This document discusses the classification and requirements for cementitious tile adhesives according to the European standard EN 12004. It describes the main classes C1 and C2, which differ based on their tensile adhesion strength requirements. C1 requires a strength of at least 0.5 N/mm2, while C2 requires 1.0 N/mm2 or higher. The document also discusses how the addition of polymers like redispersible powder is necessary to meet the C1 and C2 specifications by reinforcing the cement matrix. Different levels of polymer addition can provide standard, flexible, or highly flexible tile adhesives for various applications.

1. CASTELL6!.: (SPAI!':)
DEFORMABILITY AND WATER RESISTANCE OF
C1 AND C2 ADHESIVES ACCORDING TO EN 12004
AND EN 12002
D r. Peter Fritze
Technical service construction. Polymer Divisi on..L-B-E T I
Wacker Polymer Systems
D 84489 Burg hause n. Tel +49-8677-83-6999. Fax +49-8677-83-5820
e-mail pctcr.fritzestwacker.com
ABSTRACT
Th e Ilew European standard EN 12004 has created two main classesfor ccmc ntitious tile
adhcsiucs:C1 mill C2. C1 reprceents thestnndard tile adhcsiocs, tolicrcas C2 defines tile mibcsiucs
toitlt illcreased requirements for tensile adhesion strength. The ieusi!e adhesion strellgtlt is
determined according to EN 1348.
GJIlcemillg deforlllallility, EN 12004 specifics I/O reqllirelllellts. EN 12002 describes a test to
measure deforlllability, but does no! require1111.'1 additional specification.
The C1 and C2 specifications cannot lie [uljilled ioitho u! addition of polYlllers to the
celllelltiiious mortar. Two proccdII res lIIay lIe usedfor titis I'llrpose:addition ofapolYlller dispcrsion
to thepremixed ccntcntitious dry lIIix orillcorporatioll of a rcdispcrsiblc polyIller powderill the dry
mix. Th e secolld way represents the 1II0dem dry m ix mortars for the ihinbcd application technique,
the importance of iohich is cO
llstlllllly growillg.
The workillg ntcclumisnt of tiu: incorporated polumcr» is the[ormation of polinuer IIridges ill
the Itydrated mortar. By this, IIIL' cement matrix is reinforced, tohich leads to a better adhesion to
dif
ficult substrates and a better deforlllilbility of the hydrated mortar.
This gllill in flexibilily allou» the tile adhesive to endure shear stresses, mused e.g. /1.'1
sltrillkillg substrates or by therntal expansion unthoul dnnuig».
There lirescnerat possibilities to llleasure this deforlllilbility:
- Trnnsuersc deformation according to EN 12002
- Dcfonnation acconiing to DIN 18156/3
- Shear resistance and deformation according to EN 1324
- Tensile adhesion strCIIgtll (700C) according to EN 1348
Extended test series dcliocrcd II good correlation bctuxen deformation according to EN 12002
and the tensile Ildllesiol/ stm lglll lifter heat treatment,
1'
. GIl-3

2. CASTEU .(JN (SPAIN)
a QUALI ~200
~2
"-- ---,===",-,,,-,-,-,= ,","
111 order 10 minimise the drop of tensile adhesion strength after waler immersion, scncm!
Iypes of copolymers were tested.
Their infiuencc 011 deforlllOl>ilily according 10 EN 12002 ilIld tensile adhesion slrellglll
according 10 EN 1348 was investigated.
1. INTR ODUCTI ON
Nowadays, almost all tile applications require polymer modified dry-mix mortars in
order to meet today's state-of-the art technical requirements concerning wor kab ility,
efficiency an d durability. The observable trend to high -qu ality "Porcelain" tiles with very
poor water absorption « 0,1 %) and to larger tile formats demand s ad hesives that allow
a sure and durable fixation of these ma terials.
The classic tile adhesive consists of a simple composition of cement and sand. The
mixtu re of both ma terials is applied in the th ick-bed method. By mod ifying these mortars
with cellulose ethers, workabi lity an d water retention are significantly improved , so that
they can be applied by the thin-bed technique. This provides a high ga in in prod uctivity
to the tiler.
However, the described tile adhesives will adhere poorly to many of the substra tes
found in the modern construction industry (e.g. polystyrene panels, wood panels, non
absorbing substrates such as old tiles etc.).
Ce mentitious mortars are very hard and brittle materials, but man y applications
dem and flexible, deformable mortars. In these cases, the mod ification of cerncntitious
mortars with polymers becomes a mu st. In dry-mix mortars, the two binder systems,
namely the mineral bind er cement, and the polymer binder red ispersible po wder (RDP;
spray dried dispersion), are ideal partners. Their incorporat ion in d ry-m ix mortars results
in outstand ing synergistic properties and cha racteristics which cannot be achieved by
either of the binders alone.
Flexible tile adhesive mortars offer ve ry good adhesion to all types of substrates
with a high degree of deformation capability. Such tile adhesives can therefore be used
universally. They offer high application and fun ction safety as well as a long-term
durab ility and reliability for all tile for ma ts, tile ma terials and substrates.
Typi cal examples for application areas of these flexible, multi-purpose and high
qua lity ceramic tile adhesives are:
- bonding of tiles on floor-heat ing sys tems, or where tile surfaces are exposed to heat
(c.g. heating-up by solar energy),
- mounting tiles on tiles
- fixing tiles on difficult substrates like gyps um backgrounds, cement fibre boards,
water proofing membranes, wood, the rmal and sound insu lation panels, light
weight concrete blocks, etc.
The question arises, how to classify tile adhesives in relation to their mechanical
properties and technical performances.
1'
. C Il - -I

3. CASTEU 6 N (SPAIN)
2. STANDARDISATION AND CLASSIFICATI ON
mQUALI ~2002
The new European sta ndard EN 12004 classifies cera m ic tile ad hesives concern ing
their chem ical composition and their mechanical properties. These classes are namely
ccmcntitious ad hesives (C), d ispersion ad hesives (D) and reaction resi n ad hesives (R).
In this paper, o nly ccmen titious ad hes ives are su bjec t o f consid e ra tion. The
classifica tion of the cernenti tious adhesives in relat ion to thei r mechani cal requi rements
is shown in table 1:
Class Tens ile adh esion Open time (N/mm 1 Open time Op en time Ten sile adhesion Slip resistan ce
strength [N/mm
2
) ace. to EN 1346 , (N/mm
2
) ace . to [Nlmm
2
] ace. to strength IN/m m
2
] [mm] ace. to EN
ace. 1
0 EN 1348 after 10 min EN 1346, aft er 20 EN 1346, after ace . to EN 1348 ; 1308
bedding time min bedding time 30 min bedd ing test afte r 24 h
time storage at
sta nda rd
con ditions
C1 > 0,5 > 0,5
C1E > 0,5 > 0,5
cn > 0,5 > 0,5 < 0,5
C1F > 0,5 ;0, 0,5 ;0, 0,5
C1ET > 0,5 ;0, 0,5 :s 0,5
C1 FT > 0,5 > 0,5 > 0,5 < 0,5
C2 > 1,0 > 0,5
C2E > 1,0 > 0,5
C2T > 1,0 ;0, 0,5 :s 0,5
C2F > 1,0 > 0,5 > 0,5
C2ET > 1,0 > 0,5 < 0,5
C2FT > 1,0 > 0,5 > 0,5 < 0,5
TaNd: class ~fi((ltioll of ccnwutitione tilt-adlll'sit>t,sde
c. to EN 12004.
As can be seen, the main d ifferentiat ion is done by the tensile adhesion strength ace.
EN 1348. For class C1, a tensile ad hesion strength of at least 0,5 N / m rn- after the four
d ifferen t cond itioni ngs is req uired, for class C2, the minimum limi t is of 1,0 N / mrn-. The
fou r cond itionings (ace. to E 1348) are given be low
- 28 d sc
- 7 d sc + 21 d water immersion
- 14 d sc + 14 d 70 °C + 1 d sc
- 7 d sc + 21 d water im mersion + 25 cycles freeze / thaw
where "d" represents d ays and "sc" stands for standard conditions (23 '" 2 °C / 50", 5 %r.h.).
In practice, 3 classes of tile adhesives prevail:
Standard, Flexible and Highly flexib le. The di stinction be tween one another
d epends on the amoun t of redi spersible powder contained in the formulati on.
The "S tandard" tile ad hesives can be sub-classified as follows:
I'
. GII - S

4. e~ QUALICt2Ji' 2002 CASTELLOI': (SI'AII':)
- Very simple standard tile adhesives, whi ch do not conta in any polym er binder in
the form of redispersible powd er. They do not meet the new Europea n standards.
Such tile adhesives with a purely mechani cal bonding by anchoring to the tile
surface or substra te can only be used for fixing sma ll, porou s tiles onto porous,
dimensionally stable, solid and strong mineral substrates, such as concrete, base
coa t render or masonry without shrinkage or movement of the substrate. Being
exposed to higher temperatures or frost. mean s a high risk of dam ages.
- Standard tile adhesives with improved adhesive bo nd stre ngth by add ition of 1-
3 % of redispersible powder on total dry mix. These types of tile adhesives
gene rally meet the requiremen ts for Cl . They can be used to lay large tiles on non -
porous, dimen sionally stab le substrates.
Tile ad hesives with higher amounts of po lymer add ition are classified as "Flexible".
They meet in general the requirements for C2.
- Flexible tile adhesives are modified to a higher exten t of red isp ersible powder in
the range of 3-8 %.These types of tile adhes ives can be used uni versally. They offer
a much higher application and fun ction safety as well as long-term durabili ty and
reliability for all sizes of tiles, tile materials and substrates.
- Hi ghly flexible tile adhesives with polym er contents up to 25 %are products for
special use, e.g. laying tiles on very fresh screeds. that will suffer a high am ount of
shri nkage.
Table 2 gives an overview of typical formulations for these different classes:
Typical formulations for ceramic tile adhesives
Requirements! Tvpe
component very simple standard flexible highly flexible
standard
Meets standard C1 no yes yes yes
orC2
Portland cement 30 - 35 %
CEM 132,5 R
Portland cement 30 - 35 % 35 -40 % 25 -40 %
CEM I 42,5 R or
CEM 152,5
Silica sand (0,05 - 64,7 - 69,7 % 61,7 - 68,7 % 46,5 - 61,5 % 29,5 -66,5 %
0,5 mm)
Cellulose ether 0,3 % 0,3 % 0,5 % 0,5 %
Redispersible - 1-3 % 3-8 % 8 -25 %
powder
Special additives - . 0-5 % 0-5 %
Table 2: typical formulations for ceramic tile adhesives.
P.GII-6

5. CA5TELL6 N (5I'A I:-.I)
3. ADHESION
The adhesion of a tile adhesive is determined by a pull off test described in EN 1348.
The tensile ad hesion strength IN/ mm-] is evalua ted using stone wa re tiles (ace. to EN 87)
laid on concrete slabs con ditioned in 4 di fferent ways as described above.
For a class Cl -tilc adhesive, the most selective test is the adhesion after heat ageing.
If the tile adhesive con tains no redispersible powder, it will fail. An addition of 1-3 % of
rcd ispersibl e powder will make it pass th is very important an d cri tical test. The hea t
ageing test indicates whethe r a tile adhesive provid es sufficient flexibil ity after curing. In
relat ion to practical application the test assesses the capability of the material to
compensate a certain level of stra ins resulting from different thermal expansion
coefficients of the tiles and the substrate wh en exposed to higher temperatures. Figure 1
shows the effect of polyme r (copo lymer of vinyl-acetate and ethy lene, TG = 10 D
C ) on the
adhesive bond strength after heat ageing with di fferent tiles.
EN 1348: Tensile adhesion strength after heat ageing
intlucnce of the amount of polymer (RDP) after heat ageing
with different types of tiles
formulation with 35 % cement content
N/mm2
.-0----- - - - -- - - - -- - -,
1.6
A--- - - - -- - - - - -
1..t
1
...1-- - - - - -- - - - -
1.2
I IA-- - - - - - -
O
.S
0.6
O
..t
0.2
o
0,5 % RDP :2 ~ ROP 6 % RDP
• earthenware t i l e~ • stoneware tiles 0 porcela in tiles
F(,/II'l' 1: i llj11 U'lI Ct' of tht' tII/wlIIII of polymcy /11'011 tt'/l:-ile adltt'siw sfrm gf h afta hrnt agt'il/Switll diJlen'1I11
.111'
(':'of tiles.
A class C2·tile adhesive requires much more formulation effort becau se of the
stringent tensile streng th requirem ents (> 1,0 N / mm-), In orde r to pass the test after
standard conditions and heat ageing, an addition of red ispersible powder in the ran ge of
3·8 % is gene rally sufficient. The most critical tests in case of C2 are those after water
immersion and freeze / thaw-cycles. Under these conditions, the dominant binder system
is the cemen t. Generally, the cement content in Cz- formulations has 10 be increased up to
abo u t 40 %. This means, th at at a co ns ta nt level of redispersible powder the
polymer / ceme nt-ra tio is decreased, thus the flexibility of the tile adhesive is lowered .
1'.(";11 · 7

6. CASTELLl~;j (SPAIN)
in QUALIC0t. 200
~2
~ ~~=",-,--,,,,-,-,,-,"-,
It has further to be conside red that a sufficiently high percentage of polymer is
required if hard-to-bond tiles, like the non-porous (so-called fully vitrified) porcelai n tiles
or glass tiles with their extremely low water absorption have to be fixed wi th a
cerncntitious ceramic tile ad hesive. In this case, a mechan ical fixation or ancho ring of the
cemc ntitious mortar on the non-porous tile surface will not take place, so that the
adhesion has to be provided by the polymer. In practice, flexible ceramic tile adhesives are
recommended and successfully used to fi x fu lly vitrified or po rcelain tiles. These high
qua lity flexible ceramic tile adhesives are modified with at least 4 % of a suitable
redispersible powder. Figure 2 shows the tensile adhesive streng th in relation to the
po lymer content at di fferen t substrates. Figure 3 illustrates the cor relation of tensile
ad hesive strength wi th the content of polymer and the type of tiles used .
EN 1348: Tensile adhesive strength on different substrates
influence of the amount of polymer (RDP) after 2R d
storage under standard conditions
~datcll IiI..:
wood panel
formulation with 35 (if, cement content
PVC
N/mm"
l ......- -- - - -- -- - - - - - - - - - ,
11.9
J..!-- - - - - - - - - -- - - -
II.X
11.7 1..+-- - - - - - - - - - - - - - - - -
11.6
W-- - - - - - - - ----
II.S
IIA J..j-- - - - - - -
J..!-------
11.3
11.2 J..j-- - -==-- - -
J..!---
II.'
II j..Ioo;;- -
Figure 2: tensile adhcsirc strmgth correlated with poly",er content and kind ( ~. f, /lbs t ral l·~.
EN 1348: Tensile adhesi ve strength
comparison between stoneware tiles - fully vitrified tiles
and correlation with amount of polymer (RDP)
formulation with 40 % cement content
full)' vin-ifled liles
stonewa re tiles
N/mm
2
I.X ..r---------------------~
1.6 -11--- - - - --1
IA -11-----1
1.2
,
II.X
11.6
IIA
0.2
II
0% RDP 2% RDP 4,5% RIW 0'1 RDP 2% RDP 4.5% RDP
• 2R d sc • water immersion 0 heat 0 free7e/lhaw
Figl/1"t> 3: tensile adht'sit'l' strellgl" correlated witlt typt'of tiles ami amount ilf polymL'r ll sI..
d.
P.G il - R

7. CA STELL6 N (SPA I!':)
Conclusions from figure 3 conce rni ng ten sile adhesive strength after heat curing:
- Risin g adhesion with increasing proportion of red ispersible powder; Secure
fixation can on ly be achieved with addition of redispersible powder.
- No employment of red ispcrsible powder: Stoneware tiles as used in EN 1348 show
still weak bon ding; No adhesion at fully vitrified tiles.
It can further be concluded, that for the stoneware tiles, the tensile adhesion strength
after sc and heat treatment improves with an increasing am ount of po lyme r. Th is
observation does not apply to the conditionings wa ter immersion and freeze / thaw. This
is explained by the fact, tha t for the stoneware tiles, the cement can still ancho r to their
surface. During the wa ter conditioning, the hyd ration of the ceme nt continues, which
lead s to a weaken ing of the cement matrix. The polym er cannot compensate this effect.
In case of the fully vitrified tiles, the adhesion d rops dramatically at all treatme nts,
bu t rises significantly with an increasing polym er amount. For this type of tiles, the
mechanical anchoring of the cement to the tiles has obviously lost its effectiveness and the
adhesion is dominated by the incorporated polym er, even after water immersion and
freeze / thaw cond itions.
This means, tha t a Cl -classified tile adhesive according to EN 12004 (2 % RDI' ) in
combination with fully vitrified tiles performs below the Cl-level and even a C2-ti le
adhesive (4,5 'ft, RDI') drops do wn to the C l-level, Expressed in practical terms: Only a
highl y polym er modified tile adhesive offers a secure and durable fixation of this type of
tiles.
4. DEFORMABILI TY OF A TILE ADHESIVE
The deformability of a tile adhesive is one of its most important properties to ensure
long-term durability. In 1997, the European standa rd EN 12002 on the transversal
deformat ion of tile adhesives was published. The fact that the classification in EN 12004
does not provide values for this deformation lead s to the problem how to measu re the
dcforrnabilitv of a tile adhesive and how to correlate it with other mechanical
requ irement; for tile adhesives.
In so me European countries, nation al approaches to define "flexible" tile adhesives
exist. In Fran ce, the C5TB (Centre Scientifique et Technique du Batiment) has crea ted a
new class called "C2S" which combines the requirements for a C2-tile adhesive ace. to EN
12004 with a deformation of 3 mm minimum acc. to EN 12002.
In Ge rma ny, the manufacturers of tile adhesives and the tilers have ag reed on a
"Richtlinie fur Ficxmortel" (Guide on flexible mortars), which defines flexible mortars
and their area of application. They combine the requirements of C2 ace. to EN 12004 with
an add itional deformation of at least 2,5 mm ace. to EN 12002.
However, the European Committee for Standardisa tion is prepar ing a new version
of EN 12002, wh ere it is discussed, to introduce also minimum requirements for
deformation. The present d raft provid es two classes: SI for deformation > 2,5 rnm and 52
for defo rmation > 5 rum .
1'
. Gil - 9

8. CASTLLL6:-< (SPAIN)
5. HOW TO DETERMINE THE DEFORMABILITY OF A TI LE AD HESIVE?
Though the flexibility of a tile adhesive is conside red as an important property for
practice conditions, the methodology of determining it, especially in a reproducible way,
still awa its definition.
It has to be kept in min d, that the most important factor for all methods to determine
the deformabi lity of a cementitious tile adhesive is the degree of hydration of the
incorporated cement. Therefore care has to be taken that the degree of hyd ration of the
ceme nt is complete. But this is not the case for most of the storage cond itions that are
prescribed in the standa rds. Especially in the case of EN 12002, the climate cond itions
during the storage influen ces in a dramatic way the resu lts of deformation as will be
sho wn below.
What possibilities do exist to measure flexibility?
Besides EN 12002, there are other method s to determine the deformab ility of a tile
adhesive:
- shear resistance and deformation ace. to UEA tc / DIN 18156/ 3
- shear resistance and deformation acc. to EN 1324
- tensile ad hes ion strength after heat cond itioning ace. to EN 1348
SHEAR RESISTANCE AND DEFORMATION ACe. TO UEATC / DIN 18156/ 3:
Thi s test was developed in the 1970's according to a theory of Mr. Wesseling. who
did a lot of investigation on deformab ility of mortars. The test is carried out as follows:
two mo rtar bars are connected with two stonewa re tiles and a tile ad hesive of 3 mm
thickness. After storage of the speci me n, a force is applied on the mortar bars and shea r
streng th and deformation until mortar failure are moni tored and recorded . Figure 4 shows
the scheme of the test configuration .
Shear strength and deformation oftile
adhesives ace. DIN 18156/3 and UEAtc
mortar bar 40 x 40 x 160 mm
~-~~---
/
,
ceramic tile
tile adhesive
Figure 4: slwar test ace. to Ll£Atc I DIN 18156/3, scheme of test configuratio".
I'. GIl - 10

9. CASTELLON (SPAIN)
A test series wa s carried out wi th formulations containing 35 % of Portland cement
and different amounts of a redispersible powder (copolymer of vinylacetate and ethylene,
TG 10 °C ). In parallel, the sa me formulations were tested ace. to E, 13-18 in order to find
out whether and eventuallv how deformation, shear resistan ce and adhesive bond
strength correlate. The storing conditions were identical for all specimens:
1-1 d sc + 14 d 70 °C + I d sc
Figure 5 shows the results for deformation of the test ace. to DI 18156/ 3. The
results of the test for shear resistan ce ace, to DII 18156 / 3 compa red with the tensile
adhesive st reng th determined ace. to E 13-1S are illustrated in figure 6.
DI 18156/3 / EAtc: Deformability
test with stone ware tiles
storage 14 d sc + 14 d 70·C + I d sc
nnll
..II1II:: I-
i -
-
-
l -
I -
~-n
I-
i -
i-
~
I
11.5
liAS
IIA
11.35
11..
11.25
11.2
11.1S
11.1
0.05
I
() 0:;0. RUP I.S ~ HUI' _
l q. KIJP
Figure 5: dc/orllla';.", acc. III DIN 18156/3 I UEAte ll:>. IJtI/ymt·' content,
EN 1348: Tensile adhesive strength after heat agei ng in
comparison with modified DIN 18156/3 / VEAte shear test
infl uence of the amount of polymer
formulation with 35 l,f Portland cement
1.2
1.6
1.4
IA.--- - - - -(-
I
O
.X
11.6
0.4
11.2
1/
adhesion strength EN IJ -Ig (10 ..C ) Sh~;H Slre n~
'1h DIN 18156/3 I UEAI~'
18 11 % Ra p 8 1.5 % Rap 03 % Rap 0 6 % RDP I
Figurt' 6: S"t'"r resistance ace. ttl DIN 18156/3 c(lmpan'll with tift' tt'tlsilt' Ild}zt'sit,(, sln'lIgtlt flee. ttl EN 13-18.
r.Gil • II

10. mQUALI .u/' 2002 CASTELL6:--J (SPAIN)
As a first and obvious result of this test series it can be seen from the graph:
the higher the amo un t of po lymer in the form ulation, the higher is the deformation
ability of the tile adhesive. This is very important to know for the practical use, where the
tile ad hesive often has to absorb enormous shea r stresses, e.g. in outdoor applications
whe re the su n may heat the floor up to 80 °C and a sudden rain cools it instantly down
to 20 "C. Only a polym er modified till' adhesive is able to absorb such stresses witho ut
cracking or loss of adhesion to the tiles.
A second finding is, tha t the tested till' adhesives show almost iden tical profiles for
shea r resistan ce and tensile ad hesive streng th, both plo tted versus RDP percen tage.
Augmenting the polymer conte nt increases the values for adhesion and shear streng th.
This shows, that the ten sile adhesive strength after heat cond itioning correlates to a high
degree with the shear strength and the deforrnab ility ace. to OJ T 18156/ 3. It can therefore
be concluded, tha t a high value for tensile adhesive strength after heat storage indicates
high flexibility of a till' ad hesive.
SHEAR RESISTANCE ACe. TO EN 132-t:
This shear test normally applies to dispersion based read y-to-use tile ad hesives,
but it may also be utilized for cementitious systems . For this pu rpose the test was
modified : the mo rtar is applied wit h a notched trowel (6 X 6 x 6 rum ) ins tead of the
pa tte rn as described in EN 132-t. Othe rw ise the mortar bed wo uld be too thin and the
mortar therefore risks drying too fast on the tiles (water absorption 15 %), wi tho ut
having the possibility to hydrate correctly. Figu re 8 shows results for shear resistan ce
and deformation of a cementitious till' adhesive containing 40 % Portland ceme nt. The
content of po lyme r (copolyme r of viny lace tatc and ethylene, TG 10 "C) was varied from
0 % to 6 %.
EN 1324 modified: Shear Resistance
mortar applied with 6 x 6 x 6 - notched trowel
storage 28 d sc
tiles 108 x 108 rnrn?
water absorption 15 %
tile adhesive
shear force
F('IIrt· 7: ~Pl'Cilllt'll acc to L ' 1324.
1'
. Gil - 12

11. CASTELL6N (SPAIN )
EN 1324: Shear Resistance
mortar applied with 6 x 6 x 6 - notched trowel storage 2& d sc
formulation with 40 % Portland cement
,-
-
- 1
-
~
I-
I I
,-
r =
)
1.5
0.5
N/mm2
mm
2
u 'l"Rur 2 't IWI' .. 't IWI' 6 '" Rill'
o Uefnrmation (mm) • Shear ITsi"hmt.'c [N/mm2]
F('oJIIy(' 8: modified shear ie:"! (l ( ( . ttl EN 1324.(llr II Ct'mm tifio/ls tile adllcsii.1l'.
Concern ing shear resistance, there is a clear influence of the amo unt of redispersible
powder used. The va lues increase with rising polymer content. At a first glance, there
seems to be a slight increase in dcformability w ith greater polymer portions in the
formulation. Since the differences are rather small and taking reproducibili ty into account,
they have to be interp reted as non- significant.
Conclusion: The modi fied shear test ace. to EN 1324 is a convenient method to
measure the shear resistan ce of a cernent itious tile adhesive and to obtain a good
indication for its capacity of strain an d shock absorption capability.
TRANSVERSAL DEFORMATION ACe. TO EN 12002:
When this method to determine the deform abilitv of cementi tious tile adhesives was
int roduced, it wa s intended to provide a simple test tJ~at overcomes the difficult and time
cons uming preparation of specimens ace. to DIN 18 156 / 3 / UEA tc, w hich often caused
poor reproducibility.
The preparation of test specimens ace, to EN 12002 is indeed fast an d easy, but as the
specimens often show curvature and torsion after drying, reproducibility is again a
problem. For this reason, Ma pei elaborated a modified procedure for the preparation of
specimens. The follow ing results were ob tained with specimens prepared after the Mapei
modification of EN 12002, but with one exception: The mortar was no t densified on the
shock table as proposed by Mapel.
As alrea dy mentioned above, a very importan t factor for the deformation is the
storage of the specimens. Figure 9 demonstrates the effect of different storage cond itions
on deformation for a formu lation containing 30 % cement and 6 % of red ispcrsible
powder,
I~ CII · IJ

12. ' QUALI~ 2002 CASTELL6:'< (SI'A I:,<)
EN 12002: transversal deformation
influence of storing conditions
formulation with 30 % Portland cement and 5 % redispersible powder
mm
12,.---
- -------;::;;IiiiiiiiiC
10
8
6
- -
o!.-......--=:!!L_-.l_-
0 28 d sc . 7 d sc + 1~ d wilier immersion + 21 d Sf
Figure 9: if~tll1l'IJCt'll
f storage conditione011 defimllatioll.
The results of figure 9 show very clearly, that in the case of the storage under
standard conditions the hyd ration of the cement is very poor, thu s leading to a very high
value of deformation . If the specimen is stored for 1-1 days in water, the cement is nearly
fully hyd rated, resulting in a deformation that is only 25 %as high as after storing under
standard conditions. This proves the necessity of a water storage instead of storage in a
plastic bag as described in EN 12002 to ensure the full hyd ration of the cement.
In a further study, the influence of the type of polymer on the deforrnability and on
the tensile adhesive strength of tile adhesives was investigated. Four d ifferent copolymers
were synthesised with the same TG of 10 0
c.The four different systems are:
poly mer 1 = copolymer of vinylacctate and ethylene
polymer 2 = copolymer of methylmethacrylate and bu tylacrylate
polym er 3 = copolymer of styrcneacrylate
polymer -I = copolymer of vinylaceta te and VeoVa
The polymers were added to the tile adhes ive as dispersions. The polymer content
was varied from 0 % to 6 % of the total dry mix. The formulation contained 30 % of
Portland cement. The results for the deformation of these tile adhes ives are given in figure
10. The figures 11 and 12 show the results for tensile adhesive strength acc. to EN 13-1R
after heat conditioning and water immersion.
['.Clt· I~

13. CASTELL6:-.J (SPAI:-.J)
EN 12002: transversal deformation
modification ace. to Mapei pro posal without shock-table;
formulati on with different types and amounts of polymer
mOl
P<ll
ymu J
poly'mer 3
pol y
"me r !
polymn I
2 1-1------~..-
o
..K------
2.5 J+-------,
1.5 1-1--==----
3.5 ~-------------------------,
05
1
_1
%D .~ ':t .6
t;f pol)'lIlu l
fi.,?l/re 10: iJlflI/CIICL' of d~ffl!re"l types ofpo lymt'rsOil deformation.
EN 1348: Tensile adhesive strength after heat
conditioning
influence of different types of polymer
N/mm 2
2<r- - - - - - - - - - - - - - - - ---,
1.8 j,j--------------~
1.6j,j---- - - - - - - - - - - -
1..I j,j-------------==--~
1.21+-- - - - - - -
I J.+-------
~::u--- - - - - - --
0.4.1-1-- - - - - -
0.2.1-1-- - - - - --1
0
jJ..------
0 %
Figure 11: infl uence oj type of polymer 011 tensile adhcsh.'t' slrCllsth after heat couditiontng.
EN 1348: Tensile adhesive strength aft er water
immersion
influence of different types of polymer
Nzmm?
0 %
0.9,-r- - - - - - - - - ------,
O.S
0.7
0.6
0.5
0,4
0."
11.2
0.1
o
t. wiloout PJ I}nlC
T • p'l}mcr I • po l)mcr 2 0 pol)mcr 3 • pol)TI
1Cr 41
figure 12: illj1/1clICt' of tyl't'of polymer 0/1 tcnsite adht'sil'l' strength after imler immersion.
P. Gil - 15

14. a QUALI:M 2002 CASTELL6:'< (SI'AI:'<)
Results:
-Increasing amoun ts of pol ymer result in higher deformability acc. to EN 12002 and
higher tensile adhesive strength ace. to EN 1348 after heat conditioning. Again, an
excellent correlation between deformabil ity and adhesive strength after heat treat-
ment exists. The onl y exception is polymer 2, which pe rforms lower than the
othe rs, especially after heat treatment.
- With out addition of polym er, the mortar fails to meet the adhesion test after heat
conditioning .
- Concern ing tensile adhesive streng th after water immersion, no type of copolymer
showed an improvement. The measured values remain at the level of the non-
modified mortar. The reason is, that the cement continues to hydrate under these
test conditions (water immersion ). Consequently, this process anticipa tes the
expected effect of the polymer, as discussed ea rlier (see 3. Adhesion).
6. CONCLUSION
Under real life conditions, cernenntious tile adhesives are subjected to stresses
between tiles and subs trate. These stresses between subs trate and tiles may be caused by
shrinkage of fresh concrete, vibrations or different expa nsions of the tiles and the
substrate (e.g, at solar exposure) due to their different therm al expansion coefficients. The
tile adhesive ha s to endure all these stresses in order to gua rantee a stable fixation of the
tiles over tim e. All test results, reported on in this study, suggest that this stability can
only be achieved with a sufficiently high pol ymer modified mortar.
The heat ageing test ace. to EN 1348 imitates the stresses between substrate and tiles
and is the refore a good indicator for the flexibility of a tile adhesive . This finding is in
excellent correlation with the results of the deform ation tests ace. to DIN 18156 / 3 and EN
12002.
The most critical issue to be respected in all the deformation tests is the storage of
the specimen. The hydration of the mortar must be almost completed prior to these tests.
Otherwise a comparison between different mortars is not possible. It has to mentioned
that the storing cond itions in EN 12002 do not allow an appropriate determination of the
flexibility of a tile adhesive.
Concerning the tensile adhesive streng th ace. to EN 1348, the water immersion is the
most difficult criterion for C2 tile adhesives to pa ss. Because of the progressing hydration
of the cement with a swelling of the cement particles during wa ter immersion, the cement
matrix is weakened . This behaviou r dominates the tensile adhesive strength.
The role of the polym er as additional binder becomes evident also under these test
conditio ns, when the test is applied to fully vitrified tiles, whe re the cement as only binder
cannot assure a stable adhesio n.
P. Gll- 16