Table of contents:
1. Background 2
1.1 Current
practices for public housing in Sembawang area 3
1.2 Problem
Statement 3
1.3 Purpose
Statement 3
2. Proposed
Solution 3
2.1 Use
mycelium bricks in place of conventional bricks 4
3. Benefits
of Proposed Solutions 4
3.1 Physical
Capabilities 4
3.2 Fire
Resistance 5
3.3 Good
thermal insulation 5
3.4
Environmentally friendly 5
3.5 Health 6
3.6
Production 6
3.7
Economical 6
4.
Limitations of Proposed Solution 6
4.1 Weak
compressive strength 6
4.2
Production 6
4.3 Long term 7
4.4
Compromised structural integrity 7
5. Methods
& Procedures 7
5.1 Primary
Research 7
5.2 Secondary
Research 7
6. Conclusion 8
Reference 8
1. Background
This report responds to a call for
proposal to recommend an engineering solution to a specific problem in the
built environment sector.
Cement is inarguably the most used
and crucial construction resource since civilizations came into existence. Over
the years, especially in recent decades, buildings are becoming bigger and
taller. In the year 1998, the Petronas twin towers, the two tallest buildings
at that time stood at 452m (Kazmierchak and Gramsbergen, 2005). Today, the
tallest building in the world, the Burj Khalifa which stands at 828m, uses
330,000m3 of concrete(Burj Khalifa, n.d.). Rodger (2018) states that most
of our concrete in the world is being used to construct buildings and that the
main ingredient of concrete is cement, whose production contributes to 8% of
the world’s carbon emissions, which is equivalent to 2.2 billion tons of carbon
dioxide per year.
In addition, the process of producing
bricks in kilns not only releases carbon into our atmosphere but also large
amounts of pollutants such as sulphur dioxide and black carbon into the
atmosphere. (Climate and Clean Air , n.d.). These effects are not easily
reversed and will accumulate in the earth’s atmosphere much to the suffering of
future generations.
The Intergovernmental Panel on
Climate Change (IPCC) mentioned in their special report that it is essential to
maintain global temperature within 1.5 degree celsius. A one-degree increment
of global temperature can result in a drastic increase of the atmospheric
temperature. According to the National Oceanic and Atmospheric Administration
(NOAA) statistics, the global temperature in September 2009 was 0.62 degree
celsius. Currently, the global temperature is at 0.95 degree celsius, an
increment of 0.33 degree celsius. With this constant rate of increment, it will
definitely affect people around the world, including Singapore.
Singapore generated 52.5 million
tonnes of greenhouse gases in 2017 which contributed 0.11% of global carbon
emissions, that equates to 8,000 tonnes of CO2 per capita in that year (Tan,
2019). According to Dr Muhammad Eeqmal Hassim, senior research scientist with
the MSS Centre for Climate Research Singapore, the constant rise of carbon
emissions around the world will lead to an increase of Singapore’s to 40 degrees
celsius by 2045 (Low, 2019). Therefore, it is necessary for Singapore to reduce
the amount of carbon emission.
The rising of carbon emissions from
production of conventional bricks have led Bricknology to source out
sustainable alternatives for brick production. Bricknology has identified
mycelium brick as an alternative brick to replace conventional bricks. Mycelium
brick is an environmentally friendly brick which does not require coal for its
production as it is created through organic components and fungus. It is
praised for its super strength, ability to withstand harsh conditions, low
cost, health benefits and its eco-friendliness. In New York City, an
architecture firm called “The Living” created a 40 feet tower, “Hi-Fy Tower”
with mycelium bricks in 2014. David Benjamin, principal architect of The Living
stated that on top of being cheaper to produce, mycelium bricks requires
minimal energy for growth, in fact, it decomposes waste to grow and does not
produce any waste itself; this in itself is a revolutionary technique for
producing building materials (Brownstone, 2014).
The use of mycelium bricks in
construction is still in its infancy stage and based on existing research,
mycelium bricks shows very promising potential in sustainability and mid tier
construction projects. Bricknology wishes to implement the use of mycelium
bricks in the upcoming Build-to-Order (BTO) flat at Sembawang area as a pilot
programme. The team have selected Sembawang as there will be more public
housing in the northern region of Singapore around existing and upcoming mass
rapid transport(MRT) stations, including the newly opened canberra MRT.
1.1 Current practices for public
housing in Sembawang area
The team had observed that the bricks
used to build the internal structure of the house in Sembawang were made up of
in-situ reinforced concrete walls, precast concrete walls and masonry walls.
In-situ reinforced concrete walls and mansory are made on site whereas precast
concrete wall is made in the factory and assembled on the worksite.
1.2 Problem Statement
Ideally, Building Construction
Authority (BCA) should authorise the use of mycelium brick for all future
construction. However, BCA is not implementing the use of mycelium bricks
despite its potential as a sustainable material for construction.
1.3 Purpose Statement
The purpose of this report is to
convince Building & Construction Authority to adopt the idea of using
mycelium bricks and initiate a pilot project in the upcoming Build-to-Order
(BTO) flat at Sembawang area.
2. Proposed Solution
The team has referenced online
research done for sustainable bricks has decided to propose the use of mycelium
brick on the upcoming BTO flat at Sembawang area for BCA to consider.
2.1 Use mycelium bricks in place of
conventional bricks
The team conducted a site visit to
the upcoming BTO public housing in sembawang area. The team was told and
observed that bricks used to build internal walls for the houses were mainly by
concrete and clay bricks. It was further elaborated by the construction staff
that in Singapore, most internal walls in buildings uses concrete or clay
bricks because of its ability and cost.
The production of concrete and clay
bricks involves burning fossil fuels to heat the bricks to high temperatures
which produces a high amount of CO2 as a by-product. It is also noteworthy that
the production of concrete and clay bricks produces a ratio of 1 tonne of
bricks to about 250kg of CO2 (Rathi, 2017).
To reduce the amount of carbon
emission, the team proposes the use of mycelium bricks. Mycelium is an organ
belonging to fungi that plays the role of digesting and absorbing nutrients for
the fungi. The current technique for growing mycelium bricks incorporates a
process of decomposing organic waste materials such as agricultural waste and
sawdust, allowing the mycelium to grow in a mould and drying them after to
inhibit growth to retain the shape (Bonnefin, 2018).
Although growing mycelium bricks does
produce CO2, the production process comes at a sustainable cost of decomposing
organic waste. This is a sustainable method of growing the mycelium as the
mycelium is recycling essential nutrients from the organic waste (Hebel,
Javadian, Saedi, 2019). Furthermore, at the end of a building’s estimated safe
habitable lifespan, the building has to be torn down with its bricks. Concrete,
the main bulk of what forms a building cannot be recycled, which means that the
carbon used to produce these concrete bricks can never be reused. On the
contrary, mycelium brick, given the right conditions, is easily biodegradable
into soil which recycles the nutrients (Critical Concrete, 2018). In comparison
with producing the same number of concrete or clay bricks, mycelium bricks
produces less CO2 by a large margin.
With the incorporation of mycelium
bricks into the built environment, BCA would be a leader in Singapore’s
sustainability, using naturally made bricks that is at the same time,
biodegradable after its projected life expectancy.
3. Benefits of Proposed Solutions
The team’s proposed solutions can
lead to many benefits for Singapore’s built environment sector.
3.1 Physical Capabilities
Mycelium brick is fifty six times per
cubic meter lighter than your typical conventional bricks. Despite it being
lighter compared to conventional bricks, mycelium bricks are stronger than
conventional bricks in terms of pound-for-pound (Critical concrete, 2018). It
is capable to withstand a high amount of compression force. Mycelium
bricks can be grown in a controlled environment where the mycelium is grown in
such a way so as to produce desired physical capabilities. In one such
experiment, the results are a mycelium brick that is 200,000 times more ductile
than steel, 10,000 more rigid than brick while still able to support the weight
of 50 cars (Abrams, 2014). As proven from architectural structures, it is able
to withstand external factors such as wind and rain.
3.2 Fire Resistance
Although mycelium does take a shorter
time to ignite in comparison with clay and concrete, the beauty about mycelium
bricks is that the moment the outer layer is burnt, a layer of char forms on
the surface of the mycelium which actually increases the flame resistance of
the entire brick itself (Jones, Bhat, Wang, John & Moinuddin, 2017). This
results in the bricks actually being able to last longer in prolonged fires,
maintaining its structural integrity long enough so that the building does not
collapse under its own weight, leaving room for people to escape.
3.3 Good thermal insulation
Mycelium insulation has way better
R-value and EPS R- value as compared to conventional insulation boards. It does
not absorb heat as fast as the conventional boards (Critical Concrete, 2018).
R-value is a measure of resistance to heat flow through a given thickness of
material. The higher it is, the greater the resistance to heat flow. It is also
thinner and lighter which makes it easier for construction process.
3.4 Environmentally friendly
Mycelium is 100% biodegradable as it
is an organic compound. It does not release any toxic or volatile compounds
when biologically broken down. It is a common misconception that since mycelium
is an organic compound, it will therefore rot easily overtime. However, this is
easily prevented by drying and coating the mycelium brick to protect it from
moisture.
3.5 Health
From an article “Production of
Mycelium brick”, (Kishan, Rahul, Rohan & Anshul, 2018) stated that the
production of conventional bricks releases many toxic pollutants such as carbon
monoxide and sulphur oxides. It was further elaborated that such pollutants
causes 27% of people to pass on due to cardiovascular related diseases and
pneumoconiosis. As mycelium brick uses bio-based materials, it reduces the
amount of toxic pollutants being released into the atmosphere. With the
decrement of toxic pollutants, it will reduce the chance of people getting
diseases.
3.6 Production
The production of mycelium brick is
simple and versatile. Pieces of agricultural waste materials and natural
organic materials can be used to make mycelium bricks, thus reducing the use of
fossil fuel required when using kiln. The reduction of fossil fuel usage will
result in less CO2 emissions.
3.7 Economical
Mycelium bricks does not rely on
conventional factories which uses expensive machines and materials but
just a mould and waste material. This reduces overall cost of production by a
huge margin. A square foot of mycelia material costs around $50
(Chitnavis,2019). It only requires more human effort to put the materials
together but overall it does not cost as much as producing conventional bricks.
4. Limitations of proposed solution
4.1 Weak compressive strength
Comparing mycelium bricks to concrete
bricks in terms of compressive strength, mycelium bricks can only withstand 30
psi whereas a concrete block can withstand 4000 psi to 10,000 psi (Bonnefin,
2018). Mycelium bricks cannot support as much weight as compared to a normal
concrete block. However, the growth of the mycelium can be controlled in such a
way so as to produce varying compressive strengths.
4.2 Production
Mycelium takes time to grow, taking a
few days to weeks to be able to use it as a component to make the bricks.
External factors such as temperature and moisture affects the rate of growth of
the mycelium. Due to the uncertainty in its completion, it affects the
marketability as an easily accessible product.
4.3 Long term
Mycelium bricks are still in the
early stages in their line of production. As a result, the full capabilities of
these bricks have yet to be known. Much of its credibility is theoretical as to
how long it is able to last in residential and non residential buildings. It
might be the solution to replacing all conventional bricks but because mycelium
bricks have only been around for about 5 years, no concrete research is
available for these bricks in a 50 year lifespan. No matter how much research
and claims from experts that says it will last, it will only remain as
projections. The only thing we are able to fully trust is to wait until it
reaches its maximum brick lifespan.
4.4 Compromised structural integrity
After the drying phase, the mycelium
has to be completely dry to kill off all of the fungus to inhibit its growth.
If the drying phase is not done properly, the fungus can still grow which risks
the brick rotting and losing its structural integrity. If the structural
integrity of the brick is at risk, it may collapse and endanger its
occupants.
5. Methods & Procedures
The team came across an article
stating that conventional bricks uses mainly concrete and masonry which
releases harmful pollutants during the process of burning in the kiln. Therefore,
the team decided to research on alternative of bricks which is environmentally
friendly and found out about mycelium bricks. This section details the methods
used by the team to gather information for the report.
5.1 Primary Research
The team went down to Sembawang
public housing estate and conducted interviews with construction staff to find
out the type of bricks they were using for construction site. As most of the
construction workers were from India, they mentioned that India is a country that
produce most of the conventional bricks. As one of the team members used to
work as a hotel technician, he was able to observe the type of cement and
bricks that they were using.
5.2 Secondary Research
The team did research through
articles, government websites and newspapers for relevant information of
mycelium bricks.
6. Conclusion
Climate change has been an ongoing
issue in the world and urgent actions are needed to prevent it. BCA can take
action through piloting the use of mycelium bricks to reduce Singapore’s demand
of conventional bricks. With the reduction of demand, the supply of
conventional bricks will be reduced thus leading to lesser carbon
emissions.
Other than implementing the proposed
solution, BCA can also explore other environmentally sustainable alternatives
and try it in a pilot programme.
With BCA paving the way through
promoting the use of mycelium brick, the private sector will be inspired to
follow suit. Collectively, Singapore will be discouraging the use of
conventional bricks and thus reducing its contribution to carbon emissions in
the world.
Reference
