1 s2.0 S095894652030202X Main
1 s2.0 S095894652030202X Main
1 s2.0 S095894652030202X Main
A R T I C L E I N F O A B S T R A C T
Keywords: This paper presents a review of the deterioration of concrete under seawater attack with particular interests in
Concrete field exposure. The research reported in the literature has shown that salinity of seawater in different areas varies
Marine environment considerably but the type of ions and their proportion are similar. Because of this variation, laboratory studies
Deterioration
should use specific artificial seawater to simulate on field environments. The phase changes induced by chloride,
Durability
Chloride penetration
magnesium and sulfate ions contained in seawater are reviewed. The interaction between hydrates and chloride
Supplementary cementitious materials ion can lead to the formation Friedel’s and Kuzel’s salts. Magnesium ion can replace the calcium in Portlandite,
and lowers the alkalinity of pore solution and eventually destabilizes C-S-H gel. The expansive ettringite is
inhibited at the presence of chloride ions. At the tidal zone, the phase change mainly occurs on the surface of
concrete, which weakens the structure and leads to spalling and delamination under the physical attack of the
wave. Based on the existing deterioration mechanisms, the protocols to enhance the durability performance of
marine concrete are also reviewed, such as using supplementary cementitious materials (SCMs) to mitigate rate
of chloride penetration and, more promisingly, to use alternative binder systems. This paper also proposes a
concept of designing a more durable concrete cover system by enhancing the chemical stability of cement hy
drates, rapid self-healing and intelligent alkalinity control.
1. Introduction However, the durability and actual service life of concrete are
affected by improper selection mixture materials or inadequate quality
The actual life of marine concrete structures is usually much shorter control during construction. Costa and Appleton [2] studied three dorks
than the designed service time due to various attacks from seawater [1]. and four wharves in Portugal, and found that the steel bars in the deck of
Chloride-induced reinforcement corrosion is regarded as the primary the wharves were seriously rusted (some of them completely lost their
durability issues [2–5]. Although corrosion resistant reinforcements net cross-section and the concrete cover of these dorks were massively
including stainless steel [6] and fiber-reinforced polymers (FRP) [7] spalled after 30 years. Dousti et al. [5] examined a 40-year-old RC jetty
have been proposed, the carbon steel is still irreplaceable currently in structure in Persian Gulf region with extensive delamination of concrete
field construction due to the practical advantages of low cost, easy field and corrosion of reinforcements, and confirmed that the structure was
processing, versatile mechanical performances, etc. In reinforced con designed and built under insufficient qualitative specifications under the
crete (RC) system, steel reinforcements are chemically protected by exposed conditions.
alkaline concrete pore solution and physically protected by the barrier It is essential to protect steel reinforcement from corrosion through
effect of the dense concrete materials, which can inhibit the access of strict concrete design. Since all aggressive ions penetrate through pore
aggressive species. That means the resistance of concrete to seawater structure, the permeability of concrete is important for durability [8].
attack is decisive to service time of RC structure in the marine Well appreciated answers based on conventional wisdom are to make
environment. concrete dense, impermeable and water-repellent by lowering the water
* Corresponding author.Key Laboratory for Green & Advanced Civil Engineering Materials and Application Technology of Hunan Province, College of Civil En
gineering, Hunan University, Changsha, 410082, PR China.
E-mail address: dzhu@hnu.edu.cn (D. Zhu).
https://doi.org/10.1016/j.cemconcomp.2020.103695
Received 25 October 2019; Received in revised form 19 May 2020; Accepted 26 May 2020
Available online 30 May 2020
0958-9465/© 2020 Elsevier Ltd. All rights reserved.
Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
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Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
Fig. 2. Influence of the salinity of seawater on concrete deterioration (laboratory exposure), (a) [33], (b)–(c) [34].
expansive calcium oxychloride (CaCl2⋅3Ca(OH)2⋅12H2O) [43], which However, the field study showed that the presence of brucite can was
can seriously crack concrete due the expansion pressure [44,45]. The mainly observed within the calcite crust and only detectable in cracks in
calcium oxychloride is mostly found in laboratory test as its formation very few specimens [41]. Meanwhile, the M-S-H was observed in most of
requires both high concentration of calcium and chloride ions, which is the investigated specimens except for several concretes with intact
usually unachievable in nature [46]. Meanwhile, Peterson et al. [47] calcite crust [41]. These results indicate that brucite, more often than
assumed that the calcium oxychloride can easily decompose under not, coexists with calcite deposits rather than M-S-H in real marine
natural environment and translate into ubiquitous secondary phase, environment. Sibbick et al. [55] also found similar phenomenon by
which consequently make it undetectable in field concrete and prevent surveying the deterioration mechanism of concrete steps in Solva,
researchers to link its formation to the deterioration. Some seawater in Pembrokeshire. Brucite was observed in three out of seven specimens
the coastal areas with high evaporation (Fig. 3), such as the Persian Gulf collected from different parts of the step structure and its coexistence
as reported in Ref. [48], might have high concentrations of Ca2þand Cl , with carbonate deposits was confirmed in cracks, while M-S-H can be
but it is still difficult to confirm the existence of calcium oxychloride in found in the three out of the four remained samples. Also phase change
field. caused by magnesium ions in seawater is restricted to the surface due to
The magnesium ion in sea water can react with the calcium hy its limited penetration ability of the concrete regardless of the quality
droxide in concrete and precipitate as brucite [49], which lowers the [41,56].
alkalinity of pore solution and eventually destabilizes the C-S-H [50]. The existence of sulfate ions can lead to notorious sulfate attack due
The decalcified C-S-H would part or completely translate into to the formation of expansive ettringite (3CaO⋅Al2O3⋅3CaSO4⋅32H2O)
non-cementitious magnesium-silicate-hydrate (M-S-H) [51,52]. Cole and gypsum (CaSO4⋅2H2O), resulting in expansion pressure and
confirmed the existence of crystalline M–S–H in the finely divide soft cracking of concrete. The presence of ettringite and gypsum can be
white deposit from an intensively deteriorated concrete sea-wall and identified both in lab-tested [54] and field-exposure [42] conditions, but
determined its composition as 3 Mg(OH)2⋅MgSiO3⋅5.5H2O from the XRD the amount of the latter is negligible due to the low concentration of
and thermogravimetric analysis [53]. The laboratory test results of sulfate ion in seawater. Furthermore, the ettringite normally does not
Weerdt and Justnes indicated that brucite and M-S-H coexist in cement lead to serious sulfate attack in concrete exposed to seawater. Santha
paste under seawater attack and the latter has constant Al/Mg ratio of nam et al. [55] compared the damage degree of concrete immersed in
about 0.2 and Si/Mg ratio of about 1, respectively [54]. Ragab et al. [40] groundwater and seawater, which had the same concentration of SO3,
reported that the morphology of brucite and M-S-H are small rosette and found that the samples in seawater had much less reduction of
shaped crystals and fiber shape respectively. In the laboratory tests, compressive strength and expansion compared the samples exposed to
brucite tends to form a thin layer on the concrete surface [49,55]. ground water after 32 weeks. Similarly, Jakobsen et al. reported that
sulfate ions in seawater mainly lead to sulfur enrichment instead of
sulfate attack in concrete [41]. There is no crack or spalling found in the
sulfur-rich zone of the concrete. This phenomenon can be caused by the
abundant chloride ion in seawater, which can enhance the dissolution of
ettringite and suppress its formation. Corner and Rippstain [57] re
ported that the solubility of ettringite in chloride solution was three
times greater than that in water. Furthermore, Ogawa and Roy [58]
found that the chloride-containing solution can lower the decomposition
temperature of the ettringite. Besides that, aluminate hydrate phases can
be consumed by formation of Friedel’s salt and/or Kuzel’s salt, which
react competitively ettringite [59,60]. The research of Santhanam et al.
indicated that less ettringite was formed in concrete soaked in seawater
indeed [55]. The less expansive ettringite can then lead to less expansive
pressure and reduced deterioration. Another sulfate-induced phase
change is the formation of thaumasite. In presence of soluble carbonate
and reactive silicate, thaumasite (CaSiO3⋅CaCO3⋅CaSO4⋅15H2O) can be
formed at low temperatures, disintegrating the microstructure and
inducing scaling of concrete [61]. When carbonate aggregates are used,
such as limestone and shell fragments, it tends to form this salt [56].
Fig. 3. Crystallization of chloride salts on concrete surface in splash zone [48].
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Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
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et al. [70] inspected the Geiger bridge in situ and found that beams and exposed to the marine environment for 19–24 years, Moffatt et al. [80]
girders located on the southern area of the bridge deteriorated appar reported that the use of high volume of fly ash (56% or 58%) could
ently more than their counterparts on the northern side. Costa and effectively delay the chloride ingress. Besides that, Thomas et al. justi
Appleton [2] reported the northern wall of one deck of presented higher fied the reliability of ground granulated blast-furnace slag (GGBS) on
level deterioration than that on the east and west walls because the blocking the penetration path of chloride ion in normal concrete [81]
sunshine duration there is longer than the other two walls. As mentioned and lightweight concrete [82] through in situ exposure test for 25 years.
above, the salinity of the seawater increases with the exposure tem A 30-year marine exposure test reported by Mohammed et al. proved
perature. Besides that, the diffusion coefficient can also be enhanced that incorporating slag in cement can significantly depress chloride
with higher temperature. Normally, the chemical interaction between ingress and mitigate corrosion of steel bar [83]. Furthermore, the
the seawater and cementitious materials will also be accelerated with improvement with adding GGBS was found to be more effective than
enhanced temperature. Hence it can be concluded the deterioration by reducing w/b. Besides, the results of another 15-year test showed that
the sea water will be accelerated with higher exposure temperature. with a similar amount of replacement level, GGBA seems more effective
Lindvall [33] found that the apparent surface chloride content decreased than fly ash [84]. These results were also supported by another 18-year
while the chloride diffusion coefficient increased with the increase of exposure tests supported this conclusion as well, i.e. concrete cubes
field exposure temperature. It should also be noticed that the influence containing 40% GGBS showed slightly better resistance to chloride
from the temperature is limited due to the relative stability of the penetration than these with 30% fly ash despite the higher w/b of the
exposure temperature in these field location (mostly ranging from 10 to former (0.44) than the latter (0.39) [85].
17 � C). Currently the influence of exposure temperature to the deterio Besides utilizing a single pozzolanic material, the application of
ration of concrete in the marine environment is quite limited. Balestra ternary SCMs to enhance resistance to chloride penetration has also been
et al. [71] reported that one concrete structure exposed in the marine conducted. The further study by Thomas and Moffatt through long term
atmosphere at Arvoredos Island, Guaruj� a city, Brazil, presented greater exposure tests supported that the combination of a small amount of
chloride ingress in the right side of the columns than that in the left side, silica fume and fly ash [86] could both effectively delay the penetration
as the right side directly facing the predominant sea wind. This indicates of chloride. Zhang et al. [87] found that concrete specimens containing
that besides temperature, environmental effects also contribute to 15% of fly ash and 5% silica fume performed better against chloride
variation in the availability of salt, relative humidity (RH) and conse ingress than these only with 5% silica fume or 20% fly ash, especially for
quently different deterioration levels of the marine concrete structure. long-term performance. The chloride profile obtained from concrete
The high salt concentration and content result in enhanced reactivity of submerged in seawater for 16 years illustrates that different concretes
deterioration, while the high RH of surrounding leads to more free water beams containing 92% Portland cement þ8%silica fume, 67% Portland
in pores of the concrete, facilitating the penetration of external ions and cementþ29% slagþ4%silica fume, 77% Portland cement þ19%fly
chemical actions between ions and solid phases. ashþ4% silica fume respectively has a comparable level of chloride
ingress [88].
3. Performance of blended-cement concretes For other less commonly used pozzolanic materials, there only exist
data from situ marine or simulated exposure experiments with relatively
3.1. Chloride penetration short exposure time to evaluate their influence on chloride resistance.
Bai et al. [89] put concrete cubes with a ternary binder system, Portland
The transport of chloride in concrete exposed to the marine envi cement (PC)–pulverised fuel ash (PFA)–metakaolin (MK) in seawater 18
ronment can be affected by both the intrinsic performance of concrete months. The results indicated that the increased replacement level of
and the exposure condition. Furthermore, the performance of concrete is cement and enhanced proportion of MK in the binder can both greatly
governed by its mix design and curing condition. Reducing water to enhance the resistance to chloride penetration. By analyzing reinforced
binder ratio, incorporating pozzolanic materials and prolonging curing concrete prisms exposed in the real marine environment for 3 years,
duration can all densify microstructure and improve the chloride- Binici et al. [90] stated that the combination of ground basaltic pumice
binding capacity to mitigate chloride penetration. Moreover, the (GBP) and GGBS owned a synergic effect on slowing down the chloride
various vicinity to seawater of each exposure zone results in different penetration and corrosion of steel bars, outperforming their counterpart
availability of chloride ions and environmental conditions (RH and incorporating with only GGBS or GBP. After 50-month exposure to
temperature). Normally, less chloride source, lower RH and temperature marine tidal conditions, Tadayon et al. [91] found that concrete with
lead to less chloride ingress. To evaluate the resistance to chloride 10% of natural zeolite has similar effects on reducing chloride ingress
penetration for concrete in marine environment, the chloride content in compared to the concrete samples with 5% metakaolin and 5% silica
concrete (water-soluble or acid-soluble) is normally determined at a fume respectively.
function of depth. The parallel experiments would also be performed to In general, as is shown in Fig. 6, the chloride content in PC-conrete
study the influence of concrete mixture design on its resistance to (solid points) is higher than in SCM-concrete (semi-solid points), i.e.
chloride penetration. Chalee et al. conducted the exposure tests using using pozzolanic materials can reduce the penetration of chloride to a
concrete specimens with different water to binder ratios and fly ash certain extent depending on the type and amount of SCMs. This is more
replacement levels in the Gulf of Thailand (tidal zone) for 10 years. The apparent in the inner layer of the concrete and with the extended
field test results indicated that the lower water to binder (w/b) ratio and exposure time. However, the knowledge gap still exists on the effect of
higher fly ash replacement level can prohibit the penetration of chloride ternary SCMs. For example, the use of silica fume, one of the most active
[72,73] through either decrease the chloride diffusion coefficient (CDC) pozzolanic materials, has been demonstrated effective to densify the
of concrete or increase its chloride binding capacity [74,75], which microstructure of concrete and reduce chloride ingress [92], but it also
consequently lead to better corrosion resistance [76,77]. Because of the reported to be inferior to its less active counterparts, fly ash and slag
improved concrete impermeability by these two methods, the required against corrosion of rebar [93]. It was observed in some cases that
thickness of concrete cover to postpone the onset of corrosion could be concrete containing SCMs tends to have clearer convection zone (skin
reduced [78]. Meanwhile, further study demonstrated that ground rice effect) after long term exposure [82,82,83,88] which is characterized by
husk–bark ash also had a similar effect to fly ash [79]. By placing con increasing or flat chloride profile against concrete depth in the surface
crete with different strength grades in the tidal zone for 10 years, layer. The formation of this zone is the combined action of capillary
Thomas and Matthews concluded that the added 30% or more of suction, convection and diffusion [94], and the depth of convection zone
pulverised-fuel ash significantly improve the concrete’s resistance of is time-dependent, ranging from several millimeters (exposed for less
penetration of chlorides [26]. According to the performance of concrete than 5 years) [87,89,91,95] to more than ten or 20 mm (exposed for
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Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
Fig. 6. Chloride profile of PC concrete with PC-SCM concrete with different exposure time.
more than 20 years) [80,82,83,96]. The type and amount of SCMs seem The FCS/ICS ratio supported that using the 28-day strength as the
to affect the feature of the convection zone. The results reported by designed strength for marine concrete structure is reliable in most cases.
Zhang et al. [87] indicated that concrete with 5% silica fume showed a To more accurately assess the durability, more investigation about
flatter chloride profile in convection zone than these with 15% of fly strength development with the extension of exposure age should be
ashþ5% silica fume and with 20% fly ash. This phenomenon was also conducted. The turning point when the strength of concrete begin to
reported by Tadayon et al., [82] (50 months tidal exposure test, concrete continuously decrease is important because it suggests that the negative
containing 5% silica fume) and Farahani et al. [95] (60 months tidal effects of seawater attack start to overtake the positive effects of
exposure test, concrete containing 5% silica fume). These convection continued hydration of cement matrix, and secondary pozzolanic re
zone depth of chloride from term exposure tests indicated that it cannot actions of mineral admixtures. Ganjian and Pouya [18,104] reported
be ignored for the prediction of long term chloride profile. However, the that the added silica fume (7–10%) and slag (50%) in concrete could
Fick’s second law solution, which is the common chloride profiles lead to more loss of compressive strength under seawater attack, which
modeling principle, fails to anticipate the convection zone. More can be caused by the magnesium ions in seawater. Similarly, Moon et al.
advanced models considering both convection zone and diffusion zone [105] and Lee et al. [106] also reported that Mg2þ oriented attack could
should be proposed and verified in the future. cause severer strength degradation of mortar with silica fume. During
the pozzolanic reaction, the silica fume consumes calcium hydroxide to
3.2. Strength loss form extra C-S-H with a low Ca/Si ratio and allows the magnesium to
more easily attack the C–S–H, leading to the gradual transition of
Table 2 summarized the compressive strength of different concrete cementious C-S-H to weak M–S–H phase. The concentration of magne
before and after exposure tests [26,79,81,83,84,86,89,90,97–104]. To sium ions in seawater is relatively low, but their decalcification effect
obtain a general impression on the effect of different mineral admix can be enhanced by coupling effects from some marine environmental
tures, the results were summarized based on binder composition as factors, including high exposure temperature and wetting and drying
depicted in Fig. 7. The strength ratios for the PC-concrete before and cycles. To further specify the role of magnesium ions on the deteriora
after the exposure tests were in the range of 0.6–1.87, which is most tion of different blended concrete exposed at the various marine envi
scattered among all type samples and may indicate that it is more sen ronments, this study recommends the utilization of parallel simulated
sitive to seawater attack. Replacing cement with mineral admixtures exposure tests and artificial seawater with/without magnesium ions.
seems to increase the strength retention of concrete in the marine
environment. Specifically, the samples with GGBS is found to be more 3.3. Disadvantages on the application of SCMs
effective than the fly ash modified specimens. This superiority of slag is
consistent with the phenomenon observed in term of resistance to Despite the advantages of incorporating SCMs on improving the
chloride penetration. The use of silica fume (SF), coupled pozzolanic durability of marine structures, some disadvantages also exist. The first
materials (CPM) and other natural pozzolanic materials (NPM) shows drawback is the decrease of chloride threshold (CT) due to reduced
some advantages as well. However, it is far from conclusive because the alkalinity of pore solution, which is defined as the acceptable chloride
available sample data is insufficient and some of these data mainly based level for the protection of reinforcing steel. The better performance of
on relatively short time tests (less than 3 years). Besides, the difference concrete containing SCMs against seawater attack is their positive effect
in concrete quality, exposure conditions and time, and environmental on the refinement of pore structure and/or increased chloride binding
fluctuation, etc. reduces the comparability among the published results capacity by reaction with Portlandite to form extra C-S-H. However, the
by different researchers and consequently confounded the conclusion. consumption of Portlandite also reduces the alkalinity and replacing
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Table 2
Compressive strength of different blended concretes before and after marine exposure.
[Ref] w/b Binder ICS(MPa) FCS(MPa) FCS/ICS Exposure [Ref] w/b binder ICS(MPa) FCS(MPa) FCS/ICS Exposure
[26] 0.32-0.68 PC 32.5–50.0 22.7–52.5 0.70-1.05 10 years tidal [97] 0.42,0.54,0.67 PC 27–51 34–69 0.67-1.60 2.33 years tidal
PCþ15–50% PFA 33.0–53.0 32.1–68.2 0.97-1.64 PCþ25–50% FA 33–40 28–61 0.70-1.53
[79] 0.45,0.65 PC 30.9–45.1 29.5–44.5 0.96-0.99 5 years tidal [98] 0.32 PC 33.8 34.7 1.02 1 year submerged
PCþ15–50% GRBA 28.6–42.9 29.1–46.3 1.02-1.10 PCþ20% MK/SF/ 36.7–59.4 43.7–61.8 1.00–1.19
SL*
[81] 0.4/0.5/ PC 24.4–29.0 37.3–47.4 1.41-1.87 25 years tidal [99] 0.2 PC 104.5 101.3 0.97 1 year submerged
0.6 PCþ25–65% SL 19.8–30.5 32.3–43.4 1.27-1.66 PCþ10–40% FA/SL/ 66.0–85.6 87–107.2 1.02-1.62
SF/LP
[83] 0.52 PC 36.6 47.5 1.30 30 years [100] 0.55 PC 32.2 28.8–35.5 0.89-1.10 10 years
PCþ30–60% SL 38.0 46.3 1.22 submerged PCþ25–50% FA 31.5–31.8 24.8–37.3. 0.78-1.17 Atmospheric/
submerged/splash
[84] 0.45 PC 37.6 45.9 1.22 15 years tidal [101] 0.4 PC 29.0 30.5 1.05 1 year submerged
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ICS: Initial compressive strength (28days, before exposure), FCS: Final compressive strength (at the end of exposure), GRBA: ground rice husk–bark ash, SL: slag, FA: fly ash, SF: silica fume, MK: metakaolin, LP: Limestone
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under seawater immersion-drying cycles. Besides, it also presented significantly improved the chloride-bearing capacity before the initial
lower chloride and water permeability, lower carbonation depth and corrosion of steel bars [129]. Interestingly, according to the research of
less freezing-thawing damage than the reference PC-concrete. Yang Lv et al., the Crassostrea gigas (CG), a local dominant sessile organism in
et al. [121] studied the resistance of magnesium potassium phosphate Yellow sea, could protect concrete from water and chloride penetration
cement (MKPC) to seawater erosion and stated that this binder is not [130]. The more this plant cemented on the concrete surface would lead
durable in seawater, which compressive strength started to reduce at to a lower ingress degree of water and chloride ion. The reason is that the
180 days. The main reason is supposed to be the hydrolysis and loss of porosity of the concrete surface was reduced by the adherent cementa
existing MgKPO4⋅6H2O in hardened MKPC pastes. However, the pro tion membrane and left valve of CG, which both have dense micro
longed initial curing and adding of LS and SF powders could mitigate the structure. Meanwhile, it is also reported two strains of bacteria,
strength loss and consequently improve its durability in seawater. By Pseudoalteromonas and Paracoccus marcusii, could decelerate the
testing full-scale reinforced beams through accelerated laboratory penetration of chloride and magnesium ions into the paste and the
methods, Pei et al. [122] reported magnesium ammonium phosphate leakage of OH out of the paste if they were abound on the surface
cement (MNPC) has better anticorrosion ability than MKPC and is [131]. Chlayon et al. [132] reported that surface covering with barna
comparable to that of OPC. The 30-year field exposure test about the cles and biofilm tended to reduce chloride diffusion rates and barnacle
durability of alumina cement (AC) concrete should be highlighted. attachments seemed not to cause surface micro-cracking. Through
Mohammed et al. [85] reported that, AC-concrete outperformed that of 5-year field exposure test, Coombes et al. [133] found that the abun
various OPC- concrete against long-term strength development, pro dance of barnacles on concrete (95% cover) can reduce the surface
tection of steel bars and resistance to chloride ingress. Surprisingly, the temperature, mitigate temperature fluctuation and chloride penetration.
AC-concrete mixed with seawater presented better performance Kawabata et al. [134] conducted a 10 years exposure test and found that
compared to its counterpart mixed with fresh water. Microscopic char the covering with marine sessile organisms could generate a dense basal
acterization indicated that the microstructure of the concrete is very membrane on the concrete surface and significantly enhance its resis
dense even after 30-year exposure. All of these imply that the hydration tance to chloride penetration. It was also observed that the detached
of alumina cement is improved by seawater and the related bulk hy area of marine sessile organisms can inhibit chloride penetration.
drates were impervious to seawater attack.
5.2. Chemical buffering
5. Techniques and approaches to enhance durability
The use of corrosion inhibitor is to increase the chloride threshold
Besides tailoring the microstructure of concrete to prevent or retard and/or decrease the rate of corrosion after the onset of corrosion
the ingress of deleterious ions, chemical admixture and surface coating through chemical buffering. Kondratova et al. [135] reported that using
have also been tried by some researchers to enhance the durability of Calcium Nitrite (CNI) and combination of the amines and esters could
concrete exposed to seawater. reduce the corrosion rate in sound and pre-cracked concrete slabs.
However, for the cracked specimens, serious corrosion in the cracked
5.1. Surface coating location was still noted after one year of marine exposure, and
corrosion-induced cracking along the longitude of the steel bars
Rodrigues et al. [123] evaluated the effect of seven acrylic coating occurred after only three years of exposure. A further factorial experi
materials on decreasing water and chloride permeability through a mental revealed that CNI alone is unable to retard the corrosion for both
2-year exposure test in the marine environment, founding that the the sound concrete with high w/b (0.45) and the pre-cracked [136].
methacrylate was more effective than the acrylate to enhance the Other studies also indicates that the corrosion of the steel bar was
durability of concrete. Schueremans et al. [124] used aggravated with the increase of the crack width [136,137]. In general,
alkyl-triethoxy-silane to enhance the hydrophobicity of the concrete according to the results of the natural marine exposure tests, the com
surface and investigated its short, medium and long term performance bination of CNI plus the use of 20–40% of fly ash significantly suppresses
on preventing chloride penetration after 3-, 5- and 12- year exposure the corrosion in cement with low w/b ratio [138,139]. Nevertheless, in
respectively, which confirmed the positive effects of this solvent-free that case, the improvement is mainly caused by reduced permeability
compound. Nanukuttan et al. [125] investigated the performance of and diffusivity instead of the addition of CNI. Østnor and Justnes placed
one chemical admixture called caltite and a silane-based surface treat concrete cylinders with embedded steel bars in the tidal zone for 4 years.
ment method through 7-year marine exposure tests. However, both of The results indicated that 3–4% calcium nitrate by weight of cement
these two methods were not beneficial to decrease the penetration of could prevent the corrosion of rebar despite the concentration of chlo
chloride in concrete. Dao et al. [126] studied two commercial ride ion nearby higher than 0.1%, which is considered sufficient to
permeability-reducing admixture in the simulated coastal environment initiate corrosion [140]. Bola and Newtson [141] checked the corrosion
for 730 days and stated that the one characterized by hydrophobic and degree of reinforcements in five different sites in Hawaii and found that
pore-blocking effects could retard the transport of chloride in concrete, when the dosages of calcium nitrite were high enough, 19.8–22.3 L/m3
while the other one characterized by crystallization activity did not in their research, the corrosion was significantly reduced even if the
work. To enhance the long-term durability of coating material under concrete is extensively cracked by shrinkage.
natural offshore environmental loading, Zhang et al. [127] assessed the
feasibility of using geopolymer as coating materials. The results from the 6. Perspectives
in-situ exposure test indicated that the bonding between geopolymer
and concrete substrate is strong but the large shrinkage led to the early 6.1. Promising examples to further improve the durability
crack of the geopolymer despite the use of Polypropylene (PP) fiber and
MgO-based expansion agent. According to the solutions discussed above, it is evident that there is
Mohammed et al. revealed that the transition interface between steel still large room to improve the durability of RC in offshore areas by
bar and matrix is porous irrespective of the cement type and the location adopting elaborate modification on the microstructure of matrix, the
of the reinforcements even after 15 years of exposure in tidal Environ interface between rebar and concrete, the crack-control ability of con
ment [128]. Based on that, they directly coated the steel bar with crete. Normally, the stereotype of concrete with good quality is char
different cement instead of the external rendering on the concrete cover acterized by its dense internal structure. However, the bulk hydrates of
layer. The results revealed that the cement coating with lower the w/c conventional concrete (C-S-H and CH) in essence is vulnerable to
and added pozzolanic materials created a denser interface and seawater. Consequently, the surface deterioration of the marine
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concrete is inevitable if the chemical inertia of the bulk hydrates is not indicated that the tested mortar with a 300-μm-wide crack presented
enhanced essentially. Jackson et al. [142] reported that the structures of similar mass loss compared to that of rebar in the sound plain mortar,
ancient Roman concrete remained cohesive and intact while under which implies they have an equivalent performance of rebar protection.
constant seawater attack for 2000 years, which is partially due to the
better chemical stability of C-A-S-H and Al-tobermorite compared to 6.2. Combination of existing practices
C-S-H. Inspired by these results, the long term performance of C-A-S-H in
the marine environment should be further investigated. If this is In general, the multiple chemical and physical attacks from the
confirmed, the durability of concrete can be further improved by arti marine environment, including chloride ingress, freezing-and-thawing
ficial promotion of the formation of C-A-S-H during hydration. damage, abrasion, and chemical erosion, requires the synergistic ac
In terms of interface-tailoring, the main principle is to restrict the tion of more than one of these aforementioned approaches to further
growth of large crystals through lowering the w/c ratio and/or consume improve the longevity of RC structure. For example, spraying a thin
them through secondary pozzolanic reactions, refining the pore struc alkali-activated binder layer on steel bars before the casting of concrete
ture of interfacial transition zone. The dense interface provides better could lead to a dense interface locally rich in hydroxyl ion, which can
physical protection for reinforcements. Thus, deterioration induced by increase the chloride threshold, reduce the capillary porosity, and buffer
the corrosion of embedded steel bars can be initially inhibited and may the deleterious topochemical reaction between chloride and the rein
only occurs after certain service years. Based on that, if a sophisticated forcement. On the other hand, the hydrates of alumina cement are
mechanism could automatically be triggered when the reinforcements is proved to be durable against the long term seawater attack [85] and
in the risk of corrosion, the service life of concrete structures could be fibers have been widely applied for crack-suppressing. Ramli et al. re
further prolonged. Wang et al. developed a type of microcapsule whose ported that incorporating low volume of natural coconut fiber (0.6%–
core and shell materials are calcium hydroxide and ethyl cellulose, 1.2%) could reduce the volume change (expansion and shrinkage)
respectively. These microcapsules can precisely release OH when the induced by the exposure of concrete to the marine environment,
PH of the surrounding is decreasing, restoring high alkaline condition to resulting in higher compressive and flexural strength, longer
prevent corrosion of steel bars [143,144], as is presented in Fig. 9. strength-improving period and steadier permeability during the testing
Because the release rate is accelerated at low PH levels and decelerated age [147]. Nevertheless, the natural degradation of the coconut fiber
at high PH levels, this kind of topochemical buffering is more efficient was undesirable. The further study demonstrated that barchip fiber
than ordinary corrosion inhibitors. Currently, the applicability of this could be a promising alternative to coconut fiber. This fiber is
material in concrete still needs further investigation, but the concept of non-corrosive under seawater attack and maintain the positive effects
“intelligent release” is promising. similar to coconut fiber [148]. Ito et al. found that the deterioration of
In most cases, cracks heavily deteriorate the resistance of concrete to PVA fiber is minimum after 10-year seawater spray, presenting slight
aggressive ions ingress. Montes et al. [136] reported that the corrosion reduction on its average molecular weight [149], which suggested that
of steel bars in slab with 20 mm concrete cover is significantly accel PVA fiber is promising for micro-reinforcement against the crack initi
erated because of the existence of cracks. The corrosion rate increase ation and propagation due to seawater attack. It, thus, can be expected
obviously with the crack width. Calvo et al. [137] reported that the that the application of fiber-reinforced alumina cement (FRAC) is likely
crack wider than 200 μm can obviously promote the corrosion rate of to reduce the chemical deterioration of concrete and the initiation of
rebar covered by 45 mm concrete and the crack width decreases to 90 cracks due to external mechanical and environmental load.
μm when concrete cover is reduced to 25 mm. The results of field To achieve the more durable concrete exposed to the marine envi
exposure by Otieno et al. [145] indicated that the corrosion rate of steel ronment, a conceptual design based on these literature review is pro
bar is higher for concrete with wider initial crack. Meanwhile, the posed as illustrated in Fig. 10. It should emphasize that the combination
presence of the initial crack can weaken the effectiveness of the common of several measures simultaneously will significantly improve the cost of
methods, namely increasing the thickness of the concrete cover, incor concrete per cube. Thus, it may be only feasible to be adopted in the
porating SCMs (slag and fly ash), reducing water to binder ratio. An cover layer.
ideal situation is that when the concrete is cracked, the embedded rebar
could still be protected by certain mechanism (corrosion inhibitors or 7. Conclusions
remained intact concrete layer) long enough until the finishing of
self-sealing of the crack to prevent ions permeation. It can be expected Based on the literature review on the studies of the in-filed perfor
that this can be easier to achieve with thin cracks and a high self-sealing mance of marine concretes, the following conclusions can be drawn:
rate. Erşan et al. proposed an example, i.e. combining the microbe-based
self-healing cementitious composites and microbial induced corrosion (1) The ion proportion of seawater in different areas around the
inhibition [146]. The results of 120-day exposure to 0.5 M Cl solution world are similar, but the total salinity varies in a wide range.
Fig. 9. Re-alkali of saturated calcium hydroxide solutions (a) and mitigated stain of steel bars (b) [143].
10
Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
Fig. 10. A proposal for durable concrete cover system against seawater attack.
11
Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
[17] O.S.B. Al-Amoudi, Durability of plain and blended cements in marine [49] N.R. Buenfeld, J.S. Newman, The development and stability of surface layers on
environments, Adv. Cement Res. 14 (3) (2002) 89–100. concrete exposed to sea-water, Cement Concr. Res. 16 (1986) 721–732.
[18] E. Ganjian, H.S. Pouya, Effect of magnesium and sulfate ions on durability of [50] E. Bernard, B. Lothenbach, F. Le Goff, I. Pochard, A. Dauzeres, Effect of
silica fume blended mixes exposed to the seawater tidal zone, Cem, Concr. Res. 35 magnesium on calcium silicate hydrate (C-S-H), Cement Concr. Res. 97 (2017)
(7) (2005) 1332–1343. 61–72.
[19] P. Garces, L.G. Andion, E. Zornoza, M. Bonilla, J. Paya, The effect of processed fly [51] P.J. Tumidajski, G.W. Chan, Durability of high performance concrete in
ashes on the durability and the corrosion of steel rebars embedded in cement- magnesium brine, Cement Concr. Res. 26 (4) (1996) 557–565.
modified fly ash mortars, Cement Concr. Compos. 32 (3) (2010) 204–210. [52] D. Bonen, Composition and appearance of magnesium silicate hydrate and its
[20] K. De Weerdt, H. Justnes, M.R. Geiker, Changes in the phase assemblage of relation to deterioration of cement-based materials, J. Am. Ceram. Soc. 75 (10)
concrete exposed to sea water, Cement Concr. Compos. 47 (2014) 53–63. (1992) 2904–2906.
[21] M. Etxeberria, A. Gonzalez-Corominas, Properties of plain concrete produced [53] W.F. Cole, A crystalline hydrated magnesium silicate formed in the breakdown of
employing recycled aggregates and seawater, Int. J. Civ. Eng. 16 (9a) (2018) a concrete sea-wall, Nauture 171 (1953) 354–355.
993–1003. [54] K. De Weerdt, H. Justnes, The effect of sea water on the phase assemblage of
[22] Y.L. Li, X.L. Zhao, R.K.R. Singh, S. Al-Saadi, Experimental study on seawater and hydrated cement paste, Cement Concr. Compos. 55 (2015) 215–222.
sea sand concrete filled GFRP and stainless steel tubular stub columns, Thin- [55] M. Santhanam, M. Cohen, J. Olek, Differentiating seawater and groundwater
Walled Struct. 106 (2016) 390–406. sulfate attack in Portland cement mortars, Cement Concr. Res. 36 (12) (2006)
[23] C.J. Yu, Q. Wu, J.M. Yang, Effect of seawater for mixing on properties of 2132–2137.
potassium magnesium phosphate cement paste, Construct. Build. Mater. 155 [56] T. Sibbick, D. Fenn, N. Crammond, The occurrence of thaumasite as a product of
(2017) 217–227. seawater attack, Cement Concr. Compos. 25 (8) (2003) 1059–1066.
[24] R. Bansal, N.K. Dhami, A. Mukherjee, M.S. Reddy, Biocalcification by halophilic [57] H. Corner, D. Rippstain, Effect of aqueous sodium chloride solution on ettringite,
bacteria for remediation of concrete structures in marine environment, J. Ind. Touindustrie-Zeitung (TIZ), Fachberichte. 109 (9) (1985) 680–683.
Microbiol. Biotechnol. 43 (11) (2016) 1497–1505. [58] K. Ogawa, D.M. Roy, C4A3S hydration,ettringite, and its expansion mechanism III
[25] A. Demayo, Elements in sea water, in: D.R. Lide (Ed.), CRC Handbook of effect of CaO, NaOH, NaCl; conclusions, Cement Concr. Res. 12 (1982) 247–256.
Chemistry and Physics, CRC Press, U.S.A., 1992, 14-10. [59] O.S.B. Al-Amoudi, M. Maslehuddin, Y.A.B. Abdul-Al, Role of chloride ions on
[26] M.D.A. Thomas, J.D. Matthews, Performance of pfa concrete in a marine expansion and strength reduction in plain and blended cements in sulfate
environment - 10-year results, Cement Concr. Compos. 26 (1) (2004) 5–20. environments, Construct. Build. Mater. 9 (1) (1995) 25–33.
[27] R.P. Jaya, B.H. Abu Bakar, M.A.M. Johari, M.H.W. Ibrahim, M.R. Hainin, D. [60] W.H. Harrison, Effect of chloride in mix ingredients on sulphate resistance of
S. Jayanti, Strength and microstructure analysis of concrete containing rice husk concrete, Mag. Concr. Res. 42 (152) (1990) 113–126.
ash under seawater attack by wetting and drying cycles, Adv. Cement Res. 26 (3) [61] J. Bensted, Thaumasite—background and nature in deterioration of cements,
(2014) 145–154. mortars, and concretes, Cement Concr. Compos. 21 (1999) 117–121.
[28] T.U. Mohammed, H. Hamada, T. Yamaji, Performance of seawater-mixed [62] S. Sadati, M.K. Moradllo, M. Shekarchi, Long-term durability of onshore coated
concrete in the tidal environment, Cement Concr. Res. 34 (4) (2004) 593–601. concrete—chloride ion and carbonation effects, Front. Struct. Civ. Eng. 10 (2016)
[29] A. Yeginobali, Sulfate resistance of mortars mixed with sea waters, Proceedings 150–161.
3rd international conference on durability of building materials and components, [63] A. Suryavanshi, R.N. Swamy, Stability of Friedel’s salt in carbonated concrete
ESPOO, Finland 3 (1984) 55–65. structural elements, Cement Concr. Res. 26 (5) (1996) 729–741.
[30] R.D. Browne, A.F. Baker, The reinforcement of structural concrete in a marine [64] Y. Wang, S. Nanukuttan, Y. Bai, P.A.M. Basheer, Influence of combined
environment, in: F.D. Lydon (Ed.), Development in Concrete Technology-I, carbonation and chloride ingress regimes on rate of ingress and redistribution of
Applied Science Publishers, Ltd., London, 1979, pp. 111–149. chlorides in concretes, Construct. Build. Mater. 140 (2017) 173–183.
[31] A. Cwirzen, P. Sztermen, K. Habermehl-Cwirzen, Effect of Baltic seawater and [65] S. Sadat, M.K. Moradllo, M. Shekarchi, Long-term performance of silica fume
binder type on frost durability of concrete, J. Mater. Civ. Eng. 26 (2) (2014) concrete in soil exposure of marine environments, J. Mater. Civ. Eng. 29 (9)
283–287. (2017), 04017126.
[32] A. D1141–98, Standard Practice for the Preparation of Substitute Ocean Water, [66] P. Castro, E.I. Moreno, J. Genesca, Influence of marine micro-climates on
ASTM International, West Conshohocken, PA, USA, 2013, p. 2013. carbonation of reinforced concrete buildings, Cement Concr. Res. 30 (2000)
[33] A. Lindvall, Chloride ingress data from field and laboratory exposure - influence 1565–1571.
of salinity and temperature, Cement Concr. Compos. 29 (2) (2007) 88–93. [67] W. Prachasaree, S. Limkatanyu, O. Wangapisit, S. Kraidam, Field investigation of
[34] S.K. Kaushik, S. Islam, Suitability of sea water for mixing structural concrete service performance of concrete bridges exposed to tropical marine environment,
exposed to a marine environment, Cement Concr. Compos. 17 (1995) 177–185. Int. J. Civ. Eng. 16 (2018) 1757–1769.
[35] A. Suryavanshi, J.D. Scantlebury, S.B. Lyon, Mechanism of Friedel’s salt [68] R. Bayuaji, M. Sigit, N.A. Husin, et al., DarmawanCorrosion damage assessment of
formation in cements rich in tri-calcium aluminate, Cem, Concr. Res. 26 (5) a reinforced concrete canalstructure of power plant after 20 years of exposure in a
(1996) 717–727. marine environment: a case study, Eng. Fail. Anal. 84 (2018) 287–299.
[36] U.A. Birnin-Yauri, F.P. Glasser, Friedel’s salt, Ca2Al(OH)6(Cl,OH).2H2O its solid [69] Y.P. Song, L.Y. Song, G.F. Zhao, Factors affecting corrosion and approaches for
solutions and their role in chloride binding, Cement Concr. Res. 28 (12) (1998) improving durability of ocean reinforced concrete structures, Ocean. Eng. 31
1713–1723. (5–6) (2004) 779–789.
[37] F.P. Glasser, A. Kindness, S.A. Stronach, Stability and solubility relationships in [70] G. Loreto, M. Di Benedetti, A. De Luca, A. Nanni, Assessment of reinforced
AFm phases Part I. Chloride, sulfate and hydroxide, Cem, Concr. Res. 29 (1999) concrete structures in marine environment: a case study, Corrosion Rev. 37 (1)
861–866. (2019) 57–69.
[38] C.Y. Qiao, P. Suraneni, J. Weiss, Damage in cement pastes exposed to NaCl [71] C.E.T. Balestra, T.A. Reichert, G. Savaris, Contribution for durability studies
solutions, Construct. Build. Mater. 171 (2018) 120–127. based on chloride profiles analysis of real marine structures in different marine
[39] C.Y. Qiao, P. Suraneni, M.T. Chang, J. Weiss, Damage in cement pastes exposed to aggressive zones, Construct. Build. Mater. 206 (2019) 140–150.
MgCl2 solutions, Mater. Struct. 51 (2018) 74. [72] W. Chalee, M. Teekavanit, K. Kiattikomol, A. Siripanichgorn, C. Jaturapitakkul,
[40] A.M. Ragab, M.A. Elgammal, O.A. Hodhod, T.E. Ahmed, Evaluation of field Effect of w/c ratio on covering depth of fly ash concrete in marine environment,
concrete deterioration under real conditions of seawater attack, Construct. Build. Construct. Build. Mater. 21 (5) (2007) 965–971.
Mater. 119 (2016) 130–144. [73] W. Chalee, C. Jaturapitakkul, P. Chindaprasirt, Predicting the chloride
[41] U.H. Jakobsen, K. De Weerdt, M.R. Geiker, Elemental zonation in marine penetration of fly ash concrete in seawater, Mar. Struct. 22 (3) (2009) 341–353.
concrete, Cement Concr. Res. 85 (2016) 12–27. [74] W. Chalee, C. Jaturapitakkul, Effects of w/b ratios and fly ash finenesses on
[42] K. De Weerdt, B. Lothenbach, M.R. Geiker, Comparing chloride ingress from chloride diffusion coefficient of concrete in marine environment, Mater. Struct.
seawater and NaCl solution in Portland cement mortar, Cement Concr. Res. 115 42 (4) (2009) 505–514.
(2019) 80–89. [75] T. Cheewaketa, C. Jaturapitakkul, W. Chalee, Long term performance of chloride
[43] Y. Farnam, S. Dick, A. Wiese, J. Davis, D. Bentz, J. Weiss, The influence of calcium binding capacity in fly ash concrete in a marine environment, Construct. Build.
chloride deicing salt on phase changes and damage development in cementitious Mater. 24 (8) (2010) 1352–1357.
materials, Cement Concr. Compos. 64 (2015) 1–15. [76] W. Chalee, P. Ausapanit, C. Jaturapitakkul, Utilization of fly ash concrete in
[44] L. Berntsson, S. Chandra, Damage of conrete sleepers by calcium chloride, marine environment for long term design life analysis, Mater. Des. 31 (3) (2010)
Cement Concr. Res. 12 (1982) 87–92. 1242–1249.
[45] C.Y. Qiao, P. Suraneni, J. Weiss, Flexural strength reduction of cement pastes [77] T. Cheewaket, C. Jaturapitakkul, W. Chalee, Concrete durability presented by
exposed to CaCl2 solutions, Cement Concr. Compos. 86 (2018) 297–305. acceptable chloride level and chloride diffusion coefficient in concrete: 10-year
[46] F.P. Glasser, J. Marchand, E. Samson, Durability of concrete-degradation results in marine site, Mater. Struct. 47 (9) (2014) 1501–1511.
phenomena involving detrimental chemical reactions, Cement Concr. Res. 38 (2) [78] T. Cheewaket, C. Jaturapitakkul, W. Chalee, Initial corrosion presented by
(2008) 226–246. chloride threshold penetration of concrete up to 10 year-results under marine
[47] K. Peterson, G. Julio-Betancourt, L. Sutter, R.D. Hooton, D. Johnston, site, Construct. Build. Mater. 37 (2012) 693–698.
Observations of chloride ingress and calcium oxychloride formation in laboratory [79] W. Chalee, T. Sasakul, P. Suwanmaneechot, C. Jaturapitakkul, Utilization of rice
concrete and mortar at 5 � C, Cem, Concr. Res. 45 (2013) 79–90. husk-bark ash to improve the corrosion resistance of concrete under 5-year
[48] M. Valipour, F. Pargar, M. Shekarchi, S. Khani, M. Moradian, In situ study of exposure in a marine environment, Cement Concr. Compos. 37 (2013) 47–53.
chloride ingress in concretes containing natural zeolite, metakaolin and silica [80] E.G. Moffatt, M.D.A. Thomas, A. Fahim, Performance of high-volume fly ash
fume exposed to various exposure conditions in a harsh marine environment, concrete in marine environment, Cement Concr. Res. 102 (2017) 127–135.
Construct. Build. Mater. 46 (2013) 63–70. [81] M.D.A. Thomas, A. Scott, T. Bremner, A. Bilodeau, D. Day, Performance of slag
concrete in marine environment, ACI Mater. J. 105 (6) (2008) 628–634.
12
Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
[82] M. Thomas, T. Bremner, Performance of lightweight aggregate concrete [111] V. Malhotra, G. Carette, T. Bremner, Durability of concrete containing
containing slag after 25 years in a harsh marine environment, Cement Concr. Res. supplementary cementing materials in marine environment, Aci. Mater. J. sp-
42 (2) (2012) 358–364. 100–63 (1986) 1227–1258.
[83] T.U. Mohammed, H. Hamada, T. Yamaji, Marine durability of 30-year-old [112] B. Lothenbach, K. Scrivener, R.D. Hooton, Supplementary cementitious materials,
concrete made with different cements, J. Adv. Concr. Technol. 1 (1) (2003) Cement Concr. Res. 41 (12) (2011) 1244–1256.
63–75. [113] D.V. Reddy, J.B. Edouard, K. Sobhan, Durability of fly ash-based geopolymer
[84] T.U. Mohammed, T. Yamaji, H. Hamada, Chloride diffusion, microstructure, and structural concrete in the marine environment, J. Mater. Civ. Eng. 25 (6) (2013)
mineralogy of concrete after 15 years of exposure in tidal environment, ACI 781–787.
Mater. J. 99 (3) (2002) 256–263. [114] F. Puertas, R. de Gutierrez, A. Fernandez-Jimenez, S. Delvasto, J. Maldonado,
[85] J. Kim, W.J. McCarter, B. Suryanto, Performance assessment of reinforced Alkaline cement mortars. chemical resistance to sulfate and seawater attack,
concrete after long-term exposure to a marine environment, Construct. Build. Mater. Construcci� on 52 (267) (2002) 55–71.
Mater. 192 (2018) 569–583. [115] A.F. Jimenez, I.G. Lodeiro, A. Palomo, Durability of alkali-activated fly ash
[86] E.G. Moffatt, M.D.A. Thomas, Performance of 25-year-old silica fume and fly ash cementitious materials, J. Mater. Sci. 42 (9) (2007) 3055–3065.
lightweight concrete blocks in a harsh marine environment, Cement Concr. Res. [116] H.E. Didamony, A.A. Amer, H.A. Ela-ziz, Properties and durability of alkali-
113 (2018) 65–73. activated slag pastes immersed in sea water, Ceram. Int. 38 (5) (2012)
[87] J.Z. Zhang, J. Zhao, Y.R. Zhang, Y.H. Gao, Y.Y. Zheng, Instantaneous chloride 3773–3780.
diffusion coefficient and its time dependency of concrete exposed to a marine [117] A. Palomo, M.T. Blanco-Varela, M.L. Granizo, F. Puertas, T. Vazquez, M.
tidal environment, Construct. Build. Mater. 167 (2018) 225–234. W. Grutzeck, Chemical stability of cementitious materials based on metakaolin,
[88] K. De Weerdt, D. Orsakova, A.C.A. Muller, C.K. Larsen, B. Pedersen, M.R. Geiker, Cement Concr. Res. 29 (1999) 997–1004.
Towards the understanding of chloride profiles in marine exposed concrete, [118] A.M. Rashad, A.S. Ouda, D.M. Sadek, Behavior of alkali-activated metakaolin
impact of leaching and moisture content, Construct. Build. Mater. 120 (2016) pastes blended with quartz powder exposed to seawater attack, J. Mater. Civ. Eng.
418–431. 30 (8) (2018), 04018159.
[89] J. Bai, S. Wild, B.B. Sabir, Chloride ingress and strength loss in concrete with [119] F. Slaty, H. Khoury, H. Rahier, J. Wastiels, Durability of alkali activated cement
different PC-PFA-MK binder compositions exposed to synthetic seawater, Cement produced from kaolinitic clay, Appl. Clay Sci. 104 (2015) 229–237.
Concr. Res. 33 (3) (2003) 353–362. [120] N. Zhang, H.X. Li, D.D. Peng, X.M. Liu, Properties evaluation of silica-alumina
[90] H. Binici, O. Aksogan, E.B. Gorur, H. Kaplan, M.N. Bodur, Performance of ground based concrete: durability and environmental friendly performance, Construct.
blast furnace slag and ground basaltic pumice concrete against seawater attack, Build. Mater. 115 (2016) 105–113.
Construct. Build. Mater. 22 (7) (2008) 1515–1526. [121] J.M. Yang, J. Zhang, S.C. Zheng, Experimental research on seawater erosion
[91] M.H. Tadayon, M. Shekarchi, M. Tadayon, Long-term field study of chloride resistance of magnesium potassium phosphate cement pastes, Construct. Build.
ingress in concretes containing pozzolans exposed to severe marine tidal zone, Mater. 183 (2018) 534–543.
Construct. Build. Mater. 123 (2016) 611–616. [122] H. Pei, Z. Li, J. Zhang, Q. Wang, Performance investigations of reinforced
[92] M. Khanzadeh-Moradllo, M. Meshkini, E. Eslamdoost, S. Sadati, M. Shekarchi, magnesium phosphate concrete beams under accelerated corrosion conditions by
Effect of wet curing duration on long-term performance of concrete in tidal zone multi techniques, Construct. Build. Mater. 93 (2015) 989–994.
of marine Environment, Int. J. Concr. Struct. Mater. 9 (4) (2015) 487–498. [123] M.P.M.C. Rodrigues, M.R.N. Costa, A.M. Mendes, M.I.E. Marques, Effectiveness of
[93] A. Abd El Fattah, I. Al-Duais, K. Riding, M. Thomas, Field evaluation of corrosion surface coatings to protect reinforced concrete in marine environments, Mater.
mitigation on reinforced concrete in marine exposure conditions, Construct. Struct. 33 (234) (2000) 618–626.
Build. Mater. 165 (2018) 663–674. [124] L. Schueremans, D. Van Gemert, S. Giessler, Chloride penetration in RC-structures
[94] P. Castro, O.T. De Rincon, E.J. Pazini, Interpretation of chloride profiles from in marine environment - long term assessment of a preventive hydrophobic
concrete exposed to tropical marine environments, Cement Concr. Res. 31 (2001) treatment, Construct. Build. Mater. 21 (6) (2007) 1238–1249.
529–537. [125] S.V. Nanukuttan, L. Basheer, W.J. McCarter, D.J. Robinson, P.A. Muhammed
[95] A. Farahani, H. Taghaddos, M. Shekarchi, Prediction of long-term chloride Basheer, Full-scale marine exposure tests on treated and untreated concretes-
diffusion in silica fume concrete in a marine environment, Cement Concr. initial 7-year results, ACI Mater. J. 105 (1) (2008) 81–87.
Compos. 59 (2015) 10–17. [126] V.T.N. Dao, P.F. Dux, P.H. Morris, A.H. Carse, Performance of permeability-
[96] C.E.T. Balestra, T.A. Reichert, W.A. Pansera, G. Savaris, Chloride profile modeling reducing admixtures in marine concrete structures, ACI Mater. J. 107 (3) (2010)
contemplating the convection zone based on concrete structures present for more 291–296.
than 40 years in different marine aggressive zones, Construct. Build. Mater. 198 [127] Z.H. Zhang, X. Yao, H. Wang, Potential application of geopolymers as protection
(2019) 345–358. coatings for marine concrete III. field experiment, Appl. Clay Sci. 67–68 (2012)
[97] R. Vedalakshmi, V. Saraswathy, A.K. Yong, Performance evaluation of blended 57–60.
cement concretes under MgSO4 attack, Mag. Concr. Res. 63 (9) (2011) 669–681. [128] T.U. Mohammed, T. Yamaji, H. Hamada, Microstructures and interfaces in
[98] H.E.H. Seleem, A.M. Rashad, B.A. El-Sabbagh, Durability and strength evaluation concrete after 15 years of exposure in tidal environment, ACI Mater. J. 99 (4)
of high-performance concrete in marine structures, Construct. Build. Mater. 24 (2002) 352–360.
(6) (2010) 878–884. [129] T.U. Mohammed, H. Hamada, A. Hasnat, M.A. Al Mamun, Corrosion of steel bars
[99] C.Z. Han, W.G. Shen, X. Ji, Z.W. Wang, Q.J. Ding, G.L. Xu, Z.J. Lv, X.L. Tang, in concrete with the variation of microstructure of Steel-Concrete Interface,
Behavior of high performance concrete pastes with different mineral admixtures J. Adv. Concr. Technol. 13 (4) (2015) 230–240.
in simulated seawater environment, Construct. Build. Mater. 187 (2018) [130] J.F. Lv, J.Z. Mao, H.J. Ba, Influence of crassostrea gigas on the permeability and
426–438. microstructure of the surface layer of concrete exposed to the tidal zone of the
[100] S.J. Kwon, H.S. Lee, S. Karthick, V. Saraswathy, H.M. Yang, Long-term corrosion Yellow Sea, Biofouling 31 (1) (2015) 61–70.
performance of blended cement concrete in the marine environment - a real-time [131] J.F. Lv, J.Z. Mao, H.J. Ba, Influence of marine microorganisms on the
study, Construct. Build. Mater. 154 (2017) 349–360. permeability and microstructure of mortar, Construct. Build. Mater. 77 (2015)
[101] K.M.A. Hossain, Pumice based blended cement concretes exposed to marine 33–40.
environment: effects of mix composition and curing conditions, Cement Concr. [132] T. Chlayon, M. Iwanami, N. Chijiwa, Combined protective action of barnacles and
Compos. 30 (2) (2008) 97–105. biofilm on concrete surface in intertidal areas, Construct. Build. Mater. 179
[102] S. Kumar, Influence of water quality on the strength of plain and blended cement (2018) 477–487.
concretes in marine environments, Cement Concr. Res. 30 (3) (2000) 345–350. [133] M.A. Coombes, H.A. Viles, L.A. Naylor, E.C. La Marca, Cool barnacles: do common
[103] H.J. Chen, S.S. Huang, C.W. Tang, M.A. Malek, L.W. Ean, Effect of curing biogenic structures enhance or retard rates of deterioration of intertidal rocks and
environments on strength, porosity and chloride ingress resistance of blast concrete? Sci. Total Environ. 580 (2017) 1034–1045.
furnace slag cement concretes: a construction site study, Construct. Build. Mater. [134] Y. Kawabata, E. Kato, M. Iwanami, Enhanced long-term resistance of concrete
35 (2012) 1063–1070. with marine sessile organisms to chloride ion penetration, J. Adv. Concr. Technol.
[104] E. Ganjian, H.S. Pouya, The effect of Persian Gulf tidal zone exposure on 10 (2012) 151–159.
durability of mixes containing silica fume and blast furnace slag, Construct. Build. [135] I.L. Kondratova, P. Montes, T.W. Bremner, Natural marine exposure results for
Mater. 23 (2) (2009) 644–652. reinforced concrete slabs with corrosion inhibitors, Cement Concr. Compos. 25
[105] H.Y. Moon, S.T. Lee, S.S. Kim, Sulphate resistance of silica fume blended mortars (2003) 483–490.
exposed to various sulphate solutions, Can. J. Civ. Eng. 30 (2003) 625–636. [136] P. Montes, T.W. Bremmer, D.H. Lister, Influence of calcium nitrite inhibitor and
[106] S.T. Lee, H.Y. Moon, R.N. Swamy, Sulfate attack and role of silica fume in crack width on corrosion of steel in high performance concrete subjected to a
resisting strength loss, Cement Concr. Compos. 27 (2005) 65–76. simulated marine environment, Cement Concr. Compos. 26 (3) (2004) 243–253.
[107] M. Thomas, Chloride thresholds in marine concrete, Cement Concr. Res. 26 (4) [137] H.Z. Lopez-Calvo, P. Montes-Garcia, V.G. Jimenez-Quero, H. Gomez-Barranco, T.
(1996) 513–519. W. Bremner, M.D.A. Thomas, Influence of crack width, cover depth and concrete
[108] U. Angst, B. Elsener, C.K. Larsen, O. Vennesland, Critical chloride content in quality on corrosion of steel in HPC containing corrosion inhibiting admixtures
reinforced concrete - a review, Cement Concr. Res. 39 (12) (2009) 1122–1138. and fly ash, Cement Concr. Compos. 88 (2018) 200–210.
[109] K.Y. Ann, H.W. Song, Chloride threshold level for corrosion of steel in concrete, [138] H.Z. Lopez-Calvo, P. Montes-Garcia, E.M. Alonso-Guzman, W. Martinez-Molina,
Corrosion Sci. 49 (11) (2007) 4113–4133. T.W. Bremner, M.D.A. Thomas, Effects of corrosion inhibiting admixtures and
[110] Y. Cao, C. Gehlen, U. Angst, L. Wang, Z.D. Wang, Y. Yao, Critical chloride content supplementary cementitious materials combinations on the strength and certain
in reinforced concrete - an updated review considering Chinese experience, durability properties of HPC, Can. J. Civ. Eng. 44 (11) (2017) 918–926.
Cement Concr. Res. 117 (2019) 58–68. [139] H.Z. Lopez-Calvo, P. Montes-Garcia, M.D.A. Thomas, T.W. Bremner, Effectiveness
of CNI in slabs with a construction joint in a marine environment, Mag. Concr.
Res. 64 (4) (2012) 307–316.
13
Y. Yi et al. Cement and Concrete Composites 113 (2020) 103695
[140] T.A. Ostnor, H. Justnes, Anodic corrosion inhibitors against chloride induced [145] M. Otieno, H. Beushausen, M. Alexander, Chloride-induced corrosion of steel in
corrosion of concrete rebars, Adv. App.l Ceram. 110 (3) (2011) 131–136. cracked concrete – Part I: experimental studies under accelerated and natural
[141] M.M.B. Bola, C.M. Newtson, Field evaluation of marine structures containing marine environments, Cement Concr. Res. 79 (2016) 373–385.
calcium nitrite, J. Perform. Constr. Facil. 19 (1) (2005) 28–35. [146] Y.C. Ersan, K. Van Tittelboom, N. Boon, N. De Belie, Nitrite producing bacteria
[142] M.D. Jackson, S.R. Chae, S.R. Mulcahy, C. Meral, R. Taylor, P.H. Li, A.H. Emwas, inhibit reinforcement bar corrosion in cementitious materials, Sci. Rep. 8 (1)
J. Moon, S. Yoon, G. Vola, H.R. Wenk, P.J.M. Monteiro, Unlocking the secrets of (2018), 14092.
Al-tobermorite in Roman seawater concrete, Am. Mineral. 98 (10) (2013) [147] M. Ramli, W.H. Kwan, N.F. Abas, Strength and durability of coconut-fiber-
1669–1687. reinforced concrete in aggressive environments, Construct. Build. Mater. 38
[143] Y.S. Wang, W.J. Ding, G.H. Fang, Y.Q. Liu, F. Xing, B.Q. Dong, Feasibility study on (2013) 554–566.
corrosion protection of steel bar in a self-immunity system based on increasing [148] M. Ramli, W.H. Kwan, N.F. Abas, Application of non-corrosive barchip fibres for
OH- content, Construct. Build. Mater. 125 (2016) 742–748. high strength concrete enhancements in aggressive environments, Compos. B Eng.
[144] Y.S. Wang, G.H. Fang, W.J. Ding, N.X. Han, F. Xing, B.Q. Dong, Self-immunity 53 (2013) 134–144.
microcapsules for corrosion protection of steel bar in reinforced concrete, Sci. [149] H. Ito, K. Watanabe, S. Todoroki, H. Suemori, R. Shinjyo, Study on performance of
Rep. 5 (1) (2015), 18484. PVA fiber reinforced concrete exposed for 10 years to seawater spray, J. Adv.
Concr. Technol. 16 (3) (2018) 159–169.
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