Construction and Building Materials 68 (2014) 277–284

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Construction and Building Materials

journal homepage: www.elsevier .com/locate /conbui ldmat

Multi-parametric characterization of a sustainable lightweight concretecontaining polymers derived from electric wires

http://dx.doi.org/10.1016/j.conbuildmat.2014.06.0750950-0618/� 2014 Elsevier Ltd. All rights reserved.

⇑ Corresponding author.E-mail address: dalessandro.unipg@ciriaf.it (F. D’Alessandro).

Francesco D’Alessandro ⇑, Francesco Asdrubali, Giorgio BaldinelliUniversity of Perugia, Department of Engineering, Via Duranti 65, 06125 Perugia, Italy

h i g h l i g h t s

� A lightweight concrete obtained mixing cement, water and polymer waste was analyzed.� The residual polymer was obtained by the recycling of electric wires.� Chemical, mechanical, thermal and acoustic tests were performed.� The results showed the possibility to use the concrete for floor screeds.

a r t i c l e i n f o

Article history:Received 3 March 2014Received in revised form 20 May 2014Accepted 30 June 2014

Keywords:Lightweight concretePolymer wasteCompressibilityThermal transmittanceImpact sound insulation

a b s t r a c t

The present paper reports the results of the experimental investigation of a sustainable lightweight con-crete containing polymers derived from the recycling of the sheets of electric wires. After the removal ofthe copper, the plastic insulating sheet is ground into small size granules. Firstly the chemical and phys-ical properties of plastic granules are investigated and their applicability in concrete is studied. Measure-ments of dynamic stiffness, impact sound pressure reduction and thermal conductivity show that thedeveloped concrete can be successfully used for thermal and acoustic insulating lightweight screeds tobe applied above the concrete structural slabs in floors.

� 2014 Elsevier Ltd. All rights reserved.

1. Introduction

Nowadays it is almost impossible to imagine a world withoutconcrete, a material with infinite applications that can be producedin order to satisfy almost every technical specification in the build-ing and transportation sector. For its excellent characteristics onaverage one ton of concrete is produced each year for every personin the world [1]: this clearly explains the incredible amount ofmaterial produced and the resulting environmental impacts. Theproduction of each ton of Portland cement releases almost oneton of carbon dioxide into the atmosphere and worldwide thecement industry alone is estimated to be responsible for about7% of all generated CO2 [2]. Furthermore cement production is veryenergy demanding: it uses approximately 1% of all energy pro-duced in the United States [3]. Of course it is not conceivable tolimit the use of concrete but there are several ways to reduce itsenvironmental impact towards a higher sustainability in order to

obtain a ‘‘green’’ concrete [4,5]. One of the most used is to replaceas much as possible Portland cement with alternate components,possibly obtained by recycled materials or by-products of indus-trial resources. Among those the most used are fly ash, groundgranulated blast furnace slag, recycled concrete, silica fume, post-consumer glass, end of life tyres, recycled plastics or other naturalmaterials [6,7].

As far as the use of recycled polymers in concrete, their applica-tion is quite problematic because of the poor bond between theplastic particles and the cement matrix with a consequent decreaseof the concrete strength [8,9]. On the other hand other propertiescan be enhanced: (i) being an excellent thermal insulator, theinclusion of plastic inside the concrete considerably improves thethermal resistance [9]; (ii) the decrease of the concrete stiffnessleads to an improved insulation against impact sounds [10]; (iii)the sustainability of the final material is definitely higher com-pared to that of a traditional concrete also considering the largeamount of plastic waste that needs to be disposed each year [11].All these aspects are currently crucial for the building sector con-sidering the increasing demand for high-performance sustainable

278 F. D’Alessandro et al. / Construction and Building Materials 68 (2014) 277–284

materials to be used in low energy or nearly Zero-Energy Buildings[12].

Even if the final strength of the concrete containing plasticwaste is reduced and structural applications are often precluded,an optimal application for this material can be found in the build-ing sector with the creation of lightweight slabs to be used in alter-native or in addition to a common floating floor system appliedabove the structural concrete slab.

The present paper studies one of these solutions containingplastic waste coming from the recycling of electric wires mixedwith cement and water in order to create a lightweight concrete:the acoustic, thermal, chemical and mechanical properties are ana-lyzed and the results are presented. Thanks to new formulations ofthe tested material, the results presented in previous publicationsby the same authors [13,14] are here updated and discussed.

2. Description of the lightweight concrete

Electric wires are made of a conductive material, commonlycopper, covered with a plastic insulator. Copper is of course themost valuable material to be recycled from end-of-life electricwires while the insulation sheet is often considered a low-valuewaste of copper recycling.

The sheets are ground and passed through calibrated sieves inorder to obtain granules of homogenous sizes. Then the polymergranules can be mixed with concrete and water in the correct pro-portions to obtain a lightweight concrete. Its main applicationshould be in the building sector and as a subfloor applicable man-ually or with pumps.

In Italy the national standard UNI 10667-14 [15] defines therequirements of the polymer materials obtained from the collec-tion of industrial and post-consumer waste that can be used asconcrete aggregates; in particular the standard gives the specifica-tions for testing several physical parameters (such as composition,shape, size, density and water content) and the corresponding limitvalues for their application.

The ground polymer granules were tested following the specifi-cations of the standard [15] in order to have a preliminary physicalcharacterization of the loose granules alone.

The percentage in weight of the tested samples of polymer is99.92% plastic and rubber while the remaining 0.08% is metal,probably not removed in the phase of separation of the sheet fromthe conductive wire.

Calibrated sieves with openings of 1, 2 and 5 mm were used tomeasure the granulometry: the size of the granules is always lowerthan 5 mm, with 13.8% in the range 2–5 mm, 54.5% in the range 1–2 mm and 31,7% with size lower than 1 mm.

The average value of the material density is 774 kg/m3 and wasmeasured according to the procedures given by ISO 61 [16].

Fig. 1. (a) View of the polymer grains obtained by the elec

Finally the residual water content evaluated by drying a samplein controlled conditions is equal to 0.62%.

The lightweight concrete (Fig. 1b) can be produced using vari-able percentage in weight of the following ingredients:

� 60–70% granules of recycled polymers (loose, density = 774 kg/m3);� 15–25% Portland cement 325 (loose, density = 1500 kg/m3);� 10–15% water (density = 1000 kg/m3).

The application studied in the present paper is the use of thedeveloped concrete for lightweight slabs to be applied above theconcrete structural slabs in addition or in alternative to commonfloating floor systems used to reduce the transmission of impactnoise.

3. Chemical characterization

Since the developed lightweight concrete is designed to beapplied indoor in building flooring screeds, the toxicity of the gran-ules was assessed in order to define the healthiness of the finalproduct.

The emissions of VOC (Volatile Organic Compounds) were mea-sured with a gas chromatograph using the solid-phase microex-traction method. The measurement procedures are given by theItalian Standard UNI 10899 [17].

The results of the measurements showed the presence of a cer-tain amount of chlorinated hydrocarbons, mainly chloroform, withan amount of 1.4 lg/g. Furthermore a reduced quantity of polycy-clic hydrocarbons (mainly toluene) was found, with an amount ofabout 0.4 lg/g.

The amounts of VOC emissions from the analyzed polymergranules cannot be ignored. However the analyses were performedon the loose granules and not directly on the concrete: so when thecomposite is mixed to form the screed, it is reasonable that theemission of VOC from the polymers trapped inside the concreteare largely decreased.

4. Mechanical characterization

The ability to bear loads and to keep the thickness unchangedare fundamental requirements of flooring screeds. So mechanicaltests were performed on sample layers of the developed light-weight concrete in order to measure its compressibility. The mea-surement procedures are given by the standard EN 12431 [18]:three levels of load (250, 2000 and 50000 Pa) are applied for adefined period of time (120 s) on a square sample with 200 mmside and the corresponding variation in thickness is recorded (fig.2a). In particular:

tric wires sheets; and (b) view of the concrete matrix.

Fig. 2. (a) Loads applied on the sample during the compressibility test; and (b) experimental setup for the mechanical test.

F. D’Alessandro et al. / Construction and Building Materials 68 (2014) 277–284 279

� dL is considered the initial thickness under a constant load;� dF is considered the thickness in normal operating conditions;� dB is considered the long-term thickness in normal operating

conditions.

The value of the compressibility c is given by the differencebetween dL and dB.

Tests were performed with a Lloyd Instruments LR30K testingmachine on three square samples of the developed concrete (fig.2b). The load is distributed to the surface of the sample by twometallic plates. As prescribed by the standard [18], the thicknessreduction was obtained by the readings of two dial type compara-tors with 10 lm precision, placed in two corners of the metallicplate and by the displacements of the dynamometer.

The samples used for this test are the same used for determin-ing the dynamic stiffness; their characteristics are reported later inthe paper in Table 2. Compressibility test were performed afterdynamic stiffness tests.

Samples were kept in controlled conditions of temperature andhumidity (T = 19� C; RH = 44%) for eight hours before the tests.

The average results of the tests performed on three samples arereported in Table 1; the initial thickness of all the samples was70 mm. According to the standard [18] the compressibility levelcorresponding to c = 0.7 mm (<2 mm) is CP2, confirming the opti-mal potentiality of the lightweight concrete layer to be used as afloor screed.

5. Thermal characterization

Being the polymers constituting the sheets of electric wiresgood thermal insulators, an increased thermal resistance isexpected from a concrete including these components. The thermalproperties of the concrete were defined by measuring its thermal

Table 1Results of compressibility tests.

dL (mm) dF (mm) dB (mm) c = dL � dB (mm)

Load (kPa) 0.25 2 50 –Test results 70.0a 69.6 (±0.1) 69.3 (±0.1) 0.7

a The displacement was lower than 0.1 mm (sensitivity required by the standard[18]).

Table 2Results of dynamic stiffness tests.

Concretemix

Density(kg/m3)

Resonancefrequency (Hz)

Dynamic stiffnesss0 (MN/m3)

Dampingratio (%)

A 758 89.0 63 13.0B 780 105.0 87 10.8C 800 112.2 100 9.2

conductivity in compliance with the standard EN 1934 [19]. Testswere performed in a calibrated hot box facility designed and buildin home at the University of Perugia (fig. 3) following the prescrip-tions of Annex E of the standard EN 14351-1 [20]. The system con-sists of two coupled rooms (dimensions: 2.0 � 0.9 � 2.7 m) kept atconstant temperatures: in the hot chamber the heating system isrealized through a heating wire; the cold room is equipped witha refrigerating system and with a heating wire that allows toachieve the target value of temperature (fig. 4). The sample isinstalled in a support structure with known insulating propertiesand with adjustable dimensions. Fig. 5 shows a detail of the devel-oped concrete mounted in the hot box apparatus: it is possible tosee, beyond the temperature probes, a heat flow meter positionedin the centre of the panel, acting as a checking measurement deviceof the sample thermal properties. A comprehensive description ofthe used test equipment can be found in [21].

Several 10 cm thick rectangular samples (1.23 � 1.48 m) weretested. The components of the concrete are mixed using the pro-portions used for the other tests (see Section 2). The variation ofthe values of thermal conductivity measured for the samples waslimited, because of the small range of variability of the componentsof the concrete, and in any case always lower than the measure-ment uncertainty.

The average thermal conductivity of the developed lightweightconcrete is resulted to be equal to 0.191 W/mK. The measurementuncertainty calculated in compliance with the standard ENV 13005[22] is 4.3%.

Considering that the thermal conductivity of concrete increaseswith material density with values ranging from 1.5–3.5 W/mK fornormal-weight concrete to 0.5–1.1 W/mK for lightweight concrete[23], as expected the thermal properties of the developed concretecan be considered excellent.

Fig. 3. Hot box setup for thermal transmittance tests.

Fig. 4. Scheme of the Hot box apparatus: (1) specimen; (2) heating system;(3) refrigeration system; (4) fan; (5) surrounding movable panel; and (6) baffle.

Fig. 5. Sample of lightweight concrete mounted in the hot box apparatus.

280 F. D’Alessandro et al. / Construction and Building Materials 68 (2014) 277–284

6. Acoustic characterization

As far as sound insulation, a floor has to limit the transmissionof two categories of sounds between the overlapping rooms: air-borne sounds, such as those originated by talking or TV, and impactsounds, such as walking on the floor itself. Airborne sound insula-tion is generally influenced by the mass of the system by means ofthe well-known mass law, while impact sound insulation dependson the ability of the materials constituting the floor to dampen thevibrations generated by the impacts. In this latter case mass is notsufficient to achieve the insulation from unwanted sounds but amass-spring-mass system has to be arranged in order to obtain aso called floating floor. Thus the dynamic stiffness s0 of the

component acting as the spring become the fundamental parame-ter to achieve an adequate impact sound pressure reduction DL.Both these parameters were studied for the developed lightweightconcrete and the results of experimental measurements arereported in this section.

6.1. Dynamic stiffness

As stated above, dynamic stiffness is the most important char-acteristic of a floor material or system to dampen impact noise. Itis defined as the frequency dependant ratio between the dynamicforce applied to the sample F and the corresponding dynamic dis-placement Dd. The Standard ISO 9052 part 1 [24] gives the defini-tion and the procedures to test the dynamic stiffness of resilientmaterials to be installed in floating floors: it considers the dynamicstiffness s0 per unit area of the sample:

s0 ¼ ðF=SÞDd½MN=m3� ð1Þ

where S is the surface of the sample.Dynamic stiffness is indirectly obtained by the measurement of

the resonance frequency fr of the mass-spring system made of theload plate placed on the sample (mass) and the sample of resilientmaterial (spring). For a common mass-spring system the resonancefrequency is given by:

fr ¼1

2p

ffiffiffiffiffikm

r½Hz� ð2Þ

where k is the spring constant and m is the mass attached to thespring. In this case the spring constant becomes the apparentdynamic stiffness s0t of the resilient material:

fr ¼1

2p

ffiffiffiffiffiffis0tm0t

s½Hz� ð3Þ

where m0t is the mass per unit area of the load plate. Finally Eq. (3)can be solved for s0t obtaining:

s0t ¼ 4p2m0tðfrÞ2½MN=m3� ð4Þ

The apparent dynamic stiffness s0t has to be corrected in orderto take into account the stiffness of the air trapped inside the sam-ple. The standard defines several corrections based on the value ofthe lateral flow resistivity of the sample. The flow resistivity of thetested samples is higher than 100 kPa s/m2: in this case the stan-dard requires no correction and dynamic stiffness s0 has the samevalue of the apparent dynamic stiffness s0t.

Tests were performed using a Microbel testing rig (fig. 6). Themain components of the test rig are a steel load plate(size = 200 � 200 mm; weight = 8 kg; mass per unit area m0t = 200 -kg/m2), a shaker and two accelerometers, one integral with theshaker and one with the plate. Further information on the testrig can be found in [25]. A thin layer (5 mm) of gypsum plaster ispreliminarily applied to the surface of the sample to cover theirregularities and then the load plate is placed on it. A sine sweepexcitation is applied to the plate by the shaker and the frequencydependant response of the system is recorded by the accelerome-ters allowing the detection of the resonance frequency. In the cur-rent work tests were performed placing the sample (and the testrig) on the floor of a reverberating room that is physically discon-nected by the outer environment by means of elastic layers. In thisway measurements are not influenced by unwanted vibrations.

As stated before, the dynamic stiffness of the resilient materialdirectly influence the final impact sound pressure reduction DL.According to the standard ISO 10140-3 [26] this parameter is thedifference between the sound pressure level measured in a lowerroom when the tapping machine (source used to simulate the steps

Fig. 6. Dynamic stiffness test rig.

Fig. 7. Resonant curve with the values of fr, f1 and f2 [28].

Fig. 8. Scheme of the test rooms (in yellow the emitting room).

F. D’Alessandro et al. / Construction and Building Materials 68 (2014) 277–284 281

on the floor) is placed in the upper room (having the floor in com-mon with the lower room) on a normalized concrete slab and thesound pressure level measured when the floating floor is installedon the concrete slab. Higher values of DL mean higher impactsound insulation.

The impact sound pressure reduction DL is frequency depen-dant; the standard ISO 717-2 allows to calculate a single numberindex DLW named weighted impact sound reduction index.

The value of DLW can be estimated from the dynamic stiffness s0

of the resilient layer and the mass m’ of the floating floor with thefollowing equation [27]:

DLW ¼ 18þ 15 logðm0=s0Þ½dB� ð5Þ

Expression (5) derives directly from the procedure reported inthe Annex C of EN Standard 12354-2 [28].

The accuracy in estimating the weight impact sound reductionindex depends also on the damping ratio d of the resilient material,which is inverse of the quality factor Q. The quality factor can beobtained by the results of the same measurement performed forevaluating the dynamic stiffness with the equation:

Q ¼ fr

f2 � f1; d ¼ 1

Qð6Þ

where fr is the resonance frequency and f1 and f2 are the frequenciesin which the resonant curve has a decrease of 3 dB from the peakcorresponding to the resonance frequency (fig. 7).

As described in [29], a good estimation of the weighted soundreduction is achievable when the material under test shows highvalues of damping ratio: for instance for a resilient layer with adamping ratio higher than 20% the error of the estimation of theweighted impact sound reduction index is about 1%; otherwise(lower values of damping ratio) the error can exceed 3 dB.

Three different concrete mixtures obtained varying the concen-tration of their components (polymers, cement, water) within theranges specified in Section 2 were tested. New formulations wereproposed with slightly different concentrations of the components,in order to optimize the properties and overtake some problemsfound in previous investigations [13,14]. Three 70 mm thick sam-ples were produced with each of the three concrete mixtures andtested as required by [24]. The measurement results (average valueof the dynamic stiffness measured for the three samples) and thedensity of the three analyzed concrete mixtures are reported inTable 2.

The concrete density has a direct influence on the dynamic stiff-ness, which decreases with decreasing values of density. The lessdense concrete (concrete mix A in Table 2) shows a value ofdynamic stiffness of 63 MN/m3: considering that the values forproperly designed resilient layers for floating floors (such as layers

made of expanded polyethylene or mineral wool) range from 4 to50 MN/m3, as indicated in the standard EN 12354-2 [28], the valueobtained for concrete mix A is an excellent value for a concrete-based screed. The low values of damping ratios were expectedbeing the concrete mixture stiffer than traditional resilient floorunderlays. In particular the damping ratio decreases from sampleA (largest percentage of polymers, most elastic sample) to sampleC (largest percentage of cement, stiffest sample).

6.2. Impact sound pressure reduction

As stated before, the reduction in impact sound pressure levelDL of a floating floor defines the ability to reduce the radiation ofthe structure-borne sounds (caused for instance by footsteps, fallsof objects, chairs moving, etc.) into the room below. This parameteris measured in compliance with the standard ISO 10140-3 [26].Test rooms [30] are two overlapping reverberating rooms havinga common 13 cm thick reinforced concrete heavyweight standardfloor (fig. 8): in the upper one (emitting room) a normalized tap-ping machine excites the sample under test while the microphoneconnected to a signal analyzer 01-dB Symphonie is placed in thelower one (receiving room).

Sound pressure levels are measured without (Ln0) and with (Ln)the sample installed on the standard floor in the one third octavebands between 100 and 5000 Hz and the reduction in impactsound pressure level DL is the difference between these values:

DL ¼ Ln0 � Ln½dB� ð7Þ

Two floor configurations including the lightweight slabs weretested. The stratigraphies are as follows:

� Configuration 1: 10 cm lightweight screed (density = 800 kg/m3); ceramic tiles.� Configuration 2: 7 cm lower lightweight screed (density = 800

kg/m3, dynamic stiffness = 100 MN/m3); 0.6 cm reticulatedpolyethylene resilient layer (declared dynamic stiffness = 45MN/m3); 6 cm upper screed (density = 1800 kg/m3); ceramictiles.

282 F. D’Alessandro et al. / Construction and Building Materials 68 (2014) 277–284

A sample with a surface area of 1 square meter was tested foreach configuration. Fig. 9 shows the pictures of the two tested con-figurations while Fig. 10 reports the reduction of impact soundpressure DL in one third octave bands between 100 and 5000 Hzfor the two configurations, together with the weighted indexDLW evaluated according to the standard ISO 717-2 [31].

The low values of impact sound reduction obtained for configu-ration 1 (DLW = 5 dB) were expected and are in line with thoseobtained by other authors for similar concrete mixes [10]: this isdue to the fact that a floating floor works as a mass-spring-massdamper where the lightweight slab acts as a mass and in this casethe upper mass (floating slab) is missing.

On the contrary configuration 2 is a proposal for a completefloating floor system and represents a proper mass-spring-massdamper.

As said in Section 6.1, the weighted impact sound reductionindex of configuration 2 can be estimated from the dynamic stiff-ness of the elastic layer using Eq. (5). In this case the dynamic stiff-ness of the system made of the lower lightweight screed and theresilient layer is obtained considering these two layers as springsin series:

s0 ¼ 1s01þ 1

s02

� ��1

¼ 1100þ 1

45

� ��1

½MN=m3� ð8Þ

The resulting dynamic stiffness is 31 MN/m3. The mass of theupper screed m0 is about 100 kg/m2. Inserting these values in Eq.(3) the estimated value of the weighted index DLW of configuration2 is 25.6 dB.

Fig. 9. Lateral view of the tested samples: (a)

Fig. 10. Impact sound pressure lev

The calculated (25.6 dB) value of DLW is different from theexperimental one (18 dB), that appears underestimated: possiblereasons for this mismatch can be identified in the followingassumptions:

� the low damping ratio of the concrete mix leads to substantialerrors in using Eq. (3);� the standard ISO 10140-3 requires a surface of the sample equal

to 10 square meter while in this case 1 square meter sampleswere tested and the influence of edge effects becomesfundamental;� the test procedure described in the standard ISO 9052-1 is

addressed to impact insulating materials with thickness ofsome millimeters or at most 1–2 cm; in this case the sampleis a 7 cm thick slab, that cannot be properly assimilated to aresilient layer.

7. Discussions and conclusions

The present paper proposes to use a concrete containing granu-lated polymeric materials obtained from sheaths of electric wiresafter the recycle of copper in the realization of lightweightunder-floor screeds.

The ground polymer composition, granulometry, density andresidual water content were tested and the results show that therequirements given by the Italian Standard UNI 10667-14 are ful-filled, that means that the granules can be used as aggregates inconcrete (at least in the Italian market).

configuration 1; and (b) configuration 2.

el reduction DL vs. frequency.

F. D’Alessandro et al. / Construction and Building Materials 68 (2014) 277–284 283

The multi-parametric characterization dealt with several prop-erties described as follows.

7.1. Chemical analysis

The chemical analysis performed on the loose granules with agas chromatograph detected the emission of VOC, in particularsome amounts of chlorinated and polycyclic hydrocarbons: how-ever when the polymers are trapped inside the concrete the emis-sion of VOC will be reasonably lower. Additional analyses on theVOC emissions from the concrete mix are required.

7.2. Structural analysis

The compressibility of the concrete made of Portland cement,water and polymers was tested in compliance with EN 12431, con-firming the optimal potentiality of the lightweight concrete layerto be used as a floor screed.

7.3. Thermal analysis

The presence of the polymer, which is a thermal insulator, givesa substantial benefit to the thermal conductivity of the concrete,which was measured using a hot box apparatus in compliance withEN 1934: the average thermal conductivity of the tested samples(k = 0.191 W/mK), is definitely lower than the one of common con-crete (k = 1.5–3.5 W/mK) and typical lightweight screeds (k = 0.5–1.1 W/mK).

7.4. Acoustic analysis

Finally the developed lightweight floor screed was character-ized from the sound insulation point of view. Dynamic stiffnesstests were performed in compliance with ISO 9052-1 on three dif-ferent samples of concrete layers obtained by varying the relativeamount of the components. Even if the developed lightweight con-crete cannot be considered a traditional resilient material, as theones the method is addressed, the high percentage of polymermakes it elastic enough to be tested with a dynamic stiffness testrig. The dynamic stiffness of the lightest sample is 63 MN/m3, anexcellent value for a concrete-based screed.

The reduction in impact sound pressure level DL of two floatingfloors including the developed concrete was measured in compli-ance with ISO 10140-3. The result for the floating floor system(DLW = 18 dB) seems underestimated with respect to the value cal-culated with experimental equations (DLW = 25 dB), which can beconsidered more representative of the real performance of thefloor: this mismatch has several causes, among which the size ofthe tested sample (1 square meter) and the high stiffness of thematerial are the most important.

The performed investigations show that it is possible to useresidual polymeric waste in a new product showing promisingacoustic and thermal performance if compared with commonlightweight screeds.

Further analyses are required to investigate the impact soundpressure level for larger sized samples (at least 10 square metersas required by [26]), to evaluate the vibration-damping propertiesof the material (for instance in compliance with ASTM E756-98[32], a method that seems more adequate to the material thanthe one provided by ISO 9052-1) and to assess the durability ofthe material. This latter aspect is crucial when dealing with thesustainability of a product, especially in the concrete industry[33], since a short lifetime of a product means production of newconcrete and creation of new solid residues to be disposed. FinallyLife Cycle Assessment will be applied to the developed concreteformulation to evaluate its environmental impacts ‘‘from cradle

to grave’’; the analysis will allow to evaluate its use in the designof eco-friendly buildings [34].

Acknowledgments

The authors would like to thank Building in the World srl forproviding the samples of the material tested in the presentresearch. The authors are also indebted with Professors Torre andCappelletti of Perugia University for their support on the executionof mechanical and chemical tests.

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