Potential Use of Binary and Composite Limestone Cements in Concrete

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  • 8/16/2019 Potential Use of Binary and Composite Limestone Cements in Concrete


    Potential use of binary and composite limestone cements in concrete


    Mohammed Seddik Meddah a,⇑, Mukesh C. Lmbachiya b, Ravindra K. Dhir c

    a Department of Civil and Architectural Engineering, College of Engineering, Sultan Qaboos University, 123 Al-khod, Muscat, Omanb School of Civil Engineering & Construction, Kingston University, London KT1 2EE, UK c School of Engineering, Physics and Mathematics, University of Dundee, Nethergate DD1 4HN, UK 

    h i g h l i g h t s

     The use of LS in binary, ternary and quaternary cementitious systems was investigated. Using LS permits the design of concrete with low environmental impact. Composite cement with LS seems to perform better than binary LS-cement. An optimal replacement level of 15% LS is recommended. LS composite cements provide a durability improvement compared to binary LS-cement.

    a r t i c l e i n f o

     Article history:

    Received 28 September 2012Received in revised form 12 November 2013Accepted 1 December 2013Available online 7 March 2014


    Binary and composite cementsCarbonationChloride diffusionCompressive strengthDrying shrinkageEmbodied CO2Freeze–thawLimestonePortland cement

    a b s t r a c t

    Over the last decades, the use of various by-products and pozzolanic materials in concrete production hasbecome a common practice, not only to reduce the environmental impact of Portland cement (PC) man-ufacturing and to save natural resources but also to enhance the mechanical and durability performanceof concrete.

    The present study highlights the main performance properties of 50 concrete mixes designed with bin-

    ary, ternary and quaternary cementitious systems, including the use of various proportions of slag (S), flyash (FA), limestone (LS), silica fume (SF) and metakaolin (MK) as a partial replacement by weight of PC.The binary cements were designed with various LS proportions ranging from 10% to 45%, while the ter-nary system consisted of 29% slag and 21% FA as a partial substitute of PC. The three quaternary systemswere designed with 25% FA and slag (50.1% or 47.5%) combined with either 4.9% SF, 4.9% MK or 2.5% LS.The concrete mixes were designed with a wide range of water-to-cementitious ratios (w/c) ranging from0.45 to 0.79.

    The main objective of this paper is to design a concrete with low environmental impact using varioustypes and proportions of cementitious materials.

    It has been observed that the use of composite cements improves concrete workability and reduces theamount of superplasticizer required to reach the same slump value compared with LS and PC cements,while the setting time is decreased for both LS-cement and composite cements. The strength results indi-cate that LS could lead to significant strength loss compared with PC and composite cement concretes. Inaddition, the quaternary PCSFALS mix appears to perform better than the binary LS-cement in terms of strength development and durability performance.

    The results indicate that PCLS15 is freeze–thaw durable (durability factor over 80%); however, withreplacement levels higher than 15%, the durability factor decreased. However, the composite cementsgenerally exhibited a satisfactory durability factor of approximately 80% or a slightly lower DF. Moreover,the composite cements exhibited improved resistance to chloride ingress, while a negative effect on car-bonation depth was observed.

    Overall, the results indicate that the mechanical and durability performance of both binary and com-posite cement concretes are strongly linked to the chemical composition, fineness, particle size distribu-tion and potential reactivity of the cementing materials used.

     2014 Elsevier Ltd. All rights reserved.


    0950-0618/ 2014 Elsevier Ltd. All rights reserved.

    ⇑ Corresponding author. Tel.: +968 2414 2672.

    E-mail address:  [email protected] (M.S. Meddah).

    Construction and Building Materials 58 (2014) 193–205

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  • 8/16/2019 Potential Use of Binary and Composite Limestone Cements in Concrete


    1. Introduction

    Since new environmental regulations have been implemented,the pressure to reduce CO2  emissions generated by the concreteindustry has increased. Over the last decades, extensive researchhas been undertaken to minimize the use of Portland cement byincreasing the amount of various supplementary cementing mate-

    rials (SCM) or fillers embedded in concrete as a partial replacementof PC. Indeed, it is well recognized that Portland cement manufac-turing, with an annual production of 3.7 billion tons in 2012, ac-counts for approximately 7% of the global CO2   emissions   [1–3].Various supplementary cementing materials, whether naturalpozzolans or those derived fromindustrial by-product waste mate-rials such as silica fume, fly ash and ground granulated blast fur-nace slag, have now been used for many years to developcomposite cements not only to reduce the environmental loadbut also to improve concrete durability.

    The use of limestone as a construction material dates back toancient times when calcined limestone or gypsum was used tomake mortar [4]. Limestone consists mainly of calcium carbonate(CaCO3), which reacts with the tricalcium aluminate (C3A) of Portland cement to form calcium carboaluminate (CCA). The ef-fects of LS, as well as other mineral admixtures such as slag,FA, SF and MK used as partial replacements for Portland cement,have been widely discussed and are now well established anddocumented   [5–14]. Natural pozzolana, fly ash, slag, silica fumeand limestone are the main cementing materials that are permit-ted by the EN 197-1  [15]. According to BS EN 197-1:2000  [15],type II cements (CEMII/A-LL 32,5/42,5) may contain variousmaterials as their main constituents in percentages ranging from6% to 35%.

    Although limestone has been widely used as a filler material, itis also used in blended cement as a partial substitution for Portlandcement  [15], with a recommended amount ranging between 6%and 20%   [16]. It has been reported that fine limestone powdercould promote the early age hydration of Portland cement

    [17,18]  and may reduce the total porosity and delay the initialand final setting time as well  [9]. While the setting time mightbe slightly shortened and the tendency to bleeding significantly re-duced, the fresh properties, such as plasticity and water retention,in Portland-Limestone mortar and concrete are slightly improvedor similar to those of a bulk Portland CEM I concrete [19].

    In addition to its filler effect, LS also has a chemical effect: thecalcium carbonate of the limestone powder can interact with thealuminate hydrates formed by the hydration reactions of Portlandcement [18,20]. This interaction leads to the stabilization of theettringite and could increase the total volume of the hydrationproducts, decrease the porosity of the concrete and consequentlyincrease its strength. Limestone powder could also interact withthe AFm and AFt hydration phases, leading to the formation of car-

    boaluminates at the expense of monosulfate, thereby stabilizingthe ettringite, as reported by De Weerdt et al. [21].

    It has been reported that the addition of LS to Portland cementincreases the rate of hydration at early ages and consequently en-hances the early strength; however, LS can reduce the 28-day andlong-term strength compared with concrete prepared with CEM Idue to the dilution effect [11,22]. Meanwhile, at the same concretestrength, Portland-LS cement concrete exhibits similarperformanceas CEM I concrete with respect to the carbonation rate, chloride in-gress and resistance to freezing and thawing (both air-entrainedand non-air-entrained concrete). It has beenobserved that depend-ing on the amount used, limestone in concrete increases chlorideion diffusion [14] while significantly reducing the peak rate of heatevolution [16]. Moreover, Ghrici et al. [11] reported that a ternary

    cementitious system containing 20% LS filler and 30% natural

    pozzolans exhibited improved early and long-term compressiveand flexural strengths and enhanced durability against sulfate, acidand chloride ion ingress.

    However, some studies have focused on the ‘‘thaumasiteproblem’’ linked withthe useof limestone-cementconcreteandcal-careous aggregates. The risk of thaumasite formation (CaSiO3-CaCO3CaSO415H2O) is a serious problem associated with the useof limestone in cement and concrete exposed for a few months tosulfate solutions at low temperature (approximately 5 C) [19,23–25]. It is believed that this form ofsulfate attackcompletelydestroysthebindingabilityof thecement by transformingthe C–S–Hgel intoa mush, weakening the C–S–H and leading to lower strength.Thaumasite formation requires a source of calcium silicate, sulfateand carbonate ions, excess humidity and preferably low tempera-ture [24,26].

    In this paper, the effect of various limestone contents (15–45%)in binary cement and various amounts of fly ash, slag, silica fume,metakaolin and limestone in composite cements (ternary and qua-ternary systems) on the resulting concrete performance is studied.The results presented herein are part of an extensive research pro- ject aiming to develop concrete made with various Portland-com-posite cements to reduce the environmental load and design moresustainable and durable concrete.

    2. Experimental work 

     2.1. Materials

    General use Portlandcement CEM I 42.5 N meeting therequirements of EN197-1:2000 was used in all the mixes with and without SCMs. Five different SCMs,namely, slag, fly ash, silica fume, metakaolin and limestone, were used in variousproportions as substitutes for Portland cement to produce binary, ternary and qua-ternary binders. The chemical and mineralogical compositions and physical proper-ties of Portland cement and the five cementing admixtures (S, FA, SF, MK and LS)used are listed in Table 1, and their particle size distribution is shown in  Fig. 1.

    Natural siliceous sand and crushed granite with maximum sizes of 5 mm and20 mm, respectively, were used as fine and coarse aggregates. A superplasticizer(SP) was used to obtain a nominal target slump value of 75 ± 5 mm, while an air-entraining agent was employed to investigate the freeze–thaw resistance of theair-entrained concrete mixes.

     2.2. Details of mixtures, concrete mixing and specimens

    Both the Portland cement and blended cement concretes were designed witha wide range of w/c ratios of 0.79, 0.65, 0.60, 0.52 and 0.45. Six types of mixesdesigned with five different SCMs were investigated in this study. A single con-tent of 4.9% (by weight) of SF and MK was introduced in the quaternary systems,while FA was used in proportions varying from 20% to 25% and slag was incor-porated at two different proportions of 29% and 25%. In addition, LS was intro-duced at 2.5% in the quaternary system, while the LS-binary cements wereformulated by varying the replacement (by weight) of PC by LS from 15% to45%. In all the mixes, the free water (185kg/m3) and coarse aggregate

    (1200 kg/m3) contents were kept constant, while the fine aggregate contentwas adjusted depending on the type and content of SCM incorporated.   Tables2 and 3 provide the mix proportions of the PCLS concretes and the various com-posite cement concretes investigated, respectively.

    All the concrete mixtures were produced using a horizontal forced-action panmixer with a 0.045 m3 capacity, and each mix was appropriately labeled. The con-crete mixes were referred to as control Portland cement (PC), binary cement-lime-stone (PCLS), ternary cement–slag–fly ash (PCSFA) and quaternary systemscement–slag–fly ash–silica fume (PCSFASF), cement–slag–fly ash–metakaolin (PCS-FAMK) and cement–slag–fly ash–limestone (PCSFALS).

    After mixing, a slump test was performed, and then, the concrete was cast intosteel molds (cubes, cylinders and prisms) in three layers and compacted using aplate vibrator, as specified by BS 1881: Part 108: 1983. All the concrete specimenswere stored for the first 24 h under a plastic sheet in a laboratory environment.The specimenswere then demoldedand wet-cured at 20 ± 2 C for the first28 days,and afterwards, specific curing conditions were applied depending on the durabilitytest. For all the concrete types, three samples of Portland and blended cement con-

    cretes (binary, ternary and quaternary) were tested.

    194   M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205

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     2.3. Test procedures

     2.3.1. Mechanical properties

    Compression tests were performed oncubicspecimensof 100 mmsizeat differ-ent ages of 1, 2, 7, 28, 60, 180 and 365 days in accordance with BS EN 12390-3. Theflexural strength test was determined under three point bending loading on pris-matic specimens with dimensions of 100  100 500 mm in accordance with EN12390-5, while the modulus of elasticity was determined on 150  300 mm cylin-der specimens at 28 days of age in accordance with BS EN 1352:1997. All the spec-imens were wet cured at 20 C from demolding at 24 h of age until testing. Thereported results are the averages obtained for three specimens.

     2.3.2. Shrinkage

    The drying shrinkage was measured on 75  75 300mm prisms with stain-

    less steel studs fixed over a 200 mm gauge length at either end of the specimen.The concrete test samples were stored in dry air conditions (20 ± 2 C and 60± 5%RH), and measurements were taken for as long as 90 days. Length change readingswere periodically recorded for 90 days using a strain frame sensitive to 2 lm.

     2.3.3. Freezing–Thawing (F–T)

    Prism specimens withdimensionsof 75 75 300mm were used to assesstheconcrete resistance to freezing–thawing according to the ASTM C666 test method[27]. Thespecimens were cured in water at 20± 2 C before their exposureto freez-ing and thawing cycles. The specimens were subjected to temperature cycling from4 C to  18 C. The duration of the cycles was 2–5 h. The freezing portion of the cy-cle was accomplished by air cooling (similar to air conditioning), while the thawingportion was performed by submersion in water.

     2.3.4. Carbonation

    Accelerated carbonation testing was performed on cubes of 100 mm size thatwere wet cured during the first 28 days. The specimens were then pre-conditioned

    by drying in the laboratory for 14 days. Before curing in the carbonation chamber,all the sides of the concrete specimens were sealed using a bituminous coating

    paint except the top side, which was exposed in a carbonation tank to a CO 2  en-riched atmosphere containing 4% CO2 at 20 ± 2 C and 55 ± 5% RH. The carbonationdepth in the tested concrete specimens was measured by applying a phenolphtha-lein color indicator spray on a freshly broken piece of the specimens. This sprayturns non-carbonated concrete pink, while carbonated concrete remains colorless.

    The depth of the uncolored zone of the concrete (the carbonated layer) from theedges of the broken piece was measured at 3 points, and the mean value was re-ported as the carbonation depth.

     2.3.5. Chloride ion ingress

    The chloride ion ingress was measured across a slice of the concrete specimensmeasuring 100 mm£ and 25 mm thick that was cut from a 150  300 mm cylin-der. The concrete cylinders were subjected to two curing systems, wet and dryaircuring, for thefirst 28 days, and theresultsof both curingsystems arepresented.The concrete slices were located in standard two compartment diffusion test cells.The inner part of the cell was filled with calcium hydroxide solution, and the cellwas partially immersed in a chloride tank, thereby exposing the outer face of theconcrete to the chloride solution. The electrochemical chloride ingress test methodused was called potential difference, where a potential difference of 7.5 V waspassed across the specimen. The chloride transport rate was evaluated from fre-quent chloride analyses of the liquid in the two chambers. Fick’s first law was used

    to calculate the chloride diffusion coefficient; it should be noted that the coeffi-cients were derived from steady-state diffusion experiments:












       P  e  r  c  e  n   t  a  g  e  p  a  s  s   i  n  g   (   %   )

    Sieve size (µm)







    1 10 100 1000

    Fig. 1.   Particle size distribution of Portland cement and the five cementing

    materials used.

     Table 2

    Mixture composition for 1 m3 of the PCLS binary concretes.

    Constituent materials, kg/m3





    Aggregates SP, % by weight of  cement


    5 mm 10 mm 20mm0.79(25) 235 100 – 700 400 800 0.30 185

    85 1575 2565 3555 45

    0.65(35) 285 100 – 730 400 800 0.24 18585 1575 2565 35

    0.60(40) 310 100 – 710 400 800 0.13 18585 1575 2565 3555 45

    0.52(50) 355 100 – 670 400 800 0.11 185

    85 1575 2565 3555 45

    0.45(60) 410 100 – 625 400 800 0.21 18585 1575 2565 3555 45

     Table 1

    Chemical composition and physical properties of the cements used.

    Cementing materials Physical properties Chemical compositions

    Density (kg/m3) Fineness (m2/kg) Residue 45 lm (%) SiO2   Al2O3   Fe2O3   CaO MgO SO3   TiO2   Alkali LOI

    PC 3140 381 6.2 21.4 4.7 2.7 65.2 1.0 2.9 – 0.55 0.9LS 2700 638 8.8 1.1 0.06 0.09 54.7 0.3 – 0.01 0.053 43.5FA 2276 450 12.8 51.1 24.9 9.0 1.5 1.4 0.7 1.0 3.97 5.7GGBS 2900 509 1.8 34.2 13.9 0.6 41.6 – – – 0.463 0.9SF 2200 15,750 0.2 95.3 0.65 0.28 0.27 0.41 0.25 – 0.767 –MK 2590 3474 0.4 55.1 40.4 0.64 0.03 0.36 – 0.01 1.392 1.2

    Bogue composition of PC C3S 67.3C2S 10.6C3A 7.9C4AF 8.2

    (Na2Oeq) = Na2O + 0.658 (K2O)= 0.55.

    M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205   195


  • 8/16/2019 Potential Use of Binary and Composite Limestone Cements in Concrete


    Q   ¼ Dc @ c 


    where Q  is the mass transport rate for onesquare-meter of concrete (mol/m2 s), Dc  isthe diffusion coefficient (m2/s), c is thetotal chloride concentration in thepore water(mol/m3), t is the time and  x  is the distance from the exposed surface (m).

     2.3.6. Initial surface absorption (ISA)

    The ISA test measures the rate at which water flows into the capillary pore net-work of concrete through a known surface area. The volume flow is estimated bymeasuring the length of flow along a capillary of known dimension. The initial sur-face absorption of the various mixeswas determined on150 mmcubes pre-curedinwater for the first 28 days as per BS 1881-208, Part 5. The concrete specimens werethen oven-dried at 105 C to constant weight before the test and left to cool to thelaboratory temperature (17–20 C) in a desiccator jar for a period of 24 h. The con-tact area was defined by a plastic cell sealed onto the concrete surface and shouldnot be less than 5000 mm2. Water was introduced into the cell via a connectingpoint and maintained at a head of 200 mm using a filter funnel. A second connec-tion point to the cap led to a horizontal capillary tube. The connection to the reser-voir was closed, and the absorption was measured by observing the movement of the end of the water line in the capillary tube with an affixed scale after 10 min.The ISA measurements were recorded 10 min after the initiation of the test. Themeasurements are referred to as ISA-10 at 10 min. More details about the testingand setup used can be found in an earlier publication by the authors  [28].

    Due to the considerable number of mixes investigated, the flexural strengthtesting and some of the durability testing were only conducted on selected mixes.

    3. Test results and discussion

     3.1. Fresh properties

    For each concrete mix investigated, the targeted nominal slumpvalue of approximately 75 ± 5 mm was reached by adjusting theamount of superplasticizer used. The mix design of concretesinvestigated presented in Tables 2 and 3 revealed that the presenceof different SCMs at various contents in the concretes was benefi-cial for workability enhancement. Generally, all the blended mixesrequired almost the same or even less amount of superplasticizer

    to reach a slump value similar to that of the control mix. As ob-served in Table 2, regardless of the w/c of concrete, the inclusion

    of various amounts of LS in the binary concrete (PCLS) designedwith different w/c did not require any increase of the SP contentto reach the targeted slump value compared with that of the Port-land cement concrete. In addition, the presence of LS in the quater-nary cement system (PCSFALS) significantly reduced the SP

    demand and required the lowest amount of SP compared with allthe other binary, ternary and quaternary systems investigated.Overall, it appears that the presence of LS in composite cementscould provide better improvement of concrete workability thanwhen it is used in a binary system LS-cement. In fact, while nochange in the SP content was recorded for the binary system LS-ce-ment to reach the targeted slump value, the reduction in theamount of SP for the quaternary system was substantial and ran-ged between 20% and 46% depending on the w/c of the concretemix. In line with these results, several previous investigators haveconcluded that LS-cement requires less water/SP demand thanPortland cement and could improve concrete workability [29–32].

    In addition, the ternary (PCSFA) and quaternary (PCSFASF andPCSFAMK) cementitious systems demonstrated a significant reduc-

    tion in the amount of SP required to reach the targeted slump value(75 ± 5 mm). This reduction in the required amount of SP generallyranged from23% to 43% for the ternary systems and from9% to 40%for the quaternary systems. Moreover, the quaternary systems de-signed with MK exhibited better workability enhancement (reduc-tion of SP content) compared with their corresponding mixesdesigned with SF. In fact, the quaternary mixes with MK led to areduction between 5% and 18% in the SP amount required com-pared with their corresponding quaternary mixes with SF. BothMK and SF are ultrafine cementing materials with high specific sur-face areas that require more SP compared with slag and FA, and, asobserved in Table 1, the fineness of SF is 4 timeshigher than that of MK, which resulted in the higher demand of SP for SF mixes com-pared with MK mixes.

    The mix compositions given in Table 3 indicate that in additionto the quaternary systems (PCSFALS), which require the lowest PS

     Table 3

    Mixture composition for 1 m3 of the composite cements concretes.

    w/c PC content PC (%) Slag (%) Constituent materials, kg/m3

    FA (%) SF (%) MK (%) LS (%) Aggregates SP,% by weight of cement Water

    5 mm 10 mm 20 mm

    0.79 235 100 – – – – – 700 400 800 0.30 18550 29 21 – – – 0.23

    50.1 25 20 4.9 – – 0.3050.1 25 20 – 4.9 – 0.2647.5 25 25 – – 2.5 0.24

    0.65 285 100 – – – – – 730 400 800 0.30 18550 29 21 – – – 0.1750.1 25 20 4.9 – – 0.2350.1 25 20 – 4.9 – 0.1847.5 25 25 – – 2.5 0.16

    0.60 310 100 – – – – – 710 400 800 0.13 18550 29 21 – – – 0.1050.1 25 20 4.9 – – 0.1350.1 25 20 – 4.9 – 0.1147.5 25 25 – – 2.5 0.08

    0.52 355 100 – – – – – 670 400 800 0.11 18550 29 21 – – – 0.0750.1 25 20 4.9 – – 0.10

    50.1 25 20 – 4.9 – 0.0847.5 25 25 – – 2.5 0.06

    0.45 410 100 – – – – – 625 400 800 0.21 18550 29 21 – – – 0.1550.1 25 20 4.9 – – 0.1750.1 25 20 – 4.9 – 0.1647.5 25 25 – – 2.5 0.14

    196   M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205

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    amount for the required slump value, the ternary system(PCSFA) isvery effective in enhancing concrete workability and reducing SPdemand. Indeed, FA is known to react slowly during the hydrationprocess, and the spherical particles retain much more free waterthan PC and other SCMs and hence reduce the water/SP demand.However, the consistency results of the various cementing materi-als used did not exhibit a uniform trend. The increase of water con-sistency when increasing the LS content is related to the relativelyhigh water absorption capacity of LS, as also noted by Heikal et al.[9].

    In fact, the major factor affecting the SP demand in such acementing system is mainly the physical properties of the materi-als used, including shape, particle size distribution, specific surface,the amount of ultrafine particles in the mix and the chemical com-position, especially the amount of unburned carbon. The propor-tion of particles retained on a 45 lm sieve also appears to be animportant parameter regarding the workability and PS demand.A higher amount of particles passing the 45lm sieve is correlatedwith a higher PS demand, as observed in Tables 1–3.

    Moreover, all the blended cements tested exhibited a longer ini-tial setting time compared with Portland cement, as observed inFig. 2. The delay of the setting time was more pronounced in allthe composite cements containing FA compared with the binaryLS-cements. The ternary systemPCSFA had the longest setting timeat 205 min, while PC had the shortest setting time at only 105 min.The delay in the setting time of the LS-cements, especially the com-posite cements containing FA, is attributed to the low early-agereactivity of both LS and FA compared with clinker as well as otherSCMs (SF, MK and slag). In fact, the setting time and hydration rateof composite cements are strongly linked to the reactivity of thepozzolanic materials and hence to their chemical composition.

     3.2. Mechanical properties

    Tables 4 and 5 present the compressive strength results of the

    different tested combinations of binary PCLS and composite ce-ments. For both the control and blended cement concretes,decreasing the water–binder ratio (w/b) of concrete and increasingthe curing time resulted in a substantial increase in the compres-sive strength. Regardless of the w/c and age of concrete, the useof various amounts of LS in the binary and quaternary systems,as well as the use of various amounts of slag, FA, MK, SF and LSin the composite cements, led to a reduction in the compressivestrength. In fact, the reduction in the compressive strength of thebinary LS-cement concretes was more pronounced compared with

    the composite cements (ternary and quaternary). Higher LS con-tents in the binary cementitious system were associated withgreater reductions of the compressive strength. For all the PCLSmixes, depending on the w/c and age of concrete, the strength lossranged from9% up to 86%. As observed inTable 4, embedding up to15% LS as a replacement for PC resulted in a moderate strength lossof approximately 12%, whereas increasing the replacement level of 

    PC by LS beyond 15% always resulted in a substantial strength loss.The results indicate that increasing the LS content from 25% to 45%almost doubled the strength loss, which was more pronounced formixes with a high w/c while tending to decrease when decreasingthe w/c of concrete at 0.45.

    Regardless of the w/c of concrete and the testing age, the LS45mixes exhibited an important strength loss over 60% comparedwith the control PC mix. This reduction could reach 80% for mixeswith high w/c values of 0.79 and 0.65 compared with mixes withlower w/c values (under 0.60). It was observed that using LS in abinary system resulted in the largest reduction in the compressivestrength compared with the other cementing systems (ternary andquaternary).

    The effect of the proportion of LS on the compressive strength

    was greater than that of w/c. This result was also reported in pre-vious research by Svermova et al. [30].It is clear that a high content of LS (over 15%) can significantly

    alter the compressive strength of the PCLS mix. This strength-reducing effect induced through the use of LS was more perceptibleat early ages (up to 7 days) compared with long-term use. Due tothe significant strength loss generated using LS, several studiesand national standards have set the optimum replacement levelof PC by LS to 20%. The relative strength results presentedin Table 6support these restrictions in terms of the maximum LS contentused. The relative strength of the LS15 mixes is approximately90% of the PC strength but decreases when the LS content is in-creased to 25% or more.

    It is believed that the strength loss of mixes made with various

    proportions of LS may be due to the significant reduction of the po-tential cementitious material content in cement, which is known










       P  C   L  S

      1  5   L  S

      2  5   L  S

      3  5   L  S

      4  5

       P  C  S   F


       P  C  S   F

      A  S   F

       P  C  S   F

      A   M   K

       P  C  S   F

      A   L  S

    Concrete mixes

       W  a   t  e  r  o   f  c  o  n  s   i  s   t  e  n  c  y   (   %   )







       S  e   t   t   i  n  g   t   i  m  e   (  m   i  n   )


    Setting time

    Fig. 2.  Setting time and consistency of the concrete mixes investigated.

     Table 4

    Compressive strength of the PCLS concretes.

    PC/LS Mix LS (%) Age (days)

    1 2 7 28 60 180 365

    w/c = 0 .79 PC 0 7.5 12.0 18.5 27.5 31.0 34.0 35.0235 kg/m3 LS15 15 6.5 10.0 16.0 24.0 27.0 28.5 29.5

    LS25 25 4.5 7.5 12.0 18.0 19.5 20.5 21.0LS35 35 3.0 4.5 8.5 13.0 14.0 14.5 14.5LS45 45 1.0 2.0 4.5 6.5 7.0 7.5 7.5

    w/c = 0 .65 PC 0 10.5 17.5 26.5 37.0 41.0 44.5 46.0285 kg/m3 LS15 15 9.0 15.0 23.0 32.5 35.5 39.0 40.0

    LS25 25 7.0 11.5 18.5 26.5 29.0 30.5 31.0LS35 35 5.0 8.0 14.0 20.0 21.5 22.5 23.0LS45 45 3.5 5.0 10.0 14.0 14.5 15.5 15.5

    w/c = 0 .60 PC 0 12.0 20.0 30.5 41.0 45.0 49.0 50.5310 kg/m3 LS15 15 10.5 17.0 26.5 36.5 39.5 42.5 44.0

    LS25 25 8.0 13.0 21.5 30.5 33.0 34.0 35.0LS35 35 6.0 10.0 17.0 23.5 25.0 26.0 26.5LS45 45 4.0 6.5 12.5 17.0 18.0 18.5 18.5

    w/c = 0 .52 PC 0 16.0 26.0 38.5 50.0 54.0 58.5 61.0355 kg/m3 LS15 15 14.0 22.5 34.5 45.5 48.5 52.0 53.5

    LS25 25 10.5 17.5 28.0 37.5 39.5 42.0 43.0LS35 35 8.0 13.5 22.5 30.0 31.5 33.0 33.5LS45 45 5.5 9.0 16.5 22.0 23.0 23.5 23.5

    w/c = 0 .45 PC 0 20.5 32.0 47.5 59.0 63.5 68.0 71.0410 kg/m3 LS15 15 18.0 28.0 42.5 53.5 57.0 61.0 63.0

    LS25 25 14.0 21.5 34.5 45.0 47.0 49.5 51.0LS35 35 10.5 15.5 28.5 36.0 38.5 39.5 40.0LS45 45 7.0 11.0 21.0 27.0 28.5 29.0 29.0

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    as dilution. It has been speculated that increasing the fineness of LScould enhance its reactivity and consequently improve the com-pressive strength of the PCLS mix. In fact, for the binary systemwith a moderate replacement level of 15%, the PCLS concretesexhibited a slight decrease of the compressive strength ranging be-tween 10.5% and 16.7% compared with the control PC mix. The ob-

    tained results indicate that to limit the reduction effect on thecompressive strength, using a maximum of 15% or less LS as a

    partial substitute for Portland cement is recommended. This rec-ommended amount is also supported by the results of several pre-vious studies [33–39].

    Livesey [33] observed that the addition of 5% LS had little effecton blended cement performance; however, beyond this limit, theproperties of limestone used resulted in a significant effect. In a

    previous study, De Weerdt et al. [34] observed that up to 15% of PC could be replaced by limestone powder without impairing thecompressive strength development. Beyond this limit, a reductionin strength was recorded, and a high replacement level (e.g., 35%)resulted in a significant strength loss. Similar results were also ob-tained by other researchers [35,29]. Bentz [36] considered that theeffect of limestone powder on the compressive strength is likely tobe more pronounced at lower w/c ratios. Findings by Bentz et al.[37]   indicated that depending on the particle size of LS, thestrength reduction at early age varied from 11% to 28%, while at28 days, the average strength loss was approximately 7%.

    A low content of LS (2.5%) appears to yield much better perfor-mance when combined with other SCMs in the quaternary systems(PCSFALS) compared with a higher content of LS (between 15% and

    45%) used in the binary system PCLS. In fact, while a significantstrength reduction (over 50%) was recorded at early age for thesequaternary PCSFALS mixes, strength development recovery at laterage with only approximately 10% strength loss was recorded.

    In addition, it is well recognized that when blended cements areproduced by intergrinding clinker together with the cementitiousmaterials (genuine cement), the resulting performance surpassesthat of the one mixed separately in the concrete mixer. The resultsobtained by other researchers  [38,39]   indicated that pre-mixedblended LS or natural pozzolana cements with low PC replacementlevels up to 15% could slightly improve the compressive strengthor at least lead to a strength comparable to that of PC concrete. In-deed, the behavior of binary cements with LS or other pozzolanicmaterials is not only linked to the replacement level but also to

    the physical properties and chemical composition of the SCMsused, especially their fineness.

     Table 5

    Compressive strength of the composite cement concretes.

    Composites Mix PC (%) Age (days)

    1 2 7 28 60 180 365

    w/c = 0.79 PC 100 7.5 12.0 18.5 27.5 31.0 34.0 35.0235 kg/m3 PCSFA 50 – 4.5 9.5 20.5 25.5 30.0 –

    PCSFASF 50.1 – 4.0 10.0 23.0 28.5 33.0 –PCSFAMK 50.1 – 3.5 9.5 21.5 26.0 31.0 –PCSFALS 47.5 – 4.0 9.0 18.5 23.0 29.5 –

    w/c = 0.65 PC 100 10.5 17.5 26.5 37.0 41.0 44.5 46.0285 kg/m3 PCSFA 50 – 7.0 14.0 29.0 35.5 40.5 –

    PCSFASF 50.1 – 6.0 14.5 32.5 39.5 44.5 –PCSFAMK 50.1 – 5.5 14.5 31.0 37.0 42.5 –PCSFALS 47.5 – 6.0 13.5 27.0 32.5 38.5 –

    w/c = 0.60 PC 100 12.0 20.0 30.5 41.0 45.0 49.0 50.5310 kg/m3 PCSFA 50 – 8.0 16.5 33.0 39.5 44.5 50.5

    PCSFASF 50.1 – 7.5 17.0 37.0 43.0 49.5 57.0PCSFAMK 50.1 – 7.5 17.0 35.0 41.0 47.0 51.0PCSFALS 47.5 – 7.0 16.0 30.0 35.5 43.0 48.0

    w/c = 0.52 PC 100 16.0 26.0 38.5 50.0 54.0 58.5 61.0355 kg/m3 PCSFA 50 – 11.0 21.0 40.5 47.5 54.5 –

    PCSFASF 50.1 – 11.0 21.5 45.0 52.5 60.5 –PCSFAMK 50.1 – 10.0 21.5 43.0 50.0 57.5 –PCSFALS 47.5 – 9.5 20.5 37.0 43.0 52.0 –

    w/c = 0.45 PC 100 20.5 32.0 47.5 59.0 63.5 68.0 71.0410 kg/m3 PCSFA 50 – 14.5 26.0 47.5 55.0 62.5 –

    PCSFASF 50.1 – 15.5 27.0 54.0 61.5 70.0 –PCSFAMK 50.1 – 14.0 27.0 51.5 59.0 66.5 –PCSFALS 47.5 – 13.5 25.0 43.5 51.0 62.0 –

     Table 6

    Relative strength of the binary and composite cement concretes investigated.

    LS-cements Relative strength Composite cements Relative strength

    7 day 28 day 7 day 28 day

    w/c = 0.79

    LS15 0.86 0.87 PCSFA 0.51 0.74LS25 0.64 0.65 PCSFASF 0.54   0.83LS35 0.46 0.47 PCSFAMK 0.51 0.78LS45 0.24 0.23 PCSFALS 0.48 0.67

    w/c = 0.65

    LS15 0.86 0.87 PCSFA 0.52 0.78LS25 0.69 0.71 PCSFASF 0.54   0.87 LS35 0.52 0.75 PCSFAMK 0.54 0.83LS45 0.37 0.37 PCSFALS 0.50 0.73

    w/c = 0.60

    LS15 0.86 0.89 PCSFA 0.54 0.80LS25 0.70 0.74 PCSFASF 0.55   0.90LS35 0.55 0.57 PCSFAMK 0.55 0.85LS45 0.41 0.41 PCSFALS 0.52 0.73

    w/c = 0.52

    LS15 0.89 0.91 PCSFA 0.54 0.81LS25 0.72 0.75 PCSFASF 0.55   0.90LS35 0.58 0.60 PCSFAMK 0.55 0.86LS45 0.42 0.44 PCSFALS 0.53 0.74

    w/c = 0.45

    LS15 0.89 0.90 PCSFA 0.54 0.80LS25 0.72 0.76 PCSFASF 0.56   0.91LS35 0.60 0.61 PCSFAMK 0.56 0.87LS45 0.44 0.45 PCSFALS 0.52 0.73

    198   M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205

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    The resulting mechanical performance of any cementing systemused in a concrete mix is strongly related to its reactivity, which isin turn linked to the chemical composition and intrinsic character-istics of each SCM used. The chemical composition given in Table 1reveals that LS is the poorest material in terms of silicates and alu-minates, which are the two main compounds of pozzolanic mate-rials and are required for the formation of additional C–S–H viapozzolanic reactions. In addition, the reactivity of cementing mate-rials is also linked to their fineness and particle size distribution.Finer particles result in higher reactivity of the SCMs. The compres-sive strength results presented in Fig. 3 and in Tables 4 and 5 indi-cate that MK and SF were much more reactive than LS and slightlymore reactive than FA and slag. The relative strength results(Table 6) indicate that the quaternary systems designed with SFand MK generated the highest relative strength compared withtheir corresponding LS mix. A simple comparison between theternary mix (PCSFA) and the LS quaternary mix (PCSFALS), withquite similar proportions of slag and FA, demonstrates that theaddition of LS had a negative effect on the strength development,as observed in Table 6.

    One major distinction between the five mineral admixturesused (S, FA, MK, SF and LS) is the kinetics of the reactions. Theuse of LS in the binary system resulted in a continuous increasingtrend of the compressive strength loss over time, while a less neg-ative effect on the compressive strength was exhibited when LSwas used in the quaternary system in a small amount (2.5%). Incontrast, a decreasing trend of the strength loss was observedwhen a combination of slag and FA was used. Embedding eitherMK or SF in the ternary system PCSFA resulted in a slight de-crease/increase of the compressive strength or a comparablestrength to that of the PC concrete.

    It could be speculated that LS used in a binary system at areplacement level ranging between 15% and 45% does not provideany significant strength improvement either at early or later ages,while using LS at a low replacement level (2.5%) in a quaternarycementitious system has a limited negative effect while having a

    positive effect on the cement matrix densification and hencestrength development. Moreover, the addition of SCM is expectedto improve the interface properties via the pozzolanic reactionand the filling effect and thus improve the strength and imperme-ability of the concrete. This improvement is intimately dependenton the SCM parameters, including the proportion, reactivity andoxide composition.

    Overall, it appears that LS did not contribute to the pozzolanicreaction but seemed to act more as additional nucleation pointsfor cement hydration and filler material and thus contributed littleto the strength development. Therefore, LS is not efficient in a

    binary system and is likely to be more appropriate as a filler mate-rial in a ternary or quaternary cementitious system.

     3.3. Flexural strength and modulus of elasticity

    Similar to the compressive strength, the use of LS, FA, S, MK andSF in binary, ternary and quaternary systems resulted in a reduc-tion in both the flexural strength and modulus of elasticity, as ob-served in   Table 7. The flexural strength reduction was lesspronounced, even insignificant, in the quaternary systems (PCS-FASF and PCSFASF) compared with the other blended cement con-crete mixes. In fact, the improved compactness of the quaternarycement pastes contributed to limit the flexural strength loss whileimproving the compressive strength.

    The reduction in the modulus of elasticity of the binary andquaternary LS-cements was proportional to the replacement leveland ranged between 5% and 33%. For the compressive and flexuralstrengths, the use of LS in both the binary and quaternary cementsresulted in a negative effect on the modulus of elasticity comparedwith the PC concrete. While using 15% LS as a partial replacementof PC had an insignificant effect on the modulus of elasticity (5%

    reduction compared with PC), increasing the replacement level be-yond 15% led to further reduction in the modulus of elasticity of the LS-cement concrete.

    In fact, while the modulus of elasticity is intimately linked tothe aggregate bulk, it is clear that the modulus of elasticity is alsoaffected by the cement paste and the interfacial transition zone(ITZ). The results appear to indicate that the blended cement paste,and especially the ITZ were weaker than their corresponding PC ce-ment pastes, which in turn led to the reduction in the modulus of elasticity. In addition, as discussed previously, the results for thePCLS mixes suggested that LS was likely acting as a filler materialrather than as a pozzolanic material, which creates a second inter-facial transition zone in the cement matrix and hence weakens themodulus of elasticity of the concrete composite.

    Moreover, because the strength of cement is a function of thehydrated part, the strength and modulus of elasticity developmentare affected by mineralogical features of the clinker, pozzolanicreactions, fineness, reactive SiO2 ratio and water demand of the ce-ment mixtures. Table 1 shows that LS is very poor in reactive silica(SiO2) and alumina (Al2O3), which, in the presence of water, reactwith (Ca(OH)2) and form an additional C–S–H gel similar to thatproduced during the hydration of PC. Therefore, the low reactivityand hence negative effect on the strengths for LS are mainly attrib-uted to its chemical composition and the very low content of reac-tive silica and alumina compared with the other cementingmaterials used. In addition, the loss on ignition could indicatethe pozzolanicity of such a material. LS exhibited a very high LOIof approximately 43.5%. It has been stated that loss on ignition

    should be less than 20% (maximum) for proper pozzolanicity of amaterial [40].









       C  o  m  p  r  e  s  s   i  v  e  s   t  r  e  n  g   t   h   (   M   P  a   )

    LS content (%)






    PCLS28 d

    0 5 10 15 20 25 30 35 40 45 50

    Fig. 3.   Effect of limestone content on the 28-day compressive strength of theconcretes.

     Table 7

    The 28-day compressive and flexural strengths and modulus of elasticity of the

    concrete mixtures investigated (reduction proportions).

    Mix code (w/c = 0.60)

    28-day cubestrength

    Flexural strength(MPa)

    Modulus of elasticity (GPa)

    PC 41.0 5.0 30.0LS15 36.5 (11) – 28.5 (5)LS25 30.5 (25.6) – 25.5 (15)

    LS35 23.5 (42.7) 4.0 (20) 22.5 (25)LS45 17.0 (58.5) – 20.0 (33)PCSFA 33.0 (19.5) 4.3 (14) 27.7 (7.7)PCSFASF 37.0 (9.7) 4.8 (4) 27.0 (10)PCSFAMK 35.0 (14.6) 4.6 (8) 27.0 (10)PCSFALS 30.0 (26.8) 4.1 (18) 25.0 (16.6)

    M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205   199


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     3.4. Durability performance

     3.4.1. Drying shrinkage

    The ultimate magnitude of drying shrinkage strains measuredafter 90 days of exposure to dry air (20 ± 2 C and 55 ± 5% RH)are summarized in Fig. 4. Note that LS caused a slight reductionin the total magnitude of shrinkage by an average of 10–17%, whilethe composite cements generally exhibited increased dryingshrinkage magnitudes by approximately 8% or developed the samemagnitude of shrinkage as the control mix. For the binary cements,increasing the LS content produced a reducing effect on the dryingshrinkage magnitude. As discussed previously, LS appears to besignificantly less reactive than PC and the other SCMs (S, FA, SFand MK) used and may behave more as an inert filler material(non-reactive material), which tends to reduce shrinkage strains.Whereas the quaternary system with LS (PCSFALS) slightly reducedthe drying shrinkage magnitude, the presence of the other cement-ing materials (S, FA, SF and MK) in the ternary and quaternarycementitious systems generated a slight increase in the dryingshrinkage magnitude. This increase in the drying shrinkage strainsmay be due to the high fineness of MK and especially SF, as well astheir chemical reactivity, compared with both PC and LS. Previousresults by other investigators have suggested that the use of LSwith suitable fineness and content could reduce the drying shrink-age strains of concrete [41].

     3.4.2. Initial surface absorption (ISA)

    Initial surface absorption testing was performed to evaluate theporosity of the concrete and cement based-materials.  Figs. 5–7present the test results of the ISA-10 of the PC, PCLS and compositecement concretes to water after 10 min. For the three w/c ratiostested, the results indicate that for the PCLS mixes, increasing theLS content in the concrete led to significant increases of the ISA-10, especially when using up to 20% LS. The increase of ISA-10 ap-pears to be more pronounced for a high w/c value of 0.79 com-pared with 0.60 and 0.45, as observed in Fig. 5. Meanwhile, forboth the binary and composite cement concretes, regardless of the type and content of SCMs used, the ISA-10 decreases whenincreasing the curing time, as observed in Figs. 6 and 7. Indeed,increasing the curing time up to 6 months results in the formationof more hydrate products, less porosity, a disconnected pore net-work, higher strength and, hence, lower ISA-10 values, especiallyfor composite cement concretes. Moreover, the use of ternaryand quaternary cementitious systems reduced the ISA-10 valuescompared with the Portland and binary LS-cement concrete.

    As expected, the PCSFASF mix followed by the PCSFAMK mixexhibited the lowest ISA-10 values, while the PCSFALS mix

    exhibited the highest ISA-10 values compared with the other com-posite cements. Beyond 6 months of curing, the composite cementPCSFASF mix generated the lowest ISA-10 value of 25 m/m2/s102,while the highest value of 78 m/m2/s102 was recorded for thebinary PCLS45 mix.

    As aforementioned, the ISA-10 indicates the porosity of the ce-ment paste, which is strongly linked to the concrete mix designand the type of cementitious materials used. Embedding a combi-nation of various cementing materials with different intrinsicproperties may induce a synergistic effect and result in a lowerporosity and finer pores compared with the PC concrete.

     3.4.3. Carbonation

    The carbonation of concrete consists of the reaction of carbondioxide (CO2) fromair with the calcium hydroxide (CH) in concreteto form calcium carbonate. This process may result in a reductionof the alkalinity (pH) of the concrete to below 10 and could leadto the initiation of the corrosion process of the steel reinforcementbar and degradation of the concrete structure.

    For the LS-cement mixes with the two w/c ratios examined,decreasing w/c from 0.65 to 0.52 resulted in a significant reductionin the carbonation depth varying from 5 mm to 15 mm, dependingon the LS content, as observed in Fig. 8. This result indicates that LSproduced a negative effect on carbonation resistance; increasingthe LS content always led to a significant increase of the carbon-ation depth. It is suggested that the LS content in concrete used










       D  r  y   i  n  g  s   h  r   i  n   k  a  g  e

      s   t  r  a   i  n  s   (  m   i  c  r  o  s   t  r  a   i  n  s   )

    Fig. 4.  Drying shrinkage of Portland and blended cement concretes investigated.








    LS content (%)




    0 10 20 30 40 50

       I   S   A  -   1   0   (  m   /  m

       2   /  s  e  c   1   0  -   2   )

    Fig. 5.  Effect of limestone content incorporated on the ISA.










       I   S   A  -   1   0   (  m   /  m   2   /  s  e  c   1   0  -   2   )

    PC LS15 LS25

    LS35 LS45


    0 50 100 150 200

    Fig. 6.  ISA versus time for the limestone-cement concretes.

    200   M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205

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    as a replacement for PC should not exceed 15%; beyond this limit,a substantial increase in the carbonation depth (over 80%) was

    recorded. However, Fig. 9 shows that all the four composite cementconcretes investigated increased the carbonation depth comparedwith the PC concrete. The increase in the carbonation depthof composite cement concretes is more pronounced at an earlyage than at 28days. Indeed, the carbonation depth wassignificantly reduced when increasing the curing time up to28 days. While the gap in the carbonation depth between the com-posite cements and the control mix is large, no significant differ-ences in the carbonation depth could be observed among thefour composite cements investigated, as demonstrated in  Figs. 9and 10.

    In fact, the increase in the carbonation depth for the compositecements, especially at early age, might be attributed to the slowreaction of FA used in these cementitious systems at the approxi-

    mately 20% replacement level. In addition, the carbonation depthappears to continuously decrease over time, as observed in thetrend in Figs. 9 and 10. It is expected that in the long term, whenFA and the other incorporated SCMs reach their full reactive poten-tial, the carbonation resistance of the composite cement concretesmight be substantially enhanced and, consequently, the carbon-ation depth would decrease.

    Indeed, as discussed previously, LS appears to act as a fillermaterial, which has a limited positive effect on carbonation resis-tance. However, the use of composite cements with a combination

    of various cementing material types and contents with differentreactivities would result in the formation of additional hydrate

    products in the system(secondary C–S–H), which contribute to fill-ingthe capillary pores, refine and disconnect the pore network and,












    0 50 100 150 200

       I   S   A  -   1   0   (  m

       /  m   2   /  s  e  c   1   0  -   2   )

    Age (days)






    Fig. 7.  ISA versus time for the composite cement concretes.











    0 10 20 30 40 50

       C  a  r   b  o  n  a   t   i  o  n   d  e  p   t   h   (  m  m   )

    LS content (%)

    20-week exposure w/b = 0.65

    w/b = 0.52

    Fig. 8.   Concrete carbonation depth versus limestone content after 20-weekexposure.









    0 5 10 15 20 25 30

       C  a  r   b  o  n  a   t   i  o  n   d  e  p   t   h   (  m  m   )

    Curing time (days)






    Fig. 9.  Concrete carbonation depth versus time of exposure for the compositecements.









    0.40 0.50 0.60 0.70 0.80

       C  a  r   b  o  n  a   t   i  o  n   d  e  p   t   h   (  m  m   )







    Fig. 10.  Concrete carbonation depth versus the w/b of concrete.








    0.40 0.45 0.50 0.55 0.60 0.65 0.70

       C  o  e   f   f   i  c   i  e  n   t  o   f   d   i   f   f  u  s   i  o  n

       (   1   0  -   1   1  m   2   /  s   )


    PCLS   LS45





    Fig. 11.  Effect of LS content and w/c ratio on the coefficient of chloride diffusion of concrete.

    M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205   201


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    hence, reduce the permeability and penetration of CO2   into thecomposite cement concrete.

     3.4.4. Chloride ingress resistance

    The chloride diffusion coefficients (D) for both the binary andcomposite cement mixes, as well as the PC, are determined basedon Fick’s second law, and the results are presented in  Figs. 11–13. Regardless of the amount and type of SCMs used, the resultsindicate that increasing the w/c ratio of concrete led to a significantincrease in the chloride diffusion coefficient. Similarly, increasingthe amount of LS in the binary system PCLS led to a significant in-crease in the chloride diffusion coefficient, especially when the LScontent reached 35% and 45%.

    For the PC mixes cured underwater, the chloride diffusion coef-ficient ranged from 11 1011 m2/s to 21.5  1011 m2/s, whilethat of the PC mixes cured in dry air ranged from

    14.8  1011 m2/s to 27  10

    11 m2/s, depending on the w/c ratio.It is clear that the PC mixes cured under dry air exhibit high chlo-ride diffusion coefficients compared with their correspondingwater-cured mixes. The water curing may allow the mixes to de-velop higher strength and refine their pore network characteristics,which reduces their chloride coefficient diffusion.

    Regardless of the curing regime used, the composite cementconcretes exhibit significantly reduced chloride diffusion coeffi-cients compared with both the PC and binary PCLS mixes. In addi-tion, as for the PC mixes, the composite cement concretes cured

    under water performed better than their corresponding mixescured in dry air. PC or composite cement mixes cured under watercould clearly enhance their cement and pozzolanic reactions and,consequently, may achieve better cement matrix compactnessand strength and a finer pore system. Therefore, enhanced perme-ability to chloride ingress compared with the mixes cured underdry air could be achieved.

    The results presented in Figs. 12 and 13 indicate that the com-posite cement concretes exhibit significantly improved chloride in-gress resistance with a maximum chloride diffusion coefficientvalue of 15 1011 m2/s for the mixes that were dry air cured; thiscoefficient was reduced by half (8.6  1011 m2/s) when the sameconcrete mixes were water cured. Indeed, the improved chlorideingress resistance generated by the composite cements comparedwith both the PC and binary PCLS cements is mainly attributedto the presence of a combination of various SCMs with differenthydration kinetics and the additional C–S–H formed, which fillsand refines the coarse capillary pores and, hence, reduces thepermeability.

    In fact, this finding suggests that the differences between thetransport coefficients of the PC concrete and blended cement con-crete are mainly due to the different pore structures developed inthe presence of the SCM particles. Mineral admixtures with higherreactivities lead to larger amounts of secondary C–S–H that areformed more rapidly and hence lower total pore volumes and finerpore structures. In turn, the fraction of interconnected pores, per-meability and diffusivity within the composite cement matrix arereduced.

    As aforementioned and observed in Fig. 11, the actual trendssuggest that using up to 15% LS has no significant effect on thechloride diffusion coefficients, while all the composite cementshad substantially reduced chloride diffusion coefficients regardlessof the w/c of concrete and the curing regime applied. These resultsare consistent with previous findings reported by Baron and Dou-vre [42], which stipulate that the use of LS-cement increases thechloride diffusion coefficient compared with PC. An earlier finding

    by Tsivilis et al. [43] indicated that using up to 15% LS did not sig-nificantly affect the porosity of concrete and hence its permeabil-ity. Recently, Thomas et al.   [44]   observed that there was nosignificant difference in the rapid chloride permeability of con-cretes containing SCMs produced with Portland cement or lime-stone cement. However, it has been concluded that using up to15% LS, which was ground together with clinker and gypsum, leadsto an improved particle size distribution and particle packing,which results in a positive effect on the concrete resistance againstchloride ingress [45].

    Althoughlimestone is often considered as filler when it is addedto Portland cement, it is not completely inert and can contribute tothe concrete’s microstructure. The fine limestone particles act asnucleation sites, increasing the rate of hydration of the silicates.

    The accelerating effect on the hydration of C3A and C3S, thechanges in the C–S–H and the better development of the micro-structure are some of the specific factors leading to improved clin-ker reactivity with limestone when the appropriate amount andfineness are used. Nevertheless, as LS is likely to behave as a fillermaterial, this addition would create an additional interfacial tran-sition zone (ITZ) and may affect the chloride diffusion coefficient.Experimental results by Persson and Boubitsas  [46,47] indicatedthat the addition of limestone filler to concrete with unchangedw/c might increase the chloride ingress of concrete.

    In fact, the conflicting results regarding the effect of LS on per-meability, diffusion and transport properties and even strengthand carbonation are strongly linked to the intrinsic properties of LS used, in particular the fineness and particle size distribution.

    In general, the use of SCMs such as slag, FA, LS, SF and MK canphysically improve the pore structure of the blended cement








    0.40 0.45 0.50 0.55 0.60 0.65 0.70

       C  o  e   f   f   i  c   i  e  n   t  o   f   d

       i   f   f  u  s   i  o  n   (   1   0  -   1   1  m   2   /  s   )   PC





    Water cured at 20 ºC

    Fig. 12.  Coefficient of diffusion of concrete prepared with composite cements andwater cured at 20 C.








    0.40 0.45 0.50 0.55 0.60 0.65 0.70

       C  o  e   f   f   i  c   i  e  n   t  o   f   d   i   f   f  u  s   i  o  n   (   1   0  -   1   1  m   2   /  s   ) PC





     Air cured at 20 ºC

    Fig. 13.  Coefficient of diffusion of concrete prepared with composite cements anddry air cured at 20 C.

    202   M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205

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    matrix particle packing by filling the voids between the clinkerparticles as well as by being reactive materials and consequentlydecreasing chloride diffusion and other harmful substances.

    Permeability to chloride ions is intimately linked to the mix de-sign parameters and, more precisely, to the capillary pore networkcharacteristics. Larger volumes of coarser and connected pores re-sult in higher permeabilities and chloride diffusion coefficients.The selection of an appropriate mix design that guarantees mini-mum porosity and a fine pore structure would enhance resistanceto chloride ingress.

    Note that both carbonation and chloride ingress are propertiesto be examined for reinforced concrete elements, while for unrein-forced concrete elements, no risk of corrosion is expected, andtherefore, carbonation and chloride ingress might be ignored.

     3.4.5. Resistance to freezing–thawing 

    The durability factors (DFs) of PC, binary PCLS and composite

    cement concrete mixes designed with various amount and typesof SCMs are provided in Fig. 14. The binary PCLS15 mix developedgood freezing–thawing resistance (durability factorP 80%), whilethe mixes containing more than 15% LS exhibited poor freezing–thawing resistance (durability factor6 80%). Nevertheless, exceptfor the quaternary mix PCSFASF, which has a DF of approximately80%, all the other composite cement concretes exhibited DF valueslower than 80%. In fact, the decrease in DF was more significant forthe quaternary mix (PCSFALS) and the binary mixes with 35% and45% LS content.

    Similarly to the chloride ions and compressive strength results,the DF appears to decrease when the replacement level of PC by LSwas higher than 15% in the binary system PCLS. In fact, the resultspresented above reveal that permeability to chloride increases and

    compressive strength decreases when increasing the replacement

    level of PC by LS beyond 15%. As discussed earlier, LS appears toact as a filler material and is not actively involved in the pozzolanicreaction and the formation of additional C–S–H gel, which couldimprove the compactness and strength of the cement paste andhence improve the F–T resistance. However, for the composite ce-ments, it appears that the combination of slowly reactive materials(FA) with slag without SF or MK (highly reactive materials) mayhave contributed to reduce the F–T resistance and, hence, the DF.The freezing–thawing durability factor clearly increases as bothimpermeability and strength increase. It could be speculated thatthe combination PCSFASF exhibited appropriate particle packingand strength development, which led to the satisfactory DF ob-tained with this mix, while the corresponding mix with MK exhib-ited a slightly lower DF (76%) that was very close to the acceptableDF (80%).

    Freezing–thawing resistance, which is expressed by the DF, isintimately linked to the air system parameters, including the totalvolume of air, spacing factor and specific surface area of the airbubbles. These parameters are in turn affected by the mix designparameters, particularly the cementitious materials type and con-tent used. The results indicate that for the mixes investigated here-in with a w/c of 0.52 and a fresh air content of 5%, the amount andtype of cementitious materials used appears to be the major factoraffecting the DF of air-entrained blended cement concrete mixes.

    4. Contribution of LS/composite cements to the embodied CO2reduction

    Many years of widespread use have demonstrated that theseSCMs mainly derived from industrial by-products can, when prop-erly designed within the cementitious system, not only improvethe quality of the concrete but also provide multiple environmen-tal benefits. Table 8 summarizes the total reduced embodied CO2(ECO2) resulting from the use of various content and types of SCMsas a partial replacement of Portland cement in 1 m3 of concrete.The results indicate that using various contents and types of SCMs

    in concrete has led to significant reduction of the (ECO2), rangingfrom14% to 43%. The reduction of the (ECO2) in the binary concretewas proportional to the LS content used. While a high LS content of 45% resulted in a significant reduction (approximately 43%) in theECO2, the overall performance of this mix LS45 was below the re-quired concrete quality, as discussed earlier. However, the use of all the composite cements generated a substantial reduction of approximately 33% in the ECO2, except the PCSFAMK mix, whichonly reduced the ECO2 by 17%.

    Overall, it can be concluded that the use of these SCMs removesan industrial by-product from the waste stream and converts itinto a beneficial additive for sustainable construction, greatlyimproving concrete quality, lowering its carbon footprint, savingmore non-renewable materials and providing economy to concrete


    5. Conclusions

    The present study highlights the performance of concrete mixesdesigned with various w/c ratios and four composite and binary ce-ments. Five types of supplementary cementitious materials, slag,fly ash, limestone, silica fume and metakaolin, were used at variousreplacement levels to prepare binary, ternary and quaternary ce-ments. Based on the test results reported herein, the followingcon-clusions may be drawn:

    1. The type and composition of blended cement appear to havea significant effect on both the fresh and hardened proper-

    ties of concrete.

       D  u  r  a   b

       i   l   i   t  y   f  a  c   t  o  r   D   F   (   %   )

    Concrete mixes

    w/c = 0.52Fresh air content = 5%

    Satisfactory DF, ASTM C494

    Fig. 14.  Durability factors of the binary and composite cement concretesinvestigated.

     Table 8

    Contribution of the binary and composite cements used to reducing the embodied

    CO2  (ECO2) of concrete.

    Materials MK Slag LS SF FA Portland cementECO2/ton 330 52 32 14 4 930Mix (w/c= 0.45) ECO2/kg Reduction in ECO2 (%)

    PC 381.3 –LS15 326 14.5LS25 289.3 24.1LS35 252.6 33.8LS45 216 43.4PCSFA 256 32.9PCSFASF 250.4 34.3PCSFAMK 314 17.7PCSFALS 242 36.6

    M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205   203


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    2. The use of LS appears to have no significant effect or slightlyimproves the concrete slump, while the use of compositecements reduced the amount of superplasticizer requiredcompared with the PC mix.

    3. The composite cements prolonged the initial setting time of all the concretes tested compared with the PC and PCLSmixes.

    4. At all the tested w/c values and ages, the compressivestrength of the binary PCLS concrete decreased whenincreasing the PC replacement level. This strength loss wasmore pronounced when the replacement level of PC by LSwas higher than 15%.

    5. The compressive strength of the composite cement con-cretes was strongly linked to the type and proportions of the SCMs used. The ternary (PCSFA) and quaternary (PCS-FALS) cementitious systems always led to a strength loss,especially at early age, while the two other quaternary sys-tems (PCSFASF and PCSFAMK) developed similar or slightlyhigher compressive strengths compared with the PC mixes.

    6. For both the binary and composite cements, a slightdecrease of the 28-day flexural strength and modulus of elasticity was recorded. The reduction was more significantin the binary LS-cement with a replacement level higherthan 15%.

    7. The use of LS-cement resulted in a reduction of the totalmagnitude of drying shrinkage strains of approximately15%, while a slight increase of the drying shrinkage strainswas recorded when using the composite cements.

    8. The use of all the composite cements improved the resis-tance to chloride ingress and resulted in much better perfor-mance than both the binary PCLS and the PC concretes.However, the carbonation depth results suggested that boththe binary and composite cements exhibited increased car-bonation depth compared with the PC mix.

    9. The experimental results demonstrated that the binary con-crete mixes designed with a w/c ratio of 0.52 and 15% LS

    with approximately 5% air content would be expected toprovide good concrete freeze–thaw resistance with a dura-bility factor higher than 80%; this DF decreased when ahigher amount of LS was incorporated.

    10. The quaternary cementitious system PCSFASF reached a sat-isfactory DF (approximately 80%), while all the other com-posite cements concretes exhibited a DF lower than 80%.

    11. Even though the LS particles are relatively reactive com-pared with other filler materials, the results indicate thatthe LS used in this study likely acted as an inert filler mate-rial rather than as a pozzolanic one. The results propose amaximum replacement level of PC by LS of 15% to limitthe strength loss and decrease in durability performance.

    12. Composite cements (ternary and quaternary), when prop-

    erly optimized, are the most advantage cementitious sys-tems that significantly reduce the environmental impactsof the concrete industry while also improving strength anddurability performance.

    13. The use of both binary and composite cements significantlycontributes to reducing the embodied CO2  emissions com-pared with Portland cement.


    [1]  Damtoft JS, Lukasik J, Herfort D, Sorrentino D, Gartner EM. Sustainabledevelopment and climate change initiatives. Cem Concr Res 2008;38(2):115–27.

    [2] United States Geological Survey. USGS mineral program cement report, January 2013. p. 38–9.

    [3]  Turanli L, Uzal B, Bektas F. Effect of large amounts of natural pozzolan additionon properties of blended cements. Cem Concr Res 2005;35(6):1106–11.

    [4] Mayfield LL. Limestone additions to Portland cement – an old controversyrevisited. Cem Concr Aggr 1988;10(1):3–8.

    [5] Livesey P. Performance of limestone-filled cements. In: Swamy RN, editor.Blended cements in construction. London: Elsevier Science; 1991. p. 1–15.

    [6]  Matthews JD. Performance of limestone filler cement concrete. In: Dhir RK, Jones MR, editors. Impact of ENV 197 on concrete construction. London: E & FNSpon; 1994. p. 113–47.

    [7] González AM, Irassar EF. Effect of limestone filler on the sulphate resistance of 

    low C3A Portland cement. Cem Concr Res 1998;28(11):1655–67.[8] Tsivilis S, Batis G, Chaniotakis E, Grigoriadis Gr, Theodossis D. Properties and

    behavior of limestone cement concrete and mortar. Cem Concr Res2000;30(10):1679–83.

    [9]  Heikal M, El-Didamony H, Morsy MS. Limestone-filled pozzolanic cement. CemConcr Res 2000;30(11):1827–34.

    [10]  Menéndez G, Bonavetti V, Irassar EF. Strength development of ternary blendedcement with limestone filler and blast-furnace slag. Cem Concr Compos2003;25(1):61–7.

    [11]  Ghrici M, Kenai S, Said-Mansour M. Mechanical properties and durability of mortar and concrete containing natural pozzolana and limestone blendedcements. Cem Concr Compos 2007;29(7):542–9.

    [12]   Chindaprasirt P, Homwuttiwong S, Sirivivatnanon V. Influence of fly ashfineness on strength, drying shrinkage and sulfate resistance of blendedcement mortar. Cem Concr Res 2004;34(7):1087–92.

    [13]  Tsivilis S, Chaniotakis E, Kakali G, Batis G. An analysis of the properties of limestone cements and concrete. Cem Concr Comp 2002;24(3–4):371–8.

    [14]  Bonavetti V, Donza H, Rahhal V, Irassar E. Influence of initial curing on theproperties of concrete containing limestone blended cement. Cem Concr Res2000;30(5):703–8.

    [15] European Committee for Standardization, Cement: Composition, Specificationsand Conformity Criteria, Part 1: Common Cements, EN 197-1, EN/TC51/WG 6rev; 2000.

    [16] Lafarge product data sheet, Portland limestone cement, Lafarge Cement UK,March 2009.

    [17]  Soroka I, Setter N. The effect of fillers on strength of cement mortars. CemConcr Res 1977;7(4):449–56.

    [18]  Bonavetti VL, Rahhal VF, Irassar EF. Studies on the carboaluminate formationin limestone filler-blended cements. Cem Concr Res 2001;31(6):853–9.

    [19] Hawthorm F. Ten years experience with composite cements in France. In:Proceedings of a seminar of the BRE/BCA/Cement Industry Working Party,Building Research Establishment, Garston, November 1989.

    [20]   LothenbachB, Le Saout G, Gallucci E, ScrivenerK. Influenceof limestone on thehydration of Portland cements. Cem Concr Res 2008;38(6):848–60.

    [21]  De Weerdt K, Kjellsen KO, Sellevold E, Justnes H. Synergy between fly ash andlimestone powder in ternary cements. Cem Concr Compos 2011;33(1):30–8.

    [22]  Lawrence P, Cyr M, Ringot E. Mineral admixtures in mortars: effect of inert

    materials on short-term hydration. Cem Concr Res 2003;33(12):1939–47.[23]  Barker AP, Hobbs DW. Performance of Portland limestone cements in mortar

    prisms immersed in sulfate solutions at 5   C. Cem Concr Compos1999;21(2):129–37.

    [24]  Bensted J. Thaumasite — background and nature in deterioration of cements,mortars and concretes. Cem Concr Compos 1999;21(2):117–21.

    [25]  Skaropoulou A, Tsivilis S, Kakali G, Sharp JH, Swamy RN. Long term behavior of Portlandlimestone cement mortars exposed to magnesium sulfate attack. CemConcr Compos 2009;31(9):628–36.

    [26]   Aguilera J, Blanco Varela MT, Vázquez T. Procedure of synthesis of thaumasite.Cem Concr Res 2001;31(8):1163–8.

    [27] ASTM C666/C666M-03. Standard test method for resistance of concrete torapid freezing and thawing. West Conshohocken, PA: ASTM International;2003.

    [28]   Limbachiya MC, Meddah MS, Ouchagour Y. Use of recycled concrete aggregatein fly-ash concrete. Constr Build Mater 2012;27(1):439–49.

    [29]  Tsivilis S, Chaniotakis E, Badogiannis E, Pahoulas G, Ilias A. A study on theparameters affecting the propertiesof Portland limestone cements. Cem ConcrCompos 1999;21(2):107–16.

    [30]   Svermova L, Sonebi M, Bartos PJM. Influence of mix proportions on rheology of cement grouts containing limestone powder. Cem Concr Compos2003;25(7):737–49.

    [31]  Selvamony C, Ravikumar MS, Kannan SU, Basil Gnanappa S. Investigation onself-compacted self-curing concrete using limestone powder and clinker.ARPN J Eng Appl Sci 2010;5(3):1–6.

    [32]  Bédérina M, Khenfer MM, Dheilly RM, Quéneudec M. Reuse of local sand:effect of limestone filler proportion on the rheological and mechanicalproperties of different sand concretes. Cem Concr Res 2005;35(6):1172–9.

    [33]   Livesey P. Strength characteristicsof Portland-limestone cements. Constr BuildMater 1991;5(3):147–50.

    [34]  De Weerdt K, Justnes H, Kjellsen KO. Fly ash–limestone ternary compositecements: synergetic effect at 28 days. Nordic Concr Res 2010;42(2):20.

    [35]  Soroka I, Stern N. Calcareous fillers and the compressive strength of Portlandcement. Cem Concr Res 1976;6(3):367–76.

    [36]   Bentz DP. Modeling the influence of limestone filleron cement hydration usingCEMHYD3D. Cem Concr Compos 2006;28(2):124–9.

    [37]  Bentz DP, Irassar EF, Bucher BE, Weiss WJ. Limestone fillers conserve cement,

    Part 2: durability issues and the effects of limestone fineness on the mixtures.ACI Concr Int 2009;31(12):35–9.

    204   M.S. Meddah et al. / Construction and Building Materials 58 (2014) 193–205


  • 8/16/2019 Potential Use of Binary and Composite Limestone Cements in Concrete


    [38]  Voglis N, Kakali G, Chaniotakis E, Tsivilis S. Portland-limestone cements. Theirproperties and hydration compared to those of other composite cements. CemConcr Compos 2005;27(2):191–6.

    [39]   Güneyisi E, Gesoglu M, Özturan T, Mermerdas K, Özbay E. Properties of mortars with natural pozzolana and limestone-based blended cements. ACIMater J 2011;108(5):493–500.

    [40] Practical action, testing methods for pozzolanas, The Schumacher centre fortechnology & development, Warwickshire, UK.

    [41] Khanh Bui V, Montgomery D. Drying shrinkage of self-compacting concretecontaining milled limestone. In: Skarendahl Å, Petersson Ö, editors.

    Proceedings PRO 7: 1st International RILEM symposium on self-compactingconcrete; 1999. p. 227–38.

    [42]  Baron J, Douvre C. Technical and economical aspects of the use of limestonefiller additions in cement. World Cem 1987;18(4):100–4.

    [43] TsivilisS, Tsantilas J, Kakali G, ChaniotakisE, Sakellariou A. The permeability of Portland limestone cement concrete. Cem Concr Res 2003;33(9):1465–71.

    [44]  Thomas MDA, Hooton D, Cail K, Smith BA, De Wal J, Kazanis KG. Field trials of concretes produced with Portland limestone cement. ACI Concr Int2010;32(1):35–41.

    [45]  Tsivilis S, Asprogerakas A. A study on the chloride diffusion into Portlandcementlimestone cementconcrete. Mater Sci Forums2010;636–637:1355–61.

    [46] Persson B. Assessment of the chloride migration coefficient, internal frostresistance, salt frost scaling and sulphate resistance of self-compactingconcrete – with some interrelated properties. Div. Building Research. Report

    TVBM-3100, Lund; 2001.[47] Boubitsas D. Studies on the efficiency of granulated blast furnace slag and

    limestone filler in mortars. Long-term strength and chloride penetration. Div.Building Research. Report TVBM-3125, Lund; 2005.

    M.S. Meddah et al. / Const