MATERIALS TECHNOLOGY  ANYAGTECHNOLÓGIA
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S udy o edge s eng h o
load bea ing glasses
KINGA PANKHARDT  Depa men o Ci il Enginee ing, Uni e si y o Deb ecen 
[email p o ec ed]
GYÖRGY L. BALÁZS  Depa men o Cons uc ion Ma e ials and Enginee ing Geology, BME 
[email p o ec ed]
Recei ed: 21.10.2009.  É keze : 2009.10.21.
A single glass laye can be conside ed as sa e y glass i empe ed o ein o ced wi h wi e mesh.
When empe ed glass ac u es i sha e s in o iny pieces wi h blun edges. Hea - o chemically
s eng hened glasses can no be conside ed as sa e y glass owing o he ac u e pa e n ( ac u es
in sha ds), unless hey a e lamina ed. Bending es s we e ca ied ou ( es a angemen acco ding
o s anda d EN 1288-3:2000) and he bending s eng h o single laye empe ed and loa glasses
we e de e mined wi h use o he well-known o mulas. The calcula ed alues o su ace s eng h
wi h use o ul ima e s ain we e compa ed o he bending s eng h esul s in he case o loa
and empe ed glasses. The ques ion a ise: he s ains measu ed in he cen e o he pane and
nea he edge a e equally? S ain measu emen s o he su ace o loaded specimens – a he
middle o he pane and nea he edge – we e also in es iga ed. The ailu e o glass o igina es
om c acks wi h mic oscopic sha p ips. In spi e o he ca e ul manu ac u e and handling o glass
panes, impac s by sha p pa icles o en i onmen al impac s can cause de ec s on he su ace.
The glass manu ac u e e.g. edge inishing echniques in luence he glass s eng h and can cause
laws which can p opaga e du ing he li e ime o he glass. De ec s o edge su aces caused by
di e en edge wo k echniques we e shown wi h scanning elec on mic oscopy. Mos o he glass
s eng hening me hods a e used o in oduce esidual comp essi e s esses in o he ou e laye s
by physical o chemical empe ing. The comp essed esul ing laye helps o close c acks ini ia ed
on he su ace, can s op c ack p opaga ion and can also inc ease he bending s eng h. Recen
s udies [6, 14] ha e shown ha su ace s eng hening can lead o subs an ial imp o emen s in
deg ada ion esis ance. The e o e, in ou doo condi ions, when he glass su ace is exposed o
humidi y e c., empe ed o hea s eng hened glass should be used.
Keywo ds: load bea ing glass, edgewo k, s eng h, glass, empe ed glass
Kinga PANKHARDT
MSc Ci il Eng. a BME (schola ships Uni .
Ka ls uhe, Ge many) in 1998. F om 1998 o
2001 PhD s uden a Dep . o Building Ma e ials,
BME. In yea 2000 a GKSS Resea ch Cen e,
Gees hach , Ge many, a Dep . o Ma e ial
Modelling (WMS), esea ch ellow. F om 2001
o 2003 Glasme al L d., ci il enginee , special
glass cons uc ions. F om 2003 o 2006 SK
Enginee ing o ice, ci il enginee and lec u e
a Uni e si y o Deb ecen. F om 2007 associa e
p o esso a Depa men o Ci il Enginee ing,
Uni e si y o Deb ecen. Membe o he Technical
commi ee o Glass Wo king G oup (MSZT/MB
112) o Hunga ian S anda diza ion Ins i u e;
Hunga ian G oup o ib; IABSE; IASS Wo king
G oup. Field o in e es s: load bea ing glass
cons uc ions, ecycling o building ma e ials.
P o . Gyö gy L. BALÁZS
(1958), PhD, D .-habil, p o esso in s uc u al
enginee ing, head o Depa men o Cons uc ion
Ma e ials and Enginee ing Geology a he
Budapes Uni e si y o Technology and
Economics. His main ields o ac i i ies a e
expe imen al and analy ical in es iga ions as
well as modelling ein o ced and p es essed
conc e e, ib e ein o ced conc e e (FRC),
c acking in conc e e, du abili y and esis ance.
He is con eno o ib Task G oups on
“Se iceabili y Models” and “ ib Semina ”.
In addi ion he is membe o se e al ib Task
G oups o Commissions. He is P esiden o he
Hunga ian G oup o ib. Membe o ib P esidium,
depu y p esiden o ib.
1. In oduc ion
Floa glass is widely used in he a chi ec u e because o he
good op ical quali y o he su ace. Th e l oa p ocess p oduces
glass shee s wi h a uni o m hickness and pe ec ly smoo h
su aces ha need no u he polishing. Th e esul ing glass
will hen be u he ea ed in a ious ways. Soda lime silica e
glass is mainly used o a chi ec u al pu poses. Th e ad anced
ea men echnologies a e applied o l oa glass p oduc s
depending on he end-p oduc s and on he applica ion. When
l oa glass is used as load bea ing elemen [1, 2] sa e y glass is
needed. Single glass laye can be conside ed as sa e y glass i
empe ed o ein o ced wi h wi e mesh. When empe ed glass
ac u es i sha e s in o iny pieces wi h blun edges. Hea -
o chemically s eng hened glasses can no be conside ed
as sa e y glasses owing o he ac u e pa e ns ( ac u es in
sha ds) unless hey a e lamina ed. Bending s eng h wi h he
well known o mulas was e alua ed in case o non hea - ea ed
l oa and empe ed glasses and was compa ed o he measu ed
su ace s esses. Th e ques ion a ise: i s ains measu ed in
he cen e o he pane and nea o he edges a e equal. S ain
measu emen s o glass su ace o loaded specimens – a he
mid o pane (Region 1) and nea o he edge (Region 2) – we e
in es iga ed (Fig. 1.).
Th e bending s eng h o a single glass pane is in l uenced by
he ollowing ac o s [3, 5]:
Fig. 1. Region 1 and Region 2 o glass su ace s ain measu emen s [3, 4]
1. áb a Ü eg elüle alak ál ozásainak mé ése R1 és R2 jelű a ományokon [3, 4]
a) hea ea men , b) su ace condi ion (e.g. non-slip
cha ac e is ics), c) a e and du a ion o loading, d) a ea o
su ace s essed in ension, e) elaxa ion, ) ambien medium,
g) age, i.e. ime elapsed om he las mechanical su ace
ea men , h) ambien empe a u e, i) edgewo k.
Mos o glass s eng hening me hods a e used o in oduce
esidual comp essi e s esses in o he ou e laye s by physical
o chemical empe ing (Fig. 2).
Su ace s esses a e ela ed o he empe a u e g adien ha
esul s om cooling. Th e p oduced comp essed laye helps o
close c acks ini ia ed on he su ace (Fig. 3) and can s op c ack
p opaga ion and can inc ease also he bending s eng h.
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Fig. 2. S ess dis ibu ions o e he hickness o empe ed glass pane. Residual
comp essi e s esses a e empe ing nea he su ace a e: 120 o 150 MPa,
ensile s ess in he middle plane is abou hal o hem [3]
2. áb a Jellemző eszül ségeloszlás az edze ü eg as agsága men én mezőközépen és
élek közelében (R2 és R1 a ományoknál). A elüle i é egek hőkezelés u án
ma adó nyomó eszül sége ál alában: σ=120-150 MPa, az ü eg belsejében lé ő
húzó eszül ség: σ/2, [3].
a) b)
Fig. 3. Vicke s diamond py amid inden a ion in o a empe ed glass su ace a) sec ion
iew, b) plane iew. Inden a ion i eld d i es he c ack, esidual empe ing i eld
opposes hem [6]
3. áb a Vicke s gyémán pi amisos beha ás izsgála edze ü eg elüle én
a) üggőleges me sze , b) elülnéze . A beha ás ál al lé ejö ő epedéseke ,
az edzés kö e ő ma adó eszül ségek összezá ják [6]
Th e e is a peak o ensile s esses a a small dis ance om
he edge ( ypically 12–25 mm om he edge (Fig. 4.). Tensile
s esses a e indica ion o an undesi able edge cooling a e and
a po en ial bending. Th e e o e, su ace s ains in Region 1
(a cen e o glass panes) and Region 2 (a edge egion) we e
measu ed in p esen expe imen s.
Fig. 4. Su ace and mid-laye s ess nea o edges [7]
4. áb a Élekhez közeli a ományok elüle közeli és belső é egeinek eszül ségei [7]
Failu e o igina es om c acks wi h a omically sha p ips. In
spi e o he ca e ul manu ac u e and anspo a ion o glass
panes, impac s wi h sha p pa icles o en i onmen al impac s
can cause de ec s on he su ace. Resea ch esul s ha e shown
[8, 9, 10, 11, 12] ha aging o newly c ea ed l aws should
be bene i cial, and esidual s esses will end o elax in ime
(especially in eac i e en i onmen s). Mould e al. (1959) [13]
showed ha he s eng h o specimens con aining ab asion
mic oc acks can inc ease wi h he aging ime (i.e., ime be ween
ab asion and es ing o ailu e). In case o glasses unde such
condi ions hose li e ime design p ocedu es will be di i cul
which y o make p edic ions o es ima ions based on ac ual
glass su ace condi ions.
Fu he s udies [6, 14] ha e shown ha su ace s eng hening
can lead o subs an ial imp o emen s in deg ada ion esis ance,
he e o e, in ou doo condi ions, when glass su ace is exposed
o humidi y e c. empe ed o hea s eng hened glass should
be used.
2. Ma e ials and expe imen al p ocedu e
An expe imen al p og amme was ca ied ou o analyse he
load bea ing capaci y o single and lamina ed glass panes. Resul s
o single glasses a e discussed in p esen publica ion. Specimens
we e es ed in ou -poin bending. In case o empe ed glass, he
s ess mus i s exceed he buil -in comp ession s esses be o e
ension de elops. Th e in l uence o edge s eng h also in l uences
he s eng h o glass pane. Th e e o e, he de o ma ions a mid
o pane and a he edge egions we e also s udied. Th e esul s o
empe ed glass specimens we e compa ed o hose o non hea
ea ed l oa glass specimens.
2.1. Tes pa ame e s and es p og amme
Tes pa ame e s o single glass specimens we e he ollo w ing:
Cons an s: es a angemen , wid h and leng h o specimens,
Va iables: hickness, ype o l oa glass (non hea ea ed o
empe ed), a e o loading, empe a u e o specimens (no
discussed he e).
Specimens es ed in ou -poin bending we e manu ac u ed
om soda-lime silica e l oa glass wi h polished edges. Any
in ended changes o he condi ion o he es specimens like
edge wo king, was comple ed a leas 24 hou s be o e es ing
[5]. Specimens we e s o ed in labo a o y condi ions o min.
1 day be o e being es ed. I he glass su ace was modi i ed by
ab asion, e ching, edge wo king e c., i was necessa y o allow
he esh damage o heal be o e he es is done. Th e con inuous
su ace modi i ca ion by mois u e a ec s he damage in a way
ha can educe any weakening e ec [8]. Single glass specimens
wi h nominal hickness o 6 mm and 12 mm as well as 19 mm
we e in es iga ed. Th e accu acy o hickness measu emen s
we e 0.01 mm. Th e measu ed alues a e he ollowing:
densi y o glass, ■ a e age ρglass: 2.50 g/cm3
leng h o specimen, ■ a e age L:
1099 mm, (1100 mm ± 5 mm)
wid h o specimen, ■ a e age b:
358 mm, (360 mm ± 5 mm)
hickness o specimen, ■ a e age hnom,6 mm:
5.87 mm, (nominal 6 mm)
hickness o specimen, ■ a e age hnom,12 mm:
11.85 mm, (nominal 12 mm)
hickness o specimen, ■ a e age hnom,19 mm:
18.99 mm, (nominal 19 mm)
Th e equi ed pieces o specimens o any combina ion o
pa ame e s we e de e mined acco ding o he s anda ds (a leas
3 specimens should be es ed). S anda d de ia ion o he es s
esul s was a mos 10% o he a e age o measu ed alues.
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2.2. Expe imen al p ocedu e
2.2.1. Fo ce measu emen
All glass specimens wi h cons an span o 1000 mm and
suppo ed a wid h o 360 mm we e es ed in ou -poin
bending. Th e load and de l ec ion a mid-span o he glass panes
we e measu ed in all es s. Th e es p ocedu e was a semi-
dynamic sho - e m es . Th e es s we e ca ied ou a specimen
empe a u e o +23 °C. Th e empe a u e o he specimens and
oom empe a u e was con inuously measu ed du ing he es s.
Th e specimens we e moun ed as shown in Fig. 5.
Fig. 5. Tes me hod in ou -poin bending (EN 1288-3:2000) whe e, 1.: specimen:
1100×360 mm, 2.: bending olle , 3.: suppo ing olle , 4.: ubbe s ips
(3 mm hick, acco ding o ISO 48), 5.: cus om-made ansduce ,
symbols: Ls: 1000 mm, Lb: 200 mm, h: hickness o he specimen (6 mm, 12
mm, 19 mm) [3, 15].
5. áb a Kísé le i el endezés ké onal men i hajlí ás ese én (EN 1288-3:2000), ahol
a számok a kö e kezőke jelölik, 1.: p óba es : 1100×360 mm,
2.: e helőhenge , 3.: alá ámasz ó henge , 4.: gumiszalag (3 mm as ag, ISO
48:1994 sze in ), 5.: sajá e ezésű e őmé ő, Ls: 1000 mm, Lb: 200 mm, h:
p óba es as agsága (6 mm, 12 mm, 19 mm agy 2×6, 3×6 mm) [3, 15].
Fig. 6. F ac u e o single empe ed glass
6. áb a Egy é egű edze ü eg önk emene ele
Fig. 7. F ac u ed lamina ed glass consis ing o h ee l oa glass laye s (c acks usually
s a ed om he edges)
7. áb a Vizsgál laminál há om é egű l oa ü eg (a epedések ál alában az élek ől
indulnak)
Rubbe s ips o 3 mm hickness and ha dness o 40 ± 10
IRHD (in acco dance wi h ISO 48) was placed be ween he
specimen and he bending and suppo ing olle s o a oid ha d
con ac s [16]. Th e bending es s we e ca ied ou a (23 ± 5) °C
oom empe a u e wi h ela i e humidi y be ween 55% and
65%. Du ing he es he empe a u e was kep cons an wi h
± 1 °C in o de o a oid he de elopmen o he mal s esses.
Load was measu ed wi h a sel -made o ce ansduce ,
de eloped by he au ho s [17] o Ins on Type o 1197 es ing
ins umen and calib a ed wi h Ho inge Baldwin Mess echnik’s
200 kN o ce ansduce (No. 76411). Th e sel -made ansduce
was i xed o he uppe pla e o he Ins on ype 1197 es ing
equipmen . Th e au ho s de eloped a s eel cons uc ion wi h
hinge connec ions a de i ned places was cons uc ed o ans e
he loads om he es equipmen Ins on o he specimens
wi h ou -poin bending. Displacemen s we e measu ed wi h
a Ho inge Baldwin Mess echnik ype W50 displacemen
ansduce . Signs o he ins umen s we e ans o med wi h
so wa e Ca man o he measu ed alues in μm/m. Measu ed
alues du ing he es s we e eco ded by compu e . Th e
ac u e p ocess and c ack pa e n o glass specimens we e
eco ded wi h digi al op ical me hods (CMOS SONY Came a).
Th e applied loading a es o glass specimens wi h hickness o
6 mm we e: 50 mm/min, 20 mm/min and 5 mm/min as well
as 1 mm/min (by Ins on Type 1197 a ailable). Th e applied
loading a e o glass specimens wi h hickness o 12 and
19 mm was: 20 mm/min. Th e specimens we e es ed un il hei
ac u e (Figs. 6., 7.).
2.2.2. S ain measu emen
S ains a selec ed poin s on he su ace (in R 1 and R 2
Region) o he glass panes wi h s ain gauges Type HBM LY11-
10/120 we e measu ed (Fig. 1).
Fo empe a u e compensa ion ano he glass specimen wi h
s ain gauges on i s su ace was applied and s o ed a he same
condi ion wi h he es ed specimens. Th e change o esis ance
in mV/V o he gauges was measu ed and ans e ed o he
digi al channels o HBM Spide 8 ins umen . Th e so wa e
Ca man a e calib a ion was able o ans o m he measu ed
mV/V da a in μm/m. S esses a glass su ace may be calcula ed
wi h Hooke’s law o linea elas ic ma e ials.
2.2.3. Scanning elec on mic oscopic analysis (SEM)
To s udy mo phologically he edge egions o single glasses
ou di e en ypes o edges we e p epa ed: a) manually a ised
edge, b) machine g ound edge, c) machine g ound + acid
e ched edge, d) machine polished edge. Type o used scanning
elec on mic oscope was: JEOL JSM-5500LV. Th e edge samples
we e co e ed wi h Au-Pd apou o elec on mic oscopy. Th e
pa ame e s o elec on mic oscopy we e he ollowing: high
acuum mode, using o seconda y elec on (SE) de ec o ,
accele a ion ol age 25 kV. Digi ally pho os we e aken wi h
magni i ca ion o ×50, ×100, ×300, ×1000. In he pho os he
scaling line is also p in ed.
3. Resul s and discussion
3.1. Th e e ec i eness o empe ing
In mos o he e e ences [18, 19] can be ound ha he load
bea ing capaci y in case o empe ed single glasses is 3 o 4
imes highe han in case o l oa glasses. Th e ques ion a ise:
is he load bea ing capaci y o empe ed glass always 3 o 4
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imes highe in case o di e en glass hicknesses o in case o
di e en applied loading a es?
Th e au ho s sugges o in oduce he de i ni ion e ec i eness
o empe ing (hea ea men ). Th e e ec i eness o empe ing
shows he p opo ion o load bea ing p ope ies (e.g. maximal
o ce) o empe ed glasses o non hea ea ed l oa glasses
wi h he same hickness. Th e au ho s ha e expe imen ally
shown ha he e ec i eness o empe ing depends on he
glass hickness and he loading a e. Based on he labo a o y
ou -poin bending es s he au ho s ha e shown ha he
e ec i eness o empe ing dec eases wi h he inc ease o glass
hickness by loading a e o 20 mm/min. Th e ela ionship
be ween e ec i eness o empe ing and glass hickness is linea
(Fig. 8.).
Fig. 8. E ec i eness o empe ing s. glass hickness in case o loading a e o
20 mm/min
8. áb a Edzés ha ékonysága az ü eg as agság ügg ényében 20 mm/min e helési
sebesség ese én
Th e au ho s ha e expe imen ally shown in case o nominal
glass hickness o 6 mm ha he e ec i eness o empe ing
dec eases wi h dec ease o loading a e om 20 mm/min o
1 mm/min (Fig. 9.) and no signi i can changes wi h inc ease
o loading a e om 20 mm/min o 50 mm/min. Explana ion
o ha is: he de elopmen o c acks s a ing om su ace
sc a ches needs ime which is a he a ailable in case o loading
a es o 5 o 1 mm/min han in case o loading a es o 50 o
20 mm/min.
Fig. 9. E ec i eness o empe ing s. a e o loading by 6 mm glass hickness
9. áb a Edzés ha ékonysága és a e helési sebesség össze üggése 6 mm as agságú
ü egeknél
Wi h he e ec i eness o empe ing (hea ea men ) i
is possible o choose he app op ia e and economic glass
hicknesses in he i eld o glasses which we e hea ea ed
( empe ed o hea s eng hened).
3.2. De o ma ions o glass su ace a mid o pane
(Region 1) and edge egion (Region 2)
S ains we e measu ed a he bo om ( ensioned) su ace
o specimens. In case o empe ed specimens he s ess mus
i s exceed he buil -in comp ession s esses be o e ension
de elops, he e o e, he so called p es essed laye s o empe ed
specimens help o educe he s ains caused by de l ec ion a
same o ce le el. Resul s o s ain measu emen s indica ed ha
he measu ed s ains a e highe in Region 2 han in Region 1,
bo h in case o l oa non hea ea ed glasses and empe ed
glasses wi h hicknesses o 6, 12, 19 mm (Fig. 10.).
Fig. 10. Maximal o ce s. s ain a bo om su ace in Region 1 (mid) and Region 2
(edge) o single empe ed and l oa glass specimens hicknesses o 6, 12 o
19 mm, wi h loading a e o 20 mm/min
10. áb a Tö őe ő és ö ési alak ál ozások az R1 és R2 a ományoknál 6, 12 és 19 mm
as agságú l oa és edze ü egek ese ében, 20 mm/pe c e helési sebességnél
Th e a io o maximal s ain and ul ima e o ce is illus a ed
as a unc ion o glass hickness in Fig. 11.
Fig. 11. Ra io o maximal s ain and ul ima e o ce a bo om su ace in Region 1
(mid) and Region 2 (edge) o single empe ed and l oa glass specimens s.
hicknesses o 6, 12 o 19 mm
11. áb a Tö ési alak ál ozás és ö őe ő a ánya R1 és R2 a ományoknál 6, 12 és
19 mm as agságú l oa és edze ü egek ese ében, 20 mm/pe c e helési
sebességnél
Fig. 11. indica es ha he a io o maximal s ain and
ul ima e o ce dec eases wi h inc ease o hickness o bo h
l oa and empe ed specimens calcula ed a Region 1 and
Region 2, espec i ely. Th is a io also indica es he e ec i eness
o empe ing in case o single glass specimens.
To de e mine bending s eng h in ou -poin bending he
ollowing o mula can be applied:
(1)
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whe e, b-wid h o specimen; h- hickness o specimen;
Ls-dis ance be ween he cen e lines o he suppo ing olle s;
Lb-dis ance be ween he cen e lines o he bending olle s;
y-cen al de l ec ion o he specimen; k=ke-dimensionless ac o
as unc ion o y/h o de e mine he s ess a he mid o span
k=1; σbB-bending s eng h; σbG-bending s ess imposed by he
sel -weigh o he specimen.
Th e bending s esses should be calcula ed by applying
a ac o k o ake in o accoun non-uni o mi y o he s ess
i led, (see ac o k in Eq. (1)) and he calcula ed bending s ess
is called e ec i e bending s ess. Fac o k is used when i is
equi ed o de e mine he bending s eng h o glass whe e he
e ec s o he edge condi ions a e impo an . Fo calcula ing he
o e all bending s eng h o equi alen bending s eng h o he
su ace a ea, including he edges he alue k=1 shall be used.
Fo calcula ing he bending s eng h o equi alen bending
s eng h o he ee edges o he glass pane k=ke shall be used.
Th e app op ia e alue o ke o use in Eq. (1) shall be ob ained
om Fig. 12., which gi es he alue o k=ke as a unc ion o he
alue o y/h.
Fig. 12. Dimensionless ac o ke as a unc ion o y/h o 6, 12, 19 mm hickness o glass,
con inuous lines as gi en in EN 1288-3:2000, dashed lines a e measu ed
alues wi h loading a e o 20 mm/min, ec angles indica e measu ed alues
o 6 mm glass wi h loading a e o 50 mm/min
12. áb a Szo zó ényező, ke 6, 12, 19 mm as agságú egy é egű ü egekhez a lehajlás/
as agság (y/h) ügg ényében 50 és 20 mm/min e helési sebességeknél.
A oly onos onalak az EN 1288-3:2000 szab ányban megado gö béke
jelzik. A szagga o onalak a 20 mm/pe c e helési sebességhez ja asol
é ékeke jelzik
Based on he labo a o y esul s he au ho s ha e shown
ha he alue o ac o ke is in l uenced by he loading a e.
Th e au ho s de e mined he alues o ac o ke wi h applied
loading a e o 20 mm/min in case o single glasses hickness
o 6 mm, 12 mm and 19 mm. Fig. 12. indica ed ha in case
o educed es ing speed om 50 mm/min o 20 mm/min ke
inc eases. De ec s caused by edgewo k a e ini ia ions loca ion
o c acks and he nuclea ion o c acks needs. Wi h inc ease o
loading ime mo e c acks can de elop, he e o e he s esses in
Region 2 inc ease. Fu he in es iga ions on he e ec o glass
s eng h in Region 2 wi h di e en ype o edge wo ks and
es ing speed should be done.
S esses a selec ed poin s on a glass su ace can be de e mined
om s ain measu emen s. Su ace s esses ha e been calcula ed
based on Hooke’s law using he heo e ical Young’s modulus
o glass E=70 000 N/mm2. Th e a e age o calcula ed su ace
s eng h, σ o indi idual single glass specimens and he bending
s eng h, σbB calcula ed wi h Eq. (1) a e indica ed in Table 1.
Mid pane s eng h, σbB (in Region 1) and edge s eng h, σbB,edge
(in Region 2) ha e been calcula ed wi h Eq. (1) on he bo om
su ace o single non hea ea ed l oa (F) and empe ed (E)
glass specimens. Table 1. gi es he su ace s esses a maximal
o ce which a e di e en om he calcula ed bending s eng hs
o single glass specimen wi h hicknesses o 6, 12 and 19 mm,
espec i ely. Th e calcula ed su ace s esses a maximal o ce a e
lowe in case o single glass specimens wi h hickness o 6 mm
han he bending s eng h. Th e maximal su ace s ess should
be conside ed in case o glass panes hinne han 6 mm o bo h
empe ed o l oa glasses [4]. In case o specimens wi h la ge
de o ma ion (no app op ia e shea esis ance) he calcula ed
s eng hs (bo h su ace and bending) a e o e es ima ed o
hin (6 mm) specimens wi h use o Eq. (1), see also [4, 20].
In case o single glass specimens hicke han 12 mm o wi h
app op ia e shea esis ance Eq. (1) can be applied.
Th e su ace s esses a e mo e in l uenced by he su ace
condi ion o glass elemen han he bending s eng h. Impac s
on glass su ace by ha d, sha p pa icles e.g. sc a ching a e
he ini ial loca ions o c acks, which can de elop and quickly
p opaga e. When he su ace s esses will each he su ace
s eng h o he pane, ac u e occu s. Th e p obabili y o glass
ailu e s a ing om he edge egion is highe han o mid
egion. Edges o panes o bo e holes con ain mo e de ec s.
Specimens
h
Measu ed alues (a g.) Theo e ical
su ace s eng h, σCalcula ed bending s eng h
Fmax, m ymax,m
εmax,m Mid
(Region 1) Edge
(Region 2) σbG
σbB
(Region 1) y/h ke
σbB edge
(Region 2)
Mid
(Region 1) Edge
(Region 2)
mm kN mm μm/m N/mm2N/mm2N/mm2N/mm2- - N/mm2
E
6 1.58 61.63 1846.14 2063.92 129.20 144.50 3.80 157.50 10.50 1.12 176.40
12 7.94 46.15 2563.46 2921.36 179.40 204.50 1.90 191.40 3.81 1.14 218.20
19 15.52 24.73 2075.88 2274.99 145.30 159.20 1.20 145.40 1.29 1.10 159.90
F
6 0.43 16.20 508.80 590.55 35.62 41.34 3.80 45.60 2.76 1.16 52.90
12 2.66 17.41 1053.20 1157.63 73.70 81.00 1.90 65.40 1.42 1.10 71.90
19 7.21 11.87 1125.55 1188.82 78.80 83.20 1.20 68.20 0.62 1.06 72.30
Table 1. Bending s eng h and su ace s eng h o es ed single glass specimens, whe e symbols a e: E - empe ed glass, F - non hea ea ed glass (a e age alues a e a a ages o ou
measu emen s)
1. ábláza Egy é egű ü egek számí o hajlí ó szilá dsága és alak ál ozásmé ések e edményeiből számí o elüle i szilá dságok ( ö idí ések: E - edze ü ege , F - l oa ü ege jelölnek )
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In case o l oa glass specimens he edge s eng h is mo e
in l uenced by hickness and edge condi ion han in case o
empe ed specimens. Reaching he ul ima e s ain in edge
egion, ac u e occu ed. Th e e o e, he e ec o he edge
quali y is impo an on load bea ing capaci y and du abili y o
glass. Load bea ing capaci y o a glass pane wi h same hickness
dec eases wi h dec ease o edge s eng h. Al hough he es ed
specimens we e manu ac u ed wi h machine polished edges,
u he glasses wi h di e en edgewo ks we e in es iga ed o
scanning elec on-mic oscopic obse a ion. Fig. 13. indica es
ha manually a ised edges con ain de ec s in mac oscopic
scale.
Fig. 13. Mac oscopic de ec s as ini ia o s o c acks a “manually a ised” edge o
a glass pane
13. áb a Mak oszkopikus zámol élmegmunkálási hibák, min a epedések kiindulási
helyei
Fig. 13. indica es ha he edge egion o glass was he mos
damaged by manually a ised edgewo k which can be ini ia o
o c acks. Th e oughness o edge su ace dec eases wi h use
o i ne ab asi es o wi h acid e ching. Edgewo k educes he
ini ia ion o c acks caused by cu ing o glass pane, see as cu
edge in Fig. 14.
Fig. 14. Typical edge in “as cu ” samples a) su ace de ec s ×50, b) ×300 as po en ial
ini ia o o c acks (pho os aken by B. Koczka, Depa men o Ino ganic and
Analy ical Chemis y, BME)
14. áb a Jellemző ágo él a) elüle i hibák ×50, b) ×300 epedések po enciális kiin-
dulási helyei
Th e adi ional edge wo k p ocess equi es a s eady s eam
o wa e and an ab asi e compound. Ab asi es a e a ailable in
many di e en sizes (called g i s), anging om a ound mesh
size 60 (= 250 mic on, which is a e y ough g i used o ini ial
g inding) o a ound mesh size 600 (= 30 mic on, an ex emely
i ne g i ). Gene ally, achie ing a highly polished i nish in ol es
using a se ies o i ne and i ne ab asi es (diamond discs o pad,
SiC silica ca bide slu y, Ce ium dioxide e c.). A i nished g ound
su ace will appea whi ish and dull (Figs. 15. b, c), bu polished
su ace will shine wi h no isible sc a ches (Fig. 15. d).
a) manually a ised edge, le : ×100; igh : ×1000
e y coa se ab asi e size a ound 420 o 250 mic on,
(diamond wheel speed in pm’s 1600-2400)
a) zámol él, bal: ×100; jobb: ×1000
b) machine g ound edge, le : ×100; igh : ×1000
o emo e la ge ough a eas o glass he p ocess begins wi h ab asi e abou 105 mic on
and equi e u he p ocessing down o medium size a ound 53 o 48 mic on,
(speed o eed om 0.5 up o 4 m/min)
b) gépi csiszol él, bal: ×100; jobb: ×1000
c) machine g ound + acid e ched edge, le : ×100; igh : ×1000,
medium ab asi e size a ound 53 o 48 mic on, acid ype o hyd ogen- l uo ide
c) gépi csiszol + sa ma a o él, bal: ×100; jobb: ×1000
d) machine polished edge, le : ×100; igh : ×1000
e y i ne Ce ium dioxide (CeO2) ab asi e, size a ound 37 o 29 mic on
d) polí ozo él, bal: ×100; jobb: ×1000
Fig. 15. Typical edge i nishing o a) manually a ised, b) machine g ound, c) machine
g ound+ acid e ched d) machine polished samples (pho os aken by
B. Koczka, Depa men o Ino ganic and Analy ical Chemis y, BME)
15. áb a Jellegze es élmegmunkálások a) zámol él, b) gépi csizsol él, c) gépi csizsol
+ sa ma a o él, d) polí ozo él (a o óka a BME Sze e len kémia és
analí ikai anszékén Koczka B. készí e e)
Fig. 15. indica es ha he manually a ised edge has he
oughes su aces and will con ain he mos de ec s. By cu ing
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p ocess ini ia ed sha p c ack ips can be elimina ed o he size
o ini ia ed c acks can be educed wi h use o edge i nishing
echniques. T anspo a ion o glass can also cause l aws on he
su ace (Fig. 16.), which can p opaga e du ing he li e ime o
glass. Th e esul s [14] ha e shown ha he na u e o l aws is
an impo an ac o in a igue cha ac e iza ion. A l aw o gi en
size may espond in di e en ways, depending on whe he
he e a e esidual s esses p esen o c acks ha e been o med.
Th is is also impo an in he con ex o li e ime design.
Su ace sc a ch ×50, caused by s eel azo , F=0,4 kN
Fig. 16. Typical su ace o l oa glass su ace sc a ch wi h ”shell-like” ac u e ×50,
(pho o aken by B. Koczka, BME Depa men o Ino ganic and Analy ical
Chemis y)
16. áb a Ü eg elüle i ka colás jellegze es „kagylós ö ési” képe 50×sze es nagyí ásban
4. Conclusions
1. Th e conclusions o he e ec i eness o empe ing can
be summa ized as ollows:
I is sugges ed he ein o in oduce he de i ni ion
e ec i eness o empe ing (hea ea men ). Th e
e ec i eness o empe ing shows he p opo ion o load
bea ing p ope ies (e.g. maximal o ce) o empe ed
glasses o non hea ea ed l oa glasses wi h he same
hickness. Th e highe he hickness he lowe is he
e ec i eness o empe ing. Th e empe ing is mo e
e ec i e in case o single laye glass specimens wi h
hicknesses lowe han 12 mm. Th e esul s indica ed ha
he e ec i eness o empe ing dec eases wi h dec ease
o loading a e om 20 mm/min o 5 mm/min and
1 mm/min.
2. Th e conclusions o he maximal s ain a a ious egions
and he in l uence o edgewo k on he edge s eng h can
be summa ized as ollows:
S eng h o a glass pane should be in es iga ed a leas
a 2 di e en egions. Region 1 a mid o pane and
Region 2 a edge egion. Th e e ec o edge wo k should
be also s udied. Th e maximal s ain o edge egion
(Region 2) is highe han o mid o pane (Region 1).
In case o l oa glass specimens he edge s eng h is
mo e in l uenced by hickness and edge condi ion han
in case o empe ed specimens. Reaching he ul ima e
s ain in edge egion ac u e occu ed, he e o e, he
e ec o he edge quali y is impo an on load bea ing
capaci y and du abili y o glass. Th e edge egion o glass
con ains mo e de ec s caused by edgewo k. When
glass ac u es, i ails p ac ically a he edges i s and
he c ack p opaga es in he di ec ion o mid o pane.
In case o educe he es ing speed om 50 mm/min o
20 mm/min ke inc eases. De ec s caused by edgewo k
a e ini ia ions loca ion o c acks and he nuclea ion o
c acks needs ime. Wi h inc ease o loading ime mo e
c acks can de elop, he e o e he s esses in Region 2
inc ease.
3. Th e conclusions o he ela ionship o bending
s eng h and su ace s eng h can be summa ized as
ollows:
Th e su ace s eng h (calcula ed by Hooke’s law) is mo e
in l uenced by he su ace condi ion o glass elemen
han he bending s eng h (calcula ed om he maximal
momen ). Su ace s eng h esul s ea lie ailu e han
bending s eng h, especially in he case o hin l oa
(h < 10 mm) glass panes. In case o l oa non hea ea ed
and ela i ely hick (h > 10 mm) specimens he s eng h
is conside ably in l uenced by he size e ec .
4. Th e conclusions o di e en ypes o edgewo k can be
summa ized as ollows:
By cu ing p ocess ini ia ed sha p c ack ips can
be elimina ed o he size o ini ia ed c acks can be
educed wi h use o edge i nishing echniques. Th e size
( oughness) o he edge de ec s dec eases wi h use o i ne
ab asi es in he edge i nishing p ocess. Th e oughness o
he edge su ace dec eases wi h use o acid e ching.
5. Acknowledgemen
Th e au ho s would like o exp ess hei hanks o RÁKOSY
GLASS L d. especially o Esz e Rákosy o p o iding he
specimens. Th e au ho s would like o hank also o he suppo
by SEM measu emen o D . Béla Koczka, Facul y o Chemical
Technology and Bio echnology, Depa men o Ino ganic and
Analy ical Chemis y, BME and D . Ka alin Kopecskó Dep .
o Cons uc ion Ma e ials and Enginee ing Geology, BME.
Th e au ho s would like o hank o D . Salem G. Nehme o
his in ellec ual suppo . Th e au ho s would also like o hank
o D . Sándo Fehé á i, M . And ás Eipl, M . Má yás Va ga,
M . Dá id Di iczi, M . Gábo Ko ács o hei echnical
suppo .
Re e ences
[1] Pankha d , K.: De elopmen o load bea ing glass s uc u es (Az ü eg a ó-
endsze ek ejlődése). Alap ajz. 7 é . 5. szám (2000), pp. 14–18.
[2] Pankha d , K.: Special load bea ing glass s uc u es in Hunga ian building
indus y (Különleges ü eg a ósze keze ek a magya épí őipa ban). Épí ő-
anyag. 55. é . 3. szám (2003), pp. 106-111.
[3] Pankha d , K.: In es iga ion on load bea ing capaci y o glass panes. Pe -
iodica Poly echnica - Ci il Enginee ing, Vol.52, No.2 (2008), pp. 73-82.,
doi:10.3311/pp.ci.2008-2.03
[4] Pankha d , K.: In es iga ion on load bea ing sa e y glass. Eligehausen R.,
Gehlen C. (Ed.), P oceedings o 7 h In e na ional PhD Symposium in Ci il
Enginee ing, S u ga (2008), pp. 53-62.
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épí ôanyagépí ôanyag
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[5] EN 1288-1:2000: Glass in Building – De e mina ion o he bending s eng h o
glass – Pa 1: Fundamen als o es ing glass. CEN B ussels (2000), pp. 7-8.
[6] Ma shall, D. B. – Lawn B.R.: An inden a ion echnique o measu ing s es-
ses in empe ed glass su aces. Jou nal o he Ame ican Ce amic Socie y,
Vol. 60. No. 1-2. (1977), pp. 86-87.
[7] Redne , A. S.: Au oma ed measu emen o edge s ess in au omo i e glass,
S ainop ic Technologies Inc., Glass P oceeding days (2000), Pos e 24.
[8]
Wiede ho n, S. M.: In l uence o wa e apo on c ack p opaga ion in soda-lime
glass. Jou nal o he Ame ican Ce amic Socie y, Vol.50 (1967), pp. 407-414.
[9] Michalske, T.A.: Th e s ess co osion limi : I s measu emen and implica-
ions. F ac u e Mechanics o Ce amics, Vol. 5, Su ace Flaws, S a is ics and
Mic oc acking, (Ed.) B ad , R.C., E ans, A.G., Hasselman, D.P.H., and
Lange, F.F., Plenum P ess, New Yo k (1977), pp. 277–289.
[10] I o, S. — Tomozawa, M.: C ack blun ing o high silica glass. Jou nal o he
Ame ican Ce amic Socie y, Vol.65, No.8 (1982), pp. 368-371.
[11] Ma shall, D.B. — Lawn, B.R.: Su ace l aws in glass. Ku kjian, C.R. (Ed.),
S eng h o ino ganic glass, Plenum Publishing Co po a ion, New Yo k
(1985), pp. 171-180.
[12] Wiede ho n, S.M. — D e zke, A. — Rödel, J.: C ack g ow h in soda–lime–
silica e glass nea he s a ic a igue limi , Jou nal o he Ame ican Ce amic
Socie y (2002), Vol.85, No.9, pp. 2287–2292.
[13] Mould R. E. — Sou hwick, R. D.: S eng h and s a ic a igue o ab aded glass
unde con olled ambien condi ions: II . J. Ame . Ce am. Soc., Vol. 42.,
No.12. (1959), pp. 582-592.
[14] Lawn, B.R. — Ma shall, D.B. — Dabbs, T.P.: Fa igue s eng h o glass: a con -
olled l aw s udy. Ku kjian, C.R. (Ed.), S eng h o ino ganic glass, Plenum
Publishing Co po a ion, New Yo k (1985), pp. 249-259.
[15] EN 1288-3:2000: Glass in Building – De e mina ion o he bending s eng h
o glass – Pa 3: Tes wi h specimen suppo ed a wo poin s ( ou -poin
bending), CEN B ussels (2000), pp. 8-11.
[16] ISO 48:1994: Rubbe , ulcanized o he moplas ic — De e mina ion o ha d-
ness (ha dness be ween 10 IRHD and 100 IRHD)., TC45/SC2
[17] Pankha d , K.: Load-bea ing glass s uc u es. Pe iodica Poly echnica, Ci il
Enginee ing. Vol. 48. No.1-2. (2004), pp. 157-172.
[18] „Glass e minology” B&G glass, h p://www.bgglass.com/glass%20 e ms.
h m Re ie ed in 2009.
[19] „Th e mal s ess, Pa wo”. Achi ec ’s guide o glass & me al (2009), h p://
www.glassguides.com/index.php/a chi es/610#
[20] Pankha d , K. — Balázs, L. Gy.: New oppo uni ies o s uc u al glazing,
loadbea ing glass s uc u es. P oceedings (Repo ) Responding o omo -
ow’s challenges in s uc u al enginee ing. IABSE Symposium Budapes
2006; Vol. 92, No. 34-35 (2006), he whole pape on CD wi h 11 pages.
Tehe ho dó ü egek éleinek szilá dsága
Az egy é egű ü egeke akko hí ha juk biz onsági ü egek-
nek, ha edze ek (hőkezelési eljá ással) agy d ó háló al
e ősí e ek. Ha az edze ü eg el ö ik, ap ó ompa szilánkok a
esik szé . A hőkezel agy kémiailag edze ü egek ö ésképeik
mia nem a oznak a biz onsági ü egek közé, csak akko ,
ha laminál o mában alkalmazzák őke . Hajlí ó izsgála oka
égez ünk (EN 1288-3:2000 szab ány sze in i el endezés-
sel), és megha á oz uk az egy é egű edze és loa ü egek
hajlí ó szilá dságá az isme össze üggésekkel. To ábbá
a számí o é ékeke összehasonlí o uk az ü eg elüle én
mé ö ési alak ál ozásokból számí o szilá dsági é ékekkel
nem hőkezel loa alamin edze egy é egű ü egeknél. Fel-
me ül a ké dés: ajon az alak ál ozások egyenlők lesznek-e
az ü eg ábla síkjának középpon jában agy a ábla élekhez
közeli helyen mé e? Alak ál ozási mé éseke égez ünk az
ü eg ábla közepén és a ábla élhez közeli a ományokban.
Az ü eg önk emene ele a mik oszkopikusan kicsiny epedés-
csúcsokból indul ki. Az ü eg áblák elüle én az elő igyáza os
gyá ásuk és szállí ásuk ellené e az éles á gyakkal aló é in -
kezésükko és a kö nyeze i ha ások kö e kez ében ka colások
kele kezhe nek. Az ü eg eldolgozás (pl. ágás, élmegmunká-
lás) ál al számos o ábbi olyan beha ás é i az ü ege , melyek
epedéseke e edményezhe nek. Pász ázó elek onmik osz-
kópos izsgála okkal kimu a uk különböző élmegmunkálási
eljá ásokkal kialakí o élek elüle ének hibái . A leg öbb ü eg
e ősí ési módsze célja, hogy ma adó nyomó eszül ségeke
ezessen az ü eg ábla elüle éhez közeli é egeibe izikai agy
kémiai ú on. A kele keze , nyomo é eg segí i a elüle i epe-
dések (ka colások) összezá ásá , ezál al gá olja a epedések
o ább e jedésé , és nö eli a hajlí ószilá dságo . Tanulmányok
[6, 14] kimu a ák, hogy az ü eg elüle e ősí ése jelen ősen
ja í ja a deg adáció al szembeni ellenállásá , így különö-
sen, ehe ho dó ü egek kül é i alkalmazásánál, edze agy
hőkezel ü egek alkalmazása ja asol .
Kulcssza ak: ehe ho dó ü eg, élmegmunkálás, szilá dság,
ü eg, edze ü eg
A bel- és kül öldi állala ok é deklődése a BAU kiállí ási e üle ei i án
eddig soha nem lá o mé e eke öl ö . A 2011. januá 17. és 22. közö
az új Müncheni Vásá á os e üle én meg endezés e ke ülő BAU 2011
e üle e gyako la ilag eljes egészében elkel . „Az épí észe , anyagok
és endsze ek ilágkiállí ása“ alkalmából, újból öbb min 40 o szágo
kép iselő min egy 1900 kiállí ó mu a kozik majd be. A ásá eze és 210
eze nél is öbb lá oga ó á , min egy 150 o szágból.
Veze ő émák
 Fenn a ha ó épí és: a enn a ha ó épüle eknek gazdaságilag ha é-
konynak, kö nyeze ba á nak és e ő o ás- aka ékosnak kell lenniük,
használóiknak kényelme , kellemes közé ze e és egészsége kell
biz osí aniuk, ezenkí ül pedig illeszkedniük kell szocio-kul u ális
kö nyeze ükbe is.
 Akadálymen es épí és: épüle ek, lakások és kö nyeze ük oly módon
meg alósuló épí ése, kialakí ása és be endezése é endő ala a, hogy
a alamilyen ogya ékossággal agy anélkül élők, nagyok és kicsik,
ia alok és idősek lehe őleg önállóan, biz onságosan és kényelmesen
élhessenek abban.
 Épüle ek elújí ása, eno álása és mode nizálása az épí őipa sok
állalkozója számá a időközben a o galom nagy észé eszi ki. Csak
Néme o szágban má a eljes lakásépí ési be uházások 60%-á ez
eszi ki.
Vásá i ó umok – BAU plus!
A kiállí ók bemu a ói melle a BAU 2011 ismé exkluzí szakmai kísé ő
p og amo kínál. A ásá i események kellős közepén elhelyeze ó umok
szabadon lá oga ha ók.
 „Az épí és jö ője“ ó umon a ilág minden ájá ól é kező ne es e e-
zők, épí észek és épí őmé nökök ogják p ojek példák segí ségé el
bemu a ni, hogyan og kinézni a jö őben az épí és és kialakí ás.
 A „Mak oÉpí észe “ az épí észek jelenlegi és jö őbeni sze epé ilágí ja
meg. Délelő önkén épí észek és állala i kép iselők közös p ojek e-
ke mu a nak majd be. Délu ánonkén pedig egy „T endpanel“ p e-
zen álja az in e diszcipliná is alapku a ás e edményei . Ennek so án
a ól lesz szó, hogy az olyan mega- endek, min a enn a ha óság
agy a digi alizáció milyen ha ással lesznek a jö őben az épí észe e,
a e mékek e és a olyama ok a.
 Időközben számos bel- és kül öldi állalkozás ese ében az üzle nagy
észé az épüle ek mode nizálása és ka ban a ása eszi ki. Éppen
ezé ebben a émában is önálló ó umo sze eznek.
To ábbi in o máció: www.messe-muenchen.de.
TELE CSARNOKOK – CSÚCSON A BAU
ÉPA 2010_1.indd 22ÉPA 2010_1.indd 22 2010.04.05. 19:30:112010.04.05. 19:30:11