Conference PaperPDF Available

MECHANICAL PROPERTIES OF CEMENT MORTAR BY USING POLYETHYLENE TEREPHTHALATE FIBERS

Authors:

Abstract and Figures

During the last three decades, recycled plastic materials have been widely used to reinforce soils and concrete materials. These waste plastics have been used as fibers, aggregates and binders in concrete and mortar components. In Iraq, it has a wide range area of waste plastics especially those that daily used such as plastic bottles. In recent years researchers interested in re-use of waste plastics as construction materials that are remarkable with economic and environmental benefits. This research investigated the utilization of recycled plastic bottles as fiber to reinforce cement mortar. We used fibers made from polyethylene terephthalate (PET) plastic bottles with different size and volume fractions. The main reason of this study was to investigate the effect of the utilization of PET fibers on the mechanical properties of cement mortar. This influence of the PET on the cement mortar has been investigated by applying an experimental programs of compressive strength, splitting tensile strength, ultrasonic pulse velocity and Schmidt tests at 7, and 28 day ages and analyzed in comparison to the control sample. The results show that the incorporation of the fibers improve the splitting tensile strength properties of the cement mortar.
Content may be subject to copyright.
1 | P a g e
MECHANICAL PROPERTIES OF CEMENT MORTAR BY USING
POLYETHYLENE TEREPHTHALATE FIBERS
Hemn U. BOINY*1, Younis M. ALSHKANE2 and Serwan Kh. RAFIQ3
*1Department of Civil Engineering, University of Sulaimani, Iraq.
(E-mail: hemn.ahmed@univsul.edu.iq)
2 Department of Civil Engineering, University of Sulaimani, Iraq.
(E-mail: younis.ali@univsul.edu.iq)
3 Department of Civil Engineering, University of Sulaimani, Iraq.
(E-mail: serwan.rafiq@univsul.edu.iq )
ABSTRACT
During the last three decades, recycled plastic materials have been widely used to reinforce
soils and concrete materials. These waste plastics have been used as fibers, aggregates and
binders in concrete and mortar components. In Iraq, it has a wide range area of waste plastics
especially those that daily used such as plastic bottles. In recent years researchers interested in
re-use of waste plastics as construction materials that are remarkable with economic and
environmental benefits. This research investigated the utilization of recycled plastic bottles as
fiber to reinforce cement mortar. We used fibers made from polyethylene terephthalate (PET)
plastic bottles with different size and volume fractions. The main reason of this study was to
investigate the effect of the utilization of PET fibers on the mechanical properties of cement
mortar. This influence of the PET on the cement mortar has been investigated by applying an
experimental programs of compressive strength, splitting tensile strength, ultrasonic pulse
velocity and Schmidt tests at 7, and 28 day ages and analyzed in comparison to the control
sample. The results show that the incorporation of the fibers improve the splitting tensile
strength properties of the cement mortar.
KEYWORDS: PET fiber, Plastic bottles, Mortar, Compressive Strength, Splitting tensile Strength.
*Corresponding author. Tel.: 00964 (0) 7501119884
E-mail address: hemn.ahmed@univsul.edu.iq, [Hemn U. Ahmed BOINY]
2 | P a g e
1 Introduction
During the last three decades, recycled plastic materials have been widely used to reinforce
soils and concrete materials. These waste plastics have been used as fibers, aggregates and
binders in concrete and mortar components [1]. After the polyethylene, the polyethylene
terephthalate forms one of the largest part in solid waste stream [2]. Most of the PET bottles
used for beverage container are thrown away after single usage and disposed PET bottles are
treated by landfill and burning which is create serious environmental problems.
According to the United States Environmental Protection Agency (1992), the municipal solid
waste generated in the U.S.A. is 200, 000,000 tons per year, among them about 8% weight is
plastics [3]. In the year of 1996, content of plastics in municipal solid waste raised to 12%
weight [4]. The world’s annual consumption of plastic materials has increased from around
204 million tons in the 2002 to nearly 300 million tons in 2013 [5]. In Iraq, as in many countries
of the world it has a wide range area of waste plastics especially those that daily used such as
plastic bottles. This type of waste plastics are serious problem for environmental issue because
of its non-biodegradable nature. Recycling of this type of waste plastic to produce new
materials like concrete or mortar appears as one of the best solution, due to its economic and
ecological advantages.
Poly (ethylene terephthalate) (PET) is the most commonly used thermoplastic polyester. PET
is a transparent polymer, with a good mechanical properties and good dimensional stability
under variable load. Moreover, PET has a good chemical resistance and good gas barrier
properties [6].
PET belongs to a thermoplastics with excellent physical properties [7]. It constitutes is around
18% of the total polymers produced worldwide and over 60% of its production is used for
synthetic fibers and bottles, which consume approximately 30% of global PET demand [8].
In recent years researchers interested in re-use of waste plastics as construction materials that
are remarkable with economic and environmental benefits, the studies showed that it was
possible to re-use of waste plastics in concrete and mortar such as polypropylene (PP) [9],
shredded and recycled plastic waste [10], polyethylene terephthalate (PET) [11], , poly vinyl
chloride (PVC) pipe [12], expanded polystyrene foam (EPS) [13], high density polyethylene
(HDPE) [14], thermosetting plastics [15], glass reinforced plastic (GRP) [16]and polycarbonate
as an aggregate, a filler or a fiber [17].Some authors [10, 13] explored, based on waste
polymeric the use of light weight aggregate, as a material in reducing the brittleness, the cost,
the unit weight, thermal insulation properties of building materials such as concrete or mortars.
Polyethylene terephthalate bottles in fiber form can be used to get better the mechanical
properties of concrete such as flexural strength, tensile strength and compressive strength
behavior of concrete [18].
In mortars, the fibers act uniformly distributed reinforcing mortars against the cracks
development due to plastic shrinkage. In the hardened mortar, the uniform distribution of fibers
inhibits the transformation of microcracks in macrocracks thus avoiding a potential for more
serious problems [19]. In hardened composites the cracking sensitivity is function of
deformation due to shrinkage and improved toughness due to incorporation of the fibers [20].
This research investigated the utilization of recycled plastic bottles as fiber to reinforce cement
mortar. We used fibers made from polyethylene terephthalate (PET) plastic bottles with
different size and volume fractions. The main reason of this study was to investigate the effect
of the utilization of PET fibers on the mechanical properties of cement mortar. This influence
of the PET on the cement mortar has been investigated by applying an experimental programs
of compressive strength, splitting tensile strength and ultrasonic pulse velocity tests at 7, 28
day ages and analyzed in comparison to the control sample. The results show that the
incorporation of the fibers improve the mechanical properties of the cement mortar.
3 | P a g e
2 Experimental programs and Materials
2.1 Experimental plan
In this research, compressive strength, splitting tensile strength, bulk density, ultrasonic pulse
velocity and Schmidt hammer tests were the experimental programs of recycled polyethylene
terephthalate fiber reinforced cement mortar were conducted.
2.1.1 Compressive strength
The compressive strengths of the cylinder (diameter 50 mm * length100 mm) cement mortar
samples have been tested at 7 and 28 days in accordance with ASTM C39-96 [21].The
specimens were loaded under a compression machine up to failure, the higher tray is fixed and
the lower support is mobile. Before testing, the faces of the specimen were suffered with a
surfacing machine, to ensure parallelism and flatness of the faces of support.
2.1.2 Splitting tensile strength
The splitting tensile strength of the cement mortar were determined at 7 and 28 days, a cement
mortar cylinder in the type which was used for compression tests was placed with it’s the
horizontal axis between the platens of a testing machine according to ASTM C496-04 [22] and
in the form of splitting indirect tension the load is increased until failure along the vertical
diameter takes place.
2.1.3 Bulk density
Characterization of the behavior of the cement mortar was performed through measurements
of the properties of this product in the hardened state, so we determine the mortar density with
a cement mortar cylinder, in the type which was used for compression tests at 7 and 28 days.
2.1.4 Ultrasonic pulse velocity
The principle for applying this test is to measure the velocity of longitudinal waves in cement
mortar samples. The determination consists of measurement of the time taken by a pulse to
travel a measured distance, knowing the distance(s) travelled by the waves, it is possible to
derive a velocity (v) equal to (l/ t) in km/s. The procedure consists in placing sensors on the
sample surface coated with a thin layer of petrolatum; this layer will prevent unwanted waves,
as described in ASTM C597-16 [23]. Measurements are recorded on digital screen at the time
of stabilization.
2.1.5 Schmidt hammer
This test is the widely used as non-destructive tests, the rebound number of the cement mortar
samples were determined in 7 and 28 days, a cement mortar cylinder, in the type which were
used for compression tests, we take the rebound numbers (RN) from different parts of the
cement mortar samples with it’s the horizontal and vertical axis of the samples according to
ASTM C805 / C805M-13 [24].The rebound hammer test is based on the principle that the
rebound of an elastic mass depends on the hardness of the surface against which the mass
impinges[25].
2.2 Materials
A commercial ordinary Portland cement and a locally available natural sand supplied by the
quarry (Darbandikhan, Sulaimaniyah, Iraq) were used to produce the mix of the cement
mortars, with the cement mortar mix proportions (1:2) by weight, ordinary Portland cement
and locally available natural sand. The ordinary Portland cement was having fineness of 10%
in accordance with ASTM C184-94[26], normal consistency was equal to 34% according to
ASTM C187-98[27] and initial and final setting time were 65 minutes and 175 minutes,
respectively in accordance with ASTM C191-99[28]. The fine aggregate having maximum
aggregate size and nominal maximum aggregate size of 4.75mm and 2.36 mm, respectively,
fineness modulus (FM) of 2.20 according to ASTM C33-13[29], Specific gravity for the sand
4 | P a g e
was 2.65 in accordance with ASTM C128-97[30].
The plastic fibers were added to the mix by weight of the total weight of the mix, i.e. 0%, 0.5%,
1.0%, 1.5%, 2.0% and 3.0%, we used two different size of the PET fibers, one of them is long
fiber (16.0 mm length and 1.0 mm width) and the other one was short fiber (8.0 mm length
and 1.0 mm width) were obtained by mechanical cutting of lateral sides of PET bottles, the
bottom and necks of the bottles were discarded, and then the PET fibers were introduced in dry
mortars during the mixing, Thus, a hand dry-mixing before the wet mixing in mortar mixer was
conducted for the mortars. For the preparation of the samples after mixing cement mortars, the
molds (cylindrical mold) are met in three phases. For each phase, a compaction of 25 tamped.
For each series, three cylindrical specimens (50mm*100mm) were prepared by using the same
composition. After de-molding, the specimens were deposited in a water until test day, the
samples were tested at 7 and 28 days, the mix proportion are presented in Table 1.
Table 1: Mix proportions of the cement mortar’s (Kg/m3)
Material
0%
PET
0.5% PET
1.0% PET
1.5% PET
1.5%
PET(short
fiber)
2.0% PET
3.0% PET
Cement
629.2
629.2
629.2
629.2
629.2
629.2
629.2
Sand
1258.5
1258.5
1258.5
1258.5
1258.5
1258.5
1258.5
water
295.8
295.8
295.8
295.8
295.8
295.8
295.8
PET
0
9.44
18.88
28.32
28.32
37.76
56.63
Fig.1 short PET fiber Fig.2 long PET fiber Fig.3 Waste plastic bottle
Fig.4 particle size distribution of fine aggregate
3 Results and discussion
The compressive strength results are presented in Table 2. The Table shows that the fibers
incorporation does not increase the magnitude of the mortar compressive strength, while with
decreasing the PET fiber length from 16.0 mm to 8.0 mm the mortar compressive strength is
increased by 15% at 28 day tests. The compressive strength of the cement mortar without fibers
5 | P a g e
increased around 35% at 28 days, by adding 0.5% of the fiber content to the total dry weight
of the mix, it decreases 8.0% of the mortar compressive strength, while by adding 3.0% of the
fiber content, decrease the mortar strength by 100%, and also by increasing the fiber content
from 7 days to 28 days there was not observed significant changes in the compressive strength
results that demonstrate a clear influence of fibers, it is expected that the cement hydration of
mortar samples is slow and the matrix is not significantly strengthen. Fig. 5 shows a typical
failure mode of compression test was obtained with the samples.
Table 2: Mortar uniaxial compression strength (UCS) [Mpa]
The splitting tensile strength of the cement mortars are presented in Table 3, it is clearly
appeared that splitting tensile strengths of the cement mortars were increases of about 18% by
adding 0.5% of the PET fiber, in comparison with the control sample, this is a desirable result
that a mortar with more ductile behavior can be obtained by using waste PET fibers. In same
way while increasing fiber content up to 0.5 % it does not significantly decrease the splitting
tensile strength and improves ductility properties of the cement mortars and also when
decreasing the PET fiber length from 16.0 mm to 8.0 mm the mortar splitting strength is
decrease by 6% at 28 day tests. A sudden failure take place in the case of 0% of fiber, while in
the case of presence of fiber a sudden failure didn’t take place. Fig. 6 shows a typical failure
mode of Splitting tensile strength tests was obtained with the samples.
Table 3: Mortar Splitting Tensile Strength (STS) [Mpa]
Fiber Length (mm)
16.0mm
8.0 mm
Fiber Content %
0
0.5
1.0
1.5
2.0
3.0
1.5
Splitting Tensile Strength (7 day)
2.54
3.11
2.54
2.19
1.99
2.13
2.15
Splitting Tensile Strength (28 day)
3.01
3.55
2.75
3.07
2.23
2.73
2.90
Ratio of (STS/UCS)
0.07
0.09
0.08
0.10
0.08
0.13
0.08
Fig.5 Typical failure of a mortar after compressive test. Fig.6 Typical failure of a mortar after splitting test
Figure 7 presents the results of mortar density with fiber content were computed at 7 and 28
days. The results in Figure 7 show that the inclusion of PET fibers caused a small decrease in
density, such a reduction does not exceed 2.0 % even for 3.0% fiber content. It is concluded
Fiber Length (mm)
16.0mm
8.0 mm
Fiber Content %
0
0.5
1.0
1.5
2.0
3.0
1.5
Compressive Strength (7 day)
32.4
30.1
26.2
26.9
24.5
19.5
27.0
Compressive Strength (28 day)
43.5
40.3
34.9
30.3
28.8
21.6
34.8
6 | P a g e
that the PET fibers incorporation, used in this study, did not significantly change the density of
the hardened cement mortar.
Fig.7 Density of Hardened Cement Mortar
The obtained results of the Ultrasonic pulse velocity of different PET fiber compositions are
presented in Figure 8. It is noted that the speed of sound (p-wave) is higher for mortar which
contains a low percentage of waste PET fibers. It is noted that the waste PET fiber mortars
compactness decreases which decreases the speed of sound. This decrease is due to the regular
shapes form of the fibers which increases the volume of voids inside mortar samples.
Fig.8 Ultrasonic Pulse Velocity of Hardened Cement Mortar
The results of the Schmidt hammer or rebound number (RN) of different PET fiber content are
given in the Figure 9. It is noted that the rebound number is a little bit higher for cement mortar
which contains a low percentage of PET fiber, which is the case of the reference concrete (0%
waste). It is noted that the incorporation of waste plastic fibers decrease the hardness of the
surface of the cement mortar compactness which decreases the speed of sound. This decrease
is due to the presence of fibers which increases the volume of voids. Also there is a little
increase by 5.0% of rebound number when decrease the fiber length from 16.0 mm to 8.0 mm.
For different samples of the same fiber content rebound numbers are same this is shows that
the fiber distribution and relative quality of the mortars are uniform.
2070
2080
2090
2100
2110
2120
2130
2140
2150
2160
0 0.5 1 1.5 2 3 short 1.5
DENSITY ( KG/M3)
FIBER CONTENT %
7 Day 28 day
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4
0 0.5 1 1.5 2 3 short 1.5
PULSE VELOCITY ( KM/SEC.)
FIBER CONTENT %
7 Day 28 Day
7 | P a g e
Fig.9 Rebound Number (RN) of Hardened Cement Mortar
Figures 10 and 11 present the stress-strain curves of the cement mortar tested in 7 and 28
days, respectively. As can be seen that with increasing the percent of PET fibers the stiffness
of the mortar decreased which increases the ductility of mortar as well as improves the post-
failure behavior.
Fig.10 StressStrain Relationship of Hardened Cement Mortar in 7 day
0
5
10
15
20
25
30
0 0.5 1 1.5 2 3 1.5 short
RN Number
Fiber Content %
7 Day 28 Day
0
5
10
15
20
25
30
35
0 0.001 0.002 0.003 0.004 0.005 0.006
Axial stress (MPa)
Axial strain
1.5 % Fiber
2.0 % Fiber
3.0% Fiber
short fiber 1.5%
0.5 % Fiber
1.0 % Fiber
0.0 % Fiber
8 | P a g e
Fig.11StressStrain Relationship of Hardened Cement Mortar in 28 day
4 Useful correlations
In this study the correlations between nondestructive tests (Ultrasonic and Schmidt hammer)
and destructive tests (uniaxial compression strength and tensile strength) were developed using
simple regression analysis. The correlations of uniaxial compressive strength (UCS) and tensile
strength with p-wave velocity are presented in Figure 12. The correlations of uniaxial
compressive strength (UCS) and tensile strength with Schmidt hammer are presented in Figure
13. It should be noted that the best correlations was between UCS and and P-wave velocity
since the coefficient of determination ( R2) is 0.89 which gives the coefficient of correlation of
0.94. Therfore, this study suggests the exponential correlation between unixail compressive
strength and P-wave velocity for cement mortar with or without fibers. The correlation
equations are presented in Figures 12 and 13 with their coefficient of correlations (R2).
Fig. 12 Correlations of Uniaxial Compressive Strength and tensile strength with Pulse Velocity
0
5
10
15
20
25
30
35
40
45
0 0.001 0.002 0.003 0.004 0.005 0.006 0.007
Axial stress (MPa)
Axial strain
1.5 % Fiber
3.0 % Fiber
2.0 % Fiber
1.0 % Fiber
0.5 % Fiber
0.0 % Fiber
short fiber 1.5 %
9 | P a g e
Fig. 13 Correlations of Uniaxial Compressive Strength and tensile strength with Schmidt number (RN)
5 Conclusion
This study investigated the utilization of recycled plastic bottles as fiber to reinforce cement
mortar. We used fibers made from polyethylene terephthalate (PET) plastic bottles with
different size and volume fractions, this influence of the PET on the cement mortar has been
investigated by applying an experimental programs of compressive strength, splitting tensile
strength, ultrasonic pulse velocity and Rebound number tests at 7, 28 day ages and analyzed in
comparison to the control sample. Based on the extensive research work, the following
conclusions can be drawn:
a) The density of hardened mortar is not significantly change by incorporation of PET fibers,
the PET fibers addition causes a small decrease in density of hardened cement mortars.
b) The PET fibers incorporation does not increase the magnitude of the mortar compressive
strength, but with decreasing the PET fiber length from 16.0 mm to 8.0 mm the mortar
compressive strength is increased by 15% at 28 day tests.
c) The splitting tensile strength of the cement mortars are increase of about 18% with respect
to the control sample by adding 0.5% of the PET fiber to the mix, this is a desirable result
that a mortar with more ductile behavior can be obtained.
d) The speed of sound waves (p-wave) is higher for mortar which contains a low percentage
of PET fibers. It is noted that the waste PET fiber mortars compactness decreases which
decreases the speed of sound waves, by adding 3.0% of fibers decreased in p-velocity by
7.0% with respect to the control sample.
e) The rebound number is a little bit higher for cement mortar which contains a low percentage
of PET fibers, whereas by decreasing the length of the fiber from 16.0 mm to 8.0 mm would
increase the rebound number by 5.0%.
f) Uniaxial compressive strength was successfully correlated with P-wave velocity and
Schmidt number for cement mortar of different ages and percentages of plastic fibers using
simple regression analysis.
ACKNOWLEDGEMENTS
The authors would like to acknowledge the contribution of Mr. Arian Omer Mahmood, a
lecturer at Civil Engineering Department of Engineering Faculty at the University of
Sulaimani, to the paper.
10 | P a g e
References
[1] F. Mahdi, H. Abbas, and A. A. Khan, "Strength characteristics of polymer mortar and concrete using different
compositions of resins derived from post-consumer PET bottles," Construction and Building Materials, vol. 24, no.
1, pp. 2536, Jan. 2010.
[2] R. Siddique, J. Khatib, and I. Kaur, "Use of recycled plastic in concrete: a review," Waste Management, vol. 28,
pp. 1835-1852, Jan. 2008.
[3] U.S. Environmental Protection Agency (USEPA), “Characterization of municipal solid waste in the United States,”
EPA/530-S-92-019 Rep., Washington, D.C. 1992.
[4] Franklin Associates, Ltd and Prairie Village, KS, "Characterization OF Municipal Solid Waste in the United States:
1998 Update," 1997.
[5] Europe Plastics, "The Facts 2014/2015. An Analysis of European Latest Plastics Production, Demand and Waste
Data," ed: Plastics Europe Brussels, Belgium, 2013
[6] A. S. Jabarin, “Polyethylene terephthalate chemistry and preparation,” The Polymeric Materials Encyclopedia, CRC
Press Inc., 1996.
[7] M. Lewin, Ed., Handbook of fiber chemistry. Boca Raton, FL, United States: Taylor & Francis, 2006.
[8] L. Bottenbruch, Ed., Engineering Thermoplastics: Polycarbonates, Polyacetales, polyesters, cellulose esters.
Germany: Carl Hanser Verlag GmbH & Co, 1996.
[9] S. Yang, X. Yue, X. Liu, and Y. Tong, "Properties of self-compacting lightweight concrete containing recycled
plastic particles," Construction and Building Materials, vol. 84, pp. 444453, Jun. 2015.
[10] A.A. Al-Manaseer, and T.R. Dalal, "Concrete containing plastic aggregates,” Concr. Int., vol. 19, pp. 4752, 1997.
[11] B. Harini, and K.V. Ramana, "Use of Recycled Plastic Waste as Partial Replacement for Fine Aggregate in
Concrete,” IJIRSET, vol. 4, pp. 8596, 2015.
[12] S. C. Kou, G. Lee, C. S. Poon, and W. L. Lai, "Properties of lightweight aggregate concrete prepared with PVC
granules derived from scraped PVC pipes," Waste Management, vol. 29, no. 2, pp. 621628, Feb. 2009.
[13] A. Kan and R. Demirboğa, "A novel material for lightweight concrete production," Cement and Concrete
Composites, vol. 31, no. 7, pp. 489495, Aug. 2009.
[14] T. R. Naik, S. S. Singh, C. O. Huber, and B. S. Brodersen, "Use of post-consumer waste plastics in cement-based
composites," Cement and Concrete Research, vol. 26, no. 10, pp. 14891492, Oct. 1996.
[15] P. Panyakapo and M. Panyakapo, "Reuse of thermosetting plastic waste for lightweight concrete," Waste
Management, vol. 28, no. 9, pp. 15811588, Jan. 2008.
[16] P. Asokan, M. Osmani, and A. Price, "Improvement of the mechanical properties of glass fibre reinforced plastic
waste powder filled concrete," Construction and Building Materials, vol. 24, no. 4, pp. 448460, Apr. 2010.
[17] K. Hannawi, S. Kamali-Bernard, and W. Prince, "Physical and mechanical properties of mortars containing PET
and PC waste aggregates," Waste Management, vol. 30, no. 11, pp. 23122320, Nov. 2010.
[18] P. Ganeshprabhu, C. A. Kumar, R. Pandiyaraj, P. Rajesh & L. S. Kumar, "Study on utilization of waste (PET) bottle
fiber in concrete," International Journal of Research in Engineering & Technology, Vol. 2, no. 5, pp. 233-240 , May
2014.
[19] L. A. Pereira de Oliveira and J. P. Castro-Gomes, "Physical and mechanical behaviour of recycled PET fibre
reinforced mortar," Construction and Building Materials, vol. 25, no. 4, pp. 17121717, Apr. 2011.
[20] A. Bentur, S. Mindess, and S. Mindess, Fibre reinforced cementitious composites, Routledge, Ed. London, United
Kingdom: Taylor & Francis, 2006.
[21] ASTM International, Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens; ASTM
C39-96, annual book of ASTM standards, Philadelphia, 1996.
[22] ASTM International, Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens;
ASTM C496-04, ASTM International: West Conshohocken, PA, 2004.
[23] ASTM International, Standard Test Method for Pulse Velocity through Concrete; ASTM C597-16, ASTM
International: West Conshohocken, PA, 2016.
[24] ASTM International, Standard Test Method for Rebound Number of Hardened Concrete; ASTM C805M-13, ASTM
International: West Conshohocken, PA, 2013.
[25] A. M. Neville, Properties of concrete, 4th ed. Harlow, Essex: Prentice-Hall, 1995.
[26] ASTM International, Standard Test Method for Fineness of Hydraulic Cement, ASTM C184-94, ASTM
International, West Conshohocken, PA, 1994.
[27] ASTM International, Standard Test Method for Normal Consistency of Hydraulic Cement, ASTM International,
West Conshohocken, PA, 1998.
[28] ASTM International, Standard Test Method for Time of Setting of Hydraulic Cement by Vicat Needle, ASTM
C191-99, ASTM International, West Conshohocken, PA, 2001.
[29] ASTM International, Standard Specification for Concrete Aggregates, ASTM C33M-13, ASTM International, West
Conshohocken, PA, USA, 2013.
[30] ASTM International, Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of
Fine Aggregate, ASTM C128-97, ASTM International, West Conshohocken, PA, 2001.

Supplementary resource (1)

... In order to produce WRPF, post-consumer plastics are processed and washed before being sliced manually through a paper shredder or a compact disk (CD) cutter device. The bottom and neck of the plastic bottles are removed for other uses [16,17,[68][69][70]. Other scientists have used long plastic chips made of machined steel waste pieces in commercial vehicle plants [71]. ...
... Furthermore, the fibers reduced the propagation of microcracks, lengthening the time before they fail, and the samples required extra load to expand the cracks. Additionally, the reasons for the decrease in CS for more than 1% fiber addition are related to the production of bulk and the segregation of fibers [30,68]. The same results were also observed in another study [118]. ...
... Furthermore, a study was conducted on cement mortars utilizing a range of waste PET fiber volume fractions. The results indicated that the addition of 0.5% fibers increased the STS to 16% [68]. Additionally, the ability of the novel concrete composite to provide resistance against the stresses of tensile forces was observed [5]. ...
Article
Full-text available
Ecological problems such as natural resource depletion and massive quantities of waste for disposal are now guiding progressive civilization towards sustainable construction. The reduction of natural resources and the discarding of debris into open landfills are the two main environmental concerns. As a result, managing these solid wastes is a major challenge worldwide. In comparison to disposal, insufficient landfills, ecological degradation and the economic load on the relevant agencies, recycling and reusing waste materials have a considerable influence. Waste fiber has been studied for use as a cement-based composite (CBC) ingredient. Recycling waste fibers not only makes the cement composite more cost-effective and long-lasting but also helps to reduce pollution. Plastics, carpets and steels are among the various types of waste fibers reviewed in this study for their applications in cement-based materials. The mechanical properties of CBCs with different kinds of recycled-waste fibers were explored, including their compressive, flexural and splitting tensile strength and durability properties. The use of recycled fibers in the construction industry can help to ensure sustainability from environmental, economic and social standpoints. As a result, additional scientific research is needed, as well as guidance for more researchers and experts in the construction sector to examine the unknown sustainability paths. The barriers to the effective implementation of waste fiber recycling techniques in the construction sector were reviewed, and various solutions were proposed to stimulate and ensure their use in CBCs. It was concluded that CBCs containing recycled fibers provide a long-term and cost-effective alternative for dealing with waste materials.
... The authors observed that UPV value has decreased with the addition of PET fibers and this reduction was more significant for higher percentages of fibers. As a comparison, specimens with short fibers had slightly higher UPV values compared to the samples containing longer fibers [45,46]. ...
... It was related to the lower transfer properties of plastic compared to concrete ingredients. Moreover, the degree of the drop was related to the percentage of plastic waste [31,43,45]. ...
... In order to better understand the reduction in the mechanical strengths of mortar containing properties of fibers compared to the concrete ingredients [44][45][46]. ...
Thesis
This study intends to investigate the effect of non-woven polyethylene terephthalate (PET) waste plastic tissue on the fresh, physical, mechanical, acoustic, thermal, and microstructural behaviors of mortar and concrete. Including reference specimens, non-woven fabrics were considered in two ways: a) as a layer with 5 various configurations of 1-Layer, 2-Layers, 2-Sides, 3-Sides, and full wrapping to strengthen specimens, and b) as cut pieces (10×10) mm with four different incorporated ratios of 0%, 0.25%, 0.50%, and 0.75%. Lastly, the bond properties between non-woven sheets and cementitious materials were investigated as well. The results indicate that the mechanical properties (compressive, split tensile, and flexural strengths) were remarkably improved while applying non-woven sheets as a layer. Even though SEM analysis observed excellent distribution of cut pieces and good bonding between cementitious materials and PET fabrics, but mechanical properties were decreased with the incorporation of non-woven tissue as cut pieces. Moreover, the control specimens showed brittle behaviors and were damaged to many fragments after mechanical testing. While samples strengthened or containing cut pieces of non-woven tissue had improved ductility, were maintained together, and not separated into many small parts. On the other hand, the incorporation of cut pieces of non-woven sheets resulted in the reduction of workability, fresh and dry densities and these reductions were more significant for higher percentages. Additionally, the porosity and water absorption were enhanced with the incorporation of cut pieces and increased further for higher volume fractions of cut pieces. Also, the attachment of non-woven tissue as a layer to strengthened concrete samples or incorporation of cut pieces in concrete mixtures resulted in remarkable improvements in acoustic and thermal properties. Furthermore, it was found that non-woven tissue has a very good bond with cementitious materials without using any adhesive materials. However, the bond behaviors enhanced with the increase of w/c ratio and reduction of superplasticizer content. This is because of the microstructure of non-woven sheet that is made of hairlines microfilaments that interacted inside the cement paste after mortar casting. This phenomenon was verified by interferometry and microscopic analysis as well. Finally, the correlations between different properties of concrete have plotted between each other, the trend of lines and R2 coefficient clearly prove the excellent accuracies. It means that certain properties of such type of concrete could be predicted from other already known behaviors. In addition, the current research data was checked by previously developed models and shows great accuracy as well.
... To tackle the negative effects of post-consumer plastics on the environment; therefore, recycling and reusing them are measured as one of the best solutions. In recent years many studies have been conducted to reuse of waste plastics in a mortar and concrete composites in different forms such as an alternative to natural aggregates [23][24][25][26][27][28][29][30][31][32], or as fiber to reinforce mortar and concretes [33][34][35]. The researchers have reused different types of post-consumer plastics, for instance, polypropylene (pp) [28,36], polyvinyl chloride (PVC) pipes [37], expanded polystyrene foam(EPS) [38], high density polyethylene (HDPE) [39], thermosetting plastics [40], polycarbonate [41], polyurethane foam [42,43], glass reinforced plastics (GRP) [44], and polyethylene terephthalate (PET) [33][34][35]45,46]. ...
... In recent years many studies have been conducted to reuse of waste plastics in a mortar and concrete composites in different forms such as an alternative to natural aggregates [23][24][25][26][27][28][29][30][31][32], or as fiber to reinforce mortar and concretes [33][34][35]. The researchers have reused different types of post-consumer plastics, for instance, polypropylene (pp) [28,36], polyvinyl chloride (PVC) pipes [37], expanded polystyrene foam(EPS) [38], high density polyethylene (HDPE) [39], thermosetting plastics [40], polycarbonate [41], polyurethane foam [42,43], glass reinforced plastics (GRP) [44], and polyethylene terephthalate (PET) [33][34][35]45,46]. ...
... A number of studies investigated the use of waste plastic aggregates [46,[81][82][83][84][85][86][87], but it is beyond the scope of this study which only focuses on the RPF studies. For the preparation of the RPFs, post-consumer plastics are collected and cleaned, after that they are cut manually [33][34][35]88,89], or by paper shredder [90,91], or by CD's cutter devise [92] to produce RPFs. In the case of using plastic bottles, the neck and bottom of the bottles are discarded. ...
Article
Full-text available
Municipal solid waste materials are growing worldwide due to human consumption. Nowadays, a different type of goods on large-scale is produced in the factories which is going to generate numerous amount of solid waste materials in the near future. Therefore, the management of these solid waste materials is a great concern around the world. Inadequate landfill, environmental pollution and its financial burden on relevant authorities, recycling and utilization of waste materials have a significant impact compared to disposing them. Studies have been done to reuse of waste materials as one of the elements of concrete composites. Each of the elements gives the concrete strength; however, the reuse of these wastes not only makes the concrete economical and sustainable, but also helps in decreasing environmental pollution. There are a number of different types of waste materials such as plastics, carpets, steels, tires, glass, and several types of ashes. In this paper, a comprehensive review was carried out on the influence of recycled plastic fibers (RPFs), recycled carpet fibers (RCFs) and recycled steel fibers (RSFs) on the fresh, mechanical and ductility properties of concrete. The previous studies were investigated to highlight the effects of these waste product fibers on the most important concrete properties such as slump, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, ultrasonic pulse velocity, energy absorption, ductility, and toughness. In this regard, more than 200 published papers were collected, and then the methods of preparation and properties of these recycled fibers (RF) were reviewed and analyzed. Moreover, empirical models using mechanical properties were also developed. As a result, RPFs, RCFs and RSFs could be used safely in concrete composites due to it is satisfactory fresh, physical and mechanical properties.
... Different mechanical properties of concrete reinforced with PET fibers were studied by the past researchers (Baldenebro-Lopez et al. 2014;Boiny et al. 2016;de Oliveira and Castro-Gomes 2011;Fraternali et al. 2011;Fraternali et al. 2013;Marthong and Marthong 2016;Nibudey et al. 2013a;Nibudey et al. 2013b;Mohammed 2017;Orasutthikul et al. 2017;Prahallada and Prakash 2011;Pelisser et al. 2012;Pereira et al. 2017;Borg et al. 2016;Wiliński et al. 2016;Al-Tulaian et al. 2016;Khatab et al. 2019;Thomas and Moosvi 2020;Adnan and Dawood 2020;Mohammed and Faqe Rahim 2020;Awoyera et al. 2021), and there is a relatively large amount of experimental data on this new construction material. Gu and Ozbakkaloglu (2016) on their review concluded that concrete containing plastic fibers have higher compressive, splitting tensile and flexural strengths than those of conventional concrete, when the concrete has a relatively low fiber content (i.e., less than 1%); an increase in the fiber content beyond this level leads to deterioration in the mechanical properties of concrete. ...
... Kim et al. (2010) used PET fibers with surface coated with maleic anhydride grafted polypropylene. However, most of the investigators worked on the properties of concrete with uncoated untreated PET fibers, obtained from mechanical cutting of drinking bottles, such as Borg et al. (2016), Orasutthikul et al. (2017, Pereira et al. (2017), Pelisser et al. (2012, de Oliveira and Castro-Gomes (2011) and Boiny et al. (2016). Analysis of data made in this investigation given in Figs. ...
Article
In this paper, comparative experimental study on the performance of steel fiber and PET fiber reinforced concrete has been performed. Experimental tests were carried out to highlight the effect of PET fiber parameters, mainly fiber dimensions, on the mechanical properties and fiber pull-out behavior of concrete. Results indicate that compared with steel fiber the performance of PET fiber is not good to enhance the mentioned properties, especially for compressive strength and modulus of rupture. Results showed that, in contrast to steel fiber, the performance of concrete with short and thick PET fiber is better. The existence of PET fiber in concrete has an influence on the crack bridging and changing the mode of failure of concrete to be less brittle. On the failed concrete surface, pull-out of PET fiber was not observed for concrete subjected to tension and flexure, and specimens were failed after large elongation of the plastic fiber. Analysis of global data was made to develop equations for calculating compressive strength, splitting tensile strength and modulus of rupture. Results of regression analysis indicate that these properties of concrete are dependent on the fiber index (Vf lf/df). Useful limits of fiber index were determined for each property helpful for the accurate using of PET fiber in concrete and avoiding high strength losses.
... Therefore, to decrease the environmental impact of PC, many researchers have been carried out to develop a new material to be an alternative to the PC [6]; among them, geopolymer technology was developed first by Davidovits in France, 1970 [7]. The green gas emission of geopolymer concrete (GC) is around 70% lower than the PC concrete due to the high consumption of waste materials in the mixed proportions of the GC [8,9]. The applicability of the water film thickness (WFT) model to the rheological properties of SCPB was briefly assessed. ...
Article
Full-text available
Abstract A variety of ashes used as the binder in geopolymer concrete such as fly ash (FA), ground granulated blast furnace slag (GGBS), rice husk ash (RHA), metakaolin (MK), palm oil fuel ash (POFA), and so on, among of them the FA was commonly used to produce geopolymer concrete. However, one of the drawbacks of using FA as a main binder in geopolymer concrete is that it needs heat curing to cure the concrete specimens, which lead to restriction of using geopolymer concrete in site projects; therefore, GGBS was used as a replacement for FA with different percentages to tackle this problem. In this study, Artificial Neural Network (ANN), M5P-Tree (M5P), Linear Regression (LR), and Multi-logistic regression (MLR) models were used to develop the predictive models for predicting the compressive strength of blended ground granulated blast furnace slag and fly ash based-geopolymer concrete (GGBS/FA-GPC). A comprehensive dataset consists of 220 samples collected in several academic research studies and analyzed to develop the models. In the modeling process, for the first time, eleven effective variable parameters on the compressive strength of the GGBS/FA-GPC, including the Activated alkaline solution to binder ratio (l/b), FA content, SiO2/Al2O3 (Si/Al) of FA, GGBS content, SiO2/CaO (Si/Ca) of GGBS, fine (F) and coarse (C) aggregate content, sodium hydroxide (SH) content, sodium silicate (SS) content, (SS/SH) and molarity (M) were considered as the modeling input parameters. Various statistical assessments such as Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), Scatter Index (SI), OBJ value, and the Coefficient of determination (R2) were used to evaluate the efficiency of the developed models. The results indicated that the ANN model better predicted the compressive strength of GGBS/FA-GPC mixtures compared to the other models. Moreover, the sensitivity analysis demonstrated that the alkaline liquid to binder ratio, fly ash content, molarity, and sodium silicate content are the most affecting parameter for estimating the compressive strength of the GGBS/FA-GPC.
... A constant compression stress loads range from 0.7 to 0.3 MPa is applied [46]. The load is increased until failure along the vertical diameter takes place [40,51]. Table 2 demonstrates some literature studies that have been conducted to illustrate the effects of adding nS on the GPC's splitting tensile strength. ...
Article
Full-text available
Geopolymer concrete is an inorganic concrete that uses industrial or agro byproduct ashes as the main binder instead of ordinary Portland cement; this leads to the geopolymer concrete being an eco-efficient and environmentally friendly construction material. Nanotechnology is one of the most active research areas with novel science and useful applications that have gradually gained attention, especially during the last two decades. Recently efforts have been made to incorporate nanoparticles in construction materials to enhance properties and produce concrete with improved performances. Progress in improving geopolymer concrete (GPC) is fast becoming a viable substitute for traditional cement-based concrete. That is because GPC is considered an eco-efficient and green concrete that consumes many waste materials. To improve the performance of GPC, several methods have been investigated, including the using of nanomaterials to enhance its chemical reactivity and provide fine particles to fill its nanopores and voids. In this paper, an overview was carried out to show the impact of nano-silica (nS) inclusions on the fresh and mechanical characteristics of GPC. Based on the analyzed data, incorporating nS affects the fresh properties adversely while improving the mechanical performance up to an appropriate dosage of the nS.
... Enhancing the strength of mortars provides a basis for further investigation of plastic waste aggregate in alkali-activated mortars. It should be mentioned that in this study, PET flakes were considered as artificial aggregate, whereas in other research, plastics also occur in powdered form [35], as fibres [24,36], pellets [37,38], melted and mixed with sand [39] and GBFS [40] or turned into resin [41]. Moreover, other types of plastics have been investigated as substitutes for natural aggregate, including PVC, LDPE, HDPE, and PP [22,[42][43][44][45]. ...
Article
Full-text available
The production of ordinary Portland cement is associated with significant CO2 emissions. To limit these emissions, new binders are needed that can be efficiently substituted for cement. Alkali-activated slag composites are one such possible binder solution. The research programme presented herein focused on the creation of alkali-activated slag composites with the addition of PET flakes as a partial substitute (5%) for natural aggregate. Such composites have a significantly lower impact in terms of CO2 emissions in comparison to ordinary concrete. The created composites were differentiated by the amount of activator (10 and 20 wt.%) and curing temperature (from 20 to 80 °C). Their mechanical properties were tested, and a scanning electron microscope analysis was conducted. Compressive and flexural strengths ranging from 29.3 to 68.4 MPa and from 3.5 to 6.1 MPa, respectively, were achieved. The mechanical test results confirmed that a higher amount of activator improved the mechanical properties. However, the influence of the PET particles on the mechanical properties and microstructure varied with the curing temperature and amount of activator. Areas that require further research were identified.
... The intensity of the toxic trace elements in FA could be 5-10 times greater than those in the raw material sources [32][33][34] and it has small amounts of polycyclic aromatic hydrocarbon and dioxins [35,36]. Therefore, the erroneous discarding of FA and any other by-product or waste materials will increment the occupation of land and destroy the environment and ecology [37][38][39]. Thus, to tackle these problems of FA and any other waste materials; efforts have been made towards re-use of them in an efficient and green way, for instance, high volume researchersresearchersresearchersresearchers have used FA have used FA have used FA have used FA to replace Portland cement in different types of concrete and cementitious composites [40][41][42][43][44][45][46]. ...
Preprint
Full-text available
The growing concern about global climate change and its adverse impacts on societies is putting severe pressure on the construction industry as one of the largest producers of greenhouse gases. Given the environmental issues associated with cement production, geopolymer concrete has emerged as a sustainable construction material. Geopolymer concrete is cementless concrete that uses industrial or agro by-product ashes as the main binder instead of ordinary Portland cement; this leads to being an eco-efficient and environmentally friendly construction material. Compressive strength is one of the most important mechanical property for all types of concrete composites including geopolymer concrete, and it is affected by several parameters like an alkaline solution to binder ratio ( l/b ), fly ash ( FA ) content, SiO 2 /Al 2 O 3 ( Si/Al ) of the FA, fine aggregate ( F ) and coarse aggregate ( C ) content, sodium hydroxide ( SH ) and sodium silicate ( SS ) content, ratio of sodium silicate to sodium hydroxide ( SS/SH ), molarity ( M ), curing temperature ( T ), curing duration ( CD ) inside the oven and specimen ages ( A ). In this regard, a comprehensive systematic review was carried out to show the effect of these different parameters on the compressive strength of the fly ash-based geopolymer concrete (FA-GPC). In addition, multi-scale models such as Artificial Neural Network (ANN), M5P-tree (M5P), Linear Regression (LR), and Multi-logistic Regression (MLR) models were developed to predict the compressive strength of FA-GPC composites. For the first time, in the modeling process, twelve effective parameters including l/b, FA, Si/Al, F, C, SH, SS, SS/SH, M, T, CD, and A were considered the modeling input parameters. Then, the efficiency of the developed models was assessed by various statistical assessment tools like Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), Scatter Index (SI), OBJ value, and the Coefficient of determination (R ² ). Results show that the curing temperature, sodium silicate content, and ratio of the alkaline solution to the binder content are the most significant independent parameters that influence on the compressive strength of the FA-GPC, and the ANN model has better performance for predicting the compressive strength of FA-GPC in compared to the other developed models.
Article
Full-text available
Abstract Alkali-activated concrete (AAC) has emerged as a sustainable construction material due to the environmental issues associated with cement production. This type of concrete is cementless concrete that employs industrial or agro by-product ashes like fly ash (FA) and ground granulated blast furnace slag (GGBFS) in their mixture proportions as the primary binders instead of conventional Portland cement. All concrete composites, including AAC, rely on compressive strength. However, the 28-day compressive strength of concrete is critical in structural design. Therefore, developing an authoritative model for estimating AAC compressive strength saves time, energy, and money while guiding the construction and formwork removal. This study used artificial neural network (ANN), M5P-tree, linear regression, non-linear regression, and multi-logistic regression models to predict blended GGBFS/FA-based AAC’s compressive strength at different mixture proportions curing ages. A comprehensive dataset consists of 469 samples collected in several academic research studies and analyzed to develop the models. In the modeling process, for the first time, twelve effective variable parameters on the compressive strength of the AAC, including the alkaline solution-to-binder ratio, FA content, SiO2/Al2O3 of FA, GGBFS content, SiO2/CaO of GGBFS, fine and coarse aggregate content, NaOH and Na2SiO3 content, Na2SiO3/NaOH ratio, molarity and age of concrete specimens were considered as the modeling input parameters. Various statistical assessment tools such as RMSE, MAE, SI, OBJ value, and R2 were used to evaluate the efficiency of the developed models. The results indicated that the ANN model better predicted GGBFS/FA-based AAC mixtures’ compressive strength than the other models. Moreover, the sensitivity analysis demonstrated that the alkaline liquid-to-binder ratio, NaOH content, and age of concrete specimens were those parameters that significantly influenced the compressive strength of the AAC.
Article
Full-text available
The building industry, which emits a significant quantity of greenhouse gases, is under tremendous pressure due to global climate change and its consequences for communities. Given the environmental issues associated with cement production, geopolymer concrete has emerged as a sustainable construction material. Geopolymer concrete is an eco-friendly construction material that uses industrial or agricultural by-product ashes as the principal binder instead of Portland cement. Fly ash, ground granulated blast furnace slag, rice husk ash, metakaolin, and palm oil fuel ash were all employed as binders in geopolymer concrete, with fly ash being the most frequent. The most important engineering property for all types of concrete composites, including geopolymer concrete, is the compressive strength. It is influenced by different parameters such as the chemical composition of the binder materials, alkaline liquid to binder ratio, extra water content, superplasticizers dosages, binder content, fine and coarse aggregate content, sodium hydroxide and sodium silicate content, the ratio of sodium silicate to sodium hydroxide, the concentration of sodium hydroxide (molarity), curing temperature, curing durations inside oven, and specimen ages. In order to demonstrate the effects of these varied parameters on the compressive strength of the fly ash-based geopolymer concrete, a comprehensive dataset of 800 samples was gathered and analyzed. According to the findings, the curing temperature, sodium silicate content, and alkaline solution to binder ratio are the most significant independent parameters influencing the compressive strength of the fly ash-based geopolymer concrete (FA-BGPC) composites.
Article
Full-text available
This study investigated the utilization of polyethylene terephthalate (PET) bottle fibre recycled as fibre-reinforced renders mortar. The fibres were obtained by simple mechanical cutting from bottles. Investigation was carried out on cement-lime mortar samples. Different volumes of fibres, i.e. 0%, 0.5%, 1.0% and 1.5%, were introduced in dry mortar mixes. Specifically, the mechanical properties as flexure, compressive strengths and mortar toughness were measured. The results indicate that the incorporation of PET fibres significantly improve the flexural strength of mortars with a major improvement in mortar toughness. The maximum volume of PET fibre for a desired workability was 1.5%.Research highlights► Polyethylene terephthalate bottle fibre recycled as fibre-reinforced renders mortar. ► Fibres obtained by simple mechanical cutting from bottles. ► PET fibre incorporation increases the mortar flexural strength and toughness. ► The optimum volume of PET fibre incorporation for a desired workability is 1.5%.
Article
Post-consumer plastic aggregates, such as those made from car bumpers, can be used successfully to replace conventional aggregates in concrete. Laboratory testing showed that the 28-day compressive strength of concrete containing plastic aggregates at different percentages of 10 to 50% ranged from 7000 to 2800 psi, while the splitting tensile strength ranged from 942 to 467 psi. Compared with conventional concrete, bulk density was reduced by 2.5% for concrete containing 10% plastic aggregates, 6% for that containing 30% plastic, 13% for concrete containing 50% plastic. A more ductile behavior was also observed for the concrete with plastic aggregates, which could be very advantageous in minimizing crack formation.
Article
This work is aimed to study the effect of incorporating recycled modified polypropylene (PP) plastic particles on the workability and mechanical behavior of self-compacting lightweight concrete (SCLC). Four replacement levels (10%, 15%, 20% and 30%) of sand by plastic by volume were introduced. The slump flow value is improved with an increase in the sand substitution. The viscosity of fresh SCLC is reduced and the passing ability is improved with the replacement level up to 15%. Both the dry bulk density and elastic modulus of SCLC decrease with an increase in sand replacement. The compressive strength, splitting tensile strength and flexural tensile strength are increased with the replacement level up to 15%. A microscopic study on the plastic-paste interface was performed.
Article
This paper describes an innovative use of post-consumer waste HDPE plastic in concrete as a soft filler. A reference concrete was proportioned to have the 28-day compressive strength of 5000 psi (35MPa). A high-density plastic was shredded into small particles for use in the concrete. These particles were subjected to three chemical treatments (water, bleach, bleach + NaOH) to improve their bonding with the cementitious matrix. The plastic particles were added to the concrete in the range of 0–5% of total mixture by weight. Compressive strengths were measured for each test mixture. The results showed that chemical treatment has a significant effect on performance of the plastic filler in concrete. Of the three treatments used on the plastic, the best performance was observed with the alkaline bleach treatment (bleach + NaOH) with respect to compressive strength of concrete.
Article
A comprehensive laboratory experiments were conducted to improve the mechanical properties of glass fibre reinforced plastic (GRP) waste powder filled concrete using superplasticiser for widening the scope for GRP waste recycling for different applications. It is imperative to note that the 28days mean compressive strength of concrete specimens developed with 5–15% GRP waste powder using 2% superplasticiser resulted 70.25±1.43–65.21±0.6N/mm2 which is about 45% higher than that of without the addition of superplasticiser (with GRP waste) and about 11% higher than that of the control concrete (without GRP waste) with 2% superplasticiser. The tensile splitting strength of the concrete showed 4.12±0.05–4.22±0.03N/mm2 with 5–15% GRP waste powder which is also higher than that of the control concrete (3.85±0.02N/mm2). The drying shrinkage, initial surface absorption and density of GRP waste filled concrete were evaluated and found better than the desirable quality for use in structural and non-structural applications.
Article
The recycled polyethylene terephthalate (PET) plastic waste was depolymerized through glycolysis to produce unsaturated polyester resin (UPER). The UPER so produced was then used as a binding agent to produce polymer mortar (PM) and polymer concrete (PC). Eight different sets of PM and PC were pro- duced by varying PET to glycol ratio, dibasic acids and initiator promoter combinations. The PET to glycol ratio used in the present study was 1:1 and 2:1. The initiator promoter combinations taken were Methyl ethyl ketone peroxide (MEKP) and cobalt naphthanate (CoNp) in one group of sets while Benzoil peroxide (BPO) and N, N-diethyl aniline (NNDA) in other group of sets. For each set, microscopic studies were con- ducted on neat resin and polymer mortar. The cube compressive strength of PM and PC so produced was found to vary from 15 to 28 MPa and from 20 to 42 MPa, respectively. The tensile strength of polymer concrete was either at par or more than the tensile strength of equivalent grade of cement concrete. The results of different sets have been com- pared and sets showing better performance have been identified.
Article
Knowledge of the quantities and composition of municipal solid waste (MSW) is a necessary tool for many aspects of solid-waste management. This report, which is an update of previous work in 1986, presents a summary of estimates of historical MSW quantities and composition from 1960 to 1986, with projections to the year 2000. The material-flows methodology developed by EPA in the early 1970s, with refinements that have been added in succeeding years, was used to make these estimates.