INVESTIGATON INTO AN OPTIMUM MIX PROPORTION FOR FOAMED CONCRETE WITH HIGH STABILITY IN

WATER

CH AN KW( )K KN': \NG

This project is submitted to Faculty of Engineering,

l'niversity ! Malaysia Sarawak in partial fulfilment of the requirement fiºr the

degree of Bachelor of Fngineering with I lonours (('i\ it Engineering) 2009

TO mº" hrlui"rcl parents and cherished /rirnclc

ACKNOWLEDGEMENT

First and foremost. the author would like to express his sincere thankfulness to Dr.

Mohammad Ibrahim Safawi Mohd Zain for his numerous advice and guidelines in

making this project success.

Acknowledgement also tbrwardcd to the staffs and technician in l1NIMAS Civil

Engineering Laboratory for their help and support in making this project success.

And also thanks to his course mate and friend for sharing their view, advice and their

physical strength in this project.

Finally. the author would like to thank to whom may directly or indirectly contribute

to the success ofthis project.

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ABSTRAK

Konkrit Bcrongga merupakan sejenis konkrit ringan yang mengandungi lebih

daripada 20 peratus udara dalam isipadunya. Hari ini, konkrit jenis demikian telah

digunakan secara mcluas dalam industri pcmhinaan. Konkrit hcrongga telah

digunakan secara meluas dalam kerja-kcrja mencmhus ruangan hcsar pada tapak

pembinaan, pcmbinaan Struktur ringan, bahan pcmhinaan kalis api, hunyi dan

sehagainya. Kchaikan konkrit berongga adalah sitätnya yang kctumpatan rcndah,

keholehaliran tinggi dan keupayaan diri untuk mernampat. Projek in adalah untuk

mcngkaji kcbolehgunaan konkrit berongga dalarn rnereka hcntuk laluan pejalan kaki

di atas tanah gamhut. Keholehapungan konkrit berongga telah diuji di atas air dcngan

muatan. Keputusan mcnunjukkan konkrit herongga dapat tapung atas air samhil

dapat mcnampung seYiikit muatan di atasnya.

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ABSTRACT

Foamed concrete is a kind of lightweight concrete that contain more that 20 % of air

in volume. This kind of concrete had been widely used in the construction industry

nowadays. Foamed concrete are widely use in high volume void fillings,

constructing lightweight structure, fire proofing material, sound proofing material

and etc. The advantages of foamed concrete are its low density, high flowahility,

self leveling and self=compacting. This project will present the applicability in using

foamed concrete to design pedestrian walkway on peat soil. The floatahility of

foamed concrete was tested in water with loading. The result shown that famed

concrete float in water and still he able to sustain some loading.

iv

Table of Content

Acknowledgement

Abstrak

Abstract

Table of Content

List of Table

List of Figure

Chapter 1 INTRODUCTION

1.1 General

1.2 Project Objectives

1.3 Design Concept

1.4 Scope of Study

1.5 Project Outlines

Chapter 2 I. ITF: RATI'RE REVIEW

2.1 (; rneral

Foamcd Concrete

'. '. I [)o-eloPmcnt

2.2.2 Characteristic

_'. '.? Forming Agent

2.2.4 Production

Pages

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3

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()

14

15

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3.5 Waxing Procedure 45

3.6 Experimental Test 46

3.6.1 Compressive Strength Test 46

3.6.2 Floatability and Settlement Test 47

3.7 Difficulties Faced in Project 48

3.7.1 Workability of the Foamed Concrete 48

3.7.2 Measurement of the Foam Quantity 48

3.7.3 Vanes in Density an Floatability of Samples

Chapter 4 RESULT AND ANALYSIS

4.1 General 50

4.2 Compressive Strength cif' Foamed Concrete 50

4.2.1 Result and Analysis cif the Compressive

Strength Test

4.2 .2 Discussion of the Result

51

53

4.3 Floatahility Test 54

4.3.1 Result and Analysis ofthe Floating Test 54

4.3.2 Discussion of the Result 58

4.4 Loading Sustainahility Test 1 (()n Water) 60

4.4.1 Result and Analysis cif' Loading 'l'est 1 60

4.4.2 Discussion of Loading 'Fest I 63

4.5 Loading Sustainahility Trst 2 (On Water) 64

4.5.1 Result and Analysis cif' Loading 'l'est 2 64

4.5.2 Discussion of' Loacfing Test 2 69

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4.6 Loading Sustainability Test 3 (On Sand) 69

4.6.1 Result and Analysis of Loading Test 3 69

4.6.2 Discussion of Loading Tcst 3 70

Chapter 5 CONCLUSION AND RECOMMENDATION 72

5.1 Conclusion 72

5.2 Recommendation 73

BIBLIOGRAPHY- REFERENCES 74

VIII

LIST OF TABLES

Table

2.1 Typical properties of foamed concrete

2.2 Comparison of thermal conductivity resistance

between foamed concrete and other materials

3.1 Suggested mix proportion carryout on this study

4.1 Density and compressive strength result for foam

concrete

4.2 Floating duration and properties of the cube samples

4.3 Comparison fior samples of'diflcrent w/c under target

density = 800 kg m`

4.4 Comparison fir samples of dificrent density under w/c

0.6

4.5 Result from Loading Test 2

4.6 Result from Loading Test 3

Pages

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41

51

55

60

61

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69

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LIST OF FIGURE

Figure Pages

2.1 Thermal conductivity versus densities of foamed

concrete

2.2 Exterior rims and arches (left) and intricate column

head produced using foamed concrete

2.3 Foamed concrete used as underlay and slab thickening

for airport project in Malaysia

2.4 Tunnel filing using foamed concrete in progress

2.5 Diagram showing the how the principle of equilibrium

works

2.6 Production of fly ash in a dry-bottom utility boiler with

electrostatic predicator

2.7 Pouring framed concrete into the hike path

2.8 Bike path was finish with asphalt after the foamed

concrete dry

2.9 Leveling of the tbamed concrete

3.1 Concrete mixer used fir the mixing

3.2 Foam generator (left) and air compressor (right)

3.3 1 UUx I OOx 100 mm site steel mould

3.4 Material required in producing foam dl concrete

3.5 Portland cement (left) and fly ash (right) use in the mix

3.6 MFV('O Fix SLF 30 firming agent

3.7 Timeline of foanudl concrete mixing process

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40

41 43

x

3.8 Curing in process

3.9 Process of waxing

3.10 Foamed concrete after waxing

3.11 Compressive strength test

3.12 Sample was tested for it floatability and loading

sustainability

4.1 Comparison of 7 days strength and 28 days strength

4.2 Cubes sample XI after curing for 7 days

4.3 Cube sample been crushed under compressive test

machine

4.4 Crushed cube sample from the test

4.5 Floating Duration of the cube samples

4.6 Cube sample FC606-B

4.7 Cube sample FC805-C

4.8 Cube sample FC606-E

4.9 Cube samples FC606-B floating on water

4.10 Companng void size between FC806-A (left) and

FC805-C (right)

4.11 Comparison for samples of different w%c under target

density 80l) kg ni'

4.12 Comparison firr samples of different density under w'e

0.6

4.13 Sample F('806-A2 hefirre adding load (left) and after

adding load (right)

4.14 Sample FC606-131 (without waxing) hefirre adding load

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S2

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(left) and after adding load (right)

4.15 Samples FC606-B3 (with waxing) before adding load

(left) and after adding load (right)

4.16 Graph show Cumulative Loading (g) versus Increment

of Water Level (mm)

4.17 Chart show maximum loading sustained by each target

density

4.18 Samples (900 kg/m ` on the left and 800kg/m ` on the

right) floating on water before test

4.19 Initial water level hetbrc test

4.20 Cube sample and water level during test

4.21 Cube sample after test and final water level

4.22 Graph show Cumulative Settlement (mm) versus

Loading Sustained (N)

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CHAPTER 1

INTRODUCTION

1.1. General

Sustainable design concept is the key requirement to present and future in

engineering design to ensure the safety. reliability and sustainability of the structure.

The design of floating platform using foam concrete on peat soil as a pedestrian

walkway is sustainable designs where the structure must he prevented from

settlement since the structure is build on the peat soil.

Peat soil is classified as soft soil with a high organic content. According to

Andncsse (1992), Peat in strict definition usually refers to the accumulation of a

purely one hundred percent organic material and the distinction between soil and

vegetative accumulation is not clear. JKR Malaysia (1995) defines peat soil as

extreme form ofsofi organic soil with organic content equal or more than 75°4.

Due to its softness and high corn when loading applied, constructing structure

above the peat soil will cause the structure to settle after a short period of time. To

remove the peat soil layer and replace it with other type of soil will he costly.

Therefore structure construct on peat soil must he light to a limit where the soil

hearing capacity of the peat soil still can support it. Here is where f6am concrete is

bringing in due to it characteristic of being light.

I

Foam concrete is classified as one of the structural lightweight concrete.

(What is Foam Concrete. 2006) Densities of the foam concrete can be range from

350 kg/m' to 1600 kg/m' with the 28 days compressive strengths range from 0.2

N/mm2 to 12.0 N/mm2. Due to its low densities, foam concrete imposes little vertical

stress on the substructure -a particularly important attribute in areas sensitive to

settlement. Foam concrete is considered as environmental friendly material due to its

forming agent chemical properties of not producing harmful toxic substances to the

environment.

Pedestrian walkway is basically constructed beside the road, riverside or

between buildings for the pedestrian to walk from one location to another location.

Thus increase the connectivity of the pedestrian circulation. Since the pedestrian

walkways are only required to stand the loading of peoples walk over it, the plattbrm

basically is design take only minimum loading.

I

1.2. Project Objectives

The main objective of this project is to investigate the optimum mix

proportion of the foamed concrete into high stability in water. This is preliminary

study before the design of floating foundation using foamed concrete as pedestrian

walkway. Before the design can be carried out, there are a few secondary objectives

need to be complete. First, required mix proportion of the foam concrete need to he

done in order to determine the required density and strength of the foam concrete to

be use. The properties of the peat soil need to be studied to understand the constraints

and difficulty of the peat soil will bring to the project. And the design standard and

requirement for the pedestrian walkway need to be stated.

1.3. Design Concept

The concept of this project is to design a foundation on top of the peat soil.

The idea is to replace some part of the peat soil with tamed concrete and put a

structure on top of it. The principle is that the combined famed concrete and

structure must he designed with a density lower or equal to the density of the

excavami soil.

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1.4. Scope of Study

To achieve the objectives of this project, the study will mainly tbcus on the

related elements of foam concrete, peat soil and floating platform pedestrian

walkway. The scope of studies will include:

a) Determine the properties and application of foam concrete.

b) Review the case study relevant to these project objectives.

c) Study the properties of the peat soil and difficulties will be face to construct a

substructure above it.

d) Study the feasibility of pozzolan fly ash (p. fa. ) as tine aggregates to

replacing sand in mix design.

e) Find the required density and compressive strength of the füam concrete to he

the replacement material.

f) Study and design the optimum mix proportion fur the experiment of this

project.

g) Producing concrete cube samples according to the designed mix proportions

at laboratory.

h) Experiment the cube samples under strength test, water permeability test.

floating test and durability test.

i) Designing the pedestrian walkway with according to the suitable mix

proportion tested.

j) Analyzing the suitable types of densities and mix proportion of loam concrete

to he use in the design of floating platform fi)r the pedestrian walkway.

k) Discussing on the experimental result and the analysis done and propose

recommendations fir the future study of this project.

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1.5. Project Outlines

This Final Year Project contains five chapters with Introduction, Literature

Review, Methodology. Analysis and Result, and finally Conclusion and

Recommendations. The summary of the report will be explained below:

" Chapter I Introduction

This chapter includes the introduction of foam concrete, peat soil and other

key elements that related to the project. the objectives and the scope of study

of the project.

" Chapter 2 Literature Review

This chapter containing the inf'ormation of this project which obtain from

reference books, journal, articles, report, case study and etc. The infimrmation

would include properties and characteristic of fbam concrete, fly ash and peat

soil, the constraints and difficulty which may face in the project, examples of

the research that relevant to this topic which had been done by other and case

study of'some application of the füam concrete.

" Chapter 3 Methodology

This chapter containing the description of'the materials and equipments used

to produce the tram concrete. The procedure of the mix design will he

evaluated in detail under this chapter. This also include the description of'the

tests will he cam out and the detailed procedures ot'the test.

S

" Chapter 4 Result and Analysis

This chapter will contain all the results obtain on the experiment test and

analysis and design process of the project. Discussion on the result will also

include in this chapter.

" Chapter 5 Conclusion and Recommendations

This chapter will contain the conclusion of this project according to the result

obtain in chapter 4 and review the objectives achieved. Recommendations

will he stated for further study.

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CHAPTER 2

LITERATURE REVIEW

2.1. General

This Final Year Project (FYP) is entitled as Designing of'Floating Foundation

above Peat Soil Using Foamed Concrete for Pedestrian Walkway. The purpose of

this FYP is to design and produce a sample of floating foundation using suitable

density of foamed concrete and test it on the peat soil sample. In this chapter, the

properties, productions, applications and advantages of'the fbamed concrete and also

the forming agent will he review according to researches done by others. Purified Fly

Ash (p. f. a. ) is used in the production of tram concrete to replace sand as the fine

aggregate in this project. The properties and advantages of the p. f. a. will he further

reviewed in this chapter. Peat soil is another keyword for this project. Therefore,

properties and construction issue due to peat soil will he review in this chapter. Since

peat soil from difti: rent locations will have diflcrent classification, this project will

only looking on the peat soil in Sarawak. The cases studies of' the application of'

tanned concrete and floating foundation done by other researchers will include in

this chapter as a guideline and references fir this project.

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2.2. Foamed Concrete

Foamed concrete, also know as cellular concrete, aerated concrete or porous

concrete is a type of lightweight concrete that contain uniform distribution of air

bubbles throughout the mass of the concrete. According to Dhir. Ncwlands, &

McCarthy (2005), foamed concrete is a specialized product that contain more than 20%

by volume of air which achieved by incorporation of pre-formed foam or foaming

surfactant into a cemcntitious base mix. In its basic form foamed concrete is a blend

of sand, cement, and water (the base mix) and pre-formed foam, which is a mixture

of foaming agent (either synthetic or protein based), water and air. Foamed concrete

can have densities range from 400 to 160) kg/m` and with the compressive strength

range from 0.5 to 10 N-'mm' according to Aldridge (2(x)5). The application of foam

concrete is widely range from wall panels, floor, and foundation to void filling.

2.2.1. Development

Foamed concrete was first used in the Europe countries as early as I920's.

Since then the development of framed concrete had grown rapidly, especially in the

past few decades. Due to the improvement in material technology, production

equipments and research in producing quality framing agents in the last fifteenth

years, toamed concrete nowadays can he produced and placed on a large scale,

therehy widening the scope of this product construction applications in the industry.

According to Aldridge. 2tN15, r. l: a. or g. g. b. s (Ground Granulated Blast

Furnace Slag) can he use as fine aggregate for }iumuel concrete, along with other

x

kind of fillers in addition to sand, such as chalk or crushed concrete depending to the

purpose or application of the foamed concrete.

With ordinary concrete, there is a compact aggregate/sand skeleton, and

cohesion is achieved inside the cement mix: compression loads are mainly

transferred via this well-stacked aggregatc/sand skeleton. Foam concrete is

composed without coarse aggregate, but with a substantial volume of the tram

bubbles. The bubbles are typically 0.3-0.4 mm in diameter, surrounded by cement,

the highest concentration being near the plateau border where there is the

conjunction of three foam bubbles. In foam concrete mortar, these bubbles provide

the stability of the fbam concrete. Once the material hydrates, load transfer takes

place via the cement matrix around the bubbles. (Cox & Dijk. 2002)

2.2.2. Characteristic

Foamed concrete is defined as tree-flowing, self-compacting and self-

levelling and theretiore expected to give a collapse slump in dump test (Dranstield.

2000). In general, the lower the density of the concrete, the lower the strength of the

tiºrmed concrete will be. Replacing air bubbles (tram) inside the concrete to replace

the coarse aggregate will further reduce the density and the strength of the concrete.

The physical properties of the tiamcd concrete are mainly depends on the quantity of

cements, fly ash, aggregates. tillers, and volume of entrained tram.

Table 2.1 compare some general characteristic of' the fclanllYl concrete with

vanes dn- density. Those characteristics shows that tamed concrete «tl«wer density

9

will have lower compressive strength, thermal conductivity, modulus of' elasticity

and drying shrinkage.

Table 2.1: Typical properties of foamed concrete (Aldridge. 2005)

DRY COMPRESIVE THERMAL MODULUS OF DRYING DENSITY. STRENGTH. CONDUCTIVITY. ELASTICITY. SHRINGKAGE,

kg/m' Nimm' W/mk kN/mm2 400 0.5-1.0 0.1 0.8-1.0 0.3-0.35 600 1.0-1.5 0.11 1.0-1.5 0.22-0.25 800 1.5-2.0 0.17-0.23 2.0-2.5 0.20-0.22 1000 2.5-3.0 0.23-0.30 2.5-3.0 0.18-0.15 1200 4.5-5.5 0.38-0.40 3.5-4. O 0.11-0.09 1400 6.0-8.0 0.50-0.55 5.0-6.0 0.09-0.07 1600 7.5-10.0 0.62-0.66 10.0-12.0 0.07-0.06

There are several other general characteristic of the foamed concrete which as

equally important in making foam concrete differ from the nominal concrete.

a) Low coefficient of permeability

The hydraulic conductivity of porous materials will decreases with an

increase in amount of air in the pores of the material. Since foamed concrete is made

up with a matrix of non-interconnecting micro bubbles, or air voids, thus the material

has a relatively low pcnneahility. (foam Concrete l. td, 2008)

b) Low water absorption

The solid matrix of cementitious slurry surrounding the fine cell structure of

the foamed concrete greatly reduces the capillary action of moisture through the

material.

W/mk kN/mm` %

1U

c) Freeze/thaw resistance

Primarily due to extremely low water absorption of foamed concrete, the

capillary water absorption (actual saturation degree) into accessible pours of' the

material never reaches a point of critical saturation (critical saturation degree), at

which point damage could occur.

d) Thermal insulating properties

Thermal insulation properties, k is the ability of a material to resist the flow

of heat. Since the makeup of low density füamcd concrete contains very large

amount of air content in the closed cell structure (up to 80% air), which provides fi r

good insulating properties. The high air content also provides fior good sound

insulating and excellent fire resistance qualities of the material. According to Aldrige

in Characteristic of Foamed Concrete (2(x)5), a 1000 kg/m` density foamed concrete

would have ak value of 0.3 w mk which compares to aI .S w/ink typical sand

cement screed, making the tamed concrete six times more thermally efficient.

Obviously the concrete will have a much greater strength, but when used in the

correct circumstances this would not create a problem.

Table 2.3 compare the thermal conductivity of foamed concrete with other

material. From the table, it is shown that fiºamed concrete have much lower thermal

conductivity value that marble concrete and clay brick, which make it more

of ectivcly used as a thermal insulation material.

I1

Table 2.2: Comparison of thermal conductivity resistance between turned

concrctc and othcr matcrials (Stray-Bcton Inc.. 2008)

Materials Density (kg/ma) Thcrmul Conductivity

(w/mk) Marbic 2700

Concrete 2400

Porous clay brick 2000

Foamcd concrete Foamed concrete

12(X)

1000

Foamed concreic 800

Foamed concrete 600

Foamed concrete --- Cork

Silicate cotton

Foamed poIvst)Tene

Foamed poIyst}Tene

400

100

1(x)

25

2.9

1.3 0.8

0.38

U. 23

0.1 8

0.14

0.03 0.032

0.030

0.022

Figure 2. I: Thernial conductivity vcmius doisiticw of fbunutil concrete. (Stroy-

Eichen Inc., 2(X)$)

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