design and testing o f fly -ash based geo polymer concrete · is that fly ash and ggbs .so using...

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International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 5, May 2017, pp. 480–491, Article ID: IJCIET_08_05_055 Available online at http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=5 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed

DESIGN AND TESTING OF FLY-ASH BASED GEO POLYMER CONCRETE

Ravi Kumar T

Assistant Professor, Department of Civil Engineering, SBIT Engineering College, Khammam, Telangana, India

Siva Krishna A

Assistant Professor, Department of Civil Engineering, SR Engineering College, Hasanparthy, Warangal, Telangana, India

ABSTRACT In the modern world, the most used material for construction buildings and to

build infrastructure the most used material is concrete. and concrete is normally manufactured by mixing with ingredients such as cement , cores aggregates ,fine aggregates ,water ,and mineral admixtures for latent concrete nowadays such as , fly ash ,GGBS and also usage of super plasterers for improving strength of concrete .The materials used for concrete manufactures such as fine aggregates are found in nature and used by trimming them into required shape &size .Water is also available in nature and clan water is used ,but cement is manufactured for raw materials available in nature .Normally the process of manufacturing of cement is very much energy consuming process .As some of the surveys said one tone manufacturing of cement produces nearly one tone of carbon dioxide .And which in turn produces green house gases which cause global warming . So if mainly cement could be replaces there may be some reduction in consumption of cement & which in turn reduces carbon dioxide production .So this will reduce global warming Instead of cement some cementations material can be used to replace cement, Some of the materials which can be replaces is that fly ash and GGBS .So using fly ash and GGBS potential replacement can be done with cement, But it is not possible to do replacement without cement. So some study is been made by replacing cement completely with fly ash and GGBS.

Key words: Geo polymer, Concrete, Mix Design, Strength, Testing. Cite this Article: Raghu Kumar C and Dr. Somasundaran T.P, Strain Energy Expression as Cost Function for Muscle Force Distribution Problem in Biomechanics. International Journal of Civil Engineering and Technology, 8(5), 2017, pp. 480–491. http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=5

Design and Testing of Fly-Ash Based Geo Polymer Concrete


1. INTRODUCTION Davidovits (1988; 1994) proposed that an alkaline liquid could be used to react with the silicon (Si) and the aluminum (Al) in a source material of geological origin or in by-product material such as fly ash and rice husk ash to produce binders. Because the chemical reaction that takes place in this case is a polymerization process, he coined the term 'Geo polymer' to represent these binders. Geo polymers are members of the family of inorganic polymers. The chemical composition of the geo polymer material is similar to natural zeolitic materials, but the microstructure is amorphous. The polymerization process involves a substantially fast chemical reaction under alkaline condition on Si-Al minerals that result in three-dimensional polymeric chain and ring structure consisting of Si-O-Al-O bonds (Davidovits, 1994).

The Schematic Formation of Geo Polymer Material Can Be Shown As Described By Equations (1) And (2) (Davidovits, 1994Van Jaarsveld Et Al, 1997)

n(Si2O5,Al2O2)+2nSiO2+4nH2O+NaOH or KOH→Na+,K+n(OH)3-Si-O-Al_OSi(OH)3→(OH)2

׀(OH)2

(Geo polymer precursor) ׀ ׀ ׀

n(OH)3-Si-O-Al-O-Si-(OH)3+NaOHorKOH→(Na+,K+)-(-Si-O-Al-O-Si-O−)+4nH2O

׀ ׀ ׀ ׀(OH)2 O O O ׀ ׀ ׀

(Geo polymer backbone) The last term in equation 2 reveals that water is released during the chemical reaction that

occurs in the formation of geopolymers. This water, expelled from the geopolymer matrix during the curing and further periods, leaves behind Nano-pores in the matrix, which provide the benefits to the performance of geopolymers. The water in a geopolymer mixture, therefore, plays no role in the chemical reaction that takes place; it merely provides the workability to the mixture during handling. This is in contrast to the chemical reaction of water in a Portland cement concrete mixture during the hydration process.

There are two main constituents of geopolymers, namely the source materials and the alkaline liquids. The source materials for geopolymers based on alumina-silicate should be rich in silicon (Si) and aluminum (Al). These should be natural minerals such as kaolite, clays etc. Alternatively, by-product materials such as fly ash, silica fume, slag, rice-husk, red mud etc, could be used as source materials. The choice of materials for making geopolymers depends on factors such as availability, cost, type of application, and specific demand of the end users.

The alkaline liquids are from soluble alkali metals that are usually Sodium or potassium based. The most common alkaline liquid used in geopolymerization is a combination of sodium hydroxide (NaOH) or potassium hydroxide (KOH) and sodium silicate or potassium silicate.

Ravi Kumar T and Siva Krishna A


2. GEOPOLYMER EXISTENCE Several efforts are in progress to supplement the use of Portland cement in concrete in order to address the global warming issues. These include the supplementary cementing materials such as fly ash, silica fume, granulated blast furnace slag, rice husk and metakaoline and development of alternate binders to Portland cement

Table 1 Applications of Geopolymer

Si/Al Application 1 Bricks, ceramics, fire protection 2 Low CO2 cements, concrete, radioactive & toxic waste encapsulation 3 Heat resistance composites, foundry equipment‘s, fiber glass composites

>3 Sealants for industry 20<Si/Al<35 Fire resistance and heat resistance fiber

Composites

3. EVOLUTION OF GEO POLYMER TECHNOLOGY. This technology was proposed by" Mr. Joseph Davidovits", French chemist (1978). Upto 1972 he was doing research on "organic binders for foundries synthetic textile fiber and organic members" which was not fire resistant member. After the catastrophic fire in France between 1970-1973, which involved him for the research work on "non inflammable and non combustible" plastic material .He found a research company in 1973 for this objective, which is today called CORDI-GEOPLYMERE (in France). In1974 -76 he developed the technology based on geosynthesis of silicon-aluminates called SILIFACTE (Blending of kaolinite with quartz Anano composite quartz surrounded with kaolinite micelles). His first application on building products such as "fire resistant chip board panels comprised of wooden faced with SILIFACE nano composite coatings and found success full resistance "against fire attack. In 1978 he produced and developed amorphous to semi-crystalline three-dimensional silicon aluminates material which he calls Geo polymer.

3.1. Polymerization Process It is a process in which presence of highly alkaline condition on silicon and aluminum mineral , a fast reaction takes place and this reaction gives three-dimensional polymeric chain and ring structure consisting of Si-O-Al-O bonds, as follows.

Mn [-(SiO2) z-AlO2] n. wH2O Where: M = the alkaline element or cation such as potassium, sodium or calcium; the

symbol‘–‘indicates the presence of a bond, n is the degree of polycondensation or polymerization; z is 1, 2, 3, or higher, up to 32



Figure 1

3.2. Comparison of Hydration and Polymerization Process Fig 2.2 shows the hydration and polymerization mechanism of traditional and Geopolymer cement.

Portland cement Geo polymeric cement

Cao+Sio2 Al2O3+ Sio2

14500 c 20-90

0 c +Alkaline Solution

Clinker Phase -SI-O-Al-O

Hydration Polycondensation

C-S-H+Ca(oH)2 Aluminosilicate 3D FrameWork



Comparison of hydration and polymerization process The normal cements are made of [Ca(OH)2] and calcium silicate hydrate (C-S-H) phases, Geopolymer cement is mainly based on an aluminosilicate framework. Aluminosilicate material much more resistant to chemical attack, and there is no calcinations step (heating to 1450 °C) synthesynthesis, thus of release of CO2.

3.3. Application of Geo polymer Technology Aeronautical engineering, , thermal insulation of building, nuclear reactor sector, furnace insulation, metal casting and molding are main regions where Geo polymer is got mainuses.In1983 the Lone star industries (leading cement manufacturers in US, 1984) and Joseph Devidoit started to develop early high strength Geo polymeric binder on both Geo polymeric and hydraulics cement chemistry. After the research works they develop the binder under the brand name of PYRAMENT. In 1984 it is titled as High early strength mineral polymer (US patent 1985).The compressive strength at 28 days with ambient temperature found around 20% higher than the ordinary Portland cement.In1986 James sawyer's research team adapted the Geo polymeric cement formulation for precast and pre stressed concrete by using heat cured PYRAMENT binder and also develops ultra-rapid high aluminates strength binder (ambient temperature cured). Later, the research work carried by the same team with Lone star company to find the properties of binder by blending 80% of ordinary Portland cement with 20% Geo polymeric raw material i.e. calcium silicate with aluminum silicate, alkali activated with potassium carbonate and retarded with citric acid. After the research with effective result they branded binder as PYRAMENT Blended cement (PBC).

3.4. Advantages Uses no ordinary Portland cement

so reduction in cement manufacturing and hence reduces carbon di oxide

No curing is required, high strength and early strength.

3.5. Chemical Resistance Geo polymer concrete cubes kept in sulfuric acid for 56 days did not cause any adverse effect. The strength was reduced negligibly about 5% of compressive strength.

4. PREPARATION OF GEOPOLYMER CONCRETE

4.1. Fresh Geo polymer Concrete The fresh Geo polymer concrete was dark in color with shiny in appearance and the mixtures were usually cohesive.(fig) The workability of the fresh concrete was measured by means of the conventional slump test (Fig ). The workability test results are tabulated in table and To find out the better workable concrete different mixtures (based on binder content) were selected by varying both fly ash content among these mixes the optimal fck is selected based on performance criteria (workability and strength) to cast the cylinders for tensile test and plain concrete beams for flexural strength. .



4.2. Description on Mix Design

Table 2 Design Parameters

DESIGN PARAMETERS VALUE UNITS EXPERIMENTAL WORK

ratio of sodium silicate to sodium hydroxide solution

2400 Kg/M3 Constant

ratio of sodium silicate to sodium hydroxide solution

2.5 Constant Constant

Water to Geopolymer solids 0.3 to 0.40 Variable Variable The Water Content To Sodium Silicate 39.42 % Percentage Constant Fly-ash 65 % Percentage Constant Coarse aggregate 55% Percentage Constant Fine Aggregate 45 % Percentage Constant Molarity of Prepared Alkaline Solution 2M Variable Variable Dosage Of Super Plasticizer 2 % Percentage Constant

NOTE The coarse aggregate and fine aggregate have been taken depending on optimum void ratio.

Aggregates are taken in saturated surface dry condition.

4.2.1. Mix Design

Table 3 Mix proportions for 0.4 water to Geo polymer solids

Mix Molarity W/Gps A.l Binder C.A F.A NaOH Na2Sio3

M40

2M

0.45

186.20

413.79

1260

540

80gm 200 4M 160gm 400 6M 240gm 600 8M 320gm 800

10M 400gm 1000 12M 480gm 1200 14M 560gm 1400 16M 640gm 1600

4.3. Mix Proportion (1:1.33:3.04:0.45) Preparation of NaOH Solution for One Liter Distilled Water

Therefore, Weight of NaOH Required for 2M= 80 gms Weight of NaOH Required for 4M=160 gms Weight of NaOH Required for 6M=240 gms Weight of NaOH Required for 8M=320 gms Weight of NaOH Required for 10M=400 gms Weight of NaOH Required for 12M=480 gms Weight of NaOH Required for 14M=560 gms Weight of NaOH Required for 16M=640 gms



4.4. Mixing The process of mixing or preparing concrete is as normal procedure as normal concrete. Intially all dry aggregates are taken as per mix design and mixed in dry state and later solution is poured and start mixing the concrete atleast for 3 to 4minutes .And casted into the cube moulds.

Figure 2 Mixing of Geo Polymer Concrete

4.4.1. Casting The fresh concrete was cast into moulds of size 150mmX150mmX150mm immediately after mixing, in three layers concrete is put and compacting is done for cube specimens and two layers and compacting is done for prism specimens and to find the compressive strength strength. Compaction of the specimen is achieved by vibration for 2 min or manual compaction is done by giving 25 blows by tamping rod, before the fresh concrete was cast into the moulds, the slump value of the fresh concrete was measured.

4.4.2. Curing For this geo polymer concrete, no need of water curing rather than we use oven curing for one day.

Figure 3 Curing method adopted in manufacture of Geo polymer concrete



5. RESULTS AND DISCUSSIONS Results and discussions on Fresh Geo polymer concrete

Table 4 Slump Value of Fresh Geo Polymer Concrete

MIX

MIX PROPORTIONS SLUMP W/GPS ALKALINE TO

BINDER BINDER

CONTENT (kg/m3)

M40 0.45 186.20 413.79 320

6. OBSERVATIONS In general from the above workability test result we can see that slump value decreases with increase in total binder. The fresh Geo polymer concrete is more cohesive compared to the ordinary Portland cement concrete and it is bit difficult to handle. For our experimental work we require concrete having good workability to cast in moulds, and beams. So we selected the concrete mix is having 375 kg/m3 binder content which involves a sub variation i.e., 0.45 Water to GPS and ratio of alkaline to binder as 0.70 for further studies. The figure shows the variation of slump, with ratio of alkaline to binder respectively.

Tests and discussion on Harden Geo polymer concrete The tests conducted on the harden Geo polymer concrete are

6.1. Compressive Strength The compressive strength test is conducted using 2000 kN capacity compressive testing machine according to IS: 516-1959. The specimens used for this test are 150X150X150 mm cubes. Compressive strength test is carried out on the various mixes by varying water to Geo polymer solids, binder contents of 375 kg/m3 and 420 kg/m3 with varying alkaline to binder ratio by keeping all other parameters as constant. The main objective of conducting the tests on various mixes is to find out the most suitable mix of having higher compressive strength with better workability. The same is used to cast split and flexural strength test specimens. The tests results on various mixes are shown in the table the compression strength.

6.2. Scheme of Work

Table 5 Scheme of Work

MIX NO OF SPECIMENS (CUBES) 24 hrs 48 hrs 96 hrs

2M 3 3 3 4M 3 3 3 6M 3 3 3 8M 3 3 3

10M 3 3 3 12M 3 3 3 14M 3 3 3 16M 3 3 3



Figure 4 Compression Strength for 1 day Curing

Figure 5 Compression Strength for 3 days Curing

150 1112.33

13.83

1719.16

20.67

23.67

0

5

10

15

20

25

Molarity 2

Molarity 4

Molarity 6

Molarity 8

Molarity 10

Molarity 12

Molarity 14

Molarity 16

COMPRESSIVE STRENGTH FOR 1 DAYS CURING

Molarity 2

Molarity 4

Molarity 6

Molarity 8

Molarity 10

Molarity 12

Molarity 14

Molarity 16

15019.33

21.16 22.33 22.6725.83 25.83

31.67

0

5

10

15

20

25

30

35

Molarity 2

Molarity 4

Molarity 6

Molarity 8

Molarity 10

Molarity 12

Molarity 14

Molarity 16


Molarity 2

Molarity 4

Molarity 6

Molarity 8

Molarity 10

Molarity 12

Molarity 14

Molarity 16



Figure 6 Compression Strength for 7 days Curing

6.3. Discussion From the above graph, it shows that with the increase in Molarity in alkaline solution strength

directly increased.

With Increasing the Curing Period Increasing The Strength.

6.4. Interpretation of Results

Figure 7 Interpretation of Results

150

3234.6 35

3739.66

43.3346

0

5

10

15

20

25

30

35

40

45

50

Molarity 2

Molarity 4

Molarity 6

Molarity 8

Molarity 10

Molarity 12

Molarity 14

Molarity 16


Molarity 2

Molarity 4

Molarity 6

Molarity 8

Molarity 10

Molarity 12

Molarity 14

Molarity 16

150 11 12.33 13.8317

19.1623.67 23.67

0

5

10

15

20

25

30

35

40

45

50

Molarity 2

Molarity 4

Molarity 6

Molarity 8

Molarity 10

Molarity 12

Molarity 14

Molarity 16

1 DAY CURING

3 DAYS CURING

7 DAYS CURING



7. SUMMARY AND CONCLUSION In the present experimental work, an attempt has been made to study the performance of Geo polymer concrete in terms of properties like workability, compressive strength, different types of mix of Geo polymer concrete were prepared for three different water to Geo polymer solids, by keeping the Molarity optimum fck was selected to cast the plain Geo polymer concrete cubesers. Low-calcium fly ash (ASTM Class F) is used as the source material (Binder) to make Geo polymer concrete.

Based on the experimental results following conclusion were made: The average density of Geo polymer concrete is very similar to that of normal conventional

concrete.

The slump value of the fresh Geo polymer concrete decreases with the increase in total binder content of the mixture.

The experimental investigations have shown that when the ratio of alkaline to geo

polymer solids is increased the strength reduced but gave a good workable mix.

The cube moulds casted with W/Gps and binder content showed that density of the concrete cubes after demoulding were same as for both with and without compaction.

Geo polymer concrete of effective/optimum mix yields a flow or mobility in between conventional concrete and self compacting concrete, which concludes more passing ability.

It was observed that with increasing water to Geo polymer solids showed decrease in its compressive strength.

It was observed that the handling of fresh Geo polymer concrete with bare hands were prone to skin irritation.

The important observation made was that for ambient curing the 7 day strength of Geo polymer concrete reached around 50 N/mm2

It was observed that with the increase in the ratio of W/Gps, development of micro cracks was more.

REFERENCES [1] M Joseph Davidovits, (1987), "Ancient and Modern Concretes: What Is the Real

Difference?" Concrete International, pp 23-28.

[2] Hardjito, D. and Rangan, B.V. (2005). "Development and Properties of low calcium fly ash based Geo polymer concrete." Research report GC 1, Curtin University of technology Perth, Australia..

[3] Wallah, S.E., and Rangan, B.V. (2006). "Low calcium fly ash based Geo polymer concrete: Long term properties." Research report GC2, Curtin University of technology Perth, Australia.

[4] Sumajouw, M.D.J., and Rangan, B.V. (2006). "Low calcium fly ash based Geo polymer concrete: Reinforced beams and columns." Research report GC 3, Curtin University of technology Perth, Australia.

[5] A Journal of Geopolymer concrete an eco-friendly construction materials

[6] Davidovits, J. 1984. “Pyramids of Egypt Made of Man- Made Stone, Myth or Fact?” Symposium on Archaeometry 1984. Smithsonian Institution, Washington, DC.

[7] M. J. Mohammad, P.V.Krishna. The Physico-chemical studies on water quality of wyra reservoir, Khammam district, Telangana, India, Pharmanest, 2014, 5(6)2528-2531.



[8] Indian Roads network from Wikipedia the free encyclopedia, Wikipedia https://en.wikipedia.org./wiki/Indian_road_network

[9] Study mafia, A seminar report on Soil cement, studymafia.org/wp-content/uploads/2015/02/civil-Soil-cement-report.pdf

[10] Appukutty.P. and Murugesan.R. “Substitution of quarry dust to sand for mortar in brick masonry works” International Journal on Design and Manufacturing Technologies, Vol.3, No.1, January 2009.

[11] Ilangovana.R, Mahendrana.N and Nagamani k. “Strength and durability properties of concrete containing quarry rock dust as fine aggregate ”.ARPN Journal of Engineering and Applied Sciences.Vol.3, no.5, October 2008.

[12] D. Annapurna, Prof. Ravande Kishore and M. Usha Sree, Comparative Study of Experimental and Analytical Results of Geo Polymer Concrete, International Journal of Civil Engineering and Technology, 7 (1), 2016, pp. 211-219.

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