http://www.iaeme.com/IJARET/index.asp 1 [email protected]
International Journal of Advanced Research in Engineering and Technology (IJARET) Volume 11, Issue 10, October 2020, pp. 1-12, Article ID: IJARET_11_10_001 Available online at http://www.iaeme.com/IJARET/issues.asp?JType=IJARET&VType=11&IType=10
ISSN Print: 0976-6480 and ISSN Online: 0976-6499
DOI: 10.34218/IJARET.11.10.2020.001
© IAEME Publication Scopus Indexed
CRACK-FREE ENGINEERED CEMENTITIOUS
COMPOSITES TO OVERCOME DURABILITY
CHALLENGES IN CONSTRUCTION INDUSTRY
Srinivasa C H
Associate Professor, Department of Civil Engineering,
Government Engineering College, Kushalnagar, India
Dr. Venkatesh
Principal, Government Engineering College, Kushalnagar, India
ABSTRACT
Almost all major infrastructures utilize concrete as construction material. Being
brittle in nature, Conventional Concrete cracks easily under mechanical and
environmental loads. The concrete materials used for next generation should be
lighter than the Traditional Concrete, should be high ductile and possess good
transport properties with self-healing properties. Additionally, it should be
environmental friendly and energy saving one. This paper focuses on development of
high ductile and self-healing Engineered Cementitious Composites by using Polyvinyl
Alcohol fiber of 2% by volume of concrete. Research results indicate that durability
challenges can be overcome by using Engineered Cementitious Composites which
have a strain capacity of nearly 1.675% times than the Ordinary Concrete. Various
transport properties such as Rapid Chloride Penetration, Sorptivity and Permeability
are studied in this paper. Because of intrinsic self-control tight crack widths and
robust self-healing performance, Engineered Cementitious Composites can be
accepted as crack-free concrete towards sustainable development.
Key words: PVA fiber, Superplasticizer, RCPT, Sorptivity, Permeability
Cite this Article: Srinivasa C H and Venkatesh, Crack-Free Engineered Cementitious
Composites to Overcome Durability Challenges in Construction Industry,
International Journal of Advanced Research in Engineering and Technology, 11(10),
2020, pp. 1-12.
http://www.iaeme.com/IJARET/issues.asp?JType=IJARET&VType=11&IType=10
1. INTRODUCTION
Portland cement concrete is widely available throughout the world but the technology and
skill required to proportion, mix, place and cure it for long-term durability has not yet spread
as widely as is necessary. This should be the priority for the next century. The knowledge
Crack-Free Engineered Cementitious Composites to Overcome Durability Challenges in
Construction Industry
http://www.iaeme.com/IJARET/index.asp 2 [email protected]
exists to select materials, proportion them appropriately, mix them thoroughly, transport and
place them without segregation and cure them to minimize cracking and optimize long-term
strength development and durability. Implementing this knowledge is a major challenge. The
Concrete Engineer should concentrate on a more permanent, low-maintenance infrastructure.
As a consequence, it will be possible to spend valuable material resources on infrastructural
developments instead of spending more and more money on replacing or maintaining a
deteriorating system.
Every concrete mixture should be proportioned in accordance with exposure conditions,
construction considerations, and structural criteria. Exposure to freezing and thawing,
sulfates, deicing chemicals, acids, varying moisture conditions and abrasive loadings should
all be considered when selecting materials and proportions.
In spite of the advances in producing the high strength concrete, infrastructure all over the
world are suffering from deterioration and damage when exposed to real and aggressive
environments. Structures seldom fail due to lack of intrinsic strength but due to Serviceability
failures. The American Society of Civil Engineers 1998 Report graded the state of American
Infrastructure with an average D (Poor). This report also required an investment of some $1.3
trillion to put the roads, bridges, and water/waste/energy utilities to good working order. In
2005, the investment needed was $1.6 trillion to raise the quality of America‟s infrastructure
to a satisfactory level. The New Civil Engineer (NCE)/Institution of Civil Engineers (ICE)
State of the Nation Report in winter 2001 graded the overall quality of the UK Infrastructure
as C (Average). It is reported that repair and maintenance make up some 40% of all
construction work in the UK. A huge amount of investment is required on Repair and
Maintenance costs in developing countries like India, Brazil, Chile, Peru, Thailand, Mexico
and Nigeria. In fact, interest rate spreads have been widened in developing countries, making
it even harder to finance their Greenfield projects.
Advances in the measurement of rheological properties, mixing technology, aggregate
handling for greater uniformity and cementitious materials blending will be key to improved
concrete production. Durable concrete can be produced from carefully selecting materials to
control and optimize their properties, reducing variability in the mixing, transport, placement,
and curing of concrete. Understanding of the interaction between concrete and its
environment is utmost important in concrete mix designs. The knowledge about the various
causes is utmost essential to all engineers concerned prior to the concrete making.
In the world of Materials Engineering, raw ingredients are shaped into a composite
material through processing. Traditionally, selection of raw ingredients is based on
empiricism. In recent years, Composite materials are systematically being designed. One such
material is “Engineered Cementitious Composite (ECC)” or “Bendable Concrete.”
ECCs are a unique class of new generation high performance fiber-reinforced cementitious
composites (HPFRCC) featuring high ductility and medium fiber content. Tensile strain capacity at a
range of 3 to 5% has been demonstrated in ECC materials using Polyethylene fibers and Polyvinyl
Alcohol (PVA) fibers with fiber volume fraction not greater than 2% [1].
The corrosion of steel in concrete is one of the major problems with respect to the durability of the
reinforced concrete structures. The penetration of chloride ions into concrete is considered to be the
major cause of corrosion. A study, conducted by Mustafa Sahmaran et.al reveals that ECC is effective
in slowing the diffusion of the chloride ion under combined and environmental (chloride exposure)
loading by virtue of its ability to achieve self controlled tight crack width. [2]
Mustafa Sahmaran et.al in their study on durability of concrete subjected to highly alkaline
environments (1N NaOH Solution) explained that the reloaded specimens (specimens which were pre-
loaded under Uniaxial tension to different strain levels and then exposed to an alkaline environment up
to 3 months at 38ºC and reloaded up to failure) showed slight loss of ductility and tensile strength but
Srinivasa C H and Venkatesh
http://www.iaeme.com/IJARET/index.asp 3 [email protected]
retained the multiple micro-cracking behaviour and tensile strain capacity of 2%. The test results
indicated strong evidence of self healing of the micro-cracked ECC material. [3]
The fracture toughness of ECC is similar to that of aluminum alloy and ECC remains ductile even
when subjected to high shear stress. High tensile ductility and toughness of ECC material greatly
elevates the mechanical performance of reinforced ECC structure by preventing brittle failure and loss
of structural integrity which is usually found in traditional reinforced concrete [4].
While long-term studies are still needed, comparison studies by the School of Natural Resources
and Environment‟s Centre for Sustainable Systems, in conjunction with Li‟s group, show that over 60
years of service on a bridge deck, the ECC is 37% less expensive, consumes 40% less energy, and
produces 39% less Carbon dioxide, a major cause of global warming than regular concrete [5].
Mustafa Sahmaran et.al in their study on ECC with PVA fibers of Nominal strength of
1620 Mpa, Young‟s Modulus of 42.8 GPa, Diameter 39µm and Length of 8mm have come
out with the following mixture properties [5].
7-day Compressive strength of 38.1 Mpa
28-day Compressive strength of 50.2 Mpa
7-day Tensile strain capacity of 3.48 %
28-day Tensile strain capacity of 3.16 %
Corrosion mass loss of 2.5% at the end of 25 hours of accelerated corrosion exposure.
Corrosion mass loss of 5.3% at the end of 50 hours of accelerated corrosion exposure
Corrosion mass loss of 11.7% at the end of 75 hours of accelerated corrosion
exposure.
Michael D. Lepech says that the material durability plays a central role in sustainable
concrete infrastructure. Therefore, adverse effects of industrial wastes on durability should be
controlled. ECC was identified as the candidate for material greening with the overall goal of
improving sustainability. ECC materials are highly durable in a number of harsh
environments. This durability results from unique pseudo strain-hardening ductility and
distributed microcracking behaviour in tension. [6]
En-Hua Yang et.al, in their study included four factors like Class C Fly ash ratio to Class
F Fly ash ratio, water to binder ratio, amount of High Range Water Reducer and amount of
Viscosity Modifying Admixture to investigate the composition effects on fresh and hardened
properties of ECC. Among the four factors, water to binder ratio has the greatest effect on
Plastic Viscosity. The plastic viscosity of fresh ECC has a significant impact on ECC tensile
properties. The tensile strain and ultimate tensile strength of ECC were found to increase with
the increase of plastic viscosity [7].
Mustafa Sahmaran and Victor Li in their investigation have come out with the two ECC
mixtures with Fly ash to Portland cement (FA/PC) of 1.2 and 2.2 by weight. This ratio was
used in their investigation [8]. The ECC mixtures were prepared in a standard mortar mixer at
a constant amount of cementitious material and constant water to cementitious material ratio
of 0.27. High Range water Reducer was added to the mixture until the desired ECC
characteristics in its fresh state were visually observed. The cement used was Ordinary
Portland Cement and Fly ash used was Class F Fly ash. The PVA fibers of tensile strength
1620 Mpa and Elastic Modulus of 42.8 GPa were used in the mix proportion.
Yangzi Yang et.al, in their study have concluded that
Four to five cycles of wet-dry conditioning are necessary to attain the full benefit of
self healing.
Self-healing in specimens subjected to a tensile strain of 0.3% and 3.0% brought the
resonance frequencies back to 100% and 76% of initial values respectively. This
Crack-Free Engineered Cementitious Composites to Overcome Durability Challenges in
Construction Industry
http://www.iaeme.com/IJARET/index.asp 4 [email protected]
exhibits the relation between the extent of self healing within the cracked ECC
specimens and the level of strain damage to which they have been subjected to.
ECC specimens subjected to pre-load straining of a high level, even up to 2% or 3%
after self healing, the tensile ductility character of ECC is retained. The self-healed
ECC material remains ductile. [ 9]
It has been reported by Michael D. Lepech and Victor C. Li that the tight crack width in
ECC are possible by using micromechanics as a tool for designing low permeability ECC
composites which meet the two critical criteria of forming multiple cracks under load and
ensuring that the maximum of fiber bridging stress verses crack opening relationship (σ-δ) for
the composite occur below a crack width opening of 100µm. this relationship can also be used
as a guide for tailoring the fiber, matrix and fiber/matrix interface within the composite to
meet the lo permeability criteria. [10]
ECC mixtures will have a tendency to undergo early-age cracking, which is a
consequence of increased Autogenous shrinkage. It has been reported by Mustafa Sahmaran
that fiber bridging stress verses crack opening relationship (σ-δ) at early ages will not be
developed to withstand internal stresses caused by the external and internal restraints. Thus,
insufficient tensile strain and Autogenous deformation may lead to the formation of some
microcracks of the order greater than 100µm. while this cracking may or may not compromise
with the mechanical properties of the composite, it may affect their long term durability.
Traditional external curing techniques are not effective in eliminating early age cracking,
since the water transportation into the ECC is hindered by the tightness of the matrix. In order
to overcome this problem, use of pre-soaked lightweight aggregate (LWA) as internal water
reservoirs has shown satisfactory results. Internal curing by means of pre-soaked LWA has
been proved to be effective in reducing Autogenous shrinkage in high performance concrete
with a low water-to-cement ratio. [11]
From the results of the study made by Mustafa Sahmaran, it is concluded that the use of
water repellent admixture further reduces the water sorptivity and absorption properties of
cracked ECC to a level significantly lower than that of normal un-cracked concrete. [12]
2. MATERIALS AND EXPERIMENTAL PROCEDURES
Bendable Concrete Mix design is based on the Micromechanics. Micromechanics can be a
powerful tool to deliberately tailor the composite ingredients, such as fiber dimensions, and
surface coatings along with addition of high volume mineral admixture such as fly ash, sand
particle amount and size. In addition, material processing and its effect on both fresh and
hardened properties aid in composite design. Various trial mixes were planned based on the
micromechanics and the relevant literatures. The trial mixes in their fresh states were studied
for the evaluation of cohesiveness. After satisfied with the mixes in its fresh state, workability
of the various mixes were studied using slump cone. T50 slump flow test is carried out to
know the filling ability (flowability) property of the concrete. Characteristic Deformable
Factor, Gamma (τ) was also studied to know the behaviour in its fresh state. This is an
important property of Bendable concrete in its fresh state. Then, the mixes were casted for the
purpose of studying the behaviour of Bendable Concrete in compression. Various durability
properties were also studied in this work.
2.1. Methodology
One of the unique features behind the high ductility of Engineered Cementitious Composites
(ECC) is a design basis that is distinctly different from that of high strength concrete. For high
strength concrete or members of this family of concrete materials, high compressive strength
Srinivasa C H and Venkatesh
http://www.iaeme.com/IJARET/index.asp 5 [email protected]
is reached by particle tight packing. The design basis of ECC, however, is based on
synergizing the mechanical interactions between fiber, matrix, and interfaces of the composite
so that multiple cracking in tension is attained. This design basis is embodied in a body of
knowledge known as the micromechanics of ECC. Micromechanics of ECC serves as a
powerful foundation for design of ECC for various performance needs for different target
applications. In this sense, the „micromechanics‟ is an effective tool for efficient design of
ECC with optimized mechanical, physical, and functional properties.
A tool such as Micromechanics is applied in arriving at suitable proportions of the
ingredients for making the composites. The suitability of all the ingredients are analysed by
conducting various tests in the laboratory and then the trial mixes are prepared to know
whether the prepared mixes satisfy wet properties and subsequently hardened properties
2.2. Ingredients of Polyvinyl Alcohol Fiber Reinforced Concrete
OPC (Ordinary Portland Cement), Natural River Sand, Class F Fly Ash, Polycarboxylic Ether
(PCE) based Superplasticizer; High flexural and tensile strength Polyvinyl Alcohol (PVA)
fibers were used. Filament Diameter and length of PVA fiber were 38 microns and 8mm
respectively. No Coarse aggregates were used due to the tendency of rupture of fibers during
mixing and transport.
3. RESULTS AND DISCUSSION
3.1. Behaviour of ECC in its wet Condition
Various Proportions were tried keeping the Water to Binder ratio as Constant and varying the
dosages of Superplasticizer for analysing the fresh property of the composites. The
Characteristic Deformability Factor test is used to quantify the effects of particle size
distribution of the fine aggregates in ECC along with other ingredients as outlined by Kong
et.al. A standard concrete slump cone is filled with fresh ECC and discharged onto a level
Plexiglas or glass plate. Following flow of ECC, two orthogonal diameters of the ECC
“pancake” are averaged and a Characteristic Deformability Factor, denoted by τ is calculated
using;
τ =
;
Where, D1 is the average of two orthogonal “pancake” diameters, in mm and D0 is the
diameter of bottom of original slump cone, in mm. Figure1 Shows the Wet Mix of ECC
having a creamy texture appearance.
Table 1 the Characteristic Deformability Test Data. The τ for an ECC should be between
2.75 and 4.00 as per the available literature. The mix was homogeneous and there was no
segregation and bleeding. Table 2 represents the typical mix proportions of various
ingredients of ECC. Figure 2 shows flowability property of ECC.
Crack-Free Engineered Cementitious Composites to Overcome Durability Challenges in
Construction Industry
http://www.iaeme.com/IJARET/index.asp 6 [email protected]
Table 1 Test Data of Characteristic Deformability Factor (τ) M
ix
Des
ign
ati
on
Cem
ent
(kg)
Sa
nd
(k
g)
Fly
Ash
(kg
)
SP
(k
g)
Wa
ter
(kg)
Fib
er %
by
Vo
lum
e
FA
/ P
C
W /
B
Av
era
ge
Dia
met
er,
D1
(mm
)
T5
0 c
m f
low
Tes
t (
Sec
on
ds)
Bo
ttom
Dia
met
er o
f
Slu
mp
Co
ne,
D0 (
mm
)
τ=
(D
1-D
0)
/ D
0
PVA
ECC-
2.00
570 456 684 3.135 338.6 2.0 1.2 0.27 790 437 200 2.95
Figure 1 Creamy Texture Appearance of Fresh PVA ECC – 2%
Figure 2 Measurement of Slump Flow (Characteristic Deformability Test)
Srinivasa C H and Venkatesh
http://www.iaeme.com/IJARET/index.asp 7 [email protected]
Table 2 Typical Mix Proportion of Engineered Cementitious Composite
Cem
ent
Sa
nd
Fly
Ash
SP
Wa
ter
Fib
er
FA
/PC
W/B
570 456 684 3.135 338.6 26 1.2 0.27 FA: Fly Ash, W/B: Water to Binder ratio, FA/PC: Fly Ash to Portland Cement
3.2. Compressive Strength Test
The specimens of size 150 mm x 150 mm x 150mm were tested for knowing he compressive
strengths in a CTM machine of capacity 200 ton for various percentages of PVA fibers. Table
3 shows Compressive Strengths of ECC Specimens for different percentages of PVA fibers
at7 Days and 28 Days of age. Figure 3 shows the line graph of Compressive Strengths verses
PVA fibers.
Table 3 Compressive Strength at 7 Days And 28 Days
PVA Fiber (%) 7 Days 28 Days
0.00 14.22 41.48
0.25 15.44 39.63
0.50 18.25 42.44
0.75 20.43 44.54
1.00 21.86 46.52
1.25 23.89 47.30
1.50 23.89 48.45
1.75 24.73 50.59
2.00 25.62 52.95
Figure 3 Compressive Strength V/S PVA Fiber
3.3. Direct Tensile Strength Test
Direct Tensile Strength is one of the fundamental properties of concrete. Direct tensile
strength test is very difficult to be carried out on concrete specimens as there will be stress
concentrations at the junctions of the steel grippers which are made to hold the tensile strength
test specimens. Use of high tensile strength PVA fibers helped us to conduct tensile tests
Crack-Free Engineered Cementitious Composites to Overcome Durability Challenges in
Construction Industry
http://www.iaeme.com/IJARET/index.asp 8 [email protected]
using UTM (Universal Testing Machine) of capacity 100 ton. A flexible concrete after
loading shows the development of microcracks. This is a clear indication of amazing
durability properties of ECC. The specimens at the age of 28 days were subjected to direct
tensile loading under displacement control of 0.005mm/s to know the strain hardening
behaviour of the PVA fiber concrete and consequent development of micro cracks. Figure 4
shows the Tensile Test Specimen and its specification. Figure 5 represents the graph of stress
verses strain of ECC for a PVA fiber content of 2.00%. ESEM image is shown in Figure 6.
3.4. Specification of the Tensile Test Specimen
Overall Length = 660 mm
Distance between Shoulders = 300 mm
Gauge Length = 200 mm
Size of the Grip Section = 90 mm x 50 mm
Size across the Gauge Length = 50 mm x 50 mm
Figure 4 Dimensions of the Tensile Test Specimen
Figure 5 Stress-Strain Graph for Bendable Concrete
Srinivasa C H and Venkatesh
http://www.iaeme.com/IJARET/index.asp 9 [email protected]
Figure 6 ESEM Image of Microcracks in Bendable Concrete
3.5. Durability Tests on Engineered Cementitious Composites
To understand the durability aspects of ECC, various transport properties such as
Permeability Tests, Rapid Chloride Penetration Test (RCPT) and Sorptivity Test were
conducted as per the Indian Standards.
3.5.1. Rapid Chloride Penetration Test
The Rapid Chloride Penetration Test (RCPT) is used to evaluate the resistance of a concrete
sample to the penetration of chloride ions. The RCPT consists of two parts: To obtain
consistent chloride permeability values for a concrete batch, each slice is conditioned to start
at the same moisture content. Then the concrete is tested by measuring the charge passed
through the slice when one side of the specimen is in contact with a Sodium Chloride (NaCl)
solution and the other side is in contact with a Sodium Hydroxide (NaOH) solution. The
current is recorded at 30 minutes intervals. The method based on Trapezoidal Rule can be
used to calculate the charge passed in Coulombs.
Charge passed = Q = 900(I0 + 2 I30 + 2 I60 + ………2 I300 + 2 I330 + 2 I360).
Where,
I0 = current immediately after voltage is applied in amperes
It = current at t min intervals after voltage is applied in amperes.
3.5.2. Sorptivity Test
The performance of concrete subjected to many aggressive environments is a function, to a
large extent, of the penetrability of the pore system. In unsaturated concrete, the rate of
ingress of water or other liquids is largely controlled by absorption due to capillary rise.
This test method is used to determine the rate of absorption (sorptivity) of water by ECC
specimens by measuring the increase in the mass of a specimen resulting from absorption of
water as a function of time when only one surface of the specimen is exposed to water. The
exposed Surface of the specimen is immersed in water and water ingress of unsaturated
concrete dominated by capillary suction during initial contact with water.
The absorption, I, is the change in mass divided by the product of the cross-sectional area
of the test specimen and the density of water. For the purpose of this test, the temperature
dependence of the density of water is neglected and a value of 0.001 g/mm3 is used. The units
of I are mm.
Crack-Free Engineered Cementitious Composites to Overcome Durability Challenges in
Construction Industry
http://www.iaeme.com/IJARET/index.asp 10 [email protected]
Where,
I = m/a *d
I = the absorption,
m = the change in specimen mass in grams, at the time t,
a = the exposed area of the specimen, in mm2, and
d = the density of the water in g/mm3.
3.5.3. Permeability Test
Onset of corrosion is possible only in the presence of Moisture, Oxygen, Carbon Dioxide,
Sulfur Trioxide and of course Chloride ions. The end product of corrosion is what we call it as
“Rust” has the volume almost equal to six times the volume of the original steel. To prevent
rusting of steel, we need to have water tight or highly impermeable concrete. If water
transport is prevented, corrosion will be arrested and ultimately we can avoid spalling up of
the concrete due to bursting pressure of rust from inside.
150mm cubes were casted for the purpose of conducting the tests on permeability. The
samples were cured for 28 days and then subjected to a water pressure of 0.5 MPa on a
surface of 100 mm diameter at the top of the specimen for a period of 72 hrs. The penetration
depth of water is measured by opening the specimen into two halves.
Table 4 shows the results of RCPT, Sorptivity Test and Permeability Test. Figures 7, 8
and 9 represent the line graph of Charged Passed, Sorptivity Slope and Depth of Permeability
verses PVA fibers respectively.
Table 4 Transport Properties of Bendable Concrete
PVA
Fiber
(%)
Rapid Chloride
Penetration Test Sorptivity Test
Permeability
Test
Charge Passed (Coulombs) Sorptivity Slope Depth of water
Penetration (mm)
0.00 1813.50 0.045 24.7
0.50 1606.50 0.036 17.8
1.00 1368.00 0.031 13.2
1.50 1210.50 0.025 11.6
2.00 1089.00 0.023 10.4
Figure 7 Charged Passed Verses PVA Fiber
Srinivasa C H and Venkatesh
http://www.iaeme.com/IJARET/index.asp 11 [email protected]
Figure 8 Sorptivity Slope Verses PVA Fiber
Figure 9 Permeability Depth Verses PVA Fiber
4. CONCLUSIONS
The results of experiments monitoring the change in the transport properties are presented in
this paper. ECC specimens with Water to Binder ratio of 0.27 with PVA fiber content of 2%
shows a significant ductility property with a strain capacity of 1.675% and the corresponding
Tensile Strength observed was 5.84 Mpa. The observed microcracks through ESEM
(Environmental Scanning Electronic Microscope) were too tiny of size from 8.98 µm to 45
µm. The Compressive strength obtained was 52.95 Mpa for 2% PVA fiber content.
The depth of water permeated through 2 percent PVA fiber specimen at the age of 28 days
was only 10.40 mm which is less than the minimum cover to be provided in concrete
elements. This shows the sign of durable concrete. For 2% fiber content, the charge passed
through 2 percent PVA fiber specimen during RCPT test was found to be 1089 Coulombs and
the sorptivity slope was obtained as 0.023.
Bendable concrete could make infrastructure safer, economical and environmental
friendly and thus helps in sustainable development.
Crack-Free Engineered Cementitious Composites to Overcome Durability Challenges in
Construction Industry
http://www.iaeme.com/IJARET/index.asp 12 [email protected]
REFERENCES
[1] En Hua Yang. et.al. (2007) “Use of high volume fly ash to improve ECC Mechanical
[2] Properties and Material Greenness,” ACI Materials Journal/November-December 2007.pp.
303-311
[3] Mustafa Sahmaran et.al. (2007), “Transport properties of Engineered Cementitious
[4] Composites under chloride environment.” ACI Materials Journal/November –December 2007,
pp 303-310
[5] Mustafa Sahmaran and Victor. C. Li (2007), “Durability of mechanically loaded engineered
Cementitious composites under highly alkaline environments.” Cement and Concrete
Composites, 30 (2008), pp 72-81.
[6] En-Hua Yang et.al. (2008) “Fiber-bridging constitutive law of engineered cementitious
composites,” Journal of advanced concrete technology Vol. 6, No. 1, pp.181-193.
[7] Mustafa Sahmaran et.al (2008), “Corrosion Resistance Performance of Steel _reinforced
Engineered Cementitious composite Beams.” ACI Materials Journal / May-June 2008, pp
243-250
[8] Michael D. Lepech (2008), “Design of Green Engineered Cementitious Composites for
improved sustainability.” ACI Materials Journal/November –December 2008, pp 567-575
[9] En-hua Yang et.al (2009), “Rheological Control in production of Engineered Cementitious
Composites.”, ACI Materials Journal/ July-August 2009, pp357-366
[10] Mustafa Sahmaran and Victor Li., “Durability properties of micro-cracked ECC containing
high volumes fly ash.” Journal of Cement and Concrete Research, 39(2009), pp 1033-1043
[11] Yingzi Yang et.al (2009), “Autogenous healing of engineered cementitious composites under
wet-dry cycles.” Cement and Concrete Research, 39 (2009), pp 382-390
[12] Michael D. Lepech and Victor. C. Li (2009), “Water permeability of engineered cementitious
composites.” Cement and Concrete Composites, 31 (2009), pp 744-753
[13] Mustafa Sahmaran et.al (2009), “Internal curing of engineered cementitious composites for
prevention of early age Autogenous shrinkage cracking.” Cement and Concrete Research,
39(2009), pp 893-901
[14] Mustafa Sahmaran and Victor. C. Li (2009), “Influence of microcracking on water absorption
and sorptivity of ECC.” Materials and structures, 30 (2009) 42, pp 593-603.