Characteristics of the mechanically fastened joints of one-layer bitumen sheets

Cha ac e is ics o he mechanically as ened join s o one-laye bi umen shee s Tomáš Pe říček1,*, Pe Kacálek1, and Tomáš Hla ačka1 1B no Uni e si y o Technology, Facul y o Ci il Enginee ing, Ins i u e o Building S uc u es, Ve eří 95, 602 00 B no, Czech Republic Abs ac . The sys em o mechanic as ening is one o he mos equen ly used a ian s o oo memb ane s abiliza ion agains he impac s o wind sucking. Wi h he g owing numbe o applica ions o mechanically as ened oo s he numbe o de ec s is also g owing. We pa icula ly see hem in he join s o wa e p oo ing memb anes. The con ibu ion is hus dedica ed o examina ion o mu ual dependence be ween he ype o he ca ie and he s eng h cha ac e is ics o mechanically as ened join s o hese shee s. Bi umen shee s wi h di e en ypes o ca ie used o one- laye mechanically as ened wa e p oo ing memb anes o la oo s we e chosen as samples. The abo e men ioned dependence is equen ly s a ed in he p ac ice, bu is no explici ly documen ed. The aim o he con ibu ion is o con i m o e u e a hypo hesis ha a ela ion be ween he bi umen shee ca ie ype and he s eng h o hei join s exis s. The esul s we e a anged on he base o s a is ic e alua ion o da a ob ained by labo a o y measu emen . 1 In oduc ion The applica ion o he single-laye mechanically as ened bi umen shee sys em is a quick and p og essi e one, which equi es high echnological discipline. High quali y bi umen shee s o a leas 0.5 mm hickness a e equi ed as s anda d o he applica ion o single- laye sys ems. The bi umen shee s also need o be o a su icien quali y ha hey a e weldable and lexible o e he long e m. The shee s a e mos ly ein o ced wi h a combina ion o PES leece s eng hened wi h glass ib es laid in one o bo h di ec ions. O e laps o a leas 120 mm wide a e ecommended o he shee s. Whole su ace mel ing o he join is essen ial o he wa e p oo ing capabili ies o he sys em as well as o he ans e o wind load o ces. A c i ical poin wi h ega ds o he wind load esis ance o a join is he p esence o a as ening elemen . 2 Fas ening o bi umen shee join s To ensu e he join is sealed co ec ly he su ace a ea along he en i e join leng h o bo h shee s need o be hea ed o mel ing poin . The as ening elemen is no placed in he cen e * Co esponding au ho : [email p o ec ed] DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 © The Au ho s, published by EDP Sciences. This is an open access a icle dis ibu ed unde he e ms o he C ea i e Commons A ibu ion License 4.0 (h p://c ea i ecommons.o g/licenses/by/4.0/). o he join bu is loca ed 10 mm (o 20 mm) om he edge o he lowe shee , whe eby he en i e su ace a ea o he join is able o ake he s ain o he as ening elemen . The e ec s o linea shea ing ( ea ) o ce and he angen ial o ces (peel esis ance) a e he e o e applied in a ying deg ees o he o e lap o e he en i e su ace a ea o he join . Acco ding o ČSN EN 13707 [1] manu ac u e s o bi umen shee s a e obliged o p oduce hem wi h su icien esis ance agains angen ial o ces (De e mina ion o peel esis ance in join s acco ding o ČSN EN 12316-1 [2]) and linea shea esis ance when joined oge he (De e mina ion o shea esis ance acco ding o ČSN EN 12317-1 [3], [4]). A mechanically as ened bi umen shee join aces a combina ion o bo h he abo e s esses. As angle β g ows (see Fig. 1), he le el o peel s ess g ows, whe eas whe e angle β (Fig. 2) is minimized, he linea shea o ce ( ea ) g ows. Wi hin his con ex , he peel esis ance es o a join is o pa icula impo ance when e alua ing he quali y o he bi umen subs ance used [5]. Fig. 1. P e ailing angen ial (peel) o ce. Sou ce: [6]. Fig. 2. P e ailing linea shea ( ea ) o ce. Sou ce: [6]. The ca ie in he bi umen shee gua an ees he s eng h p ope ies, olume s abili y, i o ms he base o he bi umen shee du ing p oduc ion and also aps and ans e s ensile s esses and edis ibu es he s ess caused by in e nal and ex e nal o ces. The esul an mechanical and s eng h cha ac e is ics o he ca ie depend on he ma e ial base o he ib es, hei mu ual di ec ion and on he p opo ion o he applied ille o hei connec ion. App oxima e compa ison o he p ope ies o ca ie s a e shown in Table 1. DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 2 Table 1. App oxima e compa ison o s eng h and duc ili y o he mos o en used ca ie s Sou ce: [6]. Ca ie ype Squa e weigh S eng h Duc ili y g/m2 longi udinal di ec ion [kN.m/-1] ans e sal di ec ion [kN.m/-1] longi udinal di ec ion [%] ans e sal di ec ion [%] Glass leece (Vlis)* 60-110 min. 3.6-8.6 min. 2.6-4.8 1.2-1.4 1.2-1.4 Glass wo en ab ic ( ug)** 152-200 min. 18-21 min. 20-24 2-3 2-3 PES leece*** 120-250 8.6-19 4.6-14 20-35 23-37 Combined**** 160-180 min. 9.6-13.3 min. 6.8-8.1 min. 23 min. 25 * Johns Man ille, DH se ies ** Sain Globain Ve o ex *** Johns Man ille, 032 se ies **** Johns Man ille, 054 se ies Tes s desc ibing ensile p ope ies p o ide compa ison o he in luence o he ca ie on he o e all s eng h pa ame e s o a bi umen shee : he highes ensile s eng h and duc ili y speci ied in he longi udinal and ans e sal di ec ion. The g aph in Fig. 3 shows compa ison o mechanical p ope ies o ca ie s and bi umen shee s wi h he espec i e ca ie s. Fig. 3. Compa ison o mechanical p ope ies o ca ie s and bi umen shee s wi h espec i e ca ie s a he empe a u e o +20 °C Sou ce: [6]. DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 3 3 Expe imen al measu emen A p essu e chambe was used in which he composi ion o a oo memb ane om a eal join segmen o mechanically as ened wa e p oo ing could be subjec ed o de ined s esses. This wind load es is de ined in he App o al Guideline o sys ems o mechanically as ened wa e p oo ing memb anes ETAG 006 [7]. Fo he expe imen al measu emen s es s we e ca ied ou on a s anda d ensile es ing machine. The specimens we e oo memb ane segmen s, no jus he wa e p oo ing memb ane. Two me al as ening s ips in he a ms o he uppe g ip o he machine held he wa e p oo ing memb ane in place. These a ms ans e ed he o ce o he applied s ess o es ma e ial. A pad, o which he wa e p oo ing memb ane was as ened by he mal insula ion, was clamped in o he lowe g ip. As he lowe g ip o he ensile es ing machine eceded i caused s ess on he join and subsequen ly i s up u e. The es specimens we e p epa ed acco ding o composi ion a ian S1 i.e. analogically o a oo wi hou he mal insula ion wi h he wa e p oo ing memb ane mechanically as ened o OSB boa d o 22 mm hickness. The as ening elemen o he ha d base was a sc ew wi h a me al o al washe . The edge o he p essu e washe o he as ening elemen was loca ed 10 mm om he edge o he lowe bi umen shee . The use o he o al p essu e washe was in en ional because i p o ides be e p essu e on he lowe shee due o i s la ge su ace a ea. As a esul , he up u e o he es specimens was dependen on he pa ame e s o he bi umen shee a he han on he ailu e o he as ening elemen . Th ee bi umen shee a ian s we e chosen as he wa e p oo ing memb anes: 1. Tes specimen B - SBS modi ied bi umen shee 5.2 mm hick, ca ie : PES 180 g/m2 ein o ced longi udinally wi h glass ib es, lexibili y a low empe a u es: -25 °C, join leng h 100 mm 2. Tes specimen E - SBS modi ied bi umen shee 5.2 mm hick, ca ie : PES 230 g/m2, un ein o ced, lexibili y a low empe a u es: -25 °C, join leng h 100 mm 3. Tes specimen F - SBS modi ied bi umen shee 5.2 mm hick, ca ie : PES 180 g/m2, ein o ced on bo h sides wi h glass ib es, lexibili y a low empe a u es: -25 °C, join leng h 100 mm Fig. 4. Tes specimen - composi ion a ian S1. Sou ce: [8]. DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 4 Fig. 5. Tes specimen in he ensile es ing machine du ing es ing. Sou ce: [8]. 4 E alua ion App oxima ely 10 specimens we e used o each es sample. The inal o ce is in he o m  xx  , whe e x is he a i hme ic a e age and  x  is he p obable measu emen e o . The la e was de e mined on he basis o he e o heo y o he de ia ions o he a i hme ic a e age using he o mula:    . 1 1 3 2 1 2      n i ixx nn x  (1) 5 Resul s o he expe imen al measu emen and discussion In he specimens wi h lowe squa e weigh (B and F) unsealing o he join occu ed and he es ended in ea ing o he ca ie on he base o he as ening elemen and in sepa a ion o he wa e p oo ing laye om he base (Fig. 6). The s eng h o specimen E exceeded he ange o he es ing machine (max. ensile 2,000 N), he cohe ence o he specimen E was so high ha no unsealing o he join occu ed in some o he samples (Fig. 7). We can assume on he base o he esul s o he expe imen al measu emen ha he s eng h o a mechanically as ened join g ows wi h he squa e weigh o he PES ug used in he bi umen shee ca ie . Specimen E (un ein o ced PES ug, 230 g/m2) achie ed he highes s eng h alues, he esul s o specimen B (PES ug longi udinally ein o ced wi h glass ib e, 180 g/m2) we e by app oxima ely 13 % lowe . Specimen F (PES ugs ein o ced wi h glass ib e on bo h sides 180 g/m2) showed he lowes s eng h, he alues we e by app oxima ely 20 % lowe compa ed o specimen E. DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 5 De ailed esul s and compa ison o he esul s o all he specimens a e shown in Table 2. Fig. 6. Typical damage o he join on specimen B. Sou ce: [8]. Fig. 7. No damage o he join on specimen E is isible a he maximum ensile. Sou ce: [8]. DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 6 Table 2. Compa ison o he es specimens Tes specimen: B E F Bi umen subs ance: SBS modi ied Flexibili y a low empe a u es: -25 °C Shee hickness: 5.2 mm Ca ie : PES longi udinally ein o ced, 180 g/m2 PES 230 g/m2, no ein o ced PES ein o ced on bo h sides, 180 g/m2 O e lap wid h: 100 mm The highes ensile s eng h: longi udinally: 900 (± 200) N/50mm, ans e sally: 700 (± 150) N/50mm longi udinally: 950 (± 200) N/50mm, ans e sally: 850 (± 150) N/50mm longi udinally: 900 (± 200) N/50mm, ans e sally: 650 (± 150) N/50mm Duc ili y: longi udinally and ans e sally: 50 (± 10) % longi udinally and ans e sally: 50 (± 10) % longi udinally and ans e sally: 45 (± 10) % Mean alue: 1,624.5 N 1,856.8 N 1,488.3 N S anda d de ia ion: 127.6 N 97.4 N 131.6 N Va ia ion coe icien : 7.9% 5.2% 8.8% Highe squa e weigh o he PES ug inc eases esis ance o a bi umen shee agains mechanical damage ( ea ing agains he shank o he p essu e washe o he as ening elemen ) when exposed o s ess. Fo combined ca ie s manu ac u e s p esen hei o al squa e weigh s, i.e. he PES ug including he ein o cemen glass ib es. In he ins ance o he PES ug ein o ced on bo h sides he p opo ion o he glass ib es in he o al weigh o he ca ie is highe , so he weigh o he PES ug i sel is lowe . This migh explain why he bi umen shee wi h longi udinally ein o ced PES ug (specimen B) achie ed highe s eng hs han he shee wi h a PES ug ein o ced in bo h di ec ions (specimen F). In he bi umen shee s ein o ced wi h combined ca ie no g adual c acking o he indi idual glass ib es ha ein o ce he ca ie was isible du ing ensioning and be o e he up u e. In he case o he combined ca ie s he pa ame e s depend on he pa icula ype – squa e weigh , loca ion and connec ion o he ein o cemen ib es o he PES ug a ec he esul ing s eng hs and duc ili y o he ca ie . The esul s o his compa ison should howe e be unde s ood in wide con ex – on he base o he abo e desc ibed esul s applica ion o bi umen shee s wi h ca ie s o non ein o ced PES ugs canno be p e e ed. Applica ion o combined ca ie s in single-laye mechanically as ened sys ems p o ides i eplaceable ad an ages. 6 Conclusion The pe o med measu emen s showed ha he s eng h o a join o mechanically as ened bi umen shee g ows wi h he squa e weigh o he PES ug used in he ca ie o he bi umen shee . In combined ca ie s he o al weigh is lowe ed by he weigh o he glass ein o cemen ib es, which migh lead o educ ion o he inal s eng h compa ed o an un ein o ced ca ie . Applica ion o combined ca ie s in single-laye mechanically as ened sys ems howe e p o ides i eplaceable ad an ages. DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 7 This pape has been wo ked ou unde he p ojec No. LO1408 "AdMaS UP - Ad anced Ma e ials, S uc u es and Technologies", suppo ed by Minis y o Educa ion, You h and Spo s unde he „Na ional Sus ainabili y P og amme I”. Re e ences 1. ČSN EN 13707+A2, Wa e p oo ing shee s and oils – Rein o ced oo wa e p oo ing bi umen shee s – De ini ions and cha ac e is ics (The Ins i u e o Technical S anda diza ion, Me ology and S a e Tes ing, P ague, 2009) 2. ČSN EN 12316-1, Wa e p oo ing shee s and oils – Pa 1: Roo wa e p oo ing bi umen shee s – De e mina ion o peel esis ance o join s (Czech S anda ds Ins i u ion, P ague, 2000) 3. ČSN EN 12317-1, Wa e p oo ing shee s and oils – Pa 1: Roo wa e p oo ing bi umen shee s – De e mina ion o shea esis ance in join s (Czech S anda ds Ins i u ion, P ague, 2000) 4. R. Smolka, T. Pe říček, P. Kacálek, en iBUILD 2014 - Buildings and En i onmen (B no, 2014) 5. T. Pe říček, P. Kacálek, R. Smolka, AMS 1041, 71-74 (2014) 6. J. Plachý, Bi umen shee join s unde he in luence o empe a u e and ime in he composi ion o single-memb ane oo s (Doc o al hesis, B no Uni e si y o Technology, Facul y o Ci il Enginee ing, B no, 2005) 7. ETAG 006. Eu opean Technical App o al Guideline – Sys ems o Mechanically Fas ened Flexible Roo Wa e p oo ing Memb anes (Eu opean O ganisa ion o Technical Assessmen - EOTA, B ussels, 2000) 8. T. Pe říček, Adhesion o join s o mechanically as ened bi umen shee s (Doc o al hesis, B no Uni e si y o Technology, Facul y o Ci il Enginee ing, B no, 2013) DOI: 10.1051/ 477 ,0 (2017) 79303007 93 ma eccon /201 MATEC Web o Con e ences Building De ec s 2016 3007 8