International Journal of Civill Engineering E and Technology (IJCIET) Volume 8, Issue 7, July 2017, pp. pp 886–892, Article ID: IJCIET_08_07_095 Available online at http://http://ww www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VT VType=8&IType=7 ISSN Print: 0976-6308 and ISSN N Online: 0976-6316 © IAEME Publication Scopus Indexed GEOPOLY YMER CONCRETE AN E ECOFRIENDLY ALTERNATIVE A TO PORT RTLAND CEMENT P PAVING GRADE CONCR CRETE Girish M. G Assistantt Professor, P Department of Civil Engineering,, Manipal Institutee of o Technology, Manipal University, Karnatak aka, India Kiran K. Shetty Profe fessor, Department of Civil Engineering, Manipal Institutee of o Technology, Manipal University, Karnatak aka, India Raja Rao A PG Student, Stu Department of Civil Engineering, Manipal Institutee of o Technology, Manipal University, Karnatak aka, India ABSTRACT The current generation ion of “Sustainable development” demands the th new concrete which uses the less natura ral resource, energy as well as generates less les CO2, without compromising on strength th and durability aspects. In this context rese search works on geopolymer concrete pre repared from conventional alkali-activatorr solutions like sodium hydroxide and so sodium silicate curable at ambient temperat rature is gaining momentum now-a-days. In this paper, the paste phase and solid phas ase properties of geopolymer concrete conta ntaining quarry dust and sand as fine aggrega gate, suitable for rigid pavement applicatio tion, curable at ambient temperature are the points of discussion.The targeted compressive co strength of 40MPa was achieved ssoon after seven days of air curing and maaximum strength attained in 28 days is nearl rly 62MPa. Both the compressive strength aand the flexural strength were within the acce cceptance limit of paving grade concrete. Key words: Alkaline activ ivators,Geopolymer concrete, Fly-ash, GGBS, S, Quarry dust Cite this Article: Girish M. M G, Kiran K.Shetty and Raja Rao A, Geopo polymer Concrete an Eco-Friendly Alternativ ive to Portland Cement Paving Grade Concret rete. International Journal of Civil Engineerin ing and Technology, 8(7), 2017, pp. 886–892. http://www.iaeme.com/IJCIE IET/issues.asp?JType=IJCIET&VType=8&ITyp ype=7 1. INTRODUCTION Concrete is the most consum med material next to water in the world. Too live, how water is essential, similarly for shelter er concrete building is important in this era.. T The manufacture of cement is considered to be hig highly energy intensive next to steel and alum minium. The process http://www.iaeme.com/IJCIE IET/index.asp 886 ed [email protected] Girish M. G, Kiran K.Shetty and Raja Rao A of manufacturing of 1000kg of Portland clinker directly generates over a 500kg of chemicalCarbon dioxides, and nearly another 500kg of Carbon dioxide comes from the combustion of carbon-fuel[1]. The only exceptions are so-called ‘blended cement', using such ingredients as coal fly-ash, where the emissions of carbon dioxides are slightly suppressed, by a maximum of 10-15%[1].Geopolymer cement (GC) does not rely on calcium carbonate and generate a very minimal amount of CO2 for its manufacture, i.e. a reduction in the range of 40% to 8090% [1]. The geopolymer cement is formed by polymerization process which involves the reaction between an aluminosilicate source material such as fly-ash, GGBS, etc. with an alkaline activator solutions. The process results in the creation of a network of a tetrahedral chain of SiO4 and AlO4 to shared oxygen atoms alternatively [2]. Hardening of GC takes place through polycondensation of potassium oligo (sialate-siloxo) into potassium poly (sialate-siloxo) cross-linked network [1]. The GC, so formed binds the aggregates and inert materials to form a matrix called geopolymer concrete (GPC). Present days, lots of researchesare being carried out on the utilisation of industrial by-product such as fly-ash, GGBS, silica fumes, metakaolin as an aluminosilicate precursor material for geopolymers[3]. The alkaline liquids used in the production of GC mainly are of soluble alkali metals that are usually sodium or potassium based. The most commonly used alkaline liquid is the combination of Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) or Potassium Hydroxide (KOH) and Potassium Silicate (K2SiO3) [4]. The molarity and molar ratio of alkaline solution, water to binder ratio, plasticiser and curing temperature is found to have a profound effect on the fresh and hardened state of geopolymer concrete [5]. The increase in molarity of NaOH solution from 8M to 14M and molar ratio increases the strength and decreases the workability of the concrete respectively. The increase of super plasticizer content and the alkali concentration improves the interfacial transition zone (ITZ) and microstructure of GPC[6]. The presence of additional water exceeding 15% causes bleeding, segregation and reduced the compressive strength of the concrete[7]. The geopolymer concrete, in future, can become a viable alternative to OPC as a binding material in mass concreting applications. In recent times researches have been carried out across many locations of the world to investigate the potentials of GPC for structural applications. However, little is known as for as its applications in the field of the highway pavements are concerned. In this paper, attempts are made to explore the possibilities of using GPC as a paving grade concrete. The production of GPC is carried out using the OPC concrete production technology methods. 2. MATERIALS AND THEIR PROPERTIES 2.1. Fly-ash Fly ash from Raichur Thermal Power Station (RTPS) located in Karnataka, India is used as one of the precursors. According to IS: 3812-2000 [8], it is classified as Class-F fly ash. Specific gravity is measured as 2.05 according to IS:1727-1967[9]. Pozzolanic activity index with Portland cement is 74.22% and Blaine’s surface area of 3225 cm2/gm. 2.2. Aggregates Locally available clean river sand and quarry dust were used as fine aggregates. The F.A belongs to grading Zone II as per IS: 383-1970[10],with the specific gravity,of 2.64 and fineness modulus of 2.935. http://www.iaeme.com/IJCIET/index.asp 887 [email protected] Geopolymer Concrete an Eco-Friendly Alternative to Portland Cement Paving Grade Concrete The quarry dust with specific gravity 2.62 and fineness modulus 2.847obtainedin the vicinityis used in the current study Crushed aggregate of 20 mm down sizehaving specific gravity 2.68 and fineness modulus 6.969is utilised as coarse aggregate. 2.3. Alkaline Solution The commonly used alkaline activators in Geopolymer concrete are sodium hydroxide and sodium silicate solutions. Sodium silicate solution (A53) is obtained from a local factory, and it is composed of Na2O- 13.54%, SiO2- 32.46% and H2O- 54.0%. Sodium hydroxide used is of analytical grade and is of 97% purity. 2.4. Water Potable water conforming to IS: 456-2000 [11]is used in all mixes. And it is free from salts and other organic impurities. The water content in GPC is the combined water present in the alkali solution. The amount of water in Silicate solution is found out by chemical analysis. 2.5. Ground Granulated Blast Furnace Slag (GGBS) GGBS was obtained from Jindal Steel Works (JSW) Bellary, Karnataka. The specific gravity of GGBS was found to be 2.88. 2.6. Super Plasticizer Conplast SP500 conforming to IS: 9103-1999, is based on Sulphonated Napthalene Polymers and is supplied as a brown liquid instantly dispersible in water. The specific gravity was found to be 1.26. 3. MIX DESIGNS The composition of the geopolymer mixes used in the present investigation is given in the Table1. The NaOH solution of 12M concentration is preferred in this study. The NaOH solution was prepared 24 hours before the mixing. Mix M1 and M2 are more or less identical in composition except that, in mix M2, sand is replaced by quarry dust by same amount. Mix M3 also has quarry dust in place of sand as fine aggregate. The quantity of coarse aggregate used in M3 is slightly higher than M1 and M2. Table 1 Composition of Mixes Materials Fly Ash GGBS NaOH soln. (L/m3) Na2SiO3 soln. (L/m3) S.P (L/m3) F.A (quarry dust) F.A (river sand) C.A Water (L/m3) Na2SiO3/NaOH Water to GPS ratio Alkaline to Binder ratio M1 (kg/m3) 330 220 45.15 112.88 16.5 735 870 24.75 2.5 0.19 0.29 http://www.iaeme.com/IJCIET/index.asp 888 M2 (kg/m3) 330 220 45.15 112.88 16.5 735 870 41.8 2.5 0.213 0.29 M3 (kg/m3) 237 158 45.15 112.88 11.85 555 1290 39.5 2.5 0.28 0.40 [email protected] Girish M. G, Kiran K.Shetty and Raja Rao A 4. EXPERIMENTAL RESULTS AND DISCUSSIONS 4.1. Fresh Properties for Paving Grade Concrete The target slump in the range 6 to 8 inches, spread in the range 11 to 13 inches and compaction factor > 95% was recognised as standard to define the fresh state properties of paving grade geopolymer concrete. Figure 1 represents the slump test and Figure 2 represents the spread test. The results of the slump test, compaction factor test and spread test are presented in Table 2. The compaction factor values of all the mixes were comparable to the set standards. The slump and spread values of mixes M1 and M2 were close to adopted standards. However, slump and spread values of mix M3 are found to be not within the range. This is due to slightly increase in quantity of coarse aggregate and reduction quarry of dust which caused stiffening of the paste and loss of mobility. Table 2 Results of slump cone and spread tests Mixes Slump (inches) Spread (inches) M1 M2 M3 9.0 8.5 5.0 16.5 15.5 9.0 Figure 1 Slump Compaction Factor (%) 98 96.5 95.6 Figure 2 Spread test 4.2. Density The density values of GPC mixes were in the range of 2300 to 2500 kg/m3 which is found to be similar to thedensity of OPC concrete. 4.3. Compressive Strength The compression strength test values of GPC cube specimens of size 100x100x100 mm of three mixes, when tested under compression load as per IS: 516-1959 [13]is presented in Table3, and same is graphically depicted in Figure.3. Table 3 Compressive strength of mixes Mix M1 M2 M3 7 days (MPa) 54.71 45.23 40.01 14 days (MPa) 58.17 46.89 40.82 28 days (MPa) 62.15 49.91 55.03 Compressive strength values of all the mixes indicates, an incremental increase in the strength over three ambient curing frequencies. This is because of the pozzolanic activity of fly ash which supplies Si and Al, GGBS rich in Ca supplies enough Ca for the reaction and the alkaline solution which binds the binder contents. All the three mixes achieved an average compressive strength of more than 40MPa in 7 days. As per Indian Road Congress code specification [14, 15], a 28days compressive strength of 40MPa is viewed as min. http://www.iaeme.com/IJCIET/index.asp 889 [email protected] Geopolymer Concrete an Eco-Friendly Alternative to Portland Cement Paving Grade Concrete compressive strength requirement of cement concrete for rigid pavement. This phenomenon of early age strength gain is known to be beneficial since this can facilitate early opening of pavement to vehicular traffic. The complete replacement of sand by quarry dust resulted in decreasing the compressive strength of GPC. On the other hand, the excess coarse aggregate content improved the compressive strength of GPC. compressive strength in MPa Compressive strength 80 60 40 7 days 20 14 days 0 28 days M1 M2 M3 Mixes of GPC Figure 3 Compressive strength of GPC mixes 4.4. Flexural Strength To measure flexural strength, beams of size 100x100x500 mm were used and tested as per IS: 516-1959 specifications[13]. Results of average flexural strength test of different mixes at the age of 28 days are given in Table 4 and shown pictorially in Figure 4. The combined stresses due to wheel load and temperature developed in the rigid pavement should be less than flexural strength of cement concrete used in rigid pavements [15]. Therefore the flexural strength of concrete is known to be of prime importance. The test results show that all the three mixes possessed a flexural strength higher than min. required i.e. 4.42MPa for paving grade concrete of compressive strength 40MPa. Mix M1 had the highest flexural strength then followed by M3 and M2 being the least. Table 4 Flexural strength test results. Mix M1 28 days (MPa) 5.30 M2 M3 4.92 5.10 Flexural Strength in MPa Flexural strength 5 4 3 2 1 0 M1 M2 M3 Mixes of GPC Figure 4 Flexural strength of GPC mixes http://www.iaeme.com/IJCIET/index.asp 890 [email protected] Girish M. G, Kiran K.Shetty and Raja Rao A 5. CONCLUSIONS The study aimed at developing a geopolymer concrete suitable for rigid pavement application. The study comprised of examining the fresh and hardened state behaviour of three different mixes of geopolymer concrete. Among the mixes; mix M1 contained sand as fine aggregate, mix M2 had quarry dust as fine aggregate and mix M3 was having more courseaggregate content along with quarry dust when compare to other two mixes. The following conclusions are arrived from the studies:• The fresh state properties of the GPC indicated that the slump and spread values were in the close proximity of assumed standards except for the mix M3. Thus it can be concluded that the developed GPC can be adopted for fixed form paving. • The compressive strength of GPC obtained was in the range of 40-60MPa which is more than the target strength. The mixes gained strength gradually over the period of times of curing. This is due to the pozzolanic action of fly ash. All the three mixes acquired a target strength of 40MPa in 7 days of curing. Thus it can be concluded the GPC may facilitate the early opening of road to traffic. The complete replacement of sand by quarry dust resulted in a reduction of compressive strength of GPC. Whereas the GPC containing a combination of more quantity of coarse aggregate and the quarry dust produced better compressive strength. • The flexural strength of GPC is found to be significantly more than the target strength. Hence, it can be concluded that the GPC can become a practicable alternative to conventional cement concrete pavement. REFERENCES [1] Joseph Davidovits, “Geopolymer cement”, a review, Institut Geopolymere, Saint-Quentin, France, www.geopolymer.org, 2013. [2] Joseph Davidovits, Properties of Geoploymer Cements, First International Conference on Alkaline Cements and Concretes, Scientific Research Institute on Binders and Materials, KIEV State Technical University, KIEV, Ukraine, 1994, 131-149. [3] Wallah, S.E. and Rangan, B.V., Low-calcium fly-ash based geopolymer concrete: longterm properties, Research Report GC 2, Faculty of Engineering Curtin University of Technology Perth, Australia, 2006. [4] Rangan, B.V., Geopolymer concrete for environmental protection, The Indian Concrete Journal, 88(4), 2014, 41-48, 50-59. [5] Hardjito, D. and Rangan, B.V., (2005), “Development and properties of low calcium flyash based geo-polymer concrete”, Research Report GC 1, Faculty of Engineering Curtin University of Technology Perth, Australia [6] Fadhil Nuruddin, M., Samuel Demie, Fareed Ahmed, M. and Nasir Shafiq, Effect of superplasticizer and NaOH molarity on workability, compressive strength and microstructure properties of self-compacting Geopolymer concrete, International Journal of Environmental, Chemical, Ecological, Geological and Geophysical Engineering, 5(3), 2011, 187-194. [7] Fareed Ahmed Memon, Muhd Fadhil Nuruddin, Samuel Demie and Nasir Shafiq, Effect of superplasticizer and extra water on workability and compressive strength of selfcompacting geopolymer concrete, Research Journal of Applied Sciences, Engineering and Technology, 4(5), 2012, 407-414. [8] IS 3812 (Part 1) (2013), Specification for pulverized fuel ash: Part 1 For use as pozzolana in cement, cement mortar and concrete, Bureau of Indian Standards, New Delhi. http://www.iaeme.com/IJCIET/index.asp 891 [email protected] Geopolymer Concrete an Eco-Friendly Alternative to Portland Cement Paving Grade Concrete [9] IS 1727-1967, Methods of test for pozzolanic materials, Bureau of Indian Standards, New Delhi. [10] IS 383-1970, Specification for coarse and fine aggregate from natural sources for concrete, Bureau of Indian Standards, New Delhi. [11] IS 456-2000, Plain and Reinforced Concrete - Code of Practice, Bureau of Indian Standards, New Delhi [12] BS 6699-1992, Specification for ground granulated blast furnace slag for use withPortland cement [13] IS 516-1959, Method of test for strength of concrete, Bureau of Indian Standards, NewDelhi. [14] IRC 15-2011, Standard specifications and code of practice for construction of concrete roads, Indian Road Congress. [15] IRC 58-2002, Guidelines for design of plain jointed rigid pavements for highways, Indian Road Congress. [16] Balaraman R, Vinodh K.R, Nithiya R and Arunkumar S, Comparative Study of Geopolymer Concrete in Flyash with Conventional Concrete. International Journal of Civil Engineering and Technology, 7(4), 2016, pp.24–36. [17] K. Chandra Padmakar and B. Sarath Chandra Kumar, An Experimental Study on Metakaolin and GGBS Based Geopolymer Concret. International Journal of Civil Engineering and Technology, 8(1), 2017, pp. 544–557. http://www.iaeme.com/IJCIET/index.asp 892 [email protected]
