels and the amount of cement used - the most effective way to decrease the carbon emissions is obviously to limit the use – while maintaining the properties and quality of the end product – most extremely is to leave the hydraulic Portland cement out and use pre-modern building technology in an industrialized way. An example is hemp-concrete – in which lime and vegetable aggregate mixed with organic hemp fibers as reinforcement for a lightweight non-structural product, with sound-absorbing properties.
[While hemp is naturally growing, one could then discuss whether crops should be grown to supply the World population before building blocks?]

Forty describes aspects of an important and more complex issue of energy use in building which means that one cannot rule out concrete as the biggest energy sinner. While concrete is heavy on carbon emissions during construction, figures from the British Concrete Centre estimate the ‘typical’ 60-year life of a building that about 10 per cent of its CO2 emissions are attributable to construction, and about 90 per cent to heating, cooling and lighting. 90 per cent. This indicates clearly the importance of focusing on the energy use and culture over buildings’ lifetime. Furthermore, heavy buildings (brick and concrete) heat and cool slowly due to the thermal mass. This means that these building types tend to overheat less than more lightweight structures – and will do so in the estimated steep rises of summertime temperatures.

I hate it when I feel like a used car sales person by pointing out benefits – my aim is to add some nuances to the good concrete vs bad concrete (non-)discussion. Judging by the quotes and the references Forty's section may have been written in 2009. This book will be read in ten and twenty years from now so accurate numbers is less important than and the multifaceted approach to the topic. The ten pages about the issue are obviously very general but highlight aspects of the topic of sustainability, of development and the politics and the blame pushed around in the world between the developed and developing countries.
The Concrete Centre uses a ‘typical’ age of 60 years for a building… what does that mean? – for sustainability’s (and everyone’s sake) build beautiful buildings. I heard partner Stephen Kieran of the architectural office Kieran Timberlake say something like this at a debate once: If architecture is ugly it will have a very short lifetime and will never be sustainable. Could this then, please, become a more prominent parameter in the various (expensive and thus complicated) certifications of buildings that pop up everywhere?

For more on the discussion about certifications and sustainability, do keep an eye and ear out for the talented architect and researcher Jan Schipull in his research and architectural work - as soon as he breaks the surface for fresh air after his PhD-dissertation-writing race. (The only decent link that includes some of his work is this presentation about Sustainable integrated product deliveries in renovation and new building construction)

The numbers in this post are all based on Adrian Forty's Concrete and Culture, a Material History, 2012

Concrete wilderness - Adrian Forty's Concrete and Culture - review

If not at the Concretely Blog then where? - I actually wanted to write a review on British architectural historian Adrian Forty's "Concrete and Culture, a Material History", published in 2012. But I haven't really finished,- so here is my recommendations to get the book as well as a few examples from the ten chapters framing dualities of concrete in regards to culture and architecture, the never changing paradox of concrete.

[Cover of Adrian Forty's Concrete and Culture. Via. Despite the beautiful picture on the cover, Forty has made a virtue of leaving out the money shots and this book is not a coffee table book - Forty has instead taken most of the photos himself and planned the research for the book to involve immense traveling to Japan, Brazil, Italy etc- oh the joy of being an architectural historian]

Anyone with an interest in concrete or in the discussion of how we understand and use concrete in architectural constructions should check out the book by British architectural historian and Professor at the Bartlett, Adrian Forty. I have been anticipating the publication of Adrian Forty’s book on concrete since I read his 2006 article ‘A Material Without a History’[1]. The article is much quoted for stating the somewhat obviously, that “concrete, let’s face it, is a process not a material.” Following this claim, Forty adds human labor as an ingredient in concrete – as well as cement, aggregate, reinforcement and water. Human labor is obviously an ingredient in other ‘natural’ materials too in order to make stones a cladding, or a tree trunk become a beam etc. For concrete, the work and process about concrete is just crucial and also links to the cultural side of the use of concrete, which is Forty's main objective.

"The book has turned out to be more about architects and architecture than I would have liked. Yet there is a good reason for this, in that architects have paid more attention to the interpretation of concrete as a medium." p11

The research on concrete as a medium (more than a material - which makes sense, I guess, because concrete is the lazy way of describing a group material technologies and practices with cement in common) started around the year 2000. Not an architect, Forty is attracted to the material “because of the inconsistency and contradictoriness of much that was said and written about it, and because of the absence of any coherent account of it as a major component of the modern world.” Forty says, “My work is not so much to increase detailed knowledge of the history of concrete, but rather to develop a general argument about concrete's role in the modern world, as well as within architecture.” [From the Bartlett profile on Forty accessed 26 oct, 2011]

[Lee Marvin as Walker in Point Blank. Via]

In the chapter on Concrete as Natural or Unnatural Forty discusses the changing views on concrete as a natural 'cultured stone' or a more unnatural, artificial building material. The continuous issue of weathering is discussed but also how concrete landscapes are used by film-makers. Though I have not seen John Boorman's 1967 Point Blank starring Lee Marvin, I especially enjoyed Forty's analysis of the use of empty concrete landscapes of Los Angeles taking the place of the classic and symbolic dessert as location. In scenes set against concrete, "men are tested, and sometimes destroyed." (p61)

[Image from the book of the reinforcement placed prior to the floor being poured in a villa by architect Rovelli. From the Hennebique archive. Image link via]

Concrete and photography is the topic of one of the interesting chapters of the book. The architect and scholar Guan Lee of the amazing Grymsdyke Farm was the first I have come across who used this comparison between the process as well as history of photography and concrete. His doctoral dissertation from the Bartlett has not yet been examined. Until then, the chapter written by Forty (also from the Bartlett, remember) offers one aspect of photography and concrete. The early pioneers such as Hennebique and Frank Gilbreth used the photographic medium commercially. Hennebique used photographs in advertisements to sell the systematic and well-proven methods using licensing. The photos had great compositions and were conveying the qualities of the product: its monolithic nature; the precision of the placement of reinforcement (which was invisible but essential features that the client could not see in the end product) – Frank Gilbreth used photography for management - quality control in order to document the construction process on remote construction sites.

Falling apart

One big shame and great nuisance is the fact that most pages have fallen out of the copy of the book I got out of the library. It is ironic that a book about a sturdy building material is not able to stay together. I hope the copy I have ordered for myself may be from another batch, that reprints will solve this major embarrassment of the printer’s. For now, I will have to tie a pretty bow around the library book for other poor readers to deal with as well as trying to make a virtue out of it when I get my own copy.

[1] in [Forty,A. (2006), 'A Material Without a History' in Cohen,J-L., Moeller,G.M. (ed.) Liquid Stone: New Architecture in Concrete, New York: Princeton Architectural Press, (ISBN: 1-56898-570-3), 34-45.] 2006

Ole Egholm - Concrete making and formwork tectonics - doctoral defense

More flexible formed formwork tectonics

The Cast Thicket project I just wrote about here reminds me of work by the Danish architect and doctoral student Ole Egholm who also explores the formwork tectonics of folded plastic sheets. Egholm  is defending his doctoral thesis on Friday September 13th 2013 in Aarhus. His project is related to my own doctoral work in the sense that it is about concrete, formwork tectonics, about flexible formwork, uses Gottfried Semper and other similar theories and key texts about tectonics, and it is investigated through making with the assistance of lots of great students, yet Ole has a digital starting point where as my own investigations were analog. Also important is his focus on building systems based on concrete elements, for example the vault shown below. 

[Youtube video of the assembly of the ReVault]

The use of concrete elements in Denmark could definitely use a lift and Ole's approach is great. His project has the title The Tectonic Potentials of Concrete and you can read an English summary of it here. The experiment shown below is from the ReVault workshop made in Aarhus as a collaboration between researchers and architecture students from Aarhus and from University of Technology, (UTS) in Sydney, Australia.

[Images from Re-vault, via. Elements are connected with zip ties. See more images here]

Ole and I have found similar sources of inspiration and this becomes clear when Ole Egholm writes about his conceptual universe that it 

"is based on research into established writings concerning tectonic thinking. The ideas of German Theorist Gottfried Semper are presented as a strategy for describing form as a result of materials and technical matter. Furthermore the idea of poetic construction is presented. Set forth by the English / American theorist Kenneth Frampton, the idea is that poetic construction is achievable though attention the properties of materials, structural logics and the craft of making. The thoughts of Marco Frascari which suggest a reading of details as a creator of meaning are introduced to be able to help establishing a progression in the case studies. Due to the narrow research focus on the making of concrete, an additional conceptual framework which emphasizes tectonics as a physical phenomenon is presented: The relationship between material, technique and form. Finally, a distinction was made between relationships surrounding mould making and the actual creation of geometric forms in concrete. The former was referred to as mould tectonics, the latter concrete tectonics." From Egholm's summary

This relation between formwork principles and the cured physical manifestation (concrete) is what I relate to as Stereogeneity - I think that Ole, as I am, is drawing on the definition of tectonics presented by Eduard Sekler. - well, I did write an entire post about Sekler, the tectonic, and the relationship between the mold and the molded here

Revault credits, participants

Eleven students from Aarhus School of Architecture (AAA) and UTS

Dave Pigram -architect, Senior lecturer - UTS

Ole Egholm Pedersen - architect, ph.d. candidate - AAA

Niels Martin Larsen - architect, ph.d. candidate - AAA

Stefan Rask Nors - architect, assistant professor - AAA

Ronni Lundoff Madsen - M.Sc. Architectural Engineering - Alectia

Jacob Christensen - M.Sc. Architectural Engineering - Vision+

Yo_cy's formwork tectonics

[Light and space inside the Cast Thicket by yo_cy, via]

Cast Thicket or filigree concrete

I have forgotten to repost this award winning project by yo_cy from Tex-Fab’s APPLIED: Research through Fabrication competition at the University of Texas at Arlington, which is posted on blog of the Architects' Newspaper A/N Blog. The project is familiar to some fabric-formed filigree-like projects with a major difference that it is facetted structure. Yet, despite being inspired by textile-like mats used for casting walls (which you can see way below), the formwork material is actually thin, lasercut plastic sheets. I enjoy the combination of digital fabrication and of combining the lasercut plastic sheets with the hydrostatic pressure from casting. 

“[With this project] we are reacting to the singular material tendency of digital fabrication and [we have shown that] we can use the computer to coordinate different methods of making a material, and simulate that on a smaller scale.” says Tracy, via

[Cast Thicket principle Via]

Cast Thicket is both a form of construction and a finished design product. To produce finished forms of reinforced concrete, construction begins with the design of prefabricated steel struts, which are positioned using a system of interlocking laser-cut plates. Formwork is also prefabricated and attached to the joints. Plastic formwork is then detached and reattached as the structure grows upwards. The final product has the possibility for infinite variation. via the competition site 

[Cast Thicket by yo_cy]

The structure is awesome and perhaps also thicket like (the title contains a new English word for me) - it rather reminds me of columns in Gaudi's Sagrada Familia as well as art pieces by the wonderful Ernesto Neto who fills spatial fabric structures with everything but concrete and plaster. Instead he uses eps, sand, and even spices.

[Ernesto Neto's fabric-formed soft world]

[Each piece of the plastic casing is connecting by a series of tabs. Photo:Kenneth Tracy]

[The plastic mold is held together with plastic zip ties. Photo:Kenneth Tracy]

While I find the work of yo_cy wonderful, I still have to let out a big sigh because of the overly time consuming construction. The idea of the 'tailor-made' as something related to flexible formwork is still so heavily labor intensive as you can tell on the image above, and thus far from being scaleable. I guess the work now can be compared to crocheting and not sewing.

Woven formwork for Kopo House

I am not sure if this house has been built but I'd love to see it if it does - the project is in Indonesia and contains the literal exploration of manufacturing a formwork textile, I mean the textile is in itself a structure with its own principles and the larger the fibers, the is it a building component and material in itself. yo_cy's Christine Yogiaman and Kenneth Tracy state as their profile that combining labor intensive acts in craft culture with rule-based, digital frameworks their projects in Indonesia multiply the everyday to intensify space. The images on the project show initial weaving samples inspired by Ketupat a sort of rise casting formwork... (!) that are manipulated and given form before it is used as formwork for plaster, I think. Other images show larger scale casts of modules and some rebar, so something is definitely being built. Fingers crossed.

The formwork principle is inspired by Indonesian cast rice dumplings known as Ketupat - wow, see below how great they are!

[Ketupat - --- I love these throwaway sturdy lunch boxes]

[woven mats used as formwork and a plaster cast for the  Kopo House project. I'd love to see the full scale version of this! via - Wait - below are bigger prototypes investigating some formwork types]

[Images of the Kopo House investigations, by Yo_cy]

Credits of the Cast Thicket:  Fabricators TOPOCAST

Competition Tex-Fab’s APPLIED: Research through Fabrication competition at the University of Texas at Arlington 

Designers Kenneth Tracy, Christine Yogiaman

Location Arlington, Texas

Date of Completion February 2013

Material limestone powder, white fiber reinforcement, Poraver glass beads, metakaolin, superplasticizer, .03-inch plastic

Process Rhino, Kangaroo, Grasshopper

Design and sculptural fun in GFRC - Hans Henrik Øhlers

['White Tube'  is a fun playground sculpture in Guldbergs Plads, Copenhagen N by Danish artist Hans Henrik Øhlers. PU-foam, Steel reinforcement, Fibre concrete. Image by the artist]

['White Tube'  by artist Hans Henrik Øhlers. PU-foam, Steel reinforcement, Fibre concrete. Image by the artist]

I notice this great sculptural playscape whenever I bike past the school and playground in the Guldberg Plads situated in Copenhagen neighborhood Nørrebro. I have not yet got off my bike and on to the sculpture - or into it - but now I came across the piece in the secret goldmine website of Contec, the manufacturer of GFRHPC ( Glass Fiber Reinforced High Performance Concrete) with references you can read more about here and here. I guess I have not passed the sculpture by night either - it must be lovely illuminated from within with the embedded fiberoptics

[Enjoy the great atmosphere and work process conveyed in the video of the last parts of making the White Tube on site by Hans Henrik Øhlers]

And if in Copenhagen, check out the entire outer Nørrebro area, which also features superstar architects BIG and cooool artists Superflex' Superkilen Urban Park

[He looks like such a nice guy. Danish artist-builder-innovator Hans Henrik Øhlers. Via]

Danish artist and builder Hans Henrik Øhlers has developed fun and curious specialities and innovative construction methods that he applies to combine sculptural work with functionality - he makes sculptural playground installations in PU-foam covered with reinforcement and GRC, he does furniture design and custom interior designs for recording studios, and acoustic and light installations. 

As you may tell as you scroll down, I am really happy to have stumbled into Øhlers web site - especially the fact that he values to communicate the process of his projects so much.

[Wave Rock by Øhlers. In PU-foam, black polyurea]

[The Slope slidable sculpture by Hans Henrik Øhlers]

[Øhlers custom designs and makes futuristic sound recording studio interiors. Image via]

[Acoustic wall sculpture by Øhlers. For GL music, studio C, via]

[Images of the process of making the acoustic wall sculpture. Via]

The acoustic sculpture is for interiors. It's really interesting because it features reflecting as well as absormant surfaces. Inside the diffusing (through the holes) sound-reflecting shell, there is sound-absorbing Paper-wool. It is placed directly behind the listener in a sound studio. Check out more images of the manufacturing process here. I am a sucker for improving acoustics and I would love to have a few of these acoustic reefs on my wall - and also, though I am enjoying the crafted work by Øhlers I would wish for the techniques he is developing that they could be scaled in numbers, that is to say industrially made. I mean, wouldn't it be great to have access to more sculptural acoustic solutions.

[Images of 'Organic Lamp 1' by Øhlers. 85 cm diameter, made from GFRC with fiberoptics. Via ]

[Furniture in GFRHPC for theater foyer. Design and production by Øhlers, image via]

More concrete designs in GFRC - wait GFHPC, no GFRHPC

Ok, so GFRC is Glass Fiber Reinforced Concrete - the Danish company Contec-prefab uses a patented GFRHPC - which is Glass Fiber Reinforced High Performance Concrete. - not catchy but efficient. See the images below to get an idea of how thin -

[Images of Glass Fiber Reinforced High Performance Concrete (GFRHPC) at Contec-Prefab, via]

Contec did the collaboration with Designer Christian Flindt, which I wrote about here. The company has 20 years of experience of working with High and Ultra High Performance concrete technologies - so, the faithful Concretely reader will not be surprised when the early work was based on a technology developed by Mr. Hans Henrik Bache in late 1970´s and early 1980´s. Compact Reinforced Concrete (CRC). (Mr. Bache is the father of Anja Bache who also explores and develops CRC). Do check out their gallery section here for more collaborations.

[Images of GRHPC designs manufactured by Contec. Images via]

[Fun playground sculpture in Guldbergs Plads, Copenhagen N by Danish artist Hans Henrik Øhlers. Image by the artist]

[Fun playground sculpture in Guldbergs Plads, Copenhagen N by Hans Henrik Øhlers. Image and manufacture via]

Cool fabric-formed contrast - Christian Flindt and Contec

[You need to know in order to notice - I love the contrasting combination of classic furniture materials like wood and upholstered seats with concrete sprayed in flexible molds. Design by Christian Flindt. Photo via]

[Fabric former and he is handsome too - the Danish designer Christian Flindt. Photo via]

It is about time I introduce you to some fabric formed concrete designs by Danish designer Christian Flindt. He may be one of the first designers to combine flexible formwork and sprayed high-performance concrete for design products. That is designs intended to actually be reproduced in greater numbers. I first came across his use of sprayed concrete on fabric molds when my mother (sweetheart, yes) sent me a cutout from her newspaper interview from when Flindt was invited to participate in the competition to make new designs to refurbish Iconic UN assembly Finn Juhl. Since the interview was from during the competition I have not seen any images – and they are not se clearly seen on Flindt’s web site – you really need to know it when you see these images of the entry prototypes that combines soft upholstered seats for the long meetings, with an alternative to backs made from bent wooden veneer ply.

[Look again - the dark finish and the back of the classic chair design is not leather nor is it wood but the smoothest concrete. Design by Christian Flindt. Photo via]

I, finally, found the images of the fabric-formed chair in a lovely hiding place of a company web site today – Contec-prefab - another treat for you, is the high-performance concrete division within the Danish company Contec. While I tend to feel stupid when a company this relevant for my concrete endeavors slips under my concrete radar – I really wish that companies would invest in being searchable online. Oh well. It turns out that Contec and Flindt have teamed up and I really love their work.

[GFRC and wood. Images from the design prototypes for the Finn Juhl Hall. Design by Christian Flindt. Photo via]

I have always had a soft spot for the contrast between the materialities of concrete next to other materials like wood or steel. – Italian architect icon Carlo Scarpa was my first encounter, the amazing Castel Vecchio. I really, really want one of Flindt’s tables where he combines wood and smooth high strength concrete. The accuracy and finishes are great!!

Oh – I nearly forgot – look at the façade prototypes in colored concrete. 

[Facade panels. Design by Christian Flindt. Photo via]

I look forward to more fruitful collaborations by Flindt and Contec. – and I hope that manufacturing technologies soon will make it economically feasible to produce sprayed concrete panels and furniture in flexible formwork in the limited numbers...

The Arizona based design-builder-educator Gore Design is another goodfella using GFRC and flexible formwork. - They do design and manufacture/contracting themselves – but you already knew about that, right?

Glazed tile loveliness

Glazed surfaces offer something distinct and at times surprisingly beautiful. The idea of the decorative concrete facade panel as something highly refined works well with how houses are built in Northern Europe anyway - cladding facades and hiding the loadbearing structure and sometimes constructing exposed concrete walls that are not as loadbearing as one would think. When the facade is 'just' a facade, tiles in geometric patterns and treated with special surfaces, offer something refreshingly different than the more traditional Nordic material principles, wood, brick and metal. As long as the facade does not look like huge, scary bathroom walls...

[In-house production and packing of the Quasi Brick tiles, via, reproduced from]

I cannot mention Anja Bache's glazed concrete investigations without coming to think of an art installation produced for a Tadao Ando home/museum in Tokyo by Olafur Eliasson, the Icelandic/Danish superstar artist - we love to call him Danish but he has resided in Berlin for almost 20 years now. 

Blogger Greg Allen describes the 'quasi brick' as "technically a rhomboid dodecahedron" and continues to remind us how "it emerged from Olafur's ongoing collaboration with the Icelandic architect and former Frei Otto student and Buckminster Fuller disciple Einar Thorsteinn. Rhomboid dodecahedrons are one of five space-filling polyhedrons, shapes that can stack on themselves and fill a solid space. Like a cube, but without the regularity."via 

[Platinum glazed bricks, Art installation by Olafur Eliasson in an Tadao Ando house for Takeo Obayashi, the head of one of Japan's leading contractors and a contemporary art collector 2007. via]

Former Eliasson employee Andreas Eggertsen is interviewed in another blog:
The idea of the quasi brick is that it is an expression of high complexity. The quasi brick is a space filling geometry based on “fivefold symmetry”, a mathematical description of a quasi-chaotic geometry, which was found by a physicist in the 80´s.

The bricks can be rotated into 6 different positions, and put together randomly they create a very complex pattern. As the Japanese are a very thorough people they were not pleased when the construction had started and we had not supplied them with a list of how each brick should be rotated. As there were thousands of bricks, we had not figured out a way to indicate the exact rotation of each and every brick and thought that it would be easier for the construction workers to rotate the bricks themselves on site.

We did not realize that the Japanese were going to be so confused by this. They could simply not work without a drawing that showed them exactly what to do. So when we received this e-mail we got a bit frustrated. The construction had already started and in order not to delay the entire project we had to supply them with new and accurate drawings the following day. Via, an account by Andreas Eggertsen of some interesting cultural clashes between Japanese regularity and the basic planned chaos rules formed by the brick bond. 

[I wonder if the facade turns into a giant mirror ball in the sun? Platinum glazed bricks by Olafur Eliasson and Einar Thorsteinn, via, reproduced from]

The geometry of the brick is fixed as a modular system but as other examples below show, the 'bricks' can be formed from any material.

[Quasi bricks made from bent steel and with mirrors, 2002 Basel, via]

[Double-fired quasi brick used for the Blind Pavillon, 2003 Olafur Eliasson in collaboration with Einar Thorsteinn and Petersen Tegl.]

Despite speaking warmly of the glazed tiles, I have rarely come across any in the Nordic neighborhood. Off the top of my head I think of Jørn Utzon who used the patterns created by white glazed and unglazed tiles for the wonderful Bagsværd Kirke with an intentional industrial look and in traditional formats (Also used more spectacularly for the Sydney Opera). 

[Detail of tile patterns in glazed tiles used in the iconic Sydney Opera, via]

The only quasi-bricks that I have experienced in person are the dark, double-fired brick used for the Blind Pavillon, 2003. I love, love, love the earthen materiality here, it is so 'of the ground' terroir like architecture. I must say that for a decade now, I have been secretly dreaming of these tiles to clad a project somewhere close by. - The closest one is the cave-like Royal Danish Playhouse in Copenhagen by Lundgaard & Tranberg and using Petersen Kolumba Bricks. But I love and want the sculpted relief pattern as well.

Want more tiles??
Explore more great tile projects informally collected at the Danish 'Klink' blog - some remarks are in English and some in Danish.