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Applied Thermal Engineering 66 (2014) 156e161

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Applied Thermal Engineering

journal homepage: www.elsevier .com/locate/apthermeng

Experimental and numerical study on effective thermal conductivityof novel form-stable basalt fiber composite concrete with PCMs forthermal storage

Juan Shi, Zhenqian Chen*, Shuai Shao, Jiayi ZhengIIUSE, School of Energy and Environment, Southeast University, Nanjing, China

h i g h l i g h t s

� Novel form-stable basalt fiber composite concrete with PCMs was prepared.� ETC of the composites with PCM was studied with experimental and numerical method.� The numerical model was validated with experimental data.� Contact thermal resistance between PCM with matrix affects ETC of the composites at solid state.

a r t i c l e i n f o

Article history:Received 12 June 2013Accepted 4 February 2014Available online 13 February 2014

Keywords:Energy storagePhase change concreteBasalt fiberEffective thermal conductivity

* Corresponding author. Tel./fax: þ86 025 8379062E-mail address: zqchen@seu.edu.cn (Z. Chen).

http://dx.doi.org/10.1016/j.applthermaleng.2014.02.011359-4311/� 2014 Elsevier Ltd. All rights reserved.

a b s t r a c t

In this paper, the study on effective thermal conductivity (ETC) of a novel form-stable fiber compositeconcrete containing dispersed phase change materials (PCMs) is presented. Such composites are used invarious thermal storage systems. The concrete matrix is prepared by mixing cement, fine sand, andgypsum with water. Paraffin is used as phase change material, and is dispersed in the matrix at liquidstate. Basalt fibers are added in order to enhance the elastic modulus and strength. The distribution offiber and paraffin particles is characterized through images taken from an electron microscope (EM). TheETC of the specimens are measured by steady-state method. A numerical model is developed to predictthe effect of PCMs and fiber on the ETC of composite. The numerical model is validated with experi-mental data. The numerical results show that finite contact thermal resistance between PCM and matrixaffects ETC of the composites at solid state, as the volume of PCM changes with temperature. Theagreement between the numerical model and the experiments provides the opportunity to study form-stable fiber composite concrete with PCMs without performing repeated experiments.

� 2014 Elsevier Ltd. All rights reserved.

1. Introduction

Phase change materials (PCMs) offer effective latent heat ther-mal storage performance in energy conservation systems. PCMswhen added to the raw materials used for constructions, providestorage of thermal energy; thereby reducing the load on heatingventilating and air conditioning (HVAC) systems [1e8]. In 1976,Godfrey and Mumma [9] studied the thermal performance ofparaffin phase change materials dispersed in a concrete mortarfiller matrix through both experimental and numerical method.The result showed that the thermal energy storage capacity of wallsmade from concrete matrix was superior in comparison to similar

6.

2

walls made either from solid concrete or from pure paraffin. Sincethen, identifying novel phase-change composite concrete has beenan active area of research in building energy management. Thebehavior of self-compacting concrete containing micro-encapsulated phase change materials during mixing, hydrationand after hardening was investigated by Hunger et al. [10]. Theysuggested that increasing the PCM concentration resulted in alower thermal conductivity and a higher heat capacity, therebyenhancing the thermal performance of concrete. However,increased PCM ratios lead to significant loss in strength. In 2010,heat transfer and thermal storage behavior of gypsum boardsincorporating micro-encapsulated PCM were studied by Lai et al.[11]. They observed that a higher Stefan number or a higher sub-cooling resulted in higher heat transfer through the hot wall.

Paraffin has been considered as a suitable thermal energy stor-age material due to its relatively large latent heat, congruent

Table 2The volume fraction of paraffin particles and basalt fiber in fiber-paraffin-concretelayer.

S0 S1 S2 S3 S4 S5 S6

Paraffin particles(volume fraction %)

0 10 30 45 10 30 45

Basalt fiber(volume fraction %)

0 0 0 0 1 1 1

Density (kg/m3) 1315 1314 1314 1373 1340 1340 1399

J. Shi et al. / Applied Thermal Engineering 66 (2014) 156e161 157

melting behavior and non-corrosiveness [12e14]. However,paraffin being a solideliquid phase change material; leakage andinsufficient strength in the solideliquid phase transition are someof the major concerns in using paraffin. Adding fiber (therebyimproving the strength and ductility [15e17]) is an effective way ofpreparing form-stable phase change composite concrete. Basaltfiber is an environmental friendly material made from naturalbasalt, and is widely used as a composite matrix. The strength andductility of basalt fiber is similar to that of carbon fiber and fiber-glass. However, basalt fiber has better strength than fiberglass, andits cost is much cheaper than carbon fiber [18e21].

Although evaluating the thermal properties of PCM compositesis necessary for thermal management and design optimization, thematerial heterogeneity of composites hinders such assessment. Tothe extent of the authors’ literature review, there are only a fewreported works on prediction of effective thermal conductivity ofform-stable fiber composite concrete with PCMs in the open liter-ature. Therefore, the aim of this paper is: 1) prepare form-stablebasalt fiber composite concrete with PCMs, 2) experimentallydetermine the effective thermal conductivity of composite concreteby steady-state method, 3) establish a numerical model for evalu-ating ETC of composite concrete, 4) validate the numerical modelwith experimental results, 5) evaluate the effect of the concentra-tion of PCM and fiber on the ETC of composite.

2. Experimental study on ETC of composite concrete

2.1. Sample preparation

In this study, PII 42.5R type Normal Portland Cement was used.The density of cement was 3.09� 103 kg/m3. Natural river sandwasused as aggregate, and its density was 1.57 � 103 kg/m3. Gypsumpowder (density 1100 kg/m3) was added to the composite. Paraffinparticles with diameter of 2e3 mmwere used as PCMmaterial. TheThermo-physical properties of paraffin are shown in Table 1.

Whenmixing thematerials for concrete, the weight proportionsof the mortar mixture were: water 14.2%, cement 23.3%, river sand59.5%, and gypsum powder 3%. The above materials are basiccomposition of concrete. Paraffin and basalt fiber were added to thematrix at certain ratio. The volume fraction of paraffin particles andbasalt fiber in specimens are shown in Table 2. In Fig. 1, a sectionalview of constructed form-stable basalt fiber composite concretewith PCMs is shown. The corewas made of paraffin, basalt fiber andconcrete. The edges were made of concrete to avoid leakage ofmolten paraffin. Images from an electron microscope (Figs. 2 and 3)were taken to highlight the surface features.

2.2. Experimental apparatus

A schematic of experimental apparatus for measuring ETC ofcomposite concrete by steady-state method is shown in Fig. 4. The

Table 1Thermo-physical properties of the paraffin.

Thermo-physical properties Paraffin

Melting temperature (�C) 53e61Total latent heat of fusion (kJ/kg) 158.2Density (kg/m3) 865(s)

780(l)Specific heat (kJ/kg K) 1.9(s)

1.5(l)Thermal conductivity (W/m K) 0.27(s)

0.15(l)

Where: l stands for liquid, s stands for solid.

experimental apparatus consisted of a thermally insulated cham-ber, which ensured an adiabatic boundary condition. An electricalheat source was positioned at the center of the chamber. Twospecimens of the composite were placed on the heating panel. Thespecimens were cooled by disc-shaped cooling blocks. Thermalpaste was used on both sides of specimens to minimize heat loss atthe interface, heating panel, as well as the cooling block. A voltageregulator (0e250 V) supplied constant heat flux (0e40 W) to theheating panel. The temperature of the cooling block was regulatedusing a water bath. The experimental data were recorded by a dataacquisition system when steady state was achieved.

2.3. Experimental measurements

The temperatures at different locations (see Fig. 4) on eachspecimen were recorded when steady state was achieved. Theexperimental data were then used for evaluating ETC of the com-posite. The calculations were based on the following assumptions:(1) heat transfer along the radial direction of the specimen wasneglected as the chamber was well insulated; (2) heat loss from thespecimen due to thermal resistance between the specimen andheating panel/cooling block was negligible; (3) the porous spec-imen was considered as homogeneous.

Based on above assumptions, the temperature distribution inthe specimen can be expressed through the one-dimensionalFourier’s Law:

q ¼ �lðTÞdTdx

(1)

The surface temperatures of the specimen were determinedexperimentally. It was assumed that the heat flux supplied to thespecimens were equal. The surface temperatures were thereforetaken as an average of the individual recorded temperatures:

Thot ¼ T2 þ T32

; Tcold ¼ T1 þ T42

(2)

where, T1 � T4 are the measured temperatures as shown in Fig. 4.By using Eqs. (1) and (2), the ETC of the specimen is given by:

lðTÞ ¼ Qd

AeðThot � TcoldÞ; T ¼

X4i¼1

Ti=4 (3)

where, Ae is the surface area of specimens, m2; Q is the input powerfrom the electric heating panel, W; d is the thickness of the spec-imen, m.

Fig. 1. Sectional view of the composite concrete structure.

Fig. 2. EM photo of the distribution of the fibers in specimen.

Fig. 4. Schematic of the experimental apparatus.

J. Shi et al. / Applied Thermal Engineering 66 (2014) 156e161158

2.4. Experimental results and discussion

In this study, seven different specimens were prepared atdifferent volume fraction of paraffin particles and basalt fiber. Themeasured thermal conductivities of specimens at different tem-peratures are shown in Table 3. It can be seen from Table 3 thattemperature fluctuations have little influence of the thermal con-ductivity of pure (no paraffin or basalt fiber added) concrete.Comparison of the measured ETC of specimens at same tempera-tures indicated that ETC of composite concrete decreases with in-crease of paraffin volume fraction and basalt fiber concentration.This relative decrease can be attributed to low conductivity ofparaffin and basalt fiber compared to other materials in the speci-mens. By comparing ETC of same specimen at different tempera-tures, it can be seen that ETC at 75 �C is higher than that at 30 �C. Asshown in Table 1, paraffin melts at about 53e61 �C. The thermalconductivity of paraffin at liquid state is lower than that at solidstate, which implies that the ETC of specimen at 75 �C should belower than at 30 �C. A possible reason for this contradiction ishigher contact thermal resistance at the interface between solidparaffin and the concrete/fiber compared to the correspondingresistance when the paraffin is at liquid state.

3. Theoretical analysis of effective thermal conductivity

3.1. Mathematical model of the composite concrete structure

In order to derive a mathematical model of the compositeconcrete, it is assumed that the composite concrete is composed ofa fiber-paraffin matrix sandwiched between two concrete layers(see Fig. 1). Based on such layered construction of the composite,the total thermal resistance Rt of composite concrete is due to thethermal resistance of individual layers in series (See Fig. 5):

Rt ¼ Rc þ Rfpc þ Rc (4)

The terms Rc and Rfpc are the thermal resistances of concretelayer and the fiber-paraffin-concrete layer, respectively, m2 �C/W. Rcand Rfpc can be expressed as:

Rc ¼ dclc;Rfpc ¼ dfpc

lfpc(5)

Where, dc, dfpc are the thickness of the concrete layer, and fiber-paraffin-concrete layer, respectively, m. lc is the thermal

Fig. 3. EM photo of the paraffin particles in specimen.

conductivity of concrete, W/m �C. lfpc is effective thermal conduc-tivity of fiber-paraffin-concrete, W/m �C.

The ETC of composite concrete lETC can be calculated as:

lETC ¼ d

Rt; d ¼ 2dc þ dfpc (6)

The composition of concrete depends on the local requirements/standards; hence thermal property data are not available in theliterature. In this paper, the experimentally measured thermalconductivity data for concrete were used to predict the ETC ofcomposite concrete. It can be seen from Table 3 that temperaturefluctuation has little influence on the thermal conductivity of pure(no paraffin or basalt fiber added) concrete. Therefore, it is assumedthat lc increases linearly with temperature in the range of 30 �Ce75 �C. Hence, the formula for determining thermal conductivity ofpure concrete can be expressed as:

lc ¼ 0:921þ 0:000089� T � 30ð Þ; 30�C � T � 75

�C (7)

When calculating lfpc, for simplicity, it is assumed that fiber-paraffin-concrete layer is a three-component porous media. InFig. 6, serial and parallel connection models for thermal conduc-tivity of porous media are shown. The expressions for the thermalconductivity based on these models are:

1lfpct

¼ 3f

lfþ 3p

l*pþ 3c

lc(8)

lfpc== ¼ 3f lf þ 3pl*p þ 3clc (9)

3f þ 3p þ 3c ¼ 1 (10)

where, 3f, 3p, and 3c are the volume fraction of fiber, paraffin, andconcrete, respectively. lf is the thermal conductivity of basalt fiber,W/m �C. lp* is the effective thermal conductivity of paraffin, W/m �C. lfpct, lfpck are the effective thermal conductivity of fiber-paraffin-concrete for series and parallel model, respectively, W/m �C.

As the thermal conductivity of paraffin changes during phasechange, lp* is expressed as:

Table 3The thermal conductivities of specimens at different temperatures W/(m �C).

Average temperaturesof specimens

S0 S1 S2 S3 S4 S5 S6

30 �C 0.921 0.8216 0.6334 0.5082 0.7085 0.5519 0.425875 �C 0.925 0.8399 0.6665 0.6135 0.7356 0.6119 0.4762

Fig. 5. Schematic of the thermal resistance net model of the composite concrete.

J. Shi et al. / Applied Thermal Engineering 66 (2014) 156e161 159

l*p ¼

8>>><>>>:

lps; T < ðTm�DTÞlpsþ lpl�lps

2DT ½T�ðTm�DTÞ�; ðTm�DTÞ� T �ðTmþDTÞlpl; T > ðTmþDTÞ

(11)

where, Tm is the phase change temperature, �C, and DT is themushyzone temperature range, �C.

Due to the geometric complexity of paraffin-concrete layer, aweighted geometric mean F is used to determine the oriented di-rection of porous media [22]:

lfpc ¼ F 0$lFfpc==$l1�Ffpct (12)

When paraffin is at liquid state, it is assumed that there is nocontact thermal resistance between paraffin and concrete/fiber.When paraffin freezes at lower temperature, the volume of paraffindecreases, thereby resulting in contact thermal resistance betweenparaffin and concrete/fiber. F’ is a correction term accounting for thevolume change of paraffin that occurs during the phase changeprocess. When paraffin is at liquid state, it is assumed that F’ equalsto 1.0.When solidification happens, F’ is affected by 3air. Therefore, F’

is expressed as

F 0 ¼�

1:0; T > ðTm þ DTÞf ð 3airÞ; T � ðTm þ DTÞ (13)

As shown in Eq. (13), when T � (Tm þ DT), F0 is a function of 3air.3air is difference between 3pl and 3ps, and can be derived as follows,

3air ¼

8>>>><>>>>:

3prplrps�rplrpsrpl

; T < ðTm � DTÞ

3prplrps�rplrpsrpl

½ðTmþDTÞ�T �2DT ; ðTm � DTÞ � T � ðTm þ DTÞ

0; T > ðTm þ DTÞ(14)

where, 3pl and 3ps represent the volume fraction of paraffin at liquidstate and solid state, respectively.

3.2. Calculation and validation

In the experiment, the thickness of form-stable basalt fibercomposite concretewas 20mm. The thickness of the concrete layer,

Fig. 6. Serial and parallel connection models for the thermal conductivity of porousmedia.

fiber-paraffin-concrete layer was 1 mm and, 18 mm, respectively.The thermal conductivity of basalt fiber was 0.04 W/(m K).

When paraffin is at liquid state, F’ equals to 1.0. Hence, Eq. (12) is

lfpc ¼ lFfpc==$l1�Ffpct (15)

Therefore, the geometric correction term F can be expressed as:

F ¼ln�lfpc=lfpct

�

ln�lfpc===lfpct

� ¼ lnðbÞlnðaÞ (16)

For simplicity, parameter a and b is used here

a ¼ lfpc==lfpct

¼ 32f þ 32p þ 32cþ

3f 3pl*p

lfþ lf

l*p

� �þ 3f 3c

lclfþ lf

lc

� �þ 3c 3p

l*p

lcþ lc

l*p

� �

b ¼ lfpclfpct

¼ 3flfpclf

þ 3plfpc

l*p

þ 3clfpclc

(17)

From Eqs. (15)e(17), it can be seen that geometric correctionterm F is related to each material’s porosity and conductivity whenF’ ¼ 1.0. Therefore, F can be expressed in terms of related param-eters as:

F ¼ g

0@ 3f

lclf; 3p

lc

l*p

1A (18)

When T ¼ 75 �C, paraffin is at liquid state and F’ ¼ 1.0. By usingEqs. (16)e(18) and themeasured thermal conductivity data at 75 �Cin Table 3, the plane surface model (Origin software) was applied tofit F with 3flc/lf and 3plc/lp*. The correlation of Eq. (18) is expressedas follows:

F ¼ 0:90065� 1:02026$ 3flclf

þ 0:03221$ 3plc

l*p(19)

Using Eqs. (12)e(14), (19) and the measured thermal conduc-tivity data at 30 �C in Table 3, F’ is given by linear fitting method(Origin software), as follows

F 0 ¼ 0:94189� 10:09486$ð 3airÞ (20)

To validate the established model, comparison between thesimulated results and experimental results is shown in Fig. 7. It isobserved from Fig. 7 that the experimental data comparedreasonably with the existing models (10% deviation). The average

Fig. 7. Experimental results compared to present model.

Fig. 8. The effect of concentration of fiber and paraffin on the ETC of the fiber-paraffin-concrete (lfpc) T ¼ 75 �C.

J. Shi et al. / Applied Thermal Engineering 66 (2014) 156e161160

error between the simulation and experiments is 3.55%. It isbelieved that the existing model is able to account for the effectivethermal conductivity of complex structure.

3.3. The effect of concentration of fiber and paraffin on ETC of fiber-paraffin-concrete (lfpc)

For composite with multiple materials, concentration of eachmaterial is an important factor which greatly influences the ETC ofmaterials. In Fig. 8, the effect of concentration of fiber and paraffinon ETC of the fiber-paraffin-concrete (lfpc) is shown. The temper-ature is 75 �C. Phase change temperature Tm is 57 �C and DT is 4 �C.It can be observed from Fig. 8 that at certain temperature lfpc de-creases with increase of 3f and 3p. The thermal conductivity ofparaffin and basalt fiber is lower than concrete. When the porosityof paraffin or basalt fiber increases, it leads to lower lfpc.

3.4. The effect of temperature on ETC of fiber-paraffin-concrete(lfpc)

Theeffect of temperatureonETCoffiber-paraffin-concrete (lfpc) isshown in Fig. 9. The porosityof basaltfiber andparaffin in liquid stateis 0.01 and 0.3, respectively. Phase change temperature Tm is 57 �Cand DT is 4 �C. The density of the composite is 1500 kg/m3. It can beseen from Fig. 9 that, lfpc increases slightly with the increase oftemperature, irrespective of the paraffin being at either solid or atliquid state. This increase occurs because thermal conductivity ofconcrete increaseswith the increaseof temperature.At temperatures

Fig. 9. The effect of temperature on the ETC of the fiber-paraffin-concrete (lfpc)3f ¼ 0.01, 3p ¼ 0.3.

close to the phase change region of paraffin, lfpc increases sharplywith the increase of temperature.Whenparaffin is at liquid state, theinterface betweenparaffin and the concrete/fiber is completely filledby the liquid paraffin. As a result, the contact thermal resistance atthe interface is very small. When paraffin is at solid state, there is afinite contact thermal resistance betweenparaffin and concrete/fiberwhich results in lower ETC, even though the thermal conductivity ofparaffin at solid state is larger than that at liquid state.

4. Conclusion

In this paper, a novel form-stable basalt fiber composite con-crete with PCMs was prepared with basalt fiber, paraffin and con-crete. The effective thermal conductivity of the composite concretewas experimentally measured by steady-state method. It wasobserved that ETC of the composite concrete decreased with in-crease of porosity of paraffin or basalt fiber. Moreover, the finitecontact thermal resistance at the interface was believed to affectthe ETC significantly. A numerical model was established to eval-uate ETC of composite concrete. The numerical results agreed wellwith the experimental results. The numerical model can assist indesigning form-stable fiber composite concrete with PCMs.

Acknowledgements

This workwas financially supported by program of InternationalS&T Cooperation of China under Grant No. 2011DFA60290,12th FiveYears Key Programs for Science and Technology Development ofChina (2012BBA07B02), Jiangsu Key Laboratory of ProcessEnhancement & New Energy Equipment Technology (NanjingUniversity of Technology).

NomenclatureAe surface area of specimens, m2

F geometric correction termF’ correction term due to volume changeq heat flux, W/m2

Q input heat, WR thermal resistance, (m �C)/WT temperature, �CDT phase change temperature range, �Cd thickness of the specimen, m3 porosityl thermal conductivity, W/(m �C)r density, kg/m3

Subscriptair airc concretef fiberl liquidm phase change temperaturefpc fiber-paraffin-concretep paraffins solidt total

References

[1] D.P. Bentz, R. Turpin, Potential applications of phase change materials inconcrete technology, Cem. Concr. Compos. 29 (2007) 527e532.

[2] M. Hadjieva, R. Stoykov, Tz Filipova, Composite salt-hydrate concrete systemfor building energy storage, Renewable Energy 19 (2000) 111e115.

[3] Z.G. Zhang, G.Q. Shi, S.P. Wang, X.M. Fang, X.H. Liu, Thermal energy storagecement mortar containing n-octadecane/expanded graphite composite phasechange material, Renewable Energy 50 (2013) 670e675.

J. Shi et al. / Applied Thermal Engineering 66 (2014) 156e161 161

[4] A.V. Sa, M. Azenha, H. Sousa, A. Samagaio, Thermal enhancement of plasteringmortars with phase change materials: experimental and numerical approach,Energy Build. 49 (2012) 16e27.

[5] A. Karaipekli, A. Sari, Capric-myristic acid/vermiculite composite as form-stable phase change material for thermal energy storage, Sol. Energy 83(2009) 323e332.

[6] R. Baetens, B.P. Jelle, A. Gustavsen, Phase change materials for building ap-plications: a state-of-the-art review, Energy Build. 42 (2010) 1361e1368.

[7] A. Pasupathy, R. Velraj, R.V. Seeniraj, Phase change material-based buildingarchitecture for thermal management in residential and commercial estab-lishments, Renewable Sustainable Energy Rev. 12 (2008) 39e64.

[8] A.M. Khudhair, M.M. Farid, A review on energy conservation in building ap-plications with thermal storage by latent heat using phase change materials,Energy Convers. Manage. 45 (2004) 263e275.

[9] R.D. Godfrey, S.A. Mumma, Thermal Performance of Paraffin Phase ChangeMaterials Dispersed in a Concrete Mortar Filler Matrix, American Society ofMechanical Engineers, 1976 n 76-WA/HT-33.

[10] M. Hunger, A.G. Entrop, I. Mandilaras, H.J.H. Brouwers, M. Founti, The behaviorof self-compacting concrete containing micro-encapsulated phase changematerials, Cem. Concr. Compos. 31 (2009) 731e743.

[11] C.M. Lai, R.H. Chen, C.Y. Lin, Heat transfer and thermal storage behavior ofgypsum boards incorporating micro-encapsulated PCM, Energy Build. 42(2010) 1259e1266.

[12] C. Hasse, M. Grenet, A. Bontemps, R. Dendievel, H. Sallee, Realization, test andmodeling of honey comb wallboards containing a phase change material,Energy Build. 43 (2011) 232e238.

[13] B. He, V. Martin, F. Setterwall, Phase transition temperature ranges andstorage density of paraffin wax phase change materials, Energy 29 (2004)1785e1804.

[14] Z.Q. Chen, M.W. Gu, D.H. Peng, Heat transfer performance analysis of a solarflat-plate collector with an integrated metal foam porous structure filled withparaffin, Appl. Therm. Eng. 30 (2010) 1967e1973.

[15] A.N. Oumer, O. Mamat, A study of fiber orientation in short fiber-reinforcedcomposites with simultaneous mold filling and phase change effects, Com-posites Part B 43 (2012) 1087e1094.

[16] S. Kurtz, P. Balaguru, Postcrack creep of polymeric fiber-reinforced concrete inflexure, Cem. Concr. Res. 30 (2000) 183e190.

[17] A. Mirmiran, M. Shahawy, et al., Behavior of concrete columns confined byfiber composites, J. Struct. Eng. 5 (1997) 583e590.

[18] W. Zhang, W.Y. Tang, Y.C. Pu, S.K. Zhang, Ultimate strength analysis of shiphulls of continuous basalt fiber composite materials, Adv. Mater. Res. 150e151 (2011) 736e740.

[19] X.H. Cong, J. Sun, F. Zhao, H.B. Liu, Experiment and research on the influence ofbasalt fiber on cement-based material performance, Adv. Mater. Res. 250e253(2011) 485e488.

[20] C. Colombo, L. Vergani, M. Burman, Static and fatigue characterization of newbasalt fibre reinforced composites, Compos. Struct. 94 (2012) 1165e1174.

[21] T.M. Borhan, Properties of glass concrete reinforced with short basalt fibre,Mater. Des. 42 (2012) 265e271.

[22] Ramvir Singh, H.S. Kasana, Computational aspects of effective thermal con-ductivity of highly porous metal foams, Appl. Therm. Eng. 24 (2004) 1841e1849.