ISSN 1392 1320 MATERIALS SCIENCE (MEDŽIAGOTYRA). Vol. 21, No. 2. 2015 Anlysis of Pre-tension Level upon Bixil Behviour of Fused Systems Dont ZUBAUSKIENE, Eugenij STRAZDIENE, Virginijus URBELIS Deprtment of Clothing nd Polymer Products, Kuns University of Technology, Studentu str. 56, Kuns LT-51424, Lithuni http://dx.doi.org/10.5755/j01.mm.21.2.5788 Received 25 Novemer 2013; ccepted 17 April 2014 The effect of unixil pre-tension level upon the regulrities of fused two-lyer systems ixil ehviour is nlysed in this reserch work. Initil pre-tension of 0.0 %, 0.4 %, 0.8 %, 1.2 %, 1.7 % nd 2.1 % ws pplied in longitudinl nd trnsverse directions seprtely. Cotton fric (100 %) of plin weve ws used s se mteril for the investigted systems. Bixil punching ws performed with three types of interlinings: woven, nonwoven nd knitted, which differed not only in surfce density, ut in the density of dhesive lyer, i. e. 52 nd 76 dots/cm 2. The smples of fused systems were punched from the side of the se cotton fric in order to mintin the sme friction force etween the punch nd the specimen. The results of the investigtions hve shown tht not only punching strength Pmx, N, nd punching height Hmx, mm, differ with the increse of pre-tension level in longitudinl nd trnsverse directions, ut lso different numer of punching force peks is chrcteristic for the investigted two-lyer systems, which is relted to the structure of pplied interlining. Keywords: fusing interlining, two-lyer system, ixil deformtion, punching, initil pre-tension. 1. INTRODUCTION In erlier investigtions the method for pull-on ese level mesurement of furniture upholstery nd the definition of its deformtionl ehviour regulrities in respect to three different levels of initil unixil pre-tension were nlysed [1]. The vlues of initil pre-tension of upholsteries pttern in trnsverse direction were: 0.0 %, 1.4 % nd 2.7 %. The prolem lies in the fct tht the vriety of upholstery mterils differ y their strength properties nd deformtionl ehviour in longitudinl nd trnsverse directions. Thus, it is not right to design upholstery ptterns with the sme ese vlues for ll pplied mterils. The result of such prctice is evident furniture coverings of low qulity, which experience significntly high residul deformtions during its exploittion. It mens tht mechnicl chrcteristics of ech pplied mteril must e tken into the ccount individully. Mny reserchers explore such undesirle deformtion s gging which is meningful not only for grment frics ut lso in soft furniture production, s well [2 5]. In this reserch the upgrded method for the nlysis of pre-tension level upon ixil ehviour of fused systems is presented. Significnt numer of reserch is done nlysing the ehviour of textiles in unixil tension nd ixil loding [6 7], e. g. woven frics [8 11] nd knitted mterils [11 14]. Fused textile systems re used not only to perfect the functionlity of clothing [15], ut for technicl purposes, s the reinforcement of uto window glss [16], rchitecturl frics, which consist of woven se cloth with n impermele coting providing wter-proofness nd weve stility [17], cellulr woven frics, which cn e used s technicl textiles sujected to ursting nd impct forces [18], s well. Other reserchers investigted the interctive effects etween wrp nd weft in ixil tension Corresponding uthor. Tel.: +370-605-50801; fx.: +370-37-353989. E-mil ddress: dont.zuuskiene@ktu.edu (D. Zuuskienė) 276 [6, 8, 19]. Severl reserchers hve nlysed the effect of pre-tension (pre-stress) [10, 20 22] upon the ehviour of composite systems with concrete, glss, fiers, etc. [23 25] nd hve found out tht pre-stressing is even more dvntegeous in the cse of high strength frics. The limit of proportionlity, the modulus of rupture nd crcking stresses considerly increse for them with the increse of pre-stressing. Mentime there is no informtion concerning the effect of pre-tension upon ixil ehviour of fused multilyer textile systems, which re often used in interior product nd soft furniture production. Testing method which is presented in this reserch is imed to solve this prolem. The sis of it comes from our previous investigtion of furniture upholsteries ehviour in situ conditions [1], which ws not comfortle from the stndpoint of specimen preprtion nd the reliility of otined testing results. This method ws perfected nd the min im of this reserch is to evlute the effect of two perpendiculr pre-tension directions nd the levels of pre-tension upon fused two-lyer textile systems performnce ehviour under ixil punching. 2. MATERIALS AND METHODS For the investigtions of pre-tension level upon ixil ehviour of fused systems 100 % cotton fric M1 of plin weve ws used s sic lyer. For the second lyer five types of 100 % PES fusing interlinings of woven (W1 nd W2), knitted (K1 nd K2) nd nonwoven (N1) structures were pplied. It cn e seen (Tle 1) tht fusing interlinings differed not only y the density of dhesive dots per cm 2, i. e., 52 nd 76, ut lso y their surfce density, i. e. from 36 g/m 2 up to 53 g/m 2. In this reserch woven interlinings were of cross twill 2/2 weve structure, which is chrcterised s hving equl length of yrn flots long wrp nd weft directions, wht cretes homogeneous structure leding to higher fric elsticity in gging deformtion. The twill 2/2 structure
Fig. 1. The device for specimens initil pre-tension () nd the device for specimens ixil punching (): 1 the pltform; 2 fixed clmp; 3 moving clmp; 4 the specimen; 5 the guides of moving clmp; 6 threded drive for specimens pre-tension; 7 strin guge; 8 circulr shped clmps; 9 the punch; 10 the tensometer; 11 stndrd drive of tensile testing mchine; 12 fixed holder deforms esier nd recovers from gging deformtion fster thn the other weve types [3]. Specific tensile strength of the se fric M1 in wrp direction ws f = 0.065 N/tex, in weft direction ws f = 0.057 N/tex. For the ixil deformtion interlinings were fused with the se mteril M1. Fusing conditions for ll smples were: temperture 140 ºC, durtion 16 s, pressure (1 3) r (5 35 N/cm 2 ). Eighteen smples of ech fused system of (250 320) mm were cut in longitudinl nd trnsverse directions. Tested smples were kept in stndrd tmosphere conditions (20 ºC ±2 ºC nd 65 % ±4 % humidity) for 24 h ccording to the requirements of stndrd ISO 139:2005. Tle 1. Chrcteristic of investigted mterils (components of fused systems) Mteril code M1 W1 W2 N1 K1 K2 Surfce density, g/m 2 136 44 53 50 50 36 Thickness, mm 0.31 0.30 0.31 0.26 0.39 0.16 Adhesive density, dots/cm 2 52 76 52 52 76 Yrn density, cm 1 Mteril structure wrp/ course weft/ wle 25 36 24 7 13 19 15 14 13 20 Woven, plin weve Woven, cross twill 2/2 Nonwoven Knitted, closed pillr stitch The scheme of specimen pre-tension is presented in Fig. 1. First of ll, the specimen 4 is fixed in specil device for unixil pre-tension with the help of clmps 2 nd 3. Certin level of pre-tension is pplied y thred drive 6. The displcement of moving clmp 3 is controlled y digitl guge 7. After tht stretched specimens were clmped into flt circulr shped clmp 8, which is plced into specil holder 12 nd mounted on stndrd tensile testing mchine Tinius Olsen (lod cell 500 N). The drive 11 pulls down the punch 9, which reks the stretched specimen 4 t the velocity of 100 mm/min. Tension meter 10 records reking force P mx, N; while strin guge mximl punching height H mx. Coefficient of vrition did not exceed 19.09 %. The smples of fused systems were punched from the side of the min cotton 277 fric in order to mintin the sme friction force etween the punch nd the specimen. During these investigtions the specimens were pretensioned y 0.0 %, 0.4 %, 0.8 %, 1.2 %, 1.7 % nd y 2.1 %. Such pretention levels were chosen to mke them more close to the testing conditions of erlier performed reserch work [1]. In order to otin more evident dependencies in respect to the erlier otined results, the numer of pre-tension steps ws incresed from three to five. Unixil tension tests were performed with the sme stndrd tensile testing mchine. Tensile velocity ws 100 mm/min. Fifteen specimens of ech tested smple (seprte components nd their fused systems) of (50 200) mm were tensioned in longitudinl nd trnsverse directions. Averge vlues of smples tensile strength Fmx nd elongtion t rek εmx, were defined. Vrition coefficient of ll fusing interlinings nd their systems did not exceed 5.87 %, except for woven W2 nd knitted K1 interlinings, which vried in the limits of 8.06 % 23.97 %. Fig. 2. Complex criterion S for the evlution of tested smples totl deformility During the reserch the evlution of the effect of pretension level upon totl deformility of ll tested smples ws performed on the sis of complex criterion S (Fig. 2). It ws clculted s the rtio etween the re of polr digrm, which ws outlined y punching height H mx vlues of non-tensioned smples nd y the re, which ws outlined y tested smples punching heights H mx t ech pre-tension level.
3. RESULTS AND DISCUSSION At the first stge of investigtion unixil ehviour of M1 fric nd its two-lyer fused systems ws nlysed. Their strength nd extension chrcteristics re presented in Tle 2. Unixil testing results show tht high elongtion nisotropy is chrcteristic for sic cotton mteril M1 nd woven interlinings nd low elongtion nisotropy for nonwoven nd knitted interlinings. Tle 2. Strength nd extension chrcteristics of investigted two-lyered systems nd their seprte components Mteril code Surfce density, g/m 2 Strength nd extension prmeters wrp/course Fmx, εmx, weft/wle Fmx, εmx, % Coefficient of nisotropy N % N M1 136 235.8 4.5 177.6 18.1 0.25 W1 44 46.7 7.9 42.6 24.4 0.32 W2 53 71.0 11.4 95.6 32.0 0.36 N1 50 8.3 22.2 9.2 31.2 0.71 K1 50 82.0 41.1 71.4 26.3 0.64 K2 36 92.3 31.9 75.0 40.1 0.80 W1+M1 181 358.4 5.6 189.2 18.3 0.31 W2+M1 184 403.5 5.5 242.3 19.0 0.29 N1+M1 178 367.6 5.4 190.6 18.4 0.29 K1+M1 184 379.6 5.4 203.2 20.1 0.27 K2+M1 168 317.2 5.2 196.6 22.2 0.24 It must e noted tht tension chrcteristics fter fusing two-lyered systems with ll investigted interlinings (woven, nonwoven nd knitted) ecme highly c nisotropic nd very close. Unixil strength F mx vried from 21.39 % to 21.91 %; reking elongtion ε mx vried from 7.27 % to 17.53 %. It must e noted tht unixil ehviour of seprte mterils differed significntly, ut fter fusing strength prmeters ecme close to the prmeters of the sic mteril M1 (Tle 2). In the cse of two-lyered system with nonwoven interlining reking force nd elongtion is slightly higher thn those of sic mteril M1. The sme cn e oserved with woven interlinings nd their systems, where reking chrcteristics of woven interlining W2 is higher compred to W1. It cn e explined y significnt difference in the density of dhesive dots per cm 2 of those two interlinings, menwhile surfce density g/m 2 nd yrn density cm 1 of them differed negligily (Tle 1). Anlysis of tension process of fused systems up to the first reking point llows to stte tht strength nd extension chrcteristics for ll systems differ insignificntly (Fig. 3, c, d). Mentime, interesting view cn e oserved nlysing further tension process where the systems with woven interlinings show different ehviour. The results of unixil tension in trnsverse direction the sme s in longitudinl direction show tht strength chrcteristics of single nonwoven interlining re very low nd significntly differ from the sic mteril M1 (Fig. 3, c). Nevertheless, strength nd extension chrcteristics of two-lyer system composed of those two mterils ecme the sme s those of the rest investigted systems. Two-lyer systems with woven interlinings show the second reking point which is higher compred to the first one (system W1+M1). c Fig. 3. Typicl force-strin curves of cotton fric M1 nd interlinings in longitudinl direction () nd in trnsverse direction (); typicl force-strin curves of frics M1 fused systems in longitudinl direction (c) nd in trnsverse direction (d) 278 d
The sme phenomenon tkes plce in the cse of knitted interlinings nd their systems. The difference is tht the third reking point ppers (system K1+M1), which is higher compred to the first nd to the second one. Breking chrcter of specimen pre-tensioned in trnsverse direction does not differ significntly from the ones pre-tensioned in longitudinl direction. In this cse the strongest is lso sic mteril M1, which reks t comprtively smll elongtions (Tle 2). The wekest is nonwoven interlining N1. Mentime reking chrcteristics of woven nd knitted interlinings in trnsverse direction is higher y 20 % 75 % compred to longitudinl direction. Anlysing tension curves up to 20 % of elongtion we cn see tht reking chrcter of the systems is very similr. The second nd the third reking points pper fter the first nd they re higher. The first pek point is relted with the reking of sic mteril M1, the second with the reking of interlining mteril nd the third with the reking of the lst threds. Fig. 3 shows tht woven interlining W2 strengthens sic mteril M1 in longitudinl nd trnsverse directions most of ll. Mentime knitted interlining K2 mkes M1 fric the most deformle in the min directions. It must e noted tht tensile ehviour of ll tested interlinings differs essentilly, ut this difference disppers for their fused systems. In generl fter fusing the strength of M1 fric in longitudinl direction incresed y 25.7 % 41.6 %, deformility incresed y 13.5 % 19.6 %. Less significnt effect ws oserved in trnsverse direction: the increse of strength ws 6.1 % 26.7 %, the increse of elongtion ws 1.1 % 18.5 %. At the second stge of investigtion punching ehviour of non-tensioned two-lyer systems ws nlysed. Fig. 4 shows tht there is no significnt difference in the ehviour of ll investigted systems up to the first reking point. Punching height H mx vried from 0.99 % to 4.55 %, while punching force P mx, N, incresed from 3.28 % to17.15 % in respect to punching strength nd height of se fric M1. These results confirm the remrks mde y Kovcevic, S. et l tht the fric which hs the highest ursting strength, hs the lowest nisotropy [8]. In our cse nisotropy coefficients of ll fused systems re very close, thus their ursting strengths re very close, s well. Fig. 4. Punching curves of non-tensioned se fric M1 nd its fused two-lyer systems The ttention cn e pointed to the system K1+M1 with knitted interlining nd the system W1+M1 with woven interlining punching heights H mx, mm, of which re lower compred to the other fused systems. The sme phenomenon ws oserved for unixil reking in oth directions (Fig. 3, c, d). The results of unixil nd ixil tension of se fric M1 nd its systems formed with woven, knitted nd nonwoven interlinings llow to summrize tht ehviour of two-lyer fused systems in oth types of tension up to first reking point ecomes very close even though interlinings of different structure were used. Significnt differences pper in further process, ecuse the second reking point revels nd the vrition of second reking results ecomes very wide. c d e f Fig. 5. Punching curves of 0.0 %, 1.2 % nd 2.1 % pre-tensioned smples in longitudinl direction for se fric M1 () nd its systems: N1+M1 (), K1+M1 (c), K2+M1 (d), W1+M1 (e), W2+M1 (f), where H descries the chnge of punching height Hmx of the first rek etween non-tensioned nd pre-tensioned smples 279
Fig. 6. The effect of initil pre-tension upon the chnges of punching height Hmx (mm) in longitudinl () nd trnsverse () directions At the third stge of investigtion the effect of pretension direction nd its level upon punching strength P mx nd punching height H mx of tested two-lyer smples ws nlysed. In the cse of longitudinl pre-tension punching height H mx of the first reking point decresed from 10.29 % to 21.50 % when pre-tension ws incresed from 0.0 % up to 2.1 % (Fig. 5). Different results were otined for pre-tension in trnsverse direction. The min difference is tht the decrese of punching height during reking is not s high s in the cse of longitudinl pre-tension nd chnged from 3.75 % to 13.17 %. The effect of initil pre-tension ecomes evident when the difference etween tested systems deformility in longitudinl nd trnsverse directions is compred (Fig. 6). Punching height H mx of the first rek of se mteril M1 nd of ll its fused systems decreses when initil pretension is incresed from 0.0 % to 2.1 % in longitudinl direction (Fig. 6, ). It cn e seen tht deformility of W2+M1 system fused with woven interlining W2 is the lowest ecuse, its punching height H mx t ll levels of pre-tension strting with 0.0 % nd ending y 2.1 % hve chnged only y 10.29 %. It cn e explined y the fct tht strength properties of this system in unixil tension re lso the highest etween tested ones (Tle 2). Wheres in trnsverse pre-tension only the ehviour of se mteril M1 cn e distinguished. For fused two-lyer systems the effect of pre-tension is insignificnt nd is smller compred to ll longitudinl pre-tension levels y 39 % (Fig. 6, ). Fig. 6 illustrtes the effect of initil pre-tensions level upon deformility of ech tested fused system nd se mteril M1. The lst step of nlysis ws to define the dependency etween the level of initil pre-tension nd totl deformility of ll investigted fused systems. For this purpose complex criterion S of totl deformility ws used, which ws clculted on the sis of polr digrm res: S = /, where is the re of ny pre-tension level except 0.0 %; is re determined y tested systems deformility without pre-tension. Fig. 7,, shows the dependencies etween the criterion of totl deformility S 1, which ws defined on the sis of the chnges of punching height H mx nd the levels of initil pre-tension in longitudinl nd trnsverse directions. Fig. 7,, illustrtes the sme dependencies of totl strength criterion S 2, which ws defined on the sis of the chnges of punching force P mx. It is evident tht the most 280 significnt effect of pre-tension is experienced in longitudinl directions. The decrese of tested systems deformility cn e descried y liner dependency (R 2 = 0.834 0.916). Different results re otined for trnsverse pre-tension. It does not hve ny effect for totl deformility criterion S 1 (R 2 = 0.084). Mentime totl strength criterion S 2 slightly increses (R 2 = 0.649) with the increse of pre-tension from 0.0 % up to 2.1 %. Fig. 7. The chnges of totl deformility criterion S1 () nd totl strength criterion S2 () in respect to the levels of initil pre-tensions in longitudinl nd trnsverse directions The investigtions, performed y the other reserchers hve shown tht there is no significnt difference etween unixil nd ixil deformtions of woven, nonwoven nd knitted systems [8]. Mentime the novelty of this work is the investigtion of pre-tension effect of differently composed systems, which reveled the difference etween pre-tension direction, e. g. reking height H mx when initil pre-tension ws incresed from 0.0 % to 2.1 % decresed y 47.88 % in longitudinl direction nd y 28.51 % in trnsverse direction. 4. CONCLUSIONS The method to evlute the effect of pre-tension direction nd level upon ixil ehviour of two-lyer mterils ws developed. After fusing unixil ehviour of two-lyer systems up till the first rek ecme very close for the investigted mterils (F mx vried etween 21.39 % nd 21.91 %, ε mx vried etween 7.27 % nd 17.53 %), even though fusing interlinings of different structure (woven, nonwoven nd knitted) nd chrcteristics were used. The sme cn e sid out ixil punching of the sme two-lyer systems the
ehviour of which ecme even more close (P mx vried etween 3.28 % nd 17.15 %, H mx vried etween 0.99 % nd 4.55 %). Breking height H mx of two-lyer textile system decresed y 47.88 % when initil pre-tension ws incresed from 0.0 % to 2.1 % in longitudinl direction. Mentime this decrese ecme less y 28.51 % when the sme initil pre-tension ws pplied in trnsverse direction. Concerning reking chrcter of two-lyer systems it ws oserved tht for fusing interlinings tht hd severl reking mximums in unixil tension, the sme tendency remins in their fused systems unixil tension even though se mteril of fused system hd only one very cler reking point. Moreover the sme tendency ecomes chrcteristic for the process of ixil loding, e. g. punching. REFERENCES 1. Zuuskiene, D., Strzdiene, E., Urelis, V., Sceviciene, V. The Investigtion of Soft Furniture Upholstery Deformtionl Behviour Mterils Science (Medžigotyr) 18 (4) 2012: pp. 367 372. 2. Jouchi, B. Study of Knitting Fctors Contriution on Residul Bgged Fric Behviour Journl of the Textile Institute 104 (10) 2013: pp. 1132 1140. 3. Doustr, K., Shikhzdeh, N. S., Mroufi, M. The Effect of Fric Design And Weft Density on Bgging Behvior of Cotton Woven Frics The Journl of the Textile Institute 101 (2) 2010: pp. 135 142. 4. Hsni, H., Zdeh, S. H., Behtj, S. Bgging Behvior of Different Fric Structures Knitted From Blended Yrns Using Imge Processing Journl of Engineering Fiers nd Frics 7 (3) 2012: pp. 8 15. 5. Bghei, B., Shneh, M., Ghreghji, A. A. Effect of Tensile Ftigue Cyclic Lods on Bgging Deformtion of Elstic Woven Frics Indin Journl of Fire & Textile Reserch 35 2010: pp. 298 302. 6. Chen, J., Chen, W., Zhng, D. Experimentl Study on Unixil nd Bixil Tensile Properties of Coted Fric for Airship Envelopes Journl of Reinforced Plstics nd Composites 2013: pp. 1 19. 7. Escrpit, D. A. A., Crdens, D., Elizlde, H., Rmirez, R., Prost, O. Bixil Tensile Strength Chrcteriztion of Textile Composite Mterils Composites nd Their Properties, InTech 2012: pp. 83 106. 8. Kovcevic, S., Ujevic, D., Brnd, S. Coted Textile Mterils. Woven Fric Engineering. Polon Donik Durovski (Ed.). ISBN: 978-953-307-194-7, 2010: pp. 241 255. 9. Potluri, P., Thmmndr, V. S. Influence of Unixil nd Bixil Tension on Meso-Scle Geometry nd Strin Fields in Woven Composite Composite Structures 77 2007: pp. 405 418. 10. Vnclooster, K., Eshghyr, A., Lomov, S. V. Bixil Extension of Knitted Steel Fire Frics The 14th Interntionl ESAFORM Conference on Mteril Forming 2011: pp. 907 912. 11. Sceviciene, V., Strzdiene, E., Vilumsone, A., Bltin, I. Anlysis of Multilyer Mterils Behviour under Bixil Deformtion Proceedings of 17 th Interntionl Conference Mechnik 2012: pp. 260 266. 12. Leong, K. H., Khondker, O. A., Herszerg, I. Vrition in Composite Tensile Properties Due to Bixil Deformtion of Knitted Glss Frics Conference ICCM-12 1999: pp. 1 10. 13. Drpier, S., Gied, I. Identifiction Strtegy for Orthotropic Knitted Elstomeric Frics under Lrge Bixil Deformtions Inverse Prolems in Science nd Engineering 15 (8) 2007: pp. 871 894. http://dx.doi.org/10.1080/17415970601162263 14. Dorich, O., Gereke, T., Cherif, C., Krzywinski, S. Anlysis nd Finite Element Simultion of the Drping Process of Multilyer Knit Structures nd the Effect of Loclized Fixtion Advnced Composite Mterils 22 (3) 2013: pp. 175 189. 15. Tijuneliene, L., Strzdiene, E., Gutusks, M. The Behviour of Polyethylene Memrne Due to Punch Deformtion Process Polymer Testing / Mteril Behviour 18 (8) 1999: pp. 635 640. 16. Ancutiene, K., Strzdiene, E. Investigtion of Fused Textile Systems Resilience Properties Scientific Journl of Rig Technicl University/ Mteril Science nd Applied Chemistry 21 2010, pp. 45 50. 17. Bridgens, B., Gosling, P., Jou, G.-T., Hsu, X.-Y. Interlortory Comprison of Bixil Tests for Architecturl Textiles The Journl of the Textile Institute 103 (7) 2012: pp. 706 718. 18. Ozdemir, H., Mert, E. The Effect of Fric Structurl Prmeters on the Tensile, Bursting, nd Impct Strengths of Cellulr Woven Frics The Journl of the Textile Institute 104 (3) 2013: pp. 330 338. 19. Wng, G., Chen, F., Cheng, H., Li, X. Interctive Effect Between Wrp nd Weft of Woven Rmie Fric under Bixil Lodings The Journl of the Textile Institute 103 (3) 2012: pp. 283 291. 20. Yng, R. H., Wu, W. M., Wn, Y. Q., Wng, H. B., Go, W. D., Xie, C. P., Wng, S. Y. Effect of Filment Pre- Tension on the Performnce of Solo-Sirofil Composite Yrn Indin Journl of Fire & Textile Reserch 37 2012: pp. 378 380. 21. Willems, A., Lomov, S. V., Verpoest, I., Vndepitte, D. Picture Frme Sher Tests on Woven Textile Composite Reinforcements with Controlled Pretension 10 th ESAFORM Conference on Mteril Forming 2007: pp. 999 1004. 22. Bekmpiene, P., Domskiene, J., Sirvitiene, A. The Effect of Pre-tension on Deformtion Behviour of Nturl Fric Reinforced Composite Mterils Science (Medžigotyr) 17 (1) 2011: pp. 56 61. 23. Reinhrdt, H. W., Krüger, M., Große, Ch. U. Concrete Prestressed with Textile Fric Journl of Advnced Concrete Technology 1 (3) 2003: pp. 231 239. http://dx.doi.org/10.3151/jct.1.231 24. Peled, A., Cohen, Z., Psder, Y., Roye, A., Gries, Th. Influences of Textile Chrcteristics on the Tensile Properties of Wrp Knitted Cement Bsed Composites Cement & Concrete Composites 30 2008: pp. 174 183. 25. Krüger, M., Reinhrdt, H. W., Fichtlscherer, M. Bond Behviour of Textile Reinforcement in Reinforced nd Prestressed Concrete Otto-Grf-Journl 12 2001: pp. 33 50. 281