Accelerating Sustainable Construction Materials Application Event V
Knowledge transfer for sustainable infra constructions
16 maart 2021 – Knowledge Structures
17 maart 2021 – Technologies & Practices
18 maart 2021 – Education Refelctions
Click here for the program
A new and important discipline is developing. The consulting role by order of the principle customer of connecting the designers (structural engineer and architect), suppliers and quality performance supervisors is more and more recognized as a value adding function.
Life Cycle Analyses by which Life Cycle Costing and Environmental Impact Shadow Costing (EISC) can be calculated, can measure SUSTAINABILITY PERFORMANCE of materials. An environmental material database, at the moment still on national criteria, is the tool by which such EISC can be established. More and more customers use these to award orders.
Specific material applications need specific actions by specialized people. The present Pantheon Performance Foundation evolved from the SUSTCON (Concrete) EPV Eco Innovation project where useful lessons were learned for ALL materials, such as the verification methodology.
Focus on concrete was kept since theoretically big CO2 reduction steps are possible there, but a complete open mind exists to all materials. International organization will be helpful to identify experts from other materials that will assist in the needed change towards a CO2 neutral construction economy, such as;
Structural CONSULTING Engineering
The structural engineer plays a key role towards the CO2 neutrality of the construction economy, but a different one then up till now. In order to make the best choice the structural engineer should be kept well informed about new materials and its performances, thus including sustainability performances. He/she has to become more critical of what suppliers are presenting. This type of structural engineer could be identified as a Pantheon Performance Consulting Engineer being rewarded for the special effort in proposing the most sustainable structure, instead of the fastest routine calculation solution for which he gets compensated now.
I – Difficult to reduce CO2
Being the number 2 in CO2 product (after energy from fossil fuel), the most used and most abused construction material in the world and emitting > 7 Billion of CO2/year, it deserved special attention. Proof has been delivered that technically this figure can be halved but concrete technology is in the grip of the Portland cement industry, their product still being the main cause of the CO2 emission but also their present earning model.
Based on experience gained with high tech refractory concrete, the civil concrete industry could and should also move away from volume habits towards quality, doing more with less. Cement content reduction can be to the benefit of all parties involved, including the cement producers, if properly understood. The Pantheon Performance Foundation proposes a detailed holistic approach to its partners to address the vast problem of CO2 emission from this economical sector. This approach will be attached to this website for Pantheon Performance Partners at a later stage but is actively worked on in 2020.
It should also be considered that 10 % of the steel production goes to reinforcement of concrete and is a burden on the sustainability of concrete as well. Different structural design and use of all sorts of fibres and promote reinforcement free designs.
With the automobile industry demanding thinner and thus cleaner/better but still affordable steel, the iron and steel industry has made considerable progress in the last 50 years. The question remains if structural steel can benefit from these steps by looking into fire resisting load bearing thin steel, maybe in composite with other materials.
Note that this subject will be further developed in due coarse.
While glass demands high energy and raw materials to be produced, no alternatives are in sight. Further window glass is very difficult to recycle so in order to make glass more sustainable the re-use has to be organized.
At this stage it is unknown to the Pantheon Performance Foundation to what extend the glass producers are organized towards sustainability, other then delivering insulating windows and possibly PV (photovoltaic) glass.
Bricks and tiles have also a considerable need for energy for its process. The reduction of both material use and the binding process will thus have a big impact. The use of Alkali Activated Geopolymer binder systems is in development and should be closely followed.
CO2 emissions of products made with compacted earth do come only from raw materials transport, processing and pressing, sometimes also from the low cement content it contains to make it relatively water proof.
II – Hybrid materials
Bio composites using a rather high (>80%) amount of organic fibres and recycled minerals could be used for modest structural applications and facades, but waterproofing remains an issue at this time.
“Bio-Concrete” where (special) cement or lime is used to bind organic materials such as hemp or miscanthus would be a typical hybrid material, the cement and lime industry realizing they do not have a market share in classic molten rock and glass insulation materials.
It should be noticed that especially in France there is a great deal of application knowledge available for this type of insulation materials.
The challenge will be to develop other intelligent hybrid structural materials and structures.
III – CO2 storing
It is of utmost importance to obtain recognition of the immediate CO2 storing capacity of these materials, regardless theoretical end of product life. This vital discussion cannot be kidnapped by classic mineral product lobby groups.
The CO2 storing materials and structures are in 2 categories;
- BIO BASED such as wood, Hempcrete (Bio Beton), Straw etc.
- Mineral CO2 absorbing bricks such as Carbstone, “Compensatiesteen etc.
The industrial development of this latter category of products has to be closely followed.
The BIO BASED materials can be;
- Load bearing on its own such as Cross Laminated Timber (CLT)
- Modest load bearing as a system (wood frame using different insulating products in between wood structures) and purely
- Insulating materials.
Note; Present common mineral and glass wool consume a considerable amount of energy to be produced plus are very difficult to be recycled.
The structural and the CO2 storage capability of wood are getting general public recognition. Especially Cross Laminated Timber (CTL), glued or laminated using wood pins, with thickness from 70 to 300 mm are gaining in popularity. Also reconstructable Japanese concepts using solid wood and metal fixings are on the market. Both require insulating and competent engineering. When volume will increase, prices will come down.
Wood-frame construction building is classic North American construction practice. In combination with straw bales or inflated cellulose or chopped straw is becoming interesting for industrial and semi-industrial pre-fabrication.
Bamboo is having a special place since it is fast growing and lighter weight (transport). Presentations at the Bio Based Building International Conference 4/5-12-2019 in Paris demonstrated the maturity of bamboo, well beyond the image as a poor man construction material. Structural engineering, especially at connection points, is an important aspect.
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