1. Supplementary cementitious material (SCM) can replace part of Portland cement and
carry out pozzolanic reaction to harden the cement. Since the cement is the main
contributor to CO2, using SCM can reduce CO2 emission. Meanwhile, it reduces
permeability, increases strength.
2.
(2a) Yes, the first is just to give a proportion to start with mix design.
(2b) For the mix design, we can use orthogonal test to reduce the quantity of test.
Because we have 4 factors (supplementary cementing materials, fine aggregate,
coarse aggregate, and fibre), and the levels will base on the percentage of these
factors. This orthogonal test can find optimal mix design.
3. Since the agricultural waste varies in different areas, selecting of the appropriate
agriculture for each local area based on harvest amount, agricultural species and
harvest season. (12 months)
Pre-processing need to identify different uses for agricultural waste. Furthermore,
based on uses, they need different treatments before they are produced into
supplementary cement, aggregates, and fibre. (3 months)
ASCON research (take corn, for example):
Testing on the CSF properties. (2 months)
Compression tests, workability tests on CCA, GCC and CSF concrete specimens,
and observe performance after 1 year (12 months)
Compression tests, workability tests on optimal mix design concrete specimens, and
observe performance after 1 year (12 months)
4. Firstly, identify and classify different agricultural waste. The different pre-processing
procedure depends on the classification of agricultural waste.
For the coarse aggregates, according to standards required by ordinary concrete and
general agricultural machinery, find suitable agriculture as coarse aggregate. Then
for agriculture that is failed to meet the requirement, they are burned to ashes for
SCM or fine aggregates. And for the fibre, they need pre-treatment, such as
immersing alkaline, thermal treatment, spinning, and grouped by different lengths of
fibre.
5. Coarse Aggregates in concrete are mainly used to increase the compressive
strength. Since Corns cob has a certain amount of compressive strength, they can be
used as aggregates. Fine aggregates are to fill in the spaces of concrete, corn cob
ash can be used as fine aggregates. As for cementitious components, ash contains
silica which reacts with Ca(OH)2 to generate C-S-H.
6. Using CCA as SCM can reduce the manufacturing of cement; CCA/GCC replace
sand/gravels can reduce or eliminate extraction, crushing and manufacturing process
of sand and gravels; fibres applied into the concrete can increase compressive
strength, hence reduce concrete materials. However, we will only know the exact
Carbon reduction that our project can achieve after our project complete.
7. Corn is the most produced cereal globally, so our project is focusing on Corn
concrete. However, we are using corn concrete project to establish a general
procedure for other potential agricultural waste concrete project globally.
8. As mentioned in the introduction, agricultural waste is abundant in developing
countries. Since there will be more demand in concrete in developing country in the
future, agricultural waste concrete will be mainly adopted in developing countries.