SURURA.Seminar of CE Department and TDS Rs 875/- (Eight orkPPT.pptx

of CE Department and TDS Rs 875/- (Eight hundred and seventy five) towards Consultant Share for the above work

1. 09-09-2025 Department of Civil Engineering, LBSCEK 1 TRANSFORMING COAL BOTTOM ASH INTO A SUSTAINABLE CONSTRUCTION MATERIAL GUIDED BY PRESENTED BY Dr.Arun N R Fathimath Surura Assistant Professor KSD22CE012 Dept. of Civil Engineering. S7 CIVIL LBS College of Engineering,KSD . LBS College of Engineering,KSD .

2. CONTENTS Introduction Properties of Coal Bottom Ash Material Preparation CBA in C oncrete Mechanical Properties Durability Studies Application of CBA Case Studies Conclusion References 09-09-2025 Department of Civil Engineering, LBSCEK 2

3. INTRODUCTION Coal-fired power plants produce Fly Ash & Coal Bottom Ash (CBA). Overuse of natural sand in concrete causes environmental degradation. CBA is a sustainable alternative to natural aggregates. Moderate replacement (25–50%) is effective, but 100% causes cracks & strength loss. 09-09-2025 Department of Civil Engineering, LBSCEK 3

4. PROPERTIES OF CBA Physical Properties: Lighter than natural sand/aggregate. High porosity & water absorption. Angular, irregular particle shape → better bonding. Chemical Properties: Rich in SiO ₂, Al₂O ₃, Fe₂O ₃. Low CaO → weak cementing ability. Similar to Class F fly ash. 09-09-2025 Department of Civil Engineering, LBSCEK 4

5. PROPERTIES OF CBA(Cont..) Mineralogical Properties: Contains quartz, mullite, hematite. Crystalline nature → brittle, low cementitious activity. Environmental / Pozzolanic: May leach heavy metals (As, Zn, Cu). Finely ground CBA → reacts with Ca(OH)₂ to form C–S–H gel. Improves long-term strength when blended with fly ash. 09-09-2025 Department of Civil Engineering, LBSCEK 5

6. PROPERTIES OF CBA(Cont..) 09-09-2025 Department of Civil Engineering, LBSCEK 6 Fig 1:Variation of physical properties of CBA aggregate: (a) Coarse CBA , (b)Fine CBA.[ Source:Adapted from [1]]

7. MATERIAL PREPARATION CBA collected from thermal power plant ash ponds. Dried to remove excess moisture. Sieving carried out to separate into fine & coarse fractions. Fine Aggregate :Passing 4.75 mm sieve,oven dried,partial replacement(10-50%). Coarse Aggregate :Retained on 4.75 mm,washed & pre- soaked,replacement (10-30%). Cement Replacement :Requires fine grinding (5-20%). 09-09-2025 Department of Civil Engineering, LBSCEK 7

8. CBA IN CONCRETE As Fine Aggregate: Replaced sand at 25%, 50%, 75%, 100%. Compressive strength satisfactory up to 100%. Tensile & flexural strength drop after 50%. As Coarse Aggregate: Effective replacement up to 50%. Beyond 50% → wider cracks, reduced durability. 09-09-2025 Department of Civil Engineering, LBSCEK 8

9. CBA IN CONCRETE(Cont..) As Cement Replacement: Limited due to low CaO & crystalline structure. Works better when blended with fly ash. Workability: Increases CBA content → reduced slump. Needs admixtures for better performance. 09-09-2025 Department of Civil Engineering, LBSCEK 9

10. MECHANICAL PROPERTIES Compressive Strength: Least affected, acceptable even at 100%. Split Tensile Strength: Sensitive, decreases with higher CBA. Flexural Strength: More affected, big drop at high replacement. RC Beams under Cyclic Load : Moderate replacement works, 100% replacement fails early. Crack Development: Control mix → ductile failure; 100% CBA → brittle fracture. 09-09-2025 Department of Civil Engineering, LBSCEK 10

11. MEC H ANICAL PROPERTIES (Cont..) 09-09-2025 Department of Civil Engineering, LBSCEK 11 Fig 2 :effect of coarse and fine CBA on compressive strength development from 7 days to 28 days of curing.[ Source:Adapted from [1]] Fig 3:effect of coarse and fine CBA on Splitting tensile strength.[ Source:Adapted from[1]]

12. MECHANICAL PROPERTIES(Cont..) 09-09-2025 Department of Civil Engineering, LBSCEK 12 Fig 4:Crack propagation through aggregates(a)Gravel (b) CBA

13. 09-09-2025 Department of Civil Engineering, LBSCEK 13 DURABILITY STUDIES Water Absorption & Sorptivity ↑ with CBA. Permeability higher → more chloride/acid penetration. Sulphate & Acid Resistance poor at 100%. Drying Shrinkage higher → cracking risk.

14. APPLICATIONS OF CBA 1.In Concrete: Partial replacement of fine and coarse aggregates. Safe replacement up to 30–50% in structural concrete. 2.In Beams: Performs well under cyclic loading at 50% replacement. 100% replacement → brittle failure. 09-09-2025 Department of Civil Engineering, LBSCEK 14

15. APPLICATIONS OF CBA 09-09-2025 Department of Civil Engineering, LBSCEK 15 3.With SCMs (Fly Ash, Slag, etc.): Enhances durability & long-term strength. 4.General Uses: Non-structural concrete elements. Pavements, blocks, lightweight concrete. Eco-friendly construction material .

16. CASE STUDIES 09-09-2025 Department of Civil Engineering, LBSCEK 16 RC beams tested with 50% & 100% CBA + 20% fly ash cement. All mixes achieved >30 MPa compressive strength. 50% replacement → acceptable performance under cyclic loading. 100% replacement → wider cracks, brittle failure. Addition of fly ash improved strength & durability

17. CONCLUSION 09-09-2025 Department of Civil Engineering, LBSCEK 17 CBA can be used as sustainable alternative to natural aggregates. Safe replacement level: 30–50% in structural concrete. Higher replacement → strength loss, poor durability, brittle failure. Performs better when blended with fly ash/SCMs. Useful for non-structural applications at higher %. Promotes waste utilization, resource conservation & eco-friendly construction.

18. REFERENCES 09-09-2025 Department of Civil Engineering, LBSCEK 18 [1] A. M. Hasim, K. A. Shahid, N. F. Ariffin, N. N. Nasrudin, M. N. S. Zaimi , and M.K. Kamarudin , “Coal bottom ash concrete: Mechanical properties and cracking mechanism of concrete subjected to cyclic load test,” Case Studies in Construction Materials, vol. 18, pp. e01580, 2023, doi : 10.1016/j.cscm.2023.e01580. [2] N. Ankur and N. Singh , "Strength characterization and sustainability assessment of coal bottom ash concrete," Environmental Science and Pollution Research, vol. 32, pp.7297–7334, 2025, doi : 10.1007/s11356-024-33303-z. [3] M. Karalar , T. Bilir, M. Çavuşlu , Y. O. Özklıç , and M. M. S. Sabri , “Use of recycled coal bottom ash in reinforced concrete beams as replacement for aggregate,” Frontiers in Materials, vol. 9, p. 1064604, Nov. 2022, doi : 10.3389/fmats.2022.1064604.

19. REFERENCES 09-09-2025 Department of Civil Engineering, LBSCEK 19 [4] N. Seav , K. S. Kim, J. H. Kim, S. W. Lee, and Y. K. Kim , “Effects of roller compacted concrete incorporating coal bottom ash as a fine aggregate replacement,”Sustainability , vol. 15, no. 14, p. 11420, Jul. 2023, doi : 10.3390/su15114120. [5] H. Ganesan, A. Sachdeva, P. Petrounias , P. Lampropoulou, P. K. Sharma, and A.Kumar , “Impact of fine slag aggregates on the final durability of coal bottom ash to produce sustainable concrete,” Sustainability, vol. 15, no. 7, p. 6076, Mar. 2023, doi:10.3390/su15076076. [6] K. Muthusamy, M. H. Rasid, G. A. Jokhio , A. M. A. Budiea , M. W. Hussin, and J.Mirza , “Coal bottom ash as sand replacement in concrete: A review,” Construction and Building Materials, vol. 236, p. 117507, 2020, doi:10.1016/j.conbuildmat.2019.117507.

20. THANK YOU. 09-09-2025 Department of Civil Engineering, LBSCEK 20