ww.sciencedirect.com

b i o s y s t em s e ng i n e e r i n g 1 1 6 ( 2 0 1 3 ) 1 1 3e1 1 9

Available online at w

journal homepage: www.elsev ier .com/locate/ issn/15375110

Research Paper

Mechanical properties of concrete containing wasteglass powder and rice husk ash

Rahmat Madandoust*, Reza Ghavidel

Department of Civil Engineering, University of Guilan, P.O. Box 3756, Rasht, Iran

a r t i c l e i n f o

Article history:

Received 1 March 2013

Received in revised form

1 July 2013

Accepted 12 July 2013

Published online 23 August 2013

* Corresponding author. Tel.: þ98 9113314970E-mail address: rmadandoust@guilan.ac.

1537-5110/$ e see front matter ª 2013 IAgrEhttp://dx.doi.org/10.1016/j.biosystemseng.20

The objective was to make use of the combination of waste glass powder (GP) and rice husk

ash (RHA) as replacement for Portland cement. Hybrid mixtures containing 0e20% GP and 0

e20% RHA were prepared. The best values of replacements by GP and RHA, based on the

28-days compressive strength and strength activity index, were determined as 10% and 5%,

respectively. From these results, the properties of hybrid concrete tended to increase with

age due to the development of higher pozzolanic activity. The results also revealed good

evidence that both GP and RHA can be used together in concrete without any adverse

effects.

ª 2013 IAgrE. Published by Elsevier Ltd. All rights reserved.

1. Introduction amorphous and contains relatively large amounts of silicon

The use of recycled materials in construction is among the

most attractive options because of the large quantity

consumed, the relatively low quality requirements and the

widespread nature of construction sites (Shi, Wu, Riefler, &

Wang, 2005; Shi & Zheng, 2007).

Recently, many studies have focused on the use of waste

glass in concrete as aggregate replacement. However, these

attempts were unsuccessful due to the alkaliesilica reaction

(ASR) that takes place in the presence of the amorphouswaste

glass and the concrete pore solution (Federico & Chidiac,

2009). ASR is a chemical reaction between Portland cement

concrete and certain aggregates. This reaction produces a gel,

which swells creating severe damage in concrete covers and

structures. Consequently it can accelerate some undesirable

reactions that can cause freezeethaw and corrosion related

damage (Terro, 2006).

The use of recycled waste glass in Portland cement and

concrete has attracted a lot of interest worldwide due to the

increased disposal costs and environmental concerns. Glass is

.ir (R. Madandoust).. Published by Elsevier Lt13.07.006

and calcium. Thus it can be claimed that it is pozzolanic or

even cementitious in nature, even when it is finely ground.

Therefore, glass powder (GP) can be considered as a replace-

ment for cement in concrete (Shao, Lefort, Moras, &

Rodriguez, 2000; Shi & Zheng, 2007).

Reviewing the past investigations revealed that the

pozzolanic properties of glass are noticeable at particle sizes

below approximately 100 mm. Studies by Shi et al. (2005), as

well as Schwarz, Cam, and Neithalath (2008), showed that

not only glass with particle size below 100 mm can have a

pozzolanic reactivity but also its effect is greater than fly

ash at low level of cement replacement (10e20%). Work by

Chen, Huang, Wu, and Yang (2006) revealed that a GP with

particle size less than 75 mm possessed cementitious capa-

bility and improves compressive strength, resistance to

sulphate attack and chloride ion penetration, for replacing

of cement up to 50%. Idir, Cyr, and Tagnit-Hamou (2011)

indicated that the pozzolanic activity has a tendency to

enhance with finer GPs. Equivalent or superior compressive

strength was attained when using up to 40% of mixed-

d. All rights reserved.

Nomenclature

ASR alkaliesilica reaction

GP glass powder

RHA rice husk ash

SP superplasticiser

b i o s y s t em s e n g i n e e r i n g 1 1 6 ( 2 0 1 3 ) 1 1 3e1 1 9114

colour GP with a particle size less than 40 mm when

compared with control specimens.

Supplementary cementing materials such as ground blast

furnace slag, fly ash, silica fume, rice husk ash (RHA) and

metakaolin as calcined natural pozzolans may all be used to

improve the properties of concrete, especially in combination

with raw pozzolanic material such as glass powder. Of course,

the effectiveness will be dependent upon the chemical and

physical characteristics of the material. Concerning this, RHA

is a highly reactive pozzolanic material produced by

controlled burning of rice husk. Based on literature it can be

generally stated that when rice husk is burnt at temperatures

<700 �C, RHA with cellular microstructure is produced

(Chindaprasirt & Rukzon, 2008). This product contains high

silica content in the form of non-crystalline or amorphous

silica. Therefore, it can be used as supplementary cementi-

tious materials (Chao-Lung, Anh-Tuan, & Chun-Tsun, 2011;

Madandoust, Ranjbar, Moghadam, & Mousavi, 2011; Mehta,

1994; Sarıdemir, 2010; Yu, Sawayama, Sugita, Shoya, & Iso-

jima, 1999).

Because it possesses a high content of amorphous silica

and very large surface area which is governed by the porous

structure of the particles, RHA is very reactive. Generally,

reactivity is increased by the fineness of the RHA (Bui, Hu, &

Stroeven, 2005; Chao-Lung et al., 2011). On the other hand,

Mehta (1979) stated that grinding of RHA to a fine powder

should be avoided, because its pozzolanic activity is mainly

related to the internal surface area of the particles. This is

related to the microporous structure of individual particles.

Work byHwang and Chandra (1996) has indicated that particle

sizes of RHA in the 10e75 mm range showed satisfactory

pozzolanic behaviour. The amount of cement that can be

replaced is influenced by the nature of the silica, fineness of

the ash and the presence of other materials such as carbon

(Madandoust et al., 2011).

This study is an attempt to use GP in combination with

RHA as cement replacement in order to reduce the costs and

Table 1 e Chemical composition and physical properties of bin

Constituents (mass %)

Chemical composition CaO

SiO2

Al2O3

Fe2O3

MgO

Na2OþK2O

Physical properties Fineness (cm2 g�1)

Pozzolanic activity index (%)

provide ecological and environmental benefits. For this pur-

pose, the optimal dosages of GP and RHAwere firstly obtained

based on (1) concrete compressive strength that was consid-

ered as one of themost important properties of concrete and a

major indicator of general quality control and (2) a strength

activity index that is defined as indicative of pozzolanic action

of the raw or calcined natural pozzolan. Then, mechanical

properties were investigated using concretes made with these

optimal proportions.

2. Experimental programme

2.1. Materials

Typical commercial Type I Portland cement that complies

with the requirements of specification ASTMC150was used as

testing cement with Blain specific surface area 3165 cm2 g�1.

The chemical composition and physical properties of cement

are given in Table 1.

The GP used in this study was obtained from glass found in

construction waste. It was a typical soda lime glass. The glass

has to be ground to a required degree of fineness to satisfy the

basic requirements for a pozzolan and in order to pacify the

alkaliesilica reaction and to activate the pozzolanic behaviour

(Shao et al., 2000). As previous work has shown, the use of

waste glass as a cement replacement has shownmixed results

over a range of replacement proportions and particle sizes

(Aly et al., 2012). Under the requirements of ASTM C 618, as

shown in Table 2, glass has the potential to acceptably func-

tion as a cement replacement; although, the undesirable ef-

fect of ASR/pozzolanic reaction must be controlled by

appropriate methods (Federico & Chidiac, 2009). To satisfy the

physical requirement for fineness, the glass has to be ground

to pass a 75 mm sieve. This was accomplished by crushing and

grinding the glass using a ball mill, and by sieving the ground

glass to the desired particle size.

The required RHAwas supplied from the north of Iran. This

product had a high content of silica (92.62%) by weight and

was obtained by burning at relatively high temperatures in the

range of 650 �C following the recommendations found in the

literature. To produce a pozzolanic material, the ash was

ground by means of a laboratory batch ball mill for 1 h. After

passing through sieve with an opening of 75 mm, the RHA was

considered suitable for the partial replacement of cement

(Madandoust et al., 2011).

der materials.

Portland Cement GP RHA

63.41 9.79 2.51

21.22 73.1 92.62

6.27 1.36 0.49

3.08 0.67 0.73

1.85 3.45 0.88

0.75 11.1 e

3165 e 9768

e e 88.94

Table 2 e Requirements of ASTM C 618 for pozzolansused in current work.

ASTM C618 GP RHA

SiO2þAl2O3þ Fe2O3, min % 70 75.13 93.84

SO3, max % 4 0.21 0.34

Moisture content, max % 3 e e

Loss on ignition, max % 10 4.35 6.12

b i o s y s t em s e ng i n e e r i n g 1 1 6 ( 2 0 1 3 ) 1 1 3e1 1 9 115

In general, the pozzolanic effect depends not only on the

pozzolanic reaction (According to ASTM C618) but also on the

physical or filler effect of the smaller particles in the mixture

(Isaia, Gastaldini, & Moraes, 2003). Consequently, one of the

most common methods to improve the pozzolanic activity of

mineral admixtures is to decrease their particle size. Most

previous studies (Chao-Lung et al., 2011; Hwang & Chandra,

1996; Mehta, 1979) have suggested that RHA particles, in the

10e75 mm range, exhibit satisfactory pozzolanic behaviour.

The particle size distribution curves of cement, RHA andGP

are displayed in Fig. 1.

The fine aggregate was washed river sand with a specific

gravity of 2.63, water absorption of 1.7% and finenessmodulus

of 3.01. The coarse aggregate was crushed limestone of 20mm

maximum size with specific gravity of 2.65 and water ab-

sorption of 0.7%.

Themixing water was local tap water. The superplasticiser

(SP) used was a polyethylene sulphonate that complied with

ASTM C494 type-F. The specific gravity of the superplasticiser

given by the supplier was 1080 kgm�3 and the pHwas 6.6 with

chloride content of less than 0.1%. The amount of SP required

to achieve a desired slump in the range of 80e100 mm is

shown in Table 3. The SP content increased along with the

RHA % (Chao-Lung et al., 2011; Cordeiro, Toledo Filho, &

Fairbairn, 2009),

2.2. Mixtures

The concrete mixtures were proportioned to give 28-day

strength of about 40 MPa based on 100 mm cubes with a

slump of about 80 mm. As mentioned above, in order to ach-

ieve the optimal dosages of GP and RHA, hybrid batches with

5e20% GP and 5e20% RHA as cement replacements were

prepared so that this replacement did not exceed a limit of

0

10

20

30

40

50

60

70

80

90

100

1 10 100 1000

Particle size, m

Cum

ulat

ive

pass

ing,

%

GP

RHA

Cement

µ

Fig. 1 e Particle size distributions of cement, RHA and GP

used in this study.

25%. Also, a concrete without any mineral additions was used

as the control material. Proportions of the concrete mixtures

are given in Table 3. In this table, ‘Con.G10.R05’ is defined as

10% by weight of Portland cement replaced by GP and 5% by

RHA.

2.3. Test methods

The compressive strengths of various concrete mixtures were

determined on 100-mm cubes at 3, 7, 14, 28, 42 and 90 days in

accordance with ASTM C39. Concrete cylinders with dimen-

sion of 100� 200-mm were used to evaluate the splitting

tensile strength and modulus of elasticity at 7, 28, 42 and 90

days in accordance with ASTM C496 and C469, respectively.

The cast specimens were covered with polyurethane sheet

and damped cloth in a 22� 2 �C chamber and were left in the

casting room for 1 day according to ASTM C192. After removal

from the mould, the specimens were transferred to a moist

curing room at 100% relative humidity with temperature of

about 20 �C.

3. Results and discussion

3.1. Optimal mixture

To select the optimal level of replacements of GP and RHA, the

28-day compressive strength and strength activity index of all

the thirteen concretes were investigated. The test results are

presented in Fig. 2.

ASTM C618 recommends that a pozzolan have a minimum

strength activity index of 75%. It can be observed that only five

mixtures satisfied the minimum of 75% as specified in ASTM

C618 so that Con.G10.R05 showed the highest value of 89%.

On the other hand, based on the 28-day strength results,

among all the mixes, only Con.G10.R05 met the strength

requirement of a 40 MPa and remaining were under required

strength. So, based on these comparisons, it seems that se-

lection of Con.G10.R05 mix is feasible and it could be adopted

as optimal hybrid mix in the further studies.

3.2. Compressive strength

Figure 3 shows the compressive strength development for

Con.G10.R05 and conventional concretes at different ages up

to 90-days .For all tests, three specimenswere tested at each of

the ages and the mean values considered with a maximum

standard deviation of (all the tests) about 8%. From the results,

it can be seen that in both cases, compressive strength

increased with age. The compressive strength of the control

concrete was seen to be greater than those of hybrid mix at all

ages. This difference had a tendency to decline with age. For

example, at the age of 3-days the amount of compressive

strength of Con.G10.R05 was 65% of conventional concrete,

this amount increased to 89% at 28 days and 96% at 90 days.

This result shows an indication of pozzolanic reactivity. This

can also be attributed to the particle sizes of the fines used in

this investigation. At least, 30% of particle sizes of the fines

used were finer than 10 mm. Furthermore, it may suggest that

the concrete quality assessment which is normally taken at

70Control

Table 3 e Concrete mixture proportions for 1 m3 of concrete.

Materials mixture Gravel(kg)

Sand(kg)

Cement(kg)

Water(kg)

GP RHA Water/binder SP(kg)

% (kg) % (kg)

Control 1015 695 410 210 e e e e 0.51 e

Con.G05R05 1015 695 369 210 5 20.5 5 20.5 0.51 0.41

Con.G05R10 1015 695 348.5 210 5 20.5 10 41 0.51 2.15

Con.G05R15 1015 695 328 210 5 20.5 15 61.5 0.51 4.43

Con.G05R20 1015 695 307.5 210 5 20.5 20 82 0.51 4.56

Con.G10R05 1015 695 348.5 210 10 41 5 20.5 0.51 0.41

Con.G10R10 1015 695 328 210 10 41 10 41 0.51 2.15

Con.G10R15 1015 695 307.5 210 10 41 15 61.5 0.51 4.43

Con.G15R05 1015 695 328 210 15 61.5 5 20.5 0.51 0.41

Con.G15R10 1015 695 307.5 210 15 61.5 10 41 0.51 2.15

Con.G20R05 1015 695 307.5 210 20 82 5 20.5 0.51 4.56

Con.G7.5R7.5 1015 695 348.5 210 7.5 30.75 7.5 30.75 0.51 1.68

Con.G12.5R12.5 1015 695 307.5 210 12.5 51.25 12.5 51.25 0.51 3.85

b i o s y s t em s e n g i n e e r i n g 1 1 6 ( 2 0 1 3 ) 1 1 3e1 1 9116

the age of 28 days need to be reconsidered at ages higher than

90 days.

Due to the combination of GP and RHA, this phenomenon

must be considered from two points of view. The outlines of

justification will be stated as follows:

3.2.1. Presence of rice husk ashThe RHA is known to be a highly pozzolanic material because

of its microporous nature with high surface area (Chao-Lung

et al., 2011) and containing high amount of silica, about 90%

bymass. The strength and durability of concrete are improved

with addition of RHA. One of themain reasons of this factmay

be attributed to the formation of more CeSeH gel and less

Portlandite in concrete due to the reaction occurring between

RHA and the Ca2þ, OH� ions, or Ca(OH)2 in hydrating cement

(Yu et al., 1999).

It is well known that a well-burnt and well-ground RHA,

with most of its silica in an amorphous form and with N2-

specific surface varying between 40 and 60 m2 g�1, is very

active and can considerably improve the properties of con-

crete (Yu et al., 1999).

Yu et al. (1999) showed that the amount of Ca(OH)2 in the

cement paste with 30% RHA addition will begin to decrease

after 3 days, but it approaches zero after 91 days. The amount

of Ca(OH)2 in the control paste without RHA added, is

adversely increased with hydration time. This phenomenon

might be ascribed to the reaction between RHA and Ca2þ, OH�

0

10

20

30

40

50

Con

trol

Con

.G05

R05

Con

.G05

R10

Con

.G05

R15

Con

.G05

R20

Con

.G10

R05

Con

.G10

R10

Con

.G10

R15

Con

.G15

R05

Con

.G15

R10

Con

.G20

R05

Con

.G7.

5R7.

5

Con

.G12

.5R

12.5

Com

pres

sive

Str

engt

h, M

Pa

30

45

60

75

90

105

120

Stre

ngth

Act

ivit

y In

dex,

%

Compressive strength

Strength Activity Index

ASTM C618

Fig. 2 e 28-Day compressive strength and strength activity

index of concretes.

ions, or Ca(OH)2 can also occur in a paste containing RHA.

Thus, in comparison to concrete without RHA, the improve-

ment of concrete strength and its durability truly may be

referred to the existence of more CeSeH gel and less Por-

tlandite in the RHA concrete.

Also, Chao-Lung et al. (2011) indicated that in the early

stages, the ground RHA added reduces the cement quantity by

10e20% but the volume of capillary pores then increases,

accumulating CH on the interface. Therefore, in comparison

to the specimen without ground RHA addition, the strength is

lower due to less compaction of structure. The density of

concrete is improved after 28 days. This fact can be expressed

as the pozzolanic reactions continue and consequently the

amount of CH is decreased. As a result, the compressive

strength is improved in the later stages.

3.2.2. Presence of glass powderThe strength activity indexes of Con.G10.R05 mix at different

ages are illustrated in Fig. 4. ASTM C618 recommends that a

pozzolan has a minimum strength activity index of 75%. As a

consequence, the activity index of Con.G10.R05 at early ages

did not satisfy the criteria. After 14 days the amount of activity

index of Con.G10.R05 concrete was 78% that is slightly higher

0

10

20

30

40

50

60

3 7 14 28 42 90

Age, days

Com

pres

sive

str

engt

h, M

Pa

Con.G10.R05

Fig. 3 e Compressive strength development of Con.G10.R05

and normal concretes with age.

0.05

0.06

0.07

0.08

0.09

0.1

20 25 30 35 40 45 50 55 60

Compressive Strength, MPa

Ten

sile

/Com

pres

sive

Str

engt

h ra

tio

Con.G10.R05

Control

Control

Con.G10.R05

Fig. 6 e Variation of tensile/compressive strength ratio

with compressive strength.

30

45

60

75

90

105

120

3 7 14 28 42 90

Age, days

Stre

ngth

Act

ivity

Ind

ex, %

Mix: Con.G10.R05ASTM C618

Fig. 4 e Strength activity indexes of Con.G10.R05 mix at

different ages.

b i o s y s t em s e ng i n e e r i n g 1 1 6 ( 2 0 1 3 ) 1 1 3e1 1 9 117

thanminimum criterion. This was indicative of low activity of

glass at early ages when RHA is presented. The activity index

of hybrid concrete has a tendency to increase with developing

concrete age. The relatively higher strength index could be

attributed to the high content of Na2O in glass. It was generally

accepted that the early strength development is promoted by

forming calcium silicate hydrate in presence of alkalis that

could act as catalysts, although, it was also reported that high

content of alkalis in cement could result in a decrease of the

28-day concrete strength (Shao et al., 2000).

Regarding the fineness of GP, the pozzolanic reactivity of

fine waste glass has been published by others. Results ob-

tained in the reported data indicated that the compressive

strength is to be higher for specimens containing very fine

glass (<100 mm) and the strength shows a tendency to decline

as particle size increases (Shao et al., 2000; Shi et al., 2005).

Federico and Chidiac (2009) demonstrated the significance

of replacing percentages of waste glass based on some avail-

able studies from the literature. Their results showed that a

cement replacement between 10% and 20% yielded the high-

est strength.

Based on the theoretical mechanism presented by Urhan

(1987) it can been shown that the pozzolanic reaction will be

favoured by calcium ions in combinationwith a relatively high

rate of CeSeH formation, and over time, any ASR product will

take on the texture of CeSeH. Pozzolanic reaction of GP will

produce a type of calcium silicate hydrate. According to the

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

7 28 42 90Age, days

Ten

sile

str

engt

h, M

Pa

Control

Con.G10.R05

Fig. 5 e Splitting tensile strength development of

Con.G10.R05 and conventional concretes with age.

study by Federico and Chidiac (2009), this product may be a

lithium silicate or perhaps a pozzolanic formation of CeSeH,

which has a potential to contribute to additional strength.

3.3. Splitting tensile strength

The splitting tensile strength development at different ages 7,

28, 42 and 90 days for Con.G10.R05 and conventional concretes

are illustrated in Fig. 5. Each result is themean value of at least

three experiments. This trend appears to be similar to

compressive strength. As concrete becomes older, the values

of tensile strength will be increased. The ratio of the tensile

strength of Con.G10.R05 concrete to the conventional concrete

was 71% at the age of 7 days whilst this ratio was 97% at the

age of 90-days. The justifications related to concrete

compressive strength could also be adopted to explain the

trend of splitting tensile strength.

The relationship between two strengths could be affected

by several factors such as; method of testing, the concrete in

tension, the size of specimen, the shape and surface texture of

coarse aggregate, concrete age and the moisture condition of

the concrete (Neville, 1981). The ratios of the tensile strength

to the compressive strength and the variation of this ratio

with compressive strength are shown in Fig. 6.

From this figure, it could be claimed that the ratios of

tensile/compressive strength are not significantly affected by

the change of compressive strength. This ratio was averaged

to be 0.071 and 0.073 for hybrid and conventional concretes,

respectively.

3.4. Modulus of elasticity

Modulus of elasticity was measured according to ASTM C469

and graphically presented in Fig. 7. The average of three speci-

mens was considered. From the results, as concrete becomes

older, the values of elastic modulus increase. The ratio of the

elastic modulus of Con.G10.R05 concrete to the conventional

concretewas88%at theageof7dayswhilst this ratiowas97%at

the age of 90 days. The structure of Con.G10.R05 concrete is less

compact, causing themodulusof elasticity to be lower than that

of the specimen without mineral additions. The pozzolanic re-

action starts to proceed after 28 days. Hence, decreasing the

amount of CH and improving the density are to be expected.

This observation has been reported by Zhang, Lastra, and

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

1 10 100

Age, days

Stre

ngth

Effi

cien

cy o

f Cem

ent,

MP

a k

g-1 (i

n 1

m3 )

Control

Con.G10.R05

Fig. 8 e Strength efficiency variation of cement with age.

20

22

24

26

28

30

7 28 42 90

Age, days

Mod

ulu

s of

Ela

stic

ity,

GP

a

Control-test

Control-ACI 318

Control-ACI 363

Con.G10.R05-test

Con.G10.R05-ACI 318

Con.G10.R05-ACI 363

Fig. 7 e Variation of modulus of elasticity with age.

b i o s y s t em s e n g i n e e r i n g 1 1 6 ( 2 0 1 3 ) 1 1 3e1 1 9118

Malhotra (1996). Therefore, the modulus of elasticity is

enhanced in the long term. Moreover, in Fig. 7, ACI 318 and ACI

363 relationships have also been presentedwhich are normally

used for the prediction of the modulus of elasticity of conven-

tional concrete.

It can be seen from this Fig. 7 that, for both concretes, the

ACI 318 and ACI 363 relationships underestimate themodulus

of elasticity for the range used in this paper. In general, it

seems that these relationships are too conservative because

they are below all the measured data. However, the ACI 318

showed better estimates.

3.5. Strength efficiency of cement

The strength efficiency of cement is defined as yielded

strength per kilogram of cement and is denoted as

MPa kg�1 cement (Chao-Lung et al., 2011). Figure 8 shows that

this value is higher with age for Con.G10.R05 than for control

concrete. The obtained results showed that the 91-days value

is about 1.13 times greater than that of the control concrete.

On the other hand, the cement consumption in such hybrid

mixture is considerably less than normal usage based on the

equal compressive strength.

4. Conclusion remarks

This study is an attempted to use GP in combination with RHA

as cement replacement. The following conclusions can be

drawn:

- Based on the 28-day compressive strength and strength

activity index, concrete containing 10% GP and 5% RHA

(Con.G10.R05) as cement replacements can be adopted as an

optimal combination.

- In the short term, the compressive strength enhancement

for Con.G10.R05 is lower than that of conventional concrete.

However, in the long term, the results have a tendency to

show a higher pozzolanic activity in hybrid concrete.

- Tensile strengthwill be increasedwith age due to the higher

pozzolanic activity. It can be claimed that the ratios of ten-

sile/compressive strength are not significantly affected by

the change of compressive strength.

- The modulus of elasticity is enhanced in the long term. The

ACI 318 and ACI 363 relationships underestimate the

modulus of elasticity for the range used in this study.

- The strength efficiency of cement in hybrid concrete is

higher than that of the control concrete as cement con-

sumption is considerably less than normal usage based on

the equal compressive strength after 90-days.

The environmental and economic benefits from the reuse

of both GP and RHA in concrete can also be significant and the

utilisation of these materials in concrete may be recom-

mended. In this study, the evaluation of concrete was per-

formed by assessing the mechanical properties. However,

further investigation is needed to study the effect of GP and

RHA in understanding the exact mechanism based on other

characteristics such as pore structure, water absorption and

the durability of concrete.

r e f e r e n c e s

Aly, M., Hashmi, M. S. J., Olabi, A. G., Messeiry, M., Abadir, E. F., &Hussain, A. I. (2012). Effect of colloidal nano-silica on themechanical and physical behaviour of waste-glass cementmortar. Materials and Design, 33, 127e135.

American Standards for Testing and Materials. (2002a). Standardpractice for making and curing concrete test specimens in thelaboratory. ASTM C 192/C 192M-02. USA.

American Standards for Testing and Materials. (2002b). Standardtest method for static modulus of elasticity and Poisson’s ratio ofconcrete in compression. ASTM C 469-02. USA.

American Standards for Testing and Materials. (2002c). Standardspecification for Portland cement. ASTM C150-02. USA.

American Standards for Testing and Materials. (2003a). Standardspecification for coal fly ash and raw or calcined natural pozzolan foruse in concrete. ASTM C618-03. USA.

American Standards for Testing and Materials. (2003b). Standardtest method for compressive strength of cylindrical concretespecimens. ASTM C 39/C 39M-03. USA.

American Standards for Testing and Materials. (2004a). Standardspecification for chemical admixtures for concrete. ASTM C 494/C494M-04. USA.

American Standards for Testing and Materials. (2004b). Standardtest method for splitting tensile strength of cylindrical concretespecimens. ASTM C 496/C 496M-04. USA.

Bui, D. D., Hu, J., & Stroeven, P. (2005). Particle size effect on thestrength of rice husk ash blended gap-graded Portland cementconcrete. Cement & Concrete Composites, 27, 357e366.

Chao-Lung, H., Anh-Tuan, B. L., & Chun-Tsun, C. (2011). Effect ofrice husk ash on the strength and durability characteristics ofconcrete. Construction and Building Materials, 25, 3768e3772.

b i o s y s t em s e ng i n e e r i n g 1 1 6 ( 2 0 1 3 ) 1 1 3e1 1 9 119

Chen, C. H., Huang, R., Wu, J. K., & Yang, C. C. (2006). Waste E-glass particles used in cementitious mixtures. Cement andConcrete Research, 36, 449e456.

Chindaprasirt, P., & Rukzon, S. (2008). Strength, porosity andcorrosion resistance of ternary blend Portland cement, ricehusk ash and fly ash mortar. Construction and Building Materials,22(8), 1601e1606.

Cordeiro, G. C., Toledo Filho, R. D., & Fairbairn, E. M. R. (2009). Useof ultrafine rice husk ash with high-carbon content aspozzolan in high performance concrete. Materials andStructures, 42(7), 983e992.

Federico, L. M., & Chidiac, S. E. (2009). Waste glass as asupplementary cementitious material in concrete e criticalreview of treatment methods. Cement & Concrete Composites, 31,606e610.

Hwang, C. L., & Chandra, S. (1996). In S. Chandra (Ed.), The use ofrice husk ash in concrete. Waste materials used in concretemanufacturing (pp. 184e234). New Jersey: Westwood.

Idir, R., Cyr, M., & Tagnit-Hamou, A. (2011). Pozzolanic propertiesof fine and coarse color-mixed glass cullet. Cement & ConcreteComposites, 33, 19e29.

Isaia, G. C., Gastaldini, A. L. G., & Moraes, R. (2003). Physical andpozzolanic action of mineral additions on the mechanicalstrength of high-performance concrete. Cement & ConcreteComposites, 25(1), 69e76.

Madandoust, R., Ranjbar, M. M., Moghadam, H. A., &Mousavi, S. Y. (2011). Mechanical properties and durabilityassessment of rice husk ash concrete. Biosystems Engineering,110, 144e152.

Mehta, P. K. (1979). The chemistry and technology of cementmade from rice husk ash. In Proceedings UNIDO/ESCAP/RCTTWorkshop on Rice Husk Ash Cements (pp. 113e122). Peshawar,Pakistan.

Mehta, P. K. (1994). Rice husk ash e a unique supplementarycementing material. In V. M. Malhotra (Ed.), Advances in

concrete technology (pp. 419e444). Ottawa: Centre for Mineraland Energy Technology.

Neville, A. M. (1981). Properties of concrete (3rd ed.). London: PitmanPublishing Limited.

Sarıdemir, M. (2010). Genetic programming approach for predictionof compressive strength of concretes containing rice husk ash.Construction and Building Materials, 24, 1911e1919.

Schwarz, N., Cam, H., & Neithalath, N. (2008). Influence of a fineglass powder on the durability characteristics of concrete andits comparison to fly ash. Cement & Concrete Composites, 30,486e496.

Shao, Y., Lefort, T., Moras, S., & Rodriguez, D. (2000). Studies onconcrete containing ground waste glasses. Cement and ConcreteResearch, 30, 91e100.

Shi, C., Wu, Y., Riefler, C., & Wang, H. (2005). Characteristics andpozzolanic reactivity of glass powders. Cement and ConcreteResearch, 35, 987e993.

Shi, C., & Zheng, K. (2007). A review on the use of waste glasses inthe production of cement and concrete. Resources, Conservationand Recycling, 52, 234e247.

Terro, M. J. (2006). Properties of concrete made with recycledcrushed glass at elevated temperatures. Building andEnvironment, 41, 633e639.

Urhan, S. (1987). Alkali silica and pozzolanic reactions inconcrete. Part 1: interpretation of published results and anhypothesis concerning the mechanism. Cement and ConcreteResearch, 17(1), 141e152.

Yu, Q., Sawayama, K., Sugita, S., Shoya, M., & Isojima, Y. (1999).The reaction between rice husk ash and Ca(OH)2 solution andthe nature of its product. Cement and Concrete Research, 29,37e43.

Zhang, M. H., Lastra, R., & Malhotra, V. M. (1996). Rice-husk ashpaste and concrete: some aspects of hydration and themicrostructure of the interfacial zone between the aggregateand paste. Cement and Concrete Research, 26(6), 963e977.