7

CHAPTER 2

REVIEW OF LITERATURE

2.1 GENERAL

In this chapter, a brief review of literature has been carried out

under the following topics, viz, factors influencing strength of high volume

fly ash concrete, durability of high volume fly ash concrete, prediction of

strength of high volume fly ash concrete, statistical analysis in strength of

concrete and Artificial Neural Network in strength of concrete. The research

work carried out by various authors are briefly discussed here.

2.2 FACTORS INFLUENCING STRENGTH OF HIGHVOLUME FLY ASH CONCRETE

Study on strength and development of high strength concrete

containing flyash and silica fume was studied by Hariharan et al (2011). The

evaluation of compressive strength of high strength concrete was made by

partial replacement of cement by fly ash (FA) and silica fume (SF). In this

study the class C fly ash used in various proportions 30%, 40% and 50% and

that of silica fume by 6% and 10% by weight of cement. The mix proportions

of concrete had a constant water binder ratio of 0.4 and super plasticizer was

added based on the required degree of workability. The compressive strength

was determined at various ages up to 90 days. The addition of silica fume

shows a early strength gaining property and that of fly ash shows a long term

strength.

8

The experimental results on workability, compressive strength and

permeability of concrete with various mixture proportions were presented by

Truly Mittal et al (2006) and studied about the effect of silica fume on

concrete mixes. It was found that microsilica increases the workability of the

fresh concrete upto a certain limit of microsilica addition (upto 20%) as

cement replacement. Compressive strength was also increased on addition of

microsilica. The ultrasonic pulse velocity results showed that during initial

compression the UPV was increased slightly but on further increasing the

compressive load the UPV was decreased. It was found from the study that

the addition of micro silica (upto 20%) in concrete reduced the permeability

by 35% - 50%.

Effect of fly ash and water in hydrated SRPC-A FTIR study was

conducted by Thiruppathi et al (2009) and studied both hydrated sulphate

resisting portland cement (SRPC) and fly ash (fly ash 20%, 30% and 50%)

composite with two different waters. Among the three percentages of fly ash

addition, 30% addition was found to be optimum. The samples (SRPC and

30% fly ash) were analyzed using the fourier transform infrared spectroscopy

(FTIR). It was concluded that increasing the fly ash concentration reduces the

setting time. This is due to the calcium sulfoaluminate (CSA) present in the

fly ash. Result of this study indicated that the performance of the blended

paste was better than the control paste hydrated with distilled water and

effluent water.

Effect of thermal cycles on compressive strength of high volume

fly ash concrete was conducted by Sravana et al (2006). The behaviour of

concrete structures which were exposed to solar temperature variations are

studied. After the basic tests were conducted on M20, M30, M40 and M50

grades of concrete containing OPC with fly ash replacement,

they were exposed for various thermal cycles at different temperatures.

9

The compressive strength of concrete at various thermal cycles of 7, 28, 56

and 90 days were evaluated.

The effect of curing conditions and temperature changes on the

compressive strength of normal and fly ash added concretes were conducted

by Yuksel Esen (2010). The compressive strength of fly ash-added concrete

and normal concrete cured in water and air were compared with their

compressive strength on 7, 14, 21 and 28 days of ages. In addition, the study

investigated temperature-induced changes in the compressive strength of

concrete samples which completed 28 days of curing period. While the

compressive strength of concretes cured in air was observed to be higher in

early days and it was detected to be higher in concretes cured in water in later

days. It was also determined that the compressive strength of fly ash added

concrete was lower than that of normal concrete. The results revealed that

concrete containing fly ash addition was more effective in resisting the effect

of thermal cycles than normal and fly ash replaced cement concrete.

Thermal properties of high-volume fly ash mortars and concretes

were extensively studied by Bentz et al (2011). The characterization of the

thermal properties such as specific heat capacity and thermal conductivity on

mortar and concrete mixtures. Both the raw materials and the finished

products (mortars and concretes) were evaluated using a transient plane

source method. Because the specimens being examined were well hydrated,

estimates of the specific heat capacity based on a law of mixtures, with a

‘bound water’ specific heat capacity value being employed for the water in

the mixture, provide reasonable predictions of the measured performance. As

with most of the materials, thermal conductivity was found to be a function of

density and type of aggregate. The measured values should provide a useful

database for evaluating the thermal performance of high-volume fly ash

concrete structures.

10

Contribution of fly ash to the properties of mortar and concrete was

carried out by Sarath Chandra Kumar and Saha (2011). An overview of the

work carried out on the chemical properties and use of fly ash as

supplementary material in mortar and concrete were prepared by them. In the

last decade, the use of supplementary cementing materials has become an

integral part of high strength and high performance concrete mix design.

These can be natural materials, by-products or industrial wastes or the ones

requiring less energy and time to produce. One of the most commonly used

supplementary cementing materials is fly ash. Fly ash is a by-product material

obtained from the combustion of coal. It is used as pozzolanic material in

mortar and concrete and it has demonstrated significant influence in

improving the properties like water requirement, workability, setting time,

compressive strength, durability of mortar and concrete.

A study on the strength development of concrete containing fly ash

and optimum use of fly ash in concrete was conducted by Oner et al (2005).

Fly ash was added according to the partial replacement method in mixtures. A

total of 28 mixtures with different mix designs were prepared. 4 of them were

prepared as control mixtures with 250, 300, 350 and 400 kg/m3 cement

content was calculated. Four groups of mixtures were prepared, each group

containing six mix designs and using the cement content of one of the control

mixture as the base for the mix design. In each group 20% of the cement

content of the control mixture was removed, resulting in starting mixtures

with 200, 240, 280 and 320 kg/m3 cement content. Fly ash in the amount of

approximately 15%, 25%, 33%, 42%, 50% and 58% of the rest of the cement

content was added as partial cement replacement. All specimens were moist

cured for 28 and 180 days before compressive strength testing. The efficiency

and the maximum content of fly ash gives the maximum compressive strength

were obtained. Hence, the maximum amount of usable fly ash amount with

the optimum efficiency was determined.

11

Performance of high volume fly ash in concrete structure was

studied in detail by Thangaraj and Thenmozhi (2012). The study was

conducted to evaluate the strength properties of high volume fly ash concrete

(HVFAC) using a cement replacement level of 50%, 55% and 60% in M20

and M25 grades of concrete. In this investigation an attempt was made to

study the strength properties of HVFAC specimens in comparison with

control OPC concrete specimens of same grade. It was observed that the

compressive strength of HVFAC was improved by about 50% cement

replacement by fly ash with 1.5% of plasticizer was equal to control concrete.

The effect of polyester fibres on engineering properties such as

impact strength and abrasion resistance of high volume fly ash concrete was

discussed by Indrajit Patel and Modhera (2011). Design mix of M25, M30,

M35 and M40 of the tested samples include replacement of cement by 50%,

55% and 60% class F fly ash. The research analysis included the test results

of key material like fly ash, fibre, mix design for all grades, 60 minutes,

slump comparison, comparative study of impact and abrasion resistance for

plain and fibre reinforced HVFA at 28 and 56 days age. Comparative studies

of economic gain with HVFA over conventional mix studied by them will be

an effective tool to achieve sustainability issue.

Optimum concrete mixture design using locally available

ingredients was studied by Shamsad Ahmad (2007). The Water/cement ratio,

coarse aggregate/total aggregate ratio and total aggregate/cement ratio are the

key parameters affecting design of a concrete mixture. For specified strength

and durability requirements, a water/cement ratio has to be selected and

should be kept constant. However, coarse aggregate/total aggregate ratio and

total aggregate/cement ratio may be varied to minimize the cement content

within constraints resulting in optimum design of a concrete mix. The present

study presents a laboratory trial procedure for optimum design of concrete

12

mixes using locally available ingredients. The optimization procedure is

formulated to find the minimum cost of a concrete mix by trying different

combinations of coarse aggregate/total aggregate ratio and total

aggregate/cement ratio within their reported optimum ranges, keeping

water/cement ratio constant and using the absolute volume method of

concrete mix design.

Effect of acidic water on strength, durability and corrosion of

concrete was studied by Saravanakumar and Dhinakaran (2010). The use

of poor quality of water in concrete leads to corrosion and ultimately causes

failure in concrete, while use of saline water in concrete affects the properties

of fresh and hardened concrete. A sincere attempt has been made in this study

to investigate the effects of various percentage of NaCl present in water used

for preparing different grades of concrete. In this study, specimens of 108

cubes (150 mm x 150 mm x 150 mm), 36 cylinders (300 mm x 150 mm) and

72 cylinders (102 mm x 51 mm) were cast and cured in various percentages

of NaCl added water to find the workability, strength, durability and corrosion

resistance characteristics of concrete. The effect of corrosion of steel in the

concrete was examined by accelerated electrolytic corrosion method. It was

found that, addition of NaCl up to 30% resulted decrease in compressive

strength, split tensile strength, higher corrosion rate and chloride ion

penetration. However for 20% addition of NaCl these values were found to be

moderate.

Use of production and brackish water in concrete mixtures was

conducted by Ramzi et al (2010). The Sultanate of Oman lies in an arid

region where fresh water sources are scarce. Economic and population growth

spur the need for more housing, schools, roads and many other civil works. In

the construction of such projects, water is needed as a component in concrete

mixing. Contractors in arid regions sometimes faced with the problem of

13

finding water of acceptable quality for their construction work. However,

plenty of production water (oily and brackish water) is produced in the oil

fields during oil production. In 2002, Petroleum Development of Oman

(PDO) produced 130,000 m3/day of crude oil with a corresponding 630,000

m3/day of production water, most of which are disposed off via deep well

injection. This research project was initiated as a possible option for the use of

production water as part of PDO’s policy on sustainable development,

materials efficiency and waste reduction. The main essence of that journal

was to present the results obtained on the use of production (oily) and

brackish water in concrete mixtures. Water samples were obtained from four

PDO asset areas. Nine water samples, including controlled potable (tap) water

were analyzed for pH, total dissolved solids (TDS), chloride, hardness,

alkalinity and sulphates. In addition, cement pastes, mortars and plain

concrete mixtures were prepared by using 100% substitution of potable water.

Nine mixtures were prepared and cured for one and a half years. Mixtures

were tested for initial setting times, compressive strength and flexural

strength. Research analysis indicated that a small decrease was found in the

initial setting times for all cement paste mixtures prepared using production

and brackish water in comparison with potable water. However, such values

still exceeded the minimum 45 minutes initial setting requirement as set forth

in ASTM C150. The use of PDO’s production and brackish water did not

cause any decrease in the compressive or flexural strength measurements of

cement mortars or concrete mixtures in comparison with potable water. In

general, there was no strength reversal with longer curing periods. However,

for most concrete mixtures, the strength tends to level off after three months

of curing. Most production water mixtures resulted in higher strength

measurements than those prepared by using potable water. Further elaborate

research activity is necessary to investigate corrosion potential in reinforced

concrete.

14

A study on the mechanical properties and durability of concrete

made with high-volume fly ash blended cement using a coarse fly ash was

conducted by Bouzoubaa et al (2001). The results were compared with those

of the HVFA concrete in which unground fly ash had been added at the

concrete mixer. The properties of the fresh concrete such as slump, air

content, slump loss, stability of air content, bleeding and setting time were

determined in this study. The properties of the hardened concrete investigated

included the compressive strength, flexural- and splitting-tensile strengths,

Young’s modulus of elasticity, drying shrinkage, resistance to abrasion,

chloride-ion penetration, freezing and thawing cycling and to de-icing salt

scaling. The results showed that except for the resistance of the concrete to

the de-icing salt scaling, the mechanical properties and the durability of

concrete made with this blended cement were superior to the concrete

prepared by mixing unground fly ash and the cement separately. Thus the

production of HVFA blended cement offers an effective way for the

utilization of coarse fly ash to meet the fineness requirements of ASTM C

618.

Variation in concrete strength due to cement was carried out by

Karthik Obla (2010). To attain good concrete quality, a concrete producer has

to maintain a low standard deviation of compressive strength. In order to

reduce the strength standard deviation, the material, manufacturing and

testing variations need to be lowered. The article discussed in length, the

concrete strength variability due to variation of cement from a single source.

The effect of salt water in the production of concrete was studied

by Mbadike and Elinwa (2011). A study was conducted by using 90 concrete

cubes for compressive strength test. Out of 90 concrete cubes prepared, 45

cubes were cast using fresh water and another 45 cubes were cast using salt

water. In order to find out flexural strength test, a study was conducted on 90

concrete beams. Forty five concrete beams were cast using fresh water and

15

another 45 concrete were cast using salt water. The concrete cubes and the

beams were cured for 7,21,28,60 and 90 days. The result of the average

compressive strength of concrete obtained using fresh water of mix ratio (1 :

1.51 : 4.01), water cement ratio (0.47) ranges from 27.35-42.34N/mm2 while

that of salt water ranges from 25.24-38.81N/mm2 for the hydration period of

7, 21, 28, 60 and 90 days. The flexural strength of concrete obtained using

fresh water of the same mix ratio and water cement ratio ranges from 6.60 -

11.20N/mm2 for 7, 21, 28, 60 and 90 days hydration period while that of salt

water ranges from 5.98-11.04N/mm2 for the same hydration period. For the

mix ratio (1 : 1.61 : 4.03) and water cement ratio (0.55), the average

compressive strength of concrete obtained using fresh and salt water ranges

from 27.26 - 40.80N/mm2 and 24.68 - 39.13N/mm2 respectively while the

flexural strength ranges from 6.55 - 11.13N/mm2 and 6.26 - 10.76N/mm2 for

fresh and salt water respectively. For the mix ratio (1: 1.66 : 4.24) and water

cement ratio (0.50), the average compressive strength of concrete obtained

using fresh and salt water ranges from 25.05 - 38.13N/mm2 and 23.58 -

36.03N/mm2 respectively while the flexural strength ranges from 6.18 -

9.88N/mm2 and 6.15 - 10.39N/mm2 for fresh and salt water respectively. The

initial and final setting time of cement using fresh water was 50 minutes and

587 minutes while that of salt water was 55 minutes and 605 minutes

respectively.

Bond strength of high-volume fly ash concrete was studied by

Michael Hayse Wolfe (2011). In this thesis, the author explored

the feasibility of using high-volume fly ash (HVFA) concrete for structural

applications by testing the materials reinforcement bond properties. A series

of pull-out tests and beam splice tests were performed on specimens with 70

percent fly ash replacement of cement and then compared with control

specimens cast from 100 percent portland cement mix. The pull-out tests

were performed on specimens with and without confinement (transverse

reinforcement) along the splice zone. The pull-out test is a comparative test,

16

which can be drawn based on the fact that the HVFA specimens demonstrated

similar bond strengths to the control specimens (based on maximum modified

applied load). The findings from the pull-out tests indicated that the use of

high volume fly ash as a cement substitute is not only feasible in terms of

bond but also superior in some cases.

The High-volume fly ash (HVFA) concrete was developed by Van

den Heede and De Belie (2010). In order to reduce the environmental

impact of cement production. By replacing at least 50% of ordinary portland

cement with pozzolanic fly ash, an important reduction in greenhouse gas

emission was achieved. However, this proposition is only valid if HVFA

concrete is as durable as portland cement concrete. In order to deal with

differences in durability, the amount of concrete needed in a 1 m³ structure

with a service life of 50 years is chosen as functional unit for life cycle

assessment (LCA). This way, additional emissions caused by structure

replacement over time were included. Accelerated test procedures for

carbonation as well as freezing and thawing with deicing salts were used.

Based on long-term damage prediction, a significant reduction in

environmental impact was observed for concrete mixtures with 50% fly ash

when subjected to carbonation. However, freezing/thawing resistance was

poor.

The carbonation depth of concrete made with fly ash was studied

by Ruixia and Huijian (2011).The effect of replacing ratio of fly ash (FA)

(0-25%), ambient relative humidity, temperature, curing age (1, 3, 7, 28 and

42days) and w/c (0.5, 0.55 and 0.6) on carbonation of concrete made with

low-volume FA was studied by them. The process was accelerated in artificial

carbonation laboratory by controlling 20% concentration of CO2, 20oC-60oC

temperature and 30%-70% relative humidity. Based on the accelerated test

and carbonation mechanism, a mathematical model for predicting the

carbonation depth of concrete made with low-volume FA was proposed, in-

17

which the replacing ratio of FA, curing age, ambient temperature, ambient

relative humidity and ability of concrete absorbing CO2 were considered. The

contrastive results showed that the carbonation model for predicting

carbonation depth had good performance. The analytical results of their work

showed a greater potential to predict the carbonation depth for the ongoing

practical purposes.

Assessment of corrosion and durability characteristics of copper

slag admixed concrete was carried out by Brindha et al (2010). The M20

grade concrete was used and the tests were conducted for various proportions

of copper slag admixed concrete. The partial replacement with sand of 0%,

20%, 40% and 60% cement of 0%, 5%, 15% and 20% and combination of

both 60% sand + 40% copper slag for fine aggregate and 85% cement+15%

copper slag for cement in concrete. The obtained results were compared with

those of control concrete made with ordinary portland cement and sand.

The results of a study on the mechanical properties and durability

of concrete made with high-volume fly ash (HVFA) blended cement produced

in a cement plant was conducted by Bouzoubaa et al (2001). The tested results

obtained were compared with those of a control concrete made with a

commercially available ASTM Type I cement. The control concrete had 28-

days compressive strength comparable to that of the concrete made with the

HVFA blended cement. The use of the HVFA blended cement improved

significantly the durability characteristics of the concrete. The only exception

was the resistance to the de-icing salt scaling as determined in ASTM C 672

test.

Comparative analysis of performance of portland cement and nano

silica and silica fume was evaluated by Tobon et al (2010). The physical

properties of Colombian portland cement type III was replaced with

nanosilica in percentages of 1, 3, 5 and 10%. The determined properties were

18

fluidity, normal consistency, setting times, heat of hydration and compressive

strength on pastes and mortars. A comparative analysis was also made with

samples substituted with commercial silica fume in percentages of 5, 10 and

15%. The results showed that the nanosilica from 5% beginning to have a

major positive influence on the mechanical strength of mortars and with a

10% of substitution improvements in compressive strength up to 120% with

respect to the control sample for one day of curing was achieved. For longer

curing time the improvement showed a slight decrease and with near 80% of

strength improvement attained after 28 days of curing.

The durability of high-volume fly ash concrete was discussed by

Camoes (2002). The evaluation of the possibility of producing low portland

cement content concrete with enhanced or even high performances, including

local by-products such as fly ash and common low cost aggregates without

any previous treatment, i.e., as received. Three different concrete mixtures

(incorporating large quantities of fly ash) were made and their mechanical,

workability and durability properties were characterized. The total binder

used (400 kg/m3, 500 kg/m3 and 600 kg/m3) was composed by 40% of

portland cement and 60% of fly ash by mass of the total cementitious

material. The overall results obtained show that the compressive strength

requirements were fulfilled and these concretes are highly durable.

The pozzolanic materials in portland cement concrete mixtureshydrate forming new calcium silicate hydrates which improve durability ofconcrete structures was studied by Mauricio Lopez and Jose Tomas Castro(2010). The role of natural pozzolans in concrete performance was studiedand the characterized porosity and pore connectivity of concrete mixtures asfunction of the content of natural pozzolans. The experimental programmeasured the compressive strength and permeability of concrete mixtureswith different levels of cement replacement by natural pozzolans between 28and 84 days of age, so the effect of pozzolans could be assessed as a function

19

of time. These results clearly showed that the gain in impermeability ofconcrete due to the use of natural pozzolans is much more pronounced incompressive strength. For instance, concrete with 33% of cement replaced bynatural pozzolans had a compressive strength 27% lower than those with nopozzolans replacement. Nevertheless, their impermeability was approximately200% superior to those with no pozzolans replacement. It can be concludedthat it is important to control compressive strength and permeabilityindependently, because they are affected very differently by pozzolanicreactions and also for taking advantage of natural pozzolans in concrete. It isimportant to specify and measure the permeability at later stages.

The results of an experimental investigation to evaluate themechanical properties of concrete mixtures in which fine aggregate (sand)was partially replaced with Class F fly ash was carried out by Rafat Siddique(2003). The fine aggregate was replaced with five percentages 10%, 20%,30%, 40% and 50% of Class F fly ash by weight. Tests were performed forproperties of fresh concrete. Compressive strength, splitting tensile strength,flexural strength and modulus of elasticity were determined at 7, 14, 28, 56,91 and 365 days. Test results indicated significant improvement in thestrength properties of plain concrete by the inclusion of fly ash as partialreplacement of fine aggregate and can be effectively used in structuralconcrete.

The carbon dioxide emission from portland cement production and

to provide a way to effectively use fly ash was conducted by Hardjito (2007).

The fly ash and the by product materials from burning coal especially in

power stations are available abundantly worldwide. Their availability is

increasing and yet their utilization to till date is very low. Without proper

plan, the management of fly ash may incur cost and potentially harm the

natural environment as well. These results discussed the technology and the

current progress of research on utilizing fly ash in concrete.

20

Prediction of compressive strength of concrete from early age test

result was discussed by Monjurul Hasan and Ahsanul Kabir (2011). The

recommended procedure to ensure the concrete strength was to perform

cylinder test. In this research activity, an attempt was made to develop a

simple mathematical model based on concrete’s nature of strength gain to

predict the compressive strength of concrete at 28 days from early age results.

The model was a simple equation known as a rational polynomial. The

proposed model had a good potential to predict concrete strength at different

age with high accuracy.

The effect of superplasticizer type on the performance of high-

volume fly ash concrete was discussed by Borsoi et al (2000).

Superplasticized high-volume fly ash concretes with 50% of portland cement

replacement were manufactured by using two different chemical admixtures

based on sulfonated naphthalene (SN) or acrylic polymer (AP). Portland

cement with a Blaine fineness of about 400 or 500 m2/kg was replaced by

50% of ground or un-ground fly ash. Due to the lower w/cm, the strength of

the concretes with the acrylic polymer was significantly higher with respect to

those with SN. The better performance of the AP superplasticizer, in terms of

compressive strength was obtained at an early and later age independently of

the curing temperature (5 and 20°C) and the fineness of the portland cement

and fly ash. Due to the lower w/cm in concrete with the AP admixture with

respect to those with the SN superplasticizer, the durability behaviour of high-

volume fly ash concrete can be further improved in terms of lower penetration

rate of CO2 or Chloride ions.

Samson and Elangovan (2011) discussed on geochemical

investigations of the groundwater samples from Namakkal district of Tamil

Nadu to assess the quality of groundwater used for drinking purpose during

the premonsoon season. Seventy three samples were collected all over the

21

district except the areas of structural hills. The collected samples were tested

for the following parameters, “electrical conductivity, turbidity, pH, total

hardness, iron, chlorides, total dissolved solids, calcium, magnesium,

potassium, manganese, sulphate, nitrate, nitrite and total alkalinity”. The test

results were interpreted using Indian standard specification IS: 10500 – 1991

and statistical plots. Higher values of turbidity, total hardness, total dissolved

solids, sulphate and total alkalinity influence the quality of groundwater of the

study area and however some of the samples collected from east, west and

central part of the study area were found to be potable. Turbidity is high in the

groundwater samples collected from the locations along the river bank which

envelops the study area at south west side. The groundwater qualities of north

and south side of the study area were unsuitable in any one of the parameters

governing the quality.

Samson and Elangovan (2011) had carried out hydro chemical

analysis and estimation of groundwater quality in Namakkal district in west

part of Tamilnadu state. The district covers an area of 3404 sq.km falling

within the semi-arid region and frequently facing water scarcity as well as

quality problems. The major sources of employment are agriculture and

animal husbandry. Water samples were collected from 73 locations during pre

and post monsoon seasons of the year 2007 and were subjected to analysis for

chemical characteristics. Mixed Ca-Mg-Cl and Na-Cl hydrochemical species

exist during pre monsoon season. Na-Cl species exist during post monsoon

season in the study area. Suitability of water for irrigation is evaluated based

on irrigation quality guide lines and Wilcox, Doneen and USSL

classifications. Salinity hazard risks are present in 8.2 % of the pre monsoon

samples and in 35.62% of the post monsoon samples. Sodium hazard were

discussed with the help of sodium accumulation indices such as RSC, SSP

and ESP. Sodium accumulation indices are high during premonsoon season

than the post monsoon season. The predominant mechanism controlling

22

groundwater chemistry from Gibbs diagram were found to be rock interaction

during both the seasons. The controlling mechanisms of evaporation

dominance and surface influences were also found during post monsoon

season in addition to the rock interactions.

2.3 DURABILITY OF HIGH VOLUME FLY ASH CONCRETE

Durability of high-volume fly ash concrete was presented by

Camoes (2002). He discussed a method to evaluate the possibility of

producing low portland cement content concrete having enhanced and even

high performing cement content concrete by mixing with locally available fly

ash and common low cost aggregates without any previous treatment. Three

different concrete mixtures (incorporating large quantities of fly ash) were

made and their mechanical, workability and durability properties were

characterized. The total binder used (400 kg/m3, 500 kg/m3 and 600 kg/m3)

was composed by 40% of portland cement and 60% of fly ash by mass of the

total cementitious material. The overall results obtained show that the

compressive strength requirements are fulfilled and that these concretes are

highly durable.

Durability of concrete incorporating large volumes of low-quality

fly ash was carried out by Linhua Jiang et al (2004).They studied about the

carbonation, corrosion of steel reinforcement in concrete and corrosion

resistance of concrete, incorporating large volumes of low quality fly ash

(LVLQFA). The effect of concentration of carbon dioxide used in the

experiment on estimating the carbonation resistance of LVLQFA concrete

were also investigated. Test results showed that the LVLQFA concrete with

an activator had good carbonation and corrosion resistances of steel

reinforcement. The corrosion resistance of LVLQFA concrete was better than

that of the control concrete. The concentration of carbon dioxide used in the

23

experiment had considerable effect on estimating the carbonation resistance of

LVLQFA concrete.

The importance of microstructural understanding for durable and

sustainable concrete was carried out by Karen Scrivener (2009) and focused

on the importance of micro structural studies for understanding concrete

durability. Three examples - sulphate attack, alkali silica reaction and

bacteriogenic corrosion in sewers were used to illustrate the pitfalls which can

arise from conventional empirical testing, particularly when blended or non-

portland cements were used. The pressure to provide more sustainable

cements with lower CO2 emissions will inevitably lead to major changes in

the chemistry of concrete. Therefore it is important to properly understand

durability and the micro structural mechanisms involved to design appropriate

performance based criteria to use the increasing diversity of concrete which

will become available.

Durability behaviour of high-volume fly ash concrete was studied

by Cox and De Belie (2007) and discussed on the results of durability tests

on 4 concrete mixtures, each with a different fly ash replacement level,

namely 0, 35, 50 and 67 %, at the age of 1 and 3 months. The resistance to

freezing and thawing with and fly ash mixtures appeared to exhibit a good

freezing and thawing resistance while the influence of deicing salts was

different on the surface and the inside of the concrete specimens. The 50 and

67% fly ash mixture exhibited a very high chloride migration coefficient at

the age of 1 month but after 3 months of curing, all the mixtures showed a

good chloride migration resistance.

Concrete durability through high volume fly ash concrete (HVFC)

was reviewed by Vanita Aggarwal et al (2010). They brought to light about

the application of concrete in the construction work even in the olden days

24

of Greek and Roman civilization. But for numerous reasons, the concrete

construction industry is not sustainable. It consumes a lot of virgin materials

and the principal raw material of concrete is cement which is responsible for

greenhouse gas emissions causing a threat to environment through global

warming. Therefore, the industry had seen various types of concrete in search

of a solution to sustainable development. Infrastructural growth has witnessed

many forms of concrete like high strength concrete, high performance

concrete, self-compacting concrete. The latest in this series is high volume

fly ash concrete (HVFC). The paradigm had shifted from one property to

other of concrete with advancement in technology. The construction

techniques have been modernized with focus on high strength, dense and

uniform surface texture, more reliable quality, improved durability and faster

construction. This paper discussed the development of high volume fly ash

concrete for construction with reference to its predecessors like HSC and

HPC. The literature available on use of fly ash in concrete had been

extensively searched for getting a platform for the start of research on use of

high volume fly ash in concrete pavements.

Hardened concrete properties and durability assessment of high

volume fly ash concrete was studied by Kyle Marie Marlay (2011). He

discussed about the hardened concrete and durability performance of several

high-volume fly ash (HVFA) concrete mixes. The various HVFA concrete

mixes evaluated within this study consisted of 70 percent replacement of

portland cement by weight of cementitious material and water-to-cementitious

ratios (w/cm) ranging from 0.30 to 0.45. Studies were conducted on hardened

properties including compressive strength, flexural strength, splitting tensile

strength and modulus of rupture. A shrinkage analysis was also performed to

evaluate drying and free shrinkage. The durability performance of the HVFA

concrete was also evaluated. Results obtained from the tests revealed that

compressive strengths of HVFA concrete are comparable to portland cement

25

concrete with a reduced w/cm. Also, a reduction in concrete shrinkage was

observed for HVFA concrete.

Reinforcing steel corrosion in high volume fly ash concrete was

conducted by Qian et al (2004). The corrosion of reinforcing steel in high-

volume fly ash (HVFA) concrete slabs were investigated. Chloride ions were

introduced into the reinforced concrete slab specimens through a natural

diffusion and migration process. That is, immersion in a ponding solution of

3.4 percent sodium chloride (NaCl). Two HVFA concrete specimens with

ASTM Class C and Class F fly ash were made with a water-to-cementitious

materials ratio (w/cm) of 0.32. Besides, three control concretes specimens

with a w/c of 0.32, 0.43 and 0.55 were also investigated. The concrete cover

depths to the steel reinforcing bars ranged from 13 mm to 76 mm. The

corrosion of the reinforcing steel bars was evaluated by means of half-cell

potential, linear polarization and AC impedance techniques. The results

indicated that the concrete incorporating Class C fly ash showed the best

performance with respect to chloride-induced reinforcing steel corrosion,

followed by the control concrete with the w/c of 0.32 and concrete containing

Class F fly ash. The control concretes with w/c of 0.43 and 0.55 showed the

poorest performance.

The carbonation, corrosion of steel reinforcement in concrete and

corrosion resistance of concrete, incorporating large volumes of low quality

fly ash (LVLQFA) was studied by Linhua Jiang et al (2004). The effect of

concentration of carbon dioxide used in the experiment on estimating the

carbonation resistances of LVLQFA concrete were also investigated. Tested

results show that the LVLQFA concrete with an activator had good

carbonation and corrosion resistances of steel reinforcement. The corrosion

resistance of LVLQFA concrete was better than that of the control concrete.

The concentration of carbon dioxide used in this experiment had considerable

effect on estimating the carbonation resistance of LVLQFA concrete.

26

Prevention of corrosion in concrete using fly ash concrete mixes

was discussed by Keith Bargaheiser and Tarunjit Butalia (2003). They

discussed the benefit of using fly ash in preventing corrosion damage in

concrete. Reduced permeability, lower water/cement ratio, decreased drying

shrinkage/cracking and increased durability are all benefits of fly ash

concrete.

The effect of curing and concrete quality on the durability of

concrete with high-volumes of supplementary cementing materials was

studied by Michael Thomas (2004). The sustainability issue for concrete

construction industry was such that the concrete structures suffered from

durability issues which had an adverse effect on the resource productivity of

the industry. Potential and optimize utilization of cementing material in

concrete would definitely lead towards sustainable concrete construction. Use

of industry waste and by products like fly ash, silica fume, grounded granular

slag to partly replace cementing material to concrete system addresses all

three sustainability issues, its adoption will enable the concrete construction

industry to become more sustainable.

Theoretical and experimental study of microcell and macro-cell

corrosion in patch repairs of concrete structures was undertaken by Shiyuan

Qian et al (2006). The patch repair is commonly used to rectify localized

corrosion induced damage in concrete structures. However, inadequate

durability in patch repair systems caused by new corrosion attack was

prevalent. This study examined the corrosion mechanism and the concept of

compatibility in patch repair systems from fundamental electrochemical

principles and experimental verification. It was illustrated that both macro-

cell and microcell corrosion mechanisms could play significant roles and the

total corrosion could be underestimated if the later is overlooked. Although

the incompatibility serves as the driving force for the macrocell corrosion, in

27

light of corrosion kinetics, it was shown that the corrosion magnitude depends

more on the individual corrosion kinetics of the anode or cathode.

The predeterminate model of corrosion rate of steel in concrete was

expressed by Ming-Te Liang et al (2005). The corrosion rate of steel in

concrete, the influence of concrete carbonation exponent and cover thickness

to steel corrosion rate and relationships among steel diameter, cover thickness

and exposure time to steel corrosion rate were mainly studied. It was shown

that (1) the steel corrosion rate was increased when the concrete carbonation

exponent increased. (2) The steel corrosion rate decreased when a mild carbon

steel with circular diameter in concrete increased. The more the concrete

carbonation exponent becomes larger, the more the effect of steel diameter

obviously appeared. (3) The steel corrosion rate increased when the concrete

cover thickness decreased. (4) The steel corrosion rate obviously increased

when the exposure time decreased. The results of present studies were

discussed in comparison with earlier findings.

Comparing corrosion measurement methods to assess the corrosion

activity of laboratory OPC and HPC concrete specimens was discussed by

Hamid Soleymani and Mohamed Ismail (2004). They explained that the

corrosion of reinforcing steels in concrete was the main reason for the

deterioration of bridge decks. An accurate method for measuring corrosion

was a fundamental prerequisite for the detection of damaged areas and for

planning an effective method for repairing bridge decks. A laboratory study

was conducted to estimate the corrosion activity of a reinforcing steel

embedded in two types of concrete, ordinary and high-performance, using

different corrosion measurement methods. Results indicated that Tafel plot

(TP), linear polarization resistance, half-cell potential (HCP) and chloride

content methods would assess the same level of corrosion activity in only

24% of specimens.

28

Corrosion measurements of steel reinforcement in concrete exposed

to a tropical marine atmosphere was revealed by Pech-Canul and Castro

(2002). The time for the onset of active corrosion was shorter for rebars in

concretes with a high water-to-cement (w/c) ratio compared to that for rebars

in low w/c ratio concrete. Results also indicate, as expected, that for equal

periods of exposure, nominal corrosion current density (icorr) values were

generally higher for rebar in concrete with higher w/c ratio than those for

rebar in low w/c ratio concrete. Analysis of the observed impedance spectra in

terms of a modified Randles circuit in which the ideal capacitor is replaced

by a constant phase element (CPE) appeared to be a reasonable

approximation.

Corrosion of steel bars with respect to orientation in concrete was

exposed by Tarek Uddin et al (1999). Corrosion of steel bars (main steel and

stirrups) with respect to the orientation in concrete is presented herein. A

detailed study on macrocell and mircocell corrosion of steel bars in concrete

was conducted on horizontal and vertical steels depending on the casting

direction. The horizontal steel was divided into top and bottom halves. The

study was conducted with chloride ions in concrete. Water-cement ratios were

0.5 and 0.7. The electrochemical investigations and microscopic and physical

observations of steel bars were performed. The study also focussed on the

influence of stirrup on macrocell formation of main steel and corrosion of

plain and deformed steel bars. The study concluded that orientation of steel

bars had a significant influence on macrocell and microcell corrosion of steel

bars in concrete. Formation of gaps under the horizontal steels caused

significant corrosion. Stirrups played an important role in increasing

macrocell corrosion of main steel. It was found that deformed bars corroded

when compared with plain bars.

29

A rapid cyclic voltametric method for studying cement factors

affecting the corrosion of reinforced concrete was studied by Frank Foulkes

and Patrick McGrath (1999). The technique employed a cement electrode

consisting of an iron or steel wire embedded in a miniature cylinder of

hardened cement paste. The rapid cyclic voltametric method was fast,

reproducible and provided information on the corrosiveness of the pore

solution environment surrounding the embedded metal. The usefulness of the

method was demonstrated by showing how it could be used to evaluate the

threshold chloride content of hardened ordinary portland cement paste at

which corrosion begins and by using it to evaluate the relative efficacy of

several admixed corrosion inhibitors.

Electrochemical experimental measurement of macrocell corrosion

half-cell potential replicating the re-corrosion of actual refurbished works in

RC Structures was discussed by Raja Rizwan Hussain (2011). In this paper

electrochemical experimentation had been conducted replicating the actual

patch repair work in the construction field. Steel reinforced concrete

experiment specimen was cast having no chloride content in the middle

portion and 5% chloride at the two ends. Here, the middle portion with no

chloride content simulates the actual patch of new concrete in the repaired

portion of reinforced concrete affected by chloride induced corrosion. From

the experiment results it was found that the specimen having no chloride

content at the middle portion showed high corrosion potential and chloride

contaminated both sides of the specimen showed even more corrosion than

before being repaired due to the separation of anode and cathode and

development of a macro-cell. The research indicated that much of the needed

research to focus on identification of corrosion mechanisms to effectuate the

successful patch repair in reinforced concrete structures.

30

Effect of condensed silica fume on steel corrosion in concrete was

studied by Gjorv (1995). In this paper current experience was reviewed on

how the presence of condensed silica fume (CSF) may affect the electrolytic

conditions in concrete and hence, the ability of concrete to protect embedded

steel against corrosion. Even in the presence of large amounts of CSF, the

passivity of embedded steel will not be destroyed. Decreased permeability

will reduce the rate of carbonation. In a chloride-containing environment,

resistance to chloride penetration will be substantially increased. Oxygen

availability will not be affected much. However even if passivity becomes

broken, either by carbonation or by penetrating chlorides, the electrical

resistivity may be so high that steel corrosion will not represent any practical

problem. If properly dispersed CSF is combined with a low water-cement

ratio and proper curing, it appears that concrete structures with an excellent

performance can be constructed even in the most aggressive environment.

Corrosion of reinforcing steel in concrete, effects of materials, mix

composition and cracking was explained by Tom Lorentz and Catherine

French (1995). This paper summarized the results from an experimental

investigation regarding corrosion of reinforcing steel in concrete. Variables

included were condensed silica fume (CSF) content, type and condition of

reinforcement coating, effect of entrapped air and effect of cracking. Test

specimens were subjected to an accelerated corrosion-inducing environment

for a period of 3.5 to 48 weeks. Comparisons of specimens with condensed

silica fume (CSF) concentration levels of 0, 7.5, or 10 percent indicated the

existence of an optimum level of CSF after which corrosion resistance was

not further enhanced. The epoxy-grit coating on undeformed reinforcement

performed well in resisting the corrosive environment. Reinforcing steel with

intentionally damaged epoxy coatings did not indicate significant levels of

corrosion during the experimental period despite high levels of chloride

present in the concrete. No direct relationship between entrapped air content

31

and specimen current or resistance values was found. Cracking had a

significant effect on corrosion of reinforcing steel in concrete.

Corrosion resistance performance of fly ash blended cement

concrete was studied by Hussain and Rasheeduzzafar (1994). Corrosion

initiation time and corrosion rate of steel reinforcement in the post-corrosion

initiation period were measured for plain and fly ash blended cements. To

explain the corrosion-resistance performance of steel in fly ash blended

cement concrete, the effect of fly ash blending on pore solution composition

and physical characteristics of hardened concrete have been evaluated.

Results show that incorporation of 30 percent fly ash in Types V and I cement

concrete increased corrosion initiation time by 2.5 and 1.9 times.

Corrosion rate was reduced 1.6 times due to fly ash blending with Type I

cement. Results of pore solution tests show that blending of 30 percent fly ash

to both parent plain cements reduced OH – concentration and unbound

chlorides and caused moderate change in Cl -/OH - ratio of the pore solution.

Partial cement replacement by fly ash caused significant pore refinement,

reduced permeability to water and chloride ions and increased electrical

resistivity. The observed superior corrosion-resistance performance of fly ash

blended cement concrete compared to plain cement concrete in terms of

corrosion initiation time and corrosion rate is attributable to the improved

physical structure of the cement matrix to fly ash blending.

Non-destructive measurement of corrosion state of reinforcing Steel

in concrete was studied by Monteiro (1998) and presented a new non-

destructive method that uses a multi electrode electrical resistivity array to

measure the complex impedance along the surface of a concrete structure in

order to determine the position of the reinforcing bars and their corrosion

32

state. A laboratory demonstration of the new method was conducted on a

concrete block with four embedded steel reinforcing rods, each with a

different surface preparation to simulate a variety of conditions such as

corroded, clean, coated bar and gold-plated. The gold-plated bar was intended

to represent a condition of complete chemical inertness and the painted bar

was intended to represent the condition that should offer only capacitive

coupling to the concrete. The surface spectral resistivity method was able to

locate the bars and distinguish between the different surface impedances of

the bars and therefore, it can be a useful tool in assessing corroded

reinforcement in concrete structures.

Rebar corrosion rate measurements for service life estimates were

expressed by Klinghoffer Oskar and Thomas Frolund et al (2000). In this

paper a rapid non-destructive polarization technique had been developed for

application to reinforced concrete structures. This technique, called the

galvanostatic pulse method, was based on the polarization of reinforcement

by means of a small constant current. The applied current resulted in an

exponential anodic change of the reinforcement potential. The corrosion rate

can be deduced from the nature of this potential change if the corroding area

of the reinforcement below the concrete surface is known. Equipment had

been developed based on this principle, which enabled corrosion rate

measurements to be made in less than 10 seconds. The half-cell potential and

the electrical resistance of concrete were measured simultaneously. Modern

reliability based methods of evaluating the residual service life of

deteriorating structures needed factual data of the key parameters of ongoing

deterioration mechanisms.

33

2.4 PREDICTION OF STRENGTH OF HIGH VOLUME FLY

ASH CONCRETE

Predicting density and compressive strength of concrete cement

paste containing silica fume using Artificial Neural Network was studied by

Rasa et al (2009). The 28-days compressive strength and saturated surface

dry (SSD) density values were considered as an aim of the prediction. A total

of 600 specimens were selected. The system was trained and validated using

350 training pairs chosen randomly from the data set and tested using the

remaining 250 pairs. Results indicated that the density and compressive

strength of concrete cement paste could be predicted much more accurately

using the ANN method compared to existing conventional methods, such as

traditional regression analysis, statistical methods, etc.

Prediction of slump in concrete using Artificial Neural Network

was conducted by Agrawal and Sharma (2010). They discussed about the

possible applicability of Neural Networks (NN) to predict the slump in high

strength concrete (HSC). Neural Network models were constructed, trained

and tested using the available test data of 349 different concrete mixes of

high strength concrete (HSC) gathered from a particular ready mix concrete

(RMC) batching plant. The most versatile Neural Network model was

selected to predict the slump in concrete. The data used in the Neural Network

models were arranged in a format of eight input parameters that covered the

cement, fly ash, sand, coarse aggregate (10 mm), coarse aggregate (20 mm),

water, super-plasticizer and water/binder ratio. To test the accuracy for

predicting slump in concrete, the final selected model was further used to test

the data of 40 different concrete mixes of high strength concrete (HSC) taken

from the other batching plants. The results were compared on the basis of

error function.

34

Early age strength prediction for high volume fly ash concrete using

maturity modeling was studied by Sushant Upadhyaya (2008). He had

discussed about the beneficial effects of high in-place hydration might be able

to compensate the slower rate strength gain of HVFA concrete that was

typically observed when tested in standard laboratory conditions. In this

effort, the maturity-based technique was employed. In addition, different

methods (match-cured cylinders and pullout testing) were used to estimate the

early-age in-place strength of HVFA concrete to confirm the maturity

predicted strengths. The results have shown that the standard and field-cured

cylinder strengths underestimate the in-place concrete strength. Higher in-

place temperatures due to the mass characteristics of structural elements

resulted in increased early age in-place strengths, adequate for construction

scheduling, as measured by match-cured cylinders, pullout testing and the

maturity approach. An extensive investigation on the use of the traditional

and alternative maturity principles was examined in order to identify it’s

applicability to these types of mixtures and to identify potential adjustments

to the maturity modeling as applicable to HVFA concrete mixtures. Finally, a

maturity-based approach was developed for estimating in-place strength of

HVFA mixtures to assist the construction industry in implementing the results

of this study.

The potential for utilizing concrete mix properties to predict

strength at different ages was studied by Zain et al (2010). It was a powerful

tool to predict its compressive strength at different ages. Novel mathematical

models were proposed and developed using multiple non-linear regression

equations to predict the concrete strength. The variables used in the prediction

models, such as the mix proportion elements, were statistically analysed.

According to the analysis, the models provided a good estimation of

compressive strength and yielded good correlation with the data used in this

35

study. The correlation coefficients were 0.995 for the prediction of 7 and 28

day compressive strength. Moreover, the proposed models proved to be a

significant tool in predicting the compressive strength of different concretes

despite variations in the data used to validate the model.

2.5 STATISTICAL ANALYSIS IN STRENGTH OF CONCRETE

Statistical modelling of fiber reinforced high performance concrete

was studied by Maruthachalam et al (2012). They discussed about the

statistical tools to test different properties of fibre reinforced high

performance concrete (FRHPC) using polyolefin macro-monofilament fibre

(PMM fibre) PMM fibre serves to effectively anchor the fibres into concrete

thus resisting matrix pullout and enhancing the concrete’s performance even

after it had developed stress cracks. Generalized coded equations were

established with the raw materials used and mix design was conducted using

absolute volume method. Test results showed that a simple linear model was

adequate to predict the mechanical and durability properties of FRHPC. This

statistical analysis assured reasonable response prediction. Statistical

approach had proved to be a useful tool for fibre reinforced high performance

concrete to predict different properties.

Applications of statistical models in proportioning medium-strength

self-consolidating concrete was studied by Mohammed Sonebi (2004). He

reviewed the statistical models obtained from a factorial design that was

carried out to determine the influence of four key parameters on filling ability,

passing ability, segregation and compressive strength. These parameters were

important for the successful development of medium-strength SCC (MS-

SCC). The parameters considered in the study were the contents of cement

and pulverized-fuel ash (PFA), water-powder ratio (W/P) and dosage of

HRWRA. The responses of the derived statistical models were slump flow,

fluidity loss, rheological parameters, Orimet time, V-funnel time, L-box, J

36

Ring combined with Orimet, J Ring combined with cone, fresh segregation,

and compressive strength at 7, 28, and 90 days. This paper established the

usefulness of the mathematical models as tools to facilitate the test protocol

required to optimize MS-SCC.

Development of analytical method using classical regression

technique was explained by Jasbir Singh et al (2012). The study was oriented

towards development of analytical method and prediction of real relationship

between absorbance and concentration variables while conforming to

validation parameters. The method was assessed with respect to all requisite

principle parameters like specificity, precision, range and inter/intra-day

variations along with linearity/non-linearity (model generation) and balancing

of the variance at various concentration levels. The specificity was notified

from constant absorbance and non-shifting absorbance wavelength maxima

max) of unspiked and spiked samples. The RSD value <5.0% for absorbance

readings of various samples. The classical approach predicted the real

relationship between concentration and absorbance values and can be applied

similarly to other spectroscopic techniques for analytical methods

development.

Multiple regression model for compressive strength prediction of

high performance concrete was expressed by Zain and Abd (2009).

A mathematical model for the prediction of compressive strength of high

performance concrete was performed using statistical analysis for the concrete

data obtained from experimental work done in this study. The multiple non-

linear regression model yielded excellent correlation coefficient for the

prediction of compressive strength at different ages (3, 7, 14, 28 and 91 days).

The coefficient of correlation was 99.99% for each strength (at each age).

Also, the model gives high correlation for strength prediction of concrete with

different types of curing.

37

2.6 ARTIFICIAL NEURAL NETWORK IN STRENGTH OF

CONCRETE

The prediction of compressive strength of concrete using neural

network was computed by Nath et al (2011). They discussed that the

compressive strength of concrete depends upon proportioning of ingredient of

mix design. Conventional methods of predicting 28-day compressive strength

of concrete are basically based upon statistical analysis by which many linear

and nonlinear regression equations had been constructed to model such a

prediction problem. Artificial Neural Network (ANN) can be effectively used

to predict the compressive strength of concrete. In this paper, Authors

developed a computer code to predict the compressive strength of the

concrete using MATLAB.

Prediction of concrete elastic modulus using adaptive neuro-fuzzy

inference system was conducted by Abdul Kadir Cuneyt Aydin (2006). The

prediction of elastic modulus was one of the fundamental facts of structural

engineering studies. The performance of Adaptive Neuro-Fuzzy Inference

System (ANFIS) for predicting the elastic modulus of normal- and high-

strength concrete was investigated. Results indicated that the proposed ANFIS

modelling approach outperformed the other given models in terms of

prediction capability. According to the results, the ANFIS approach was a

viable tool for modelling the elastic modulus, as it resulted in more accurate

predictions.

Artificial Neural Network approach to predict compressive strength

of concrete through ultrasonic pulse velocity was conducted by Bilgehan and

Turgut (2010). They had discussed in detail about the possible effects of using

ultrasonic pulse velocity (UPV) as a measure of concrete compressive

strength. In this article, an Artificial Neural Network (ANN) approach had

been proposed for the evaluation of relationship between concrete

38

compressive strength and UPV values by using the data obtained from many

cores taken from different reinforced concrete structures having different ages

and unknown ratios of concrete mixtures.

Neural network based identification of material model parameters

to capture experimental load-deflection curve was computed by Novak and

Lehky (2004). A new approach was presented for identifying material model

parameters. This approach was based on coupling stochastic nonlinear

analysis and an Artificial Neural Network. The model parameters played the

role of random variables. The Monte Carlo type simulation method was used

for training the neural network. The feasibility of the presented approach was

demonstrated using examples of high performance concrete for prestressed

railway sleepers and an example of a shear wall failure.

Predicting the initial setting time of self compacting concrete using

Artificial Neural Network (ANN) with the various of learning rate coefficient

was evaluated by Akhmad Suryadi et al (2011). The development of

Artificial Neural Network (ANN) could be used in predicting the setting time

of self compacting concrete (SCC). To predict the setting time of SCC six

input parameters were identified. A total of 250 different data sets of SCC

were collected. Training data sets comprised 120 data entries and the

remaining data entries (130) were divided between the testing and validation

sets. Different combinations of architecture, number of neurons in hidden

layer, different coefficient for learning rate and momentum were considered

and the results were validated using an independent validation data set. A

detailed study was carried out, considering one hidden layer for the

architecture of ANN. The results of the present investigation indicated that

ANN have strong potential as a feasible tool for predicting the setting time of

concrete.

39

An Artificial Neural Network for prediction of long-term strength

properties of steel fiber reinforced concrete containing flyash was conducted

by Okan Karahan et al (2008). An Artificial Neural Network (ANN) model

for studying the strength properties of steel fiber reinforced concrete (SFRC)

containing fly ash was devised. The mixtures were prepared with 0 wt%, 15

wt%, and 30 wt% of fly ash, at 0 vol.%, 0.5 vol.%, 1.0 vol.% and 1.5 vol.% of

fiber. The parameters such as amount of cement, fly ash replacement, sand,

gravel, steel fiber and the age of samples were selected as input variables.

The compressive and flexural strengths of the concrete were chosen as the

output variables. The results obtained from the model and the experiments

were compared and it was found that the suitable algorithm was LM

algorithm. The analysis of variance (ANOVA) method was used to determine

how the experimental parameters affect the strength of these mixtures.

Predicting density and compressive strength of concrete cement

paste containing silica fume using Artificial Neural Network was evaluated

by Rasa et al (2009). The various types of ANN models were developed and

used for different problems. An Artificial Neural Network of the feed-

forward back-propagation type had been applied for the prediction of density

and compressive strength properties of concrete mixtures. A total of 600

specimens were selected. The system was trained and validated using 350

training pairs chosen randomly from the data set and tested using the

remaining 250 pairs. Results indicated that the density and compressive

strength of concrete cement paste could be predicted much more accurately

using the ANN method compared to existing conventional methods, such as

traditional regression analysis, statistical methods, etc.

A Fuzzy-Neuro model for normal concrete mix design was

computed by Nataraja et al (2006). The concrete mix design is a process of

proportioning the ingredients in right proportions. Though it was based on

40

sound technical principles and heuristics, the entire process was not in the

realm of science and precise mathematical calculations. This was because of

impreciseness, vagueness, approximations and tolerances involved. The

development of a novel technique was essential for approximate

proportioning of standard concrete mixes. Distinct fuzzy inference modules in

five layers had been framed to capture the vagueness and approximations in

various steps of design as suggested in IS: 10262-2003 and IS 456-2000. A

trained three layer back propagation neural network was integrated in the

model to remember experimental data pertaining to w/c ratio v/s 28 days

compressive strength relationship of three popular brands of cement. The

results in terms of quantities of cement, fine aggregate, course aggregate and

water obtained through the present method for various grades of standard

concrete mixes were in good agreement with those obtained by the prevalent

conventional method. Details of the system model were described and

comparative graphs were presented.

An Artificial Neural Network (ANN) was evaluated by Bakhary

et al (2007). It was an increasing attention for use in detecting damage in

structures based on vibration model parameters. However, uncertainties

existing in the finite element model used and the measured vibration data may

lead to false or unreliable output result from such network. In this study, a

statistical approach was proposed to take into account the effect of

uncertainties in developing an ANN model. By applying Rosenblueth’s point

estimate method verified by Monte Carlo simulation, the statistics of the

stiffness parameters were estimated. The probability of damage existence

(PDE) was then calculated based on the probability density function of the

existence of undamaged and damaged states. The developed approach was

applied to detect simulated damage in a numerical steel portal frame model

and also in a laboratory tested concrete slab. The effects of using different

41

severity levels and noise levels on the damage detection results were

discussed.

Prediction of 28-days compressive strength of concrete on the third

day using Artificial Neural Network was evaluated by Vahid Alilou and

Mohammad Teshnehlab (2009). They had discussed about the

implementation of an Artificial Neural Network and the same had been

developed for prediction of compressive strength of concrete. A MISO (Multi

input single output) adaptive system had been introduced which can model

the proposed phenomenon. The data had been collected by experimenting on

concrete samples and then the neural network had been trained using these

data. Among 432 specimens, 300 data sample had been used for training, 66

data sample for validation and 66 data sample for the final test of the network.

The 3-days strength parameter of concrete in the introduced structure had

been used as an important index for predicting the 28-days strength of the

concrete. The simulations in this paper were based on real data obtained from

concrete samples which indicated the validity of the proposed tool.

Analytic formulae for concrete mix design based on experimental

data base and predicting the concrete behaviour using ANN technique was

computed by Mostafa Abdeen and Hossam Hodhod (2010). They discussed

about the local Egyptian practice in producing concrete for different structural

applications based on the known properties of cement. Cement had been

produced locally under the Egyptian standards ES 372, 373 and 584 for

ordinary, rapid hardening and sulphate resisting types. In 2007, the Egyptian

standards issued ES 4756 that adopted the European standard EN 197 for

producing cement. This resulted in new types of cements to replace the types

that local construction companies used to apply for decades. Many doubts

appeared about whether the rules applied for concrete mix proportioning were

still valid. In the current research, an experimental investigation of concrete

42

properties is made using two of the locally most common types of cements

CEM I 32.5 R & CEM I 42.5 N. Slump, compressive strength, rebound

number and ultrasonic pulse velocities were investigated for 64 mixes. The

main parameters were type of cement, cement content, water content and

fine/coarse aggregate ratio. Data base was established for the mix proportions

and corresponding properties. Analytic formulae were proposed for utilizing

the collected data base for concrete mix design. Also, using the experimental

data base numerical approach was adopted to simulate the concrete behavior

for different mix proportions. Artificial Neural Network (ANN) technique

was developed in the present work to simulate the concrete slump and

concrete compressive strength for different mix proportions at different ages.

Analysis of strength of concrete using design of experiments and

Neural Networks was conducted by Cheng Yeh (2006). He discussed about

the potential of using experiments and Neural Networks to determine the

effect of fly ash replacements, from 0 to 50% on early and late compressive

strength, from 3 to 56 days, of low and high-strength concrete at water

cementitious material ratios in the range of 0.3–0.7. The article came out with

the following conclusions: 1. Using a simplex-centroid mixture experiment

design, smaller number of experiments needed to be performed to obtain

meaningful data, 2. high correlations between the compressive strength and

the composition of concrete can be developed using the generalization

capabilities of neural network, 3. analyses of variance to test the effects of the

variables and their interactions on concrete strength can be performed, 4. the

strength ratio, i.e., percentage of strength of concrete containing fly ash to

strength of concrete without flyash was significantly reduced as the fly ash

replacement increased.

43

Estimation of concrete compressive strength by using ultrasonic

pulse velocities and Artificial Neural Network was evaluated by Serkan

Tapkin et al (2006). In this study a neural network approach had been

proposed for the evaluation of concrete compressive strength by the use of

ultrasonic pulse velocity values and some other factors. By this tool,

researchers can easily evaluate the compressive strength of concrete

specimens by using the ultrasonic pulse velocity value and some material

properties. The neural network toolbox of MATLAB had been utilised in

order to estimate the compressive strength of concrete specimens without

carrying out real tests, using the predetermined test data. The results for

predicted compressive strength values were analysed in a root mean squared

error basis.

2.7 SUMMARY OF LITERATURE REVIEW

The literature review has been carried out in the areas as factors

influencing strength of high volume fly ash concrete, durability of high

volume fly ash concrete, prediction of strength of high volume fly ash

concrete, statistical analysis in strength of concrete and artificial neural

network in strength of concrete. The review of literature has been helpful in

carrying out the research in experimental study on strength and durability of HVFA

concrete with theoretical modeling using soft technical tools in brackish water

environment.