Effects of Particle Size of Coarse Aggregates on the Compressive

Strength of Fly ash-based Geopolymer ConcreteA Thesis Proposal Presented to the

College of Engineering and Technology, NwSSU

(October 8, 2015)

Supervisor:

Engr. Ernesto J. Guades

Presented by:

- Arillo, Ellen Rose J. - Collamat, Myrelle Charm O.

- Datiles, Philip A. - Dublin, Christine FC

-Francisco, Cristofer M. - Julien, Jane

-Loyola, Hanzel Mae - Siervo, Eddieliza Joy V.

-Tan, Darwin Z.

Presentation Outline

Background

ObjectivesMaterials and MethodsWork Plan

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(What is geopolymer and its advantage)

Background

Concrete is widely used as one of the important construction material 2

(Nachi.org)

architecturebeast.com

Concrete Coarse Aggregates

Fine Aggregate

Water

Binder

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(Ordinary Portland Cement, OPC)

Using Ordinary Portland Cement (OPC) as Concrete Binder The production of one ton of cement

liberates about one ton of CO2 to the atmosphere, as the result of de-carbonation of limestone during manufacturing of cement and the combustion of fossil fuels (Malathi et al., 2012).

The global cement industry contributes around 2.8 billion tons of the greenhouse gas emissions annually, or about 7% of the total man-made greenhouse emissions to the earth’s atmosphere(Vora & Dave, 2013).

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The demand of concrete is increasing day by day for satisfying the need of development of infrastructure facilities.

One of the alternatives that have been carried out to produce more environmentally friendly concrete is to replace the amount of Portland cement in concrete with by product materials.

USING FLY ASH AS BINDER IN GEOPOLYMER CONCRETE

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Fly Ash Fly ash is a by-product of coal burning

power plants and is usually considered as a waste material.

Estimated 1 billion tons of fly ash is produced annually in coal-fired steam power plants around the world (Kupaei et al., 2013).

The disposal of this waste material is a matter of great concern from the environmental and ecological point of viewHence, the reuse of fly ash is a positive step to reduce pollution 6

Geopolymer Concrete Geopolymer concrete is a concrete which

does not utilize any Portland cement in its production. Rather, the binder is an alkali activated alumino-silicate.

Fly ash is a by-product of coal burning power plants

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Lightworkers.org mistralni.co.ukboya-chemical.com

Coarse Aggregates Concrete is usually associated with coarse

aggregates, as one of the main component of manufacturing concrete.

The size distribution of aggregate is important characteristic because it determines the paste requirement for workable concrete. (Mehta and Montero, 1993) In cement based concrete, the smaller is the size of coarse aggregates, the higher is the compressive strength. (N Moayed et al.)However, this findings may not be similar to

fly ash based concrete due to their different characteristics.

This becomes the motivation of the study.

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Objectives

1. Characterize the effect of particle size of coarse aggregate on the compressive behavior of geopolyper concrete in terms of:

Days of Curing

Curing Method

2. Compare the compressive strength of fly ash based and cement based concrete with varying coarse aggregate particle size.

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Review of Literature

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AUTHORS STUDIES

Malathi V et. al (2012) studied the compressive strength of fly ash-based geopolymer concrete to that of Portland Cement.

Al Bakri et. al (2011) investigated the compressive strength of fly ash-based geopolymer concrete, as well as its exposure to aggressive environment, workability and exposure to high temperature.

M.M.A. Abdullah et. al (2011) investigated the chemical composition of fly ash which depends on the mineral composition of the coal gangue (the inorganic part of the coal).

M. Olivia et. al (2008)presented a study on water penetrability properties, namely water absorption,volume of permeable voids, permeability and sorptivity of low calcium fly ash geopolymer concrete.

Fernández-Jimnez and Palomo (2003)

studied the suitability of various types of fly ash to be geopolymer source material.

Xu and van Deventer (2000) studied the addition of sodium silicate solution to the sodium hydroxide solution as the alkaline liquid.

Aldred and Day (2000) studied about the suitability of geopolymer concrete as an alternative to traditional concrete.

Palomo et. al (1999) investigated on the important role of alkaline liquid in the polymerization process.

Mehta and Monteiro (1993) studied the importance of the size distribution of aggregate.

Materials and MethodsA. Materials

A1. Fly Ash

Class F dry fly ash conforming ASTM C - 618 will be obtained from available suppliers here in the Philippines.

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A2. Aggregates

Coarse aggregates and fine aggregates will be obtained from either locally dealer or outside of the Calbayog City.

A3. Alkaline Solution

The alkaline solution will be prepared using commercially available sodium hydroxide and sodium silicate.

B. Mix Design Proportion

A previous study conducted by Benny Joseph and George Matthew (2012) revealed that these ratio gave the highest average compressive strength of fly ash based geopolymer.

Alkali : fly ash = 0.55

Aggregate Content = 70% Total

Fine : Coarse = 0.35

Na2SiO3/NaOH : 2.5

Extra Water = 25% of fly ash (mass, workability)

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Table 3.1.Mix Design of Geopolymer Concrete by mass

D. Preparation & Casting of Geopolymer ConcreteThe fly ash and the aggregate will be mixed manually and the alkaline solution will be added.They will be kept in moulds for a rest period of 4 days and it will be cured by two (2) different methods: Ambient Curing and heat curing at 100º C for 24 hours in hot air oven.

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C. Preparation of Alkaline Solution A combination of sodium hydroxide solution and

sodium silicate solution.

E. Sieving of Coarse Aggregates

F. Slump TestASTM C143

G. Concrete cylinder testASTM C873M

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Sieve Designation Nominal Size of Opening (mm)

200 4.75

3/8” 9.5

½” 12.5

1” 25

1 ½” 37.5

2” 50

Work Plan

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