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Tribhuvan University Kathmandu, Nepal Arvind Pathak, Ambar B. Rangu Magar, Dipak Paudel, Rishi B. Bhandari and Vinay Kumar Jha Central Department of Chemistry.

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Presentation on theme: "Tribhuvan University Kathmandu, Nepal Arvind Pathak, Ambar B. Rangu Magar, Dipak Paudel, Rishi B. Bhandari and Vinay Kumar Jha Central Department of Chemistry."— Presentation transcript:

1 Tribhuvan University Kathmandu, Nepal Arvind Pathak, Ambar B. Rangu Magar, Dipak Paudel, Rishi B. Bhandari and Vinay Kumar Jha Central Department of Chemistry Institute of Science and Technology October 10-12, 2012 International Conference on TIM, 2012, Nepal Synthesis and Characterization of Geopolymer from Various Types of Construction Wastes

2 Abstract Construction wastes such as coal fly ash (CFA), demolished cement-sand-mixture (DCSM), demolished cement sand-concrete mixture (DCSCM), brick dust (BD) are rich sources of alumino- silicate and thus can be used as raw material for the synthesis of geopolymer. Geopolymers have been synthesized from construction wastes using alkali and alkali-silicate as activators. Geopolymerization can transform a wide range of alumino-silicate materials into building materials with excellent physicochemical properties such as fire, acid and earthquake resistant. Geopolymers have been synthesized from CFA, DCSM, DCSCM and BD of compressive strength 41.9, 47.0, 45.5 and 60.0 MPa respectively. 2 International Conference on TIM, 2012, Nepal

3 Introduction Geopolymer is a class of synthetic aluminosilicate materials. It has a number of potential uses in several areas but predominantly as replacement of cement. The name GEOPOLYMER was first given to these materials by Prof. John Davidovits in 1970. 3 The existence of geopolymer can be seen in Egypts famous Pyramids. Roman cement and small artifacts, which were previously thought to be stone, were made using the knowledge of geopolymer techniques. International Conference on TIM, 2012, Nepal

4 Some Features of Geopolymer Paver Land slide stabilization Ceramics Hazardous waste encapsulation Precast structural pipes Concrete sleepers 4 International Conference on TIM, 2012, Nepal

5 Geopolymer and Portland cement 5 International Conference on TIM, 2012, Nepal

6 Geopolymer and Portland cement Hardening of Portland cement (P.C.) through simple hydration of calcium silicate into calcium di-silicate hydrate and lime Ca(OH) 2. Hardening of Geopolymer resin (GP) through poly- condensation of potassium oligo-(sialate-siloxo) into potassium poly(sialate- siloxo) cross linked network. 6 International Conference on TIM, 2012, Nepal

7 Geopolymer and Portland cement 7 International Conference on TIM, 2012, Nepal

8 Objectives To synthesize geopolymer from the construction waste with comparable compressive strength like ordinary cement materials. To reduce the CO 2 emission in the atmosphere. To reduce the disposal problem of construction wastes. 8 International Conference on TIM, 2012, Nepal

9 Basic Mechanism of Geopolymerization Smaller particle size of construction waste, sodium silicate and higher content of alkali metals enhance the dissociation and dissolution of alumino-silicate and thereby the formation of geopolymer will have positive influence. Construction Waste 9 International Conference on TIM, 2012, Nepal Sodium Silicate Sodium Hydroxide Geopolymer

10 Barboca et al., 2000 Geopolymer Structure 10 International Conference on TIM, 2012, Nepal

11 Compressive Strength and XRD Pattern Measurements SLF 9 Load frame machine Bruker, D8 Advance Diffractometer 11 International Conference on TIM, 2012, Nepal

12 XRD-Patterns BDDCSCMDCSM 12 International Conference on TIM, 2012, Nepal

13 Comp. Strength With NaOH Variation 13 International Conference on TIM, 2012, Nepal

14 Comp. Strength With Particle Size Variation 14 International Conference on TIM, 2012, Nepal

15 Comp. Strength With Na 2 SiO 3 /CW ratio 15 International Conference on TIM, 2012, Nepal

16 Comp. Strength With Curing Time Variation 16 International Conference on TIM, 2012, Nepal

17 Characterization of Geopolymer Products 17 International Conference on TIM, 2012, Nepal

18 The most suitable raw material for the synthesis of geopolymer is brick-dust. Geopolymeric products of compressive strength more than 40 MPa was obtained with all types of construction wastes. Furthermore, with brick dust geopolymer of 60 MPa was achieved Thus Produced geopolymer can provide better alternate for ordinary cement. This will solve the problem of disposal and hence Geopolymers could turn construction waste into wealth. Conclusion 18 International Conference on TIM, 2012, Nepal

19 Acknowledgements Associate Prof. Dr. Vinay Kumar Jha, Central Department of Chemistry, Tribhuvan University. Nepal Academy of Science and Technology (NAST) for Ph.D. Fellowship and financial support (Project 2067/68). Central Material Testing Laboratory, Institute of Engineering (IOE), Pulchowk Campus, Tribhuvan University, Kathmandu. Assoc. Prof. Dr. Lalu Prasad Paudel, Head of Central Dept. of Geology, T. U., Kirtipur, Kathmandu for his valuable help in X- Ray diffraction measurement of samples. Central Department of Chemistry, Tribhuvan University for providing me the necessary facilities to carry out my Doctoral study. Organizing Committee and TIM Conference-2012 Team. 19 International Conference on TIM, 2012, Nepal

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