Presentation of a research project which was about investigating the effect of using sugarcane trash ash as a substitute of cement on carbonation induced corrosion of concrete.

1. INVESTIGATING RESISTIVITY OF CONCRETE
CONTAINING SUGARCANE TRASHASH (STA) TO
CARBONATION INDUCED CORROSION
PRESENTED BY:
Name: MHOSOLE, EMMANUEL M
Reg No: 2019-04-07130
Supervisor: MR BENITO LYAKWIPA

2. INTRODUCTION
When burnt at 650⁰C, sugarcane trash turn into ash containing amorphous silica, thereby acquiring
pozzolanic properties.
We investigate the potential of concrete containing STA to resist carbonation, to which structures are
susceptible.
Main Objective:
To ascertain the potential of concrete containing sugarcane trash ash to resist carbonation induced
corrosion.
Specific Objectives:
·To measure the resistivity of concrete samples containing different proportions of sugarcane trash ash
·To compare the resistivity of concrete containing sugarcane trash ash to that of conventional concrete
·To determine the influence of sugarcane trash ash on the carbonation depth of concrete
·To investigate the relationship between sugarcane trash ash content and the resistance of concrete to
carbonation induced corrosion

3. METHODOLOGY
Tests Carried out:
A. Particle size distribution:
This was conducted using sieve analysis method as per BS 1377 (Part II) –1990 to ensure
fine and coarse aggregates complied with the standard.
B. Mix Design
Mix Designation Mix Mix Mix Mix Mix
No.1 No.2 No.3 No.4 No.5
STA 0 5 10 15 20
w/c Ratio 0.6 0.6 0.6 0.6 0.6
Cement {Kgs/m3) 384.8 365.6 346.5 326.8 307.6
STA (Kgs/m3) 0 19.2 38.5 58 77.1
Sand (Kgs/m3) 790.3 790.3 790.3 790.3 790.3
Coarse aggregates
(Kgs/m3)
1073.3 1073.3 1073.3 1073.3 1073.3
Water (Litres/m3) 230 230 230 230 230

4. METHODOLOGY
C. Sample Preparation:

5. METHODOLOGY
C. Sample Preparation(Cont'd)

6. METHODOLOGY
D. Exposing of Samples to Carbon dioxide rich Environment:
• After the concrete specimens were cured, they were placed in
a carbon dioxide-rich environment for controlled carbonation
testing.
• The specimens were placed inside high-pressure plastic
barrels designed to withstand elevated pressures and
maintain airtight seals. These barrels were then filled with
carbon dioxide gas at higher concentrations and pressures
than typically found in the atmosphere.

7. •
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8. RESULTS AND DATAANALYSIS
Testing depth of Carbonation

9. RESULTS AND DATAANALYSIS
Data Analysis:
• Carbonation depth increases with higher STA replacement.
• Conventional samples (0% STA) have low carbonation depth (0.1-0.3 mm) showing good resistance.
• High STA replacement (15%, 20%) leads to high carbonation depth (1.6-5 mm) indicating durability
issues.
• Moderate STA replacement (10%) gives moderate carbonation depth (0.4-1.1 mm) balancing
sustainability and resistance.
• This indicates that a 10% STA replacement can simultaneously meet sustainability goals and
maintain desired carbonation resistance in concrete.

10. Cost Analysis for 1 𝒎𝟑
of concrete produced:
• Conventional concrete mix costs 133,328.6
Tshs/m³; 10% STA mix costs 122,828.6 Tshs/m³.
• Incorporating 10% STA results in 7.9% cost
savings (10,500 Tshs/m³).
• 10% STA mix offers environmental, sustainability,
and cost benefits.
• 10% STA mix is a promising, cost-effective, and
sustainable alternative. However further testing
and study is needed.
Material Rate
per
kg(Tsh
)
Conventional
Mix
10% STA Mix
Quantity Cost
(TSh)
Quantit
y
Cost
(TSh)
Cement 280 384 10752
0
346.5 97020
STA 0 0 0 38.5 0
Fine
Aggregates
12 790.3 9483.6 790.3 9483.6
Coarse
Aggregates
15 1073 16095 1073 16095
Water 1 230 230 230 230
Total 13332
8.6
122828.
6
RESULTS AND DATAANALYSIS

11. CONCLUSION
• While the resistance to carbonation decreases
with increasing STAreplacement, 5-10% STA
replacements demonstrated feasibility in the
tested samples.
• STA, easily available in sugarcane producing
areas, is a suitable supplementary material for
cement replacement.
• The 10% STAconcrete mix is more economical
than conventional concrete mix, decreasing the
cost by approximately 7.9%.
CONCLUSION AND RECOMMENDATIONS
RECOMMENDATIONS
• STAcan be utilized to produce concrete durable enough
to resist corrosion induced by carbonation.
• STAcan be incorporated at a maximum replacement
level of 10% (Ordinary Portland Cement) by mass.
• The construction industry, particularly in sugarcane
producing regions, should leverage the technical and
economic advantages of incorporating STAin concrete.
• Volume batching should be employed in works involving
STA, as its density varies from that of ordinary Portland
cement.
• Similar studies are recommended for concrete beams,
slab sections, and other durability properties.

12. THANK YOU