STUDY ON THE MECHANICAL PROPERTIES OF THE FLY ASH GEOPOLYMER CONCRETE

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1 International Journal of Civil Engineering and Tehnology (IJCIET) Volume 8, Issue 3, Marh 2017, pp Artile ID: IJCIET_08_03_095 Available online at ISSN Print: and ISSN Online: IAEME Publiation Sopus Indexed STUDY ON THE MECHANICAL PROPERTIES OF THE FLY ASH GEOPOLYMER CONCRETE Tran Viet Hung University of Transport and Communiations, Hanoi, Vietnam Dao Van Dong University of Transport Tehnology, Hanoi, Vietnam Nguyen Ngo Long University of Transport and Communiations, Hanoi, Vietnam Ta Duy Hien University of Transport and Communiations, Hanoi, Vietnam ABSTRACT This paper presents the results of the researh on the mehanial harateristis of fly ash geopolymer onrete (GPC). Three mixture of geopolymer onrete graded 30, 40 and 50 MPa were prepared. The proess of experimental studies that is used to determine the ompressive strength, modulus of elastiity, flexural strength is performed in aordane with ASTM standards. The results are analysed and evaluated aording to statistial methods. The value of modulus of elastiity and harateristi bending tensile strength of geopolymer onrete will be ompared with the value of the equivalent ement onrete that are alulated aording to the prevailing theory. The evaluation of the mehanial properties of the fly ash geopolymer onrete is needed for the researh and appliation of this material in the onstrution. Key words: Geopolymer, fly ash, strength. Cite this Artile: Tran Viet Hung, Dao Van Dong, Nguyen Ngo Long and Ta Duy Hien, Study on the Mehanial Properties of the Fly Ash Geopolymer Conrete. International Journal of Civil Engineering and Tehnology, 8(3), 2017, pp INTRODUCTION Geopolymer is an inorgani polymer bonding, developed firstly by Frenh sientist, Joseph Davidovits, in the 1970s. Geopolymerization is a hemial reation between aluminum oxide and silion oxide. Highly alkaline solution will reate solid three-dimensional strutures of Si-O-Al [15]. The proess of geopolymerization an be shown in Figure 1 [11]. The geopolymerization reation takes plae in atmospheri pressure and below 100 C [10]. The editor@iaeme.om

2 Study on the Mehanial Properties of the Fly Ash Geopolymer Conrete final produt will be haraterized by many fators related to the hemial omposition of ativated materials and alkaline solutions. Figure 1 Coneptual model for geopolymerization [11] Materials rih of aluminum and silia in geopolymerisation are industrial wastes suh as fly ash, steel slag, blast furnae slag... In speifi, fly ash is the most suitable material for both its size and hemial omposition. Fly ash geopolymer onrete has been studied and used for ivil, inluding road and airport onstrution works in Australia for the past 10 years but in other ountries, this material usage in onstrution is limited. To apply fly ash geopolymer onrete in struture, the evaluation of its mehanial properties is neessary. The mehanial properties are tested and assessed inlude ompressive strength, elasti modulus, tensile bending strength. Results of researhes will be the basis for this material development in the field of onstrution in the oming time. 2. MATERIALS & EXPERIMENTAL PROCEDURES 2.1. Materials Coarse Aggregate Coarse aggregate onrete used for the experiment is quarry rubble of diameter D max = 25mm. It is sieved into size group by partile size sieves and mixed to satisfy partile sizes in ompliane with ASTM C [7] as seen in Figure 2 and Figure 3 below editor@iaeme.om

3 Tran Viet Hung, Dao Van Dong, Nguyen Ngo Long and Ta Duy Hien Figure 2 Partile size of aggregate after sieved aording to ASTM C [7] Figure 3 Grading of oarse aggregate aording to ASTM C [7] Fine Aggregate Fine aggregate used for experiments is river sand. The partile size larger than 5 mm is removed by sieving in the lab. Sand has partile modules M k = 2.55 whih meets the requirements of ASTM C [4]. Figure 4 below is desribed the grading of sand. Figure 4 Grading of fine aggregate aording to ASTM C [7] Fly Ash (FA) Fly ash in the experiment is supplied by the fatory Vina F & C fly ash origin from Thermal Power Plant, Pha Lai. Test results of hemial omposition of fly ash provided by the Institute of Building Materials are presented in Table 1 below. This is similar to fly ash type F in ASTM C [9] editor@iaeme.om

4 Study on the Mehanial Properties of the Fly Ash Geopolymer Conrete Table 1 Chemial omposition of fly ash used in the study (% by weight) SiO 2 Al 2 O 3 Fe 2 O 3 CaO MgO K 2 O Na 2 O TiO 2 SO 3 Weight loss by heating Alkaline Ativator Solution (AAS) Ativated alkaline solution is a mixture of Sodium solution (NaOH) and Sodium Siliate or glass liquid (Na 2 SiO 3 ). Sodium solution is prepared from dry flake NaOH (98% purity) mixing with water to ahieve the required molar onentration. Glass liquid is supplied by Viet Tri hemial ompany with ratio of Na 2 O/SiO 2 /H 2 O was 11.8/28.5/59.7% by weight respetively. Mixing proportion (Na 2 SiO 3 /NaOH) was 2.5 [13] Component Proportion of Fly Ash Geopolymer Component proportion of fly ash geopolymer used in testing is presented in Table 2 [1]: Table 2 Proportion for 1m 3 mixture of GPC grade 30, 40, and 50 Mpa (Kg) [1] Compositions of GPC G 30 G40 G50 Fly ash mm Coarse aggregate mm (rushed stone) mm mm Fine aggregate (Sand) Solution NaOH (12 M) (14 M) (16 M) Solution Na 2 SiO Na 2 SiO 3 /NaOH (by mass) AAS/FA (by mass) Speimens were ured at 60 o C in 24 hours 2.3. Testing Plan With 30 ylindrial samples of 15x30 m were used to verify the ompressive strength and elasti modulus, 18 prisms of 15x15x60 m to find out flexural strength, orresponding to eah GPC mixture. Determining ompressive strength by C39-01 [5], tensile flexural strength by ASTM C78-02 [6], elasti modulus by ASTM C [8] 2.4. Testing Proedure Fly ash geopolymer onrete an be reated by applying onventional tehnology like ement onrete. After asting for 2 days, the samples are removed and plaed in a drying hamber at 60 o C/24 hours. Selet temperature of 60 C to ensure the best performane in both the intensity and energy ategories [16]. After thermal treatment, samples are stored in the laboratory for 28 days of age (Figure 5) and laboratory tests were performed to determine mehanial properties (Figure 6) editor@iaeme.om

5 Tran Viet Hung, Dao Van Dong, Nguyen Ngo Long and Ta Duy Hien Figure 5 Samples in laboratory Figure 6 Testing of GPC elasti modulus and tensile flexural strength 3. RESULT AND DICUSSION 3.1. Testing Result After got the testing results of eah test sample, statistial analysis and evaluation of the results with a 99% assurane probability are onduted in aordane with ACI 214.R-02 [2]. The results of experiments to find the ompressive strength, elasti modulus and tensile flexure strength of the samples were presented in Table 3 as follows: Table 3 Experimental results determine the mehanial properties of GPC Items Compressive strength Elasti modulus Tensile flexure strength Mix GPC Total sample Average (Mpa) Standard deviation S (Mpa) Varianeoeffiient C v (%) Speifi value (Mpa) G_ ,46 3,34 8,48 31,68 G_ ,86 4,03 8,09 40,46 G_ ,81 3,33 5,56 52,07 G_ , G_ , G_ , G_ ,93 0,49 9,88 3,79 G_ ,29 0,50 7,98 5,02 G_ ,13 0,53 7,38 5, Elasti Modulus From the elasti modulus result test, the authors develop a relationship hart between the elasti modulus and the speifi ompressive strength. The results of GPC are ompared with editor@iaeme.om

6 Study on the Mehanial Properties of the Fly Ash Geopolymer Conrete the modulus of elastiity of the OPC by ACI [4], AASHTO 2012 [14], and by Hardjito et al. experiment formula for fly ash geopolymer onrete [12]. The proposed formula of the Amerian Conrete Institute, ACI [4]: E f (MPa) (1) ' The formula from AASHTO 2012 [14]: E 0,043 f (MPa) (2) 1,5 ' Hardjito et al s experiment formula for fly ash geopolymer onrete [12]: E (MPa) (3) ' 2707 f 5300 M«un µn håi (GPa) ,74 25,58 25,06 GPC AASHTO 2007 ACI 363 Hardjito 31,36 28,02 26,39 20,53 22,52 35,57 30,85 27,16 24, Compressive strength (MPa) Figure 7 Elasti modulus of GPC The results in Figure 7 desribe that the elasti modulus of fly ash geopolymer onrete is less valuable than the modulus of elastiity of OPC at the same level from alulated by ACI between 2-14% and muh lower than the AASHTO 2012 alulation of 10-30%. The main ause is that GPC uses a fly ash geopolymer mix as a ompletely different ement onrete. As the intensity of the GPC inreases, the differene is more. However, the value of elasti modulus of GPC was higher than elasti modulus of GPC reate in Australia by Hardjito's [12]. This may be due to the omposition of the substanes in the fly ash binder, from the elasti modulus of the original stone and different aggregates. This result shows that GPC has lower elasti modulus than OPC, whih leads to the possibility of deformation when subjeted to the load, in turn GPC greater than that of OPC with the same ompressive strength Tensile Flexure Strength The testing results to determine the tensile flexure strength of GPC are ompared with the flexure strength of onrete on the same grade as speified in the Amerian Conrete Institute ACI [3]. Formula for determining the tensile flexure strength of OPC onrete in aordane with ACI [3]: f r 0,63. f ' (MPa) (4) editor@iaeme.om

7 Tran Viet Hung, Dao Van Dong, Nguyen Ngo Long and Ta Duy Hien 6,5 6,0 GPC ACI 318 5,8 Tensile strength (MPa) 5,5 5,0 4,5 4,0 3,5 3,79 3,55 5,02 4,01 4,55 3, Compressive strength (MPa) Figure 8 Tensile flexure strength of GPC The results in Figure 8 show that the tensile strength of GPC is muh greater than the alulated for ement onrete on the same ompressive strength. This value is greater than the range from 1.07 to 1.27 times. This shows that the advantage of GPC more than OPC. The high tensile flexure strength redues the raks in the onrete, reduing the rebar of the tensile zone of the tensile flexural struture. 4. CONCLUSION From the testing results in this study, the onlusions and reommendations an be drawn: Fly ash geopolymer onrete is molded and maintained in laboratory onditions has low dispersion in the test results With the same strengths of MPa, ompared with OPC, GPC's elasti modulus is lower than OPC is that alulated for ementitious standards, due to differenes of binder in the ement onrete. The tensile flexue strength of GPC is higher than 7-27% that alulated by ACI Mehanial harateristis of GPC are important in orientinggpc researh in the onstrution setor. REFERENCES [1] Tran Viet Hung, Dao Van Dong và Nguyen Ngo Long (2016), "Mix design for low alium of fly ash base Geopolymer onrete", ACF The 7th International Conferene of Asian Conrete Federation Sustainable Conrete For Now And The Future, Hanoi, Vietnam. [2] ACI 214R (2002), "Evaluation of Strength Test Results of Conrete", Amerian Conrete Institute. [3] ACI 318M (2011), "Building Code Requirements for Strutural Conrete and Commentary", Amerian Conrete Institute, Detroit, USA. [4] ACI Committee 363 (2010), "State-of-the-Art Report on High-Strength Conrete", Amerian Conrete Institute, Detroit, USA. [5] ASTM C39 (2003), "Standard Test Method for Compressive Strength of Cylindrial Conrete Speimens". [6] ASTM C78 (2002), "Standard Test Method for Flexural Strength of Conrete" editor@iaeme.om

8 Study on the Mehanial Properties of the Fly Ash Geopolymer Conrete [7] ASTM C136 (2001), "Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates". [8] ASTM C469 (2002), "Standard Test Method for Stati Modulus of Elastiity and Poisson s Ratio of Conrete in Compression". [9] ASTM C (2003), "Standard Speifiation for Coal Fly Ash and Raw or Calined Natural Pozzolan for Use in Conrete". [10] J. Davidovits (2008), "Geopolymer Chemistry and Appliations", Institut Géopolymère, Saint-Quentin, Frane. [11] P. Duxson, Fernández-Jiménez, J. L. Provis, G. C. Lukey, A. Palomo và J. S. J. Van Deventer (2007), "Geopolymer tehnology: The urrent state of the art", Journal of Materials Siene. 42(9), pp [12] Hardjito D., Wallah S. E. và Sumajouw M. J. (2005), "The stress strain behaviour of fly ash-based geopolymer onrete. In: Developments in mehanis of strutures and materials", A A Balkema Publishers, The Netherlands, pp [13] D. Hardjito và B. V. Rangan (2005), Development and Properties of Low Calium Fly Ash Based Geopolymer Conrete, Researh Report GC1, Faulty of Engineering, Curtin University of Tehnology, Australia. [14] Amerian Assoiation of State Highway and Transportation Offiials (2007), "AASHTO LRFD Bridge Design Speifiations". [15] A. Palomo, M. W. Grutzek và M. T. Blano (1999), "Alkali-ativated fly ashes A ement for the future.", Cement and Conrete Researh. 29, pp [16] B. V. Rangan (2014), "Geopolymer onrete for environmental protetion", The Indian Conrete Journal. 88(4), pp , [17] V. Keerthy and Y. Himath Kumar, Experimental Studies on Properties of Geopolymer Conrete with GGBS and Fly Ash. International Journal of Civil Engineering and Tehnology, 8(1), 2017, pp [18] Chennur Jithendra Reddy and Dr. S. Elavenil, Geopolymer Conrete with Self Compating: A Review. International Journal of Civil Engineering and Tehnology, 8(2), 2017, pp editor@iaeme.om