Publisher’s version / Version de l'éditeur:
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
International ISAP symposium on asphalt pavements and environment
[Proceedings], pp. 1-12, 2008-08-18
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright
NRC Publications Archive Record / Notice des Archives des publications du CNRC : https://nrc-publications.canada.ca/eng/view/object/?id=50c57b47-67a6-4276-95ba-cd8738faaf7a https://publications-cnrc.canada.ca/fra/voir/objet/?id=50c57b47-67a6-4276-95ba-cd8738faaf7a
This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur.
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Prediction of bonding characteristics of hot-poured bituminous
sealants to aggregates
P r e d i c t i o n o f b o n d i n g c h a r a c t e r i s t i c s o f h o t - p o u r e d
b i t u m i n o u s s e a l a n t s t o a g g r e g a t e s
N R C C - 5 0 8 3 4
A l - Q a d i , I ; F i n i , E . H . ; M a s s o n , J - F .
2 0 0 8 - 0 8 - 1 8
A version of this document is published in / Une version de ce document se trouve dans:
International ISAP symposium on asphalt pavements and environment, Zurich,
Switzerland, August 18, 2008, pp. 1-12
The material in this document is covered by the provisions of the Copyright Act, by Canadian laws, policies, regulations and international agreements. Such provisions serve to identify the information source and, in specific instances, to prohibit reproduction of materials without
written permission. For more information visit http://laws.justice.gc.ca/en/showtdm/cs/C-42
Les renseignements dans ce document sont protégés par la Loi sur le droit d'auteur, par les lois, les politiques et les règlements du Canada et des accords internationaux. Ces dispositions permettent d'identifier la source de l'information et, dans certains cas, d'interdire la copie de
Prediction of Bonding Characteristics of Hot-Poured
Bituminous Sealants to Aggregates
Al-Qadi. I. L. First, University of Illinois at Urbana-Champaign, U.S. Fini. E. Second, University of Illinois at Urbana-Champaign, U.S.
Masson. J-F. Third, National Research Council of Canada
ABSTRACT: Crack sealing is one of the most common pavement maintenance methods. It
extends pavement service life through preventing water and debris from entering pavement structure and cause further deterioration. To ensure sealant adhere to crack walls adequately and resist traffic and thermal loading, there is a great need for test methods which can predict interface bonding based on bituminous sealant rheology. To address this issue this paper introduces three laboratory tests to evaluate the interfacial bonding of bituminous sealants to pavements. The first test incorporates surface energy approach to calculate work of adhesion for each pair of sealant-substrate. While compatibility of sealant with aggregate is required for sealant desirable performance, this parameter alone cannot ensure sealant performance. Therefore, it needs to be used in conjunction with a mechanical test. Two mechanical tests have been developed in this study. Considering that both tests utilize aluminum as substrate, the compatibility test is strongly needed as the first screening step. The second test can rank different pairs of sealant-substrate based on their maximum load, Pmax and required energy to
failure, E. The third test is the blister test. This test is self-contained and able to provide the sealant modulus and the interfacial fracture energy (IFE). Tests were conducted using several sealant types with aluminum and three aggregate types. Aluminum was found to be an appropriate reference substrate. Laboratory results were in agreement with field performnce for evaluated sealants.
Key Words: Pressurized blister test, interfacial fracture, debonding, rheology, sealants
1. Introduction
A major cause of bituminous crack sealant failure in the field is debonding of the sealant from the crack walls (1), developing a comprehensive test method which is practical and able to assess the bond characteristics of sealant-crack wall was urgently needed. The three laboratory tests described in this study evaluate the bond through three separate methods. The three tests are designed to address the need of producers, pavement agencies and researchers, respectively.
The first test uses surface energy approach to calculate work of adhesion between each pair of adhesive/adhered. Work of adhesion can be used to examine the compatibility of a pair of adhesive and adhered (1, 2). Therefore, this test helps the sealant producers to assess the compatibility between sealant and aggregate. In this study, the thermodynamic work of adhesion of several sealants with aggregates and aluminium were calculated through measuring the surface energy of each sealant and the contact angle between sealant and aggregate/aluminium substrate.
The second test is a mechanical test. This test is a qualitative method for quality control purposes. The direct tensile test was selected and the setup was designed so that it can be implemented in the current DTT device (3). In this method, direct tensile force is applied to the assembly of sealant-aggregate to bring it to failure. The maximum load, Pmax, and energy
for these parameters will help select the appropriate sealant which can develop an adequate bond with the crack wall.
The third test is the blister test, which is a fundamental test uses a fracture mechanics approach to measure interfacial fracture energy (IFE). Interfacial fracture energy is a fundamental property of the bond and is more suited for profound studies (4, 5). The blister test provides two fundamental parameters, the sealant modulus and the interfacial fracture energy. The latter is expressed by two experimental parameters, the pressure load and the blister height, so that data analysis is straightforward. Advising a lower limit for the IFE value can serve to select the right sealant based on a fundamental bond property (6).
In an attempt to standardize the test methods, the research team found aluminium as an appropriate replacement for aggregate because of the low diffusion, controllable roughness, high resistance to both very high and very low temperatures, and availability. It also has a similar thermal coefficient to the aggregates. Finally, due to its rapid oxidation, aluminium substrate has chemical surface similar to aggregates like granites, quartzite, and sandstone (6). Therefore, tests were conducted with aluminium plates in addition to three representative aggregates (limestone, quartzite and granite). This paper describes the implementation of each method to study the bond characteristics of bituminous materials.
2. Backgrounds
Adhesion is a fundamental property which directly depends on interatomic and intermolecular forces between the adhesive (sealant) and substrate (hot-mix asphalt) (7). Surface energy approach is one of the common methods to evaluate the interface bonding (1, 2). Cheng et al. measured the thermodynamic surface free energy of aggregates using the universal sorption device to predict the most compatible asphalt-aggregate combination (8). Bhasin et al. used the same approach to determine the bond energy between the aggregate and asphalt (9). They found the same asphalt adheres differently to aggregate with various chemical compositions (9). It was shown the bond strength in reality is generally several orders of magnitude higher than the bond energy derived through this approach, this difference is attributed to a dissipative contribution (10). While the measured work of adhesion does not measure the real bond strength it can serve to check the adhesive-adhered compatibility.
To account for the dissipated energy, many mechanical testing methodologies have been used to measure adhesion. Masson and Lacasse used both a small scale and a full scale adhesion test to measure the level of sealant adhesion to heat-treated substrates (11). Using tensile force to bring an assembly of adhesive/adherend to failure is very common in the adhesive industry (e.g., pull out test, butt joint test). This method has received attention because it resembles crack/joint opening and contraction. Masson and Lacasse (11) and Zanzotto (12) independently measured the bond strength of sealants to concrete by bringing sealant-concrete assemblies to tensile failure. In both studies, bond strength was taken as the energy that is required to bring the assembly to failure. Traditional adhesive joint strength tests (e.g., butt tensile test, pull out test and lap shear test) continue to be used. However, because of their unknown stress distributions and mode-mixities at the interface, data from different geometries cannot be compared, so they are currently used as a qualitative method (4).
Another test is a fracture type test called blister test. This test can be used to predict the adhesion strength of an adhesive film deposited on or attached to a substrate. The blister test configuration has been widely used to predict adhesion strength in a variety of interlaminated structures, such as dental cements and teeth (13), thin film coatings (14), polymer composite and microelectronic devices (15, 16). This test can measure interfacial fracture energy (IFE), which is a fundamental property of the interface (4, 5). The principle of the test is to inject a
gas/liquid medium at the interface between the film and the substrate. In this study, tests were conducted at temperatures ranging from -4ºC to -40ºC. To conduct the test at such low temperatures, alcohol was selected as both the cooling and pressurizing medium, because its freezing temperature is relatively low. In addition, at low temperatures, it is nearly incompressible and does not react with sealant specimens during limited conditioning time. The principle of the test was to inject alcohol at the interface between the substrate (aggregate/aluminium) and the adhesive (crack sealant) to separate adhesive from the substrate. The fluid pressure and blister profile were measured as function of time and used to obtain the interfacial fracture energy.
3. Experimental Program
Three laboratory experiments were conducted to evaluate the bond between bituminous sealant and aggregates/aluminium. The three tests are designed to address the needs of producers, pavement engineers, and researchers, respectively.
1. First test determines the compatibility of sealants to aggregates having different chemical composition.
2. Second test is to qualitatively rank various sealants based on the maximum load and energy required to break their bonds to a reference substrate.
3. Third test is to quantify the interface bonding of each sealant to a reference material based on a fundamental property of the interface.
3.1 Surface Energy Approach
The sessile drop method was used to determine the surface energy of the hot-poured crack sealants and their contact angle to each substrate (wettability). Surface energy components of five different sealants were measured using this method (13). Each sealant was heated and mixed at the manufacturer’s recommended installation temperature and poured onto an aluminium sheet to form a thin, smooth surface. The sealants were cooled at room temperature to solidify and shaped into thin plates. A five-micrometer pipette was used to manually apply liquid drops from three probe liquids (water, formamide, and glycerol) onto the sealant plate. The image of each drop was captured by microscope within 15s after it was applied. For each sealant, the surface energy components were determined. Surface energy of each material is composed of a polar and a non-polar component; for instance, surface energy of probe liquid can be written as in Equation 1 (17). The surface energy of each sealant was calculated using Young- Dupré Equation. Young- Dupré equation is basically the sum of the individual surface energies for the two materials involved (i.e. sealant and probe liquids). Van Oss et al. presented the full version of the Young-Dupré Equation for interaction between a liquid droplet and solid surface in Equation 2 (2).
AB LW
l
γ
γ
γ
=
+
(1)where
γl is iquid surface energy (mJ/m 2
) γLW
denotes the Lifshitz-van der Waals component γAB is acid-base component
]
)
(
)
(
)
[(
)
cos
1
(
2
21+
+ − 12+
− + 21+
=
s l s l LW l LW s lθ
γ
γ
γ
γ
γ
γ
γ
(2) where γl LWis Lifshitz van der Waals (non-polar) component of the liquid γl
+
is acid (electron accepting) component of the liquid γl
-
γs LW, γ s +, and γ s -
are the solid surface energy components θ is contact angle between sealant and each probe liquid
Knowing the surface energy component of the three probe liquids (2), one can solve Equation 2 to determine the surface energy component of the sealant (γs
LW, γ s +, and γ s - ). Equation 3 can then be used to calculate the total surface energy of the sealant (solid), γs
total
. Following this approach surface energy of five sealants was measured using the aforementioned three probe liquids (Table 1).
2 1
)]
)(
[(
2
+ −+
=
s s LW s total sγ
γ
γ
γ
(3)To calculate the thermodynamic work of adhesion, Wa, between sealant and specific substrate, the contact angle between a sealant droplet and the substrate is measured. A droplet of liquid sealant is placed on the substrate and the angle between the droplet and the substrate is recorded. Knowing the surface energy of each sealant and the contact angle between sealant and specific substrate, Wa can be calculated using Equation 4. Using this method, work of adhesion between the aforementioned five sealants and four substrates (limestone, quartzite, granite, and aluminum) was measured and presented in Figure 1.
)
cos
1
(
θ
γ
+
=
total s aW
(4) whereWa is thermodynamic work of adhesion between sealant and substrate
θ is contact angle between sealant and substrate total
s
γ
is total surface energy of the sealantTable 1. Surface Energy and Its Components for Various Crack Sealants
γLW γ - γ + γ total Sealant (mJ/m2) (mJ/m2) (mJ/m2) (mJ/m2) BB 9.97 40.01 0.94 22.25 AE 43.99 5.21 4.36 53.53 ZZ 10.03 5.17 0.39 12.89 NN 6.63 19.99 0.37 12.06 UU 2.39 6.32 4.75 13.35
3.2 Direct Adhesion Test
The principle of this test is to bring a sealant-aggregate assembly to failure using tensile forces, for which a Direct Tension Tester (DTT) was used. To conduct the experiment, a testing fixture was developed to accommodate the DTT. The briquette assembly consists of two half-cylinder aggregates of 25mm diameter and 12mm length. Each aggregate is confined within an aluminum grip designed to work with the DTT sitting posts. The assembly has a half cylinder mold, open at the upper part. The mold is placed between the two aggregates on an even surface. In order to ensure adhesive failure will occur, a
pre-debonded area is made at one side of the sealant-aggregate interface. A 12.5-mm-long and 2-mm-deep notch is used at the upper edge of one of the aggregate-sealant interface to create the pre-deboned area. Each sealant is heated to the recommended pouring
temperature, mixed thoroughly and poured in the mold confined with two aggregates. After 1h of curing, the specimen is trimmed and kept in the DTT cooling bath for 15min; then it is demolded and placed back in the bath for 45min before testing. During the testing, aggregate end pieces are pulled apart by moving one of the end pieces at a speed of 0.05mm/s (strain rate of 0.005mm/mm/s), Figure 2. The force and displacement of the end pieces are used to calculate the maximum load and the energy to failure. The energy to failure is the area under the load-displacement curve calculated up to peak load and divided by contact area (Figure 3). 0 5 10 15 20 25 30 35 BB AE ZZ NN UU W o rk o f Ad hes io n ( m J/ m 2) Limestone Quartzite Granite Aluminum
Figure 1. Work of Adhesion between Sealants and Limestone, Quartzite, and Aluminum
Figure 2.Sealant-Aggregate/Aluminum Assembly during Testing and after Adhesive Failure
Notch
Figure 3. Maximum Load and Area under the Load-Displacement Curve
before the Peak Point (A Is the Contact Area between Aggregate and Sealant)
Follwoing this approach, tests were conducted on eight sealants which are widely used in various regions in North America. These sealants have various rheological characteristics, and are used in regions with lowest temperature between -4ºC to -40ºC. Bond chacteristics of sealants with aluminum was measured using the adhesion test setup. Maximum load and energy to failure was calculated for each pair. Figures 4 show the results for sealants at temperatures ranging from +2ºC to -34ºC. Statistical analysis showed that Pmax provided
better repeatability than E; it also can more clearly differentiate between sealants. Therefore, Pmax was selected as a parameter to rank the adhesion capability of various pairs of
(Figure 5). Each sealant was aged to simulate short-term aging in the kettle. Aging was conducted in accordance with the procedure developed by Masson and Al-Qadi (18). It is evident that bonding of the same sealant varies with substare. The chemical composition and surafce characteristics of the substrate affect the interface bonding. In addition, interface bonding varies with temperature and sealants property.
0 20 40 60 80 100 120 140 -4 -10 -16 -22 -28 -34 -40 Temperature (ºC) Pma x (N ) NN WW PP AE UU LL DD VV 0 20 40 60 80 100 120 140 -4 -10 -16 -22 -28 -34 Temperature (ºC) E n er gy (J/ m 2) NN WW PP AE UU LL DD VV E (a) (b)
Figure 4. Maximum Load (a) and Resultant Energy (b) Measured for the Interface bonding between Sealants and Aluminium
0 100 200 300 400
LLA-22 QQA-4 PPA-34
Pma x (N) Aluminum Limestone Granite Quartzite
Figure 5. Maximum Load Measured for the Interface bonding between Sealants and Substrates
3.3 Blister Test
A weak bond leads to cracks or delamination under loading; hence a practical fracture test can be an appropriate approach for assessing interfacial bonding (15). Therefore, the third test was to implement one of the fracture mechanics tests. Among potential tests, blister test was selected. The main advantage of this test is that it does not need any mechanical contact with sealant. In addition, due to the small peeling angle in blister test, in contrast to peel test, most of the energy is spent to break the bond instead of deforming the sealant. Furthermore, since the test environment at the interface is the pressurizing liquid, coupling effect of hydrostatic water pressure (if any) and traffic loading can be accounted for simultaneously using water as the pressurizing liquid. Finally, interfacial fracture energy (IEF), which can be calculated from the test, is a fundamental property of the interface.
In blister test, a servo-hydraulic system displaces a piston; the upward movement of the piston injects a constant volume of alcohol at the interface between the substrate and bituminous material through an orifice in the substrate. Alcohol pressure deforms the bituminous layer to form a blister (Figure 6). This blister keeps growing while its diameter is constant at the base (the bulging period of the test in which no debonding occurs). Displacement and the alcohol pressure are recorded during the bulging and can be used to calculate time dependent adhesive modulus. Figure 7a shows pressure versus blister
displacement for sealant UU at six temperatures at a loading rate of 0.6mm/s. The slope of these curves is directly related to the sealant modulus, Equation 5 (6). It can be seen that the slope of the curves decreases with time. In addition, as the temperature decreases, adhesive material becomes stiffer, and the slope of the curves (and, hence, the adhesive modulus) increases.
Figure 6. Schematic of the Blister Test
]
7
.
1
)
1
(
3
.
5
)
1
(
[
)
(
)
(
)
(
2 3 4 2h
a
v
h
a
v
t
d
t
p
t
E
=
−
+
+
(5) whereE (t) is time dependent modulus, P(t) is t alcohol pressure d(t) is blister height,
a is radius of the orifice in the aluminum plate, h is sealant/binder thickness, and
ν is Poisson ratio of sealant
As the piston moves upward, alcohol pressure increases until it reaches its maximum level, at which point bituminous material gradually starts debonding from the substrate. From that point on, the blister not only does grow vertically but also grows in the horizontal direction (Figure 7b). Knowing the sealant modulus, maximum pressure and corresponding blister height, IFE can be calculated for each sealant-substrate interface (Equation 6). For relatively long cracks, the last term in Equation 6 can be neglected. Rewriting Equation 6 in terms of blister height, it can be simplified as in Equation 7.
] ) 2 1 ( 2 10 ) 1 ( 3 3 32 ) 2 1 ( 3 3 [ ) ( 2
π
v h v a h v a t E a c p EIF
= − + + + − (6)c
d
c
p
IFE
=
0
.
5
(7) whereIFE is interfacial fracture energy pc is alcohol pressure at peak,
Follwoing this approach, 12 sealants were tested with aluminum. Interfacial fracture energy (IFE) of these sealants with aluminum was measured using the blister test (Figure 8). Statistical analysis showed IFE can clearly distinguish between various sealants. In addition, no significant differences was found between operators. To examine the effect of substare variation, tests were conducted for three aged sealants and four substrates (Figure 9). While sealant UU shows a good bond with quartzite, selant ZZ and AE adhere well to both quartzite and granite. In general quartzite shows the highest interface bonding while limestone and aluminum have the lowest values.
0 40 80 120 160 200 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Blister Height (mm) Pr es s u re (k Pa ) -4 ºC -10 ºC -16 ºC -22 ºC -28 ºC -34 ºC
(a) (b)
Figure 7. Pressure versus Displacement of the Blister during Bulging (a) And Debonding
Period (b) 0 50 100 150 200 250 300 350 2 -4 -10 -16 -22 IF E ( J /m 2) EE DD UU AB QQ 0 200 400 600 800 1000 1200 -22 -34 -40 IF E ( J /m 2) AD BB PP NN LL AE MM
Figure 8. IFE at Peak Pressure for Interface Bonding between Aluminium and Sealant
4. Field Comparison
Many attempts have been made to evaluate the field performance of different types of crack sealants installed in various configurations (19-21). Among those, studies conducted by Masson and his coworkers were used in this paper to validate laboratory results and compare laboratory ranking with those based on field observations (21).
Masson et al. (21) monitored, the debonding and pull-out lengths of 12 hot-poured bituminous crack sealants installed in the city of Montreal, Canada. All sealed cracks were routed, cleaned, and heat treated. Debonding (sealant is detached from the crack walls, but still is filling the crack) and pull-out (sealant is removed from the crack by passing traffic) lengths were periodically surveyed using a measuring wheel. The percent failure length were calculated per rout size and per crack orientation. For each sealant a performance index was calculated (Equation 8): ) ( 100 D nP PI = − + (8) where
PI is performance index,
D is percent debonded length of the sealant, and P is percent pull-out length,
n was taken as 4 (pull-out) or 1 (debonding)
0 100 200 300 400 500 600 700 800
Aluminum Limestone Quartzite Granite
IF E ( J /m 2) ZZA+8 UUA-16 AEA-34
Figure 9. Interfacial Fracture Energy (IFE) for Combinations of Three Sealants and Four
Substrates
Sealant performance varies significantly and the performance index found to be between 8 (very poor performance) and 75 (good performance). Using this index, several sealants were ranked as shown in Table 2 (21). This paper considers four of those sealants ranked by Masson et al. in addition to two sealants from the U.S. The compatibility and interface bonding of these sealants to aluminum was evaluated in the laboratory. Sealants at original status, laboratory aged, short-term and long-term field aged were tested using the three laboratory tests (Figure 10). Also, kettle aged sealants which were only available for the U.S. sealants were tested. Among those, sealant E was too soft and its excessive flow prevented any debonding to occur. Sealant G failed cohesively in the adhesion test and its result was discarded. The Wa (compatibility test), Pmax (adhesion test) and the IFE (blister test) results
for tested sealant-aluminum pairs are shown in Figure 13. Sealant PP showed the highest work of adhesion followed by LL, BB, A and G; with G having the lowest value among all. For the adhesion test, Pmax of laboratory-aged sealant found to be the highest for sealant LL
follwed by PP, B and A; while G failed cohesively and its results were discarded. For the blister test, , IFE of laboratory-aged sealant found to be the highest for sealant PP followed by B and LL; with A being relatively low and sealant G found to be the lowest. Using test results from each approach, field survey for Montreal sealant is reported in Table 2. Sealants were ranked and reported in Table 3; sealants PP and LL were monitored separately in the U.S. Base on the limited field performance observations, it appears that the ranking based on the laboratory testing is consistent with field performance.
0 1 2 3 4 5 6 7 8 LL PP A B G W o rk of Ad h e s ion (m J/ m 2)
0 20 40 60 80 100 120 140 160 180 200
Non-aged Oven-aged Kettle aged Short term Long Term
Pma x (N ) A B PP LL 0 200 400 600 800 1000 1200 1400
Unaged Oven Aged Kettle aged Short Term Long Term
IF E ( J/m 2) A B G PP LL
Figure 10-b.Pmax (a) and IFE (b) of the Sealant-Aluminium at Various Aging Conditioning
Table 2. Field Performance of Montreal Sealants (21)
Sealant De-bonding Pull-out Performance A 11 14 Poor B 22 1 Good E 20 2 Good G 36 14 Poor
Table 3. Laboratory Ranking Based on Three Laboratory Tests
Sealant Work of Adhesion (mJ/m2) Pmax (N) IFE (J/m2) Laboratory Ranking A 3.54 58.99 211.54 Fair B 6.78 156.99 638.95 Good G 1.11 50.11 100.67 Poor PP 7.59 168.62 1331.7 Good LL 6.50 181.38 619.68 Good
E pass pass Excellent
5. Summary
A major cause of bituminous crack sealant failure in the field is debonding of the sealant from the crack walls. The three laboratory tests, described in this paper, can serve to select sealants based on interface bonding capability. Tests are developed to address the need of producers, pavement engineers, and researchers, respectively.
The first test incorporates surface energy approach to calculate work of adhesion for each pair of sealant-substrate. Work of adhesion is a fundamental property of the bond which can be used as a compatibility measure. If sealant producers provide the compatibility index for their sealants with different aggregates, users can select the potential sealants for their specific geological condition. While compatibility of sealant with aggregate is required for sealant desirable performance, this parameter alone cannot ensure sealant performance. Therefore, it needs to be used in conjunction with a mechanical test. Two mechanical tests have been developed in this study. Considering that both tests utilize aluminum as substrate, the compatibility test is strongly needed as the first screening step.
The second test can rank different pairs of sealant-substrate based on their maximum load, Pmax and required energy to failure, E. It was found that maximum load can differentiate
between sealants more clearly; hence, it was selected as the second test’s parameter. The third test is the blister test. This test is self-contained and able to provide the sealant modulus and the interfacial fracture energy (IFE).
Tests were conducted using several sealant types with aluminum and three aggregate types, limestone, granite and quartzite. Aluminum was found to be an appropriate reference substrate. Laboratory results were in agreement with field performnce for evaluated sealants.
6. Acknowledgments
This research is sponsored by the Federal Highway Administration’s pooled-fund study TPF5 (045) and the US-Canadian Crack Sealant Consortium. The contribution of the participating states, industry, and provinces is acknowledged. The contents of this paper reflect the view of the authors, who are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Federal Highway Administration or the consortium members. This paper does not constitute a standard, specification, or regulation.
4. References
1. Masson, J-F., and Lacasse, M.A., “A Review of Adhesion Mechanisms at the Crack Sealant/Asphalt Concrete Interface”, Proceedings of the 3rd International Symposium on Durability of Building and Construction Sealants, A.T. Wolf, Ed., Fort Lauderdale, Florida, (2000) 259-274.
2. Van Oss, C. J., Chaudhury, M. K., and Good, R. J., “Interfacial Lifshitz-van der Waals and Polar Interactions in Macroscopic Systems”, In Chemical Reviews, 88(6) (1988) 927-941.
3. Fini, E., Al-Qadi, I. L. and Dessouky, S. H. “Adhesion of Hot-Poured Crack Sealant to Aggregate,” 85th Transportation Research Board Annual Meeting, paper 01020259, Washington, D.C. (2006).
4. Jiang, K.R., and Penn, L. S., “Use of the Blister Test to Study the Adhesion of Brittle Materials, Test Modification and Validation”, Journal of Adhesion, 32 (1990) 203-216. 5. Bennett, S. J., Devries, K. L. and Williams, M. L., “Adhesion Fracture Mechanics,”
International Journal of Fracture, 10 (1) (1974) 33–43.
6. Fini, E., Al-Qadi, I. L. and Masson, J-F. “A New Blister Test to Measure Bond Strength of Asphaltic Materials” Association of Asphalt Paving Technology (AAPT) Journal, 77 (2007) 2754-302.
7. Thelen, E. “Surface Energy and Adhesion Properties in Asphalt-Aggregate Systems”, 37th Annual Meeting Highway Research Board; Rheological and Adhesion
Characteristic of Asphalt, Bulletin 192 (1958).
8. Cheng, D. X., Little, D., Lytton, R., and Holste, J. C., “Surface Free Energy
Measurement of Aggregates and Its Application to Adhesion and Moisture Damage of Asphalt Aggregate Systems”, International Center for Aggregates Research, 9th annual symposium, Austin, Texas, (2001)
9. Bhasin, A., Masad, E., Little, D., and Lytton, R., “Limits on Adhesive Bond Energy for Improved Resistance of Hot Mix Asphalt to Moisture Damage”, the 85th
Transportation Research Board Annual Meetings, paper 01024807, Washington, D.C. (2006).
10. Galerie, A., Toscan, F., N’Dah, E., Przybylski, K., Wouters, Y., and Dupeux, M., “Measuring Adhesion of Cr2O3 and AL2O3 Scales on Fe-based Alloys”, Material Science Forum, 461 (2004) 631-638.
11. Masson, J-F., and Lacasse, M. A., “Effect of the Hot-Aired Lance on Crack Sealant Adhesion”, Journal of Transportation Engineering, 125 (1999) 357-363.
12. Zanzotto, L., “Laboratory Testing of Crack Sealing Materials for Flexible Pavement”, Transportation Association of Canada, Ottawa, Canada (1996).
13. Despain, R. R., DeVries, K. L., Luntz, R. D., and William, M. L. A Strength Comparison of Barnacle and Commercial Dental Cements, 49th International Association for Dental Research General Meeting, UTEC DO (1970) 70-195. 14. Dannenberg, H., “Measurement of Adhesion by a Blister Method”, Journal of Applied
Polymer Science, V (1961) 125-134.
15. Shirani, A., and Liechti, K. L., “A Calibrated Fracture Process Zone Model for Thin Film Blistering”, International Journal of Fracture, 93 (1998) 281-314.
16. Chu, Y. Z., and Durning, C. J., “Application of the Blister Test to the Study of Polymer-Polymer Adhesion”, Journal of Applied Polymer Science, 45 (1992) 1151-1164.
17. Fowkes, F. M., “Attractive Forces at Interfaces”, Industrial and Engineering Chemistry, 56(12) (1964) 40-52.
18. Masson, J-F., and Al-Qadi, I. L., “Long-Term Accelerated Aging and Low
Temperature BBR Testing of Sealants”, Internal Report, National Research Council of Canada, No. B5508.5, Ottawa, Canada (2004).
19. Belangie, M. C., and Anderson, D. I., “Crack Sealing Methods and Materials for Flexible Pavements”, Final Report, No. FHWA-UT-85-1, 74p, Utah Department of Transportation, Salt Lake City, UT (1985).
20. Cook, J. P., Weisgerber, F. E., and Minkarah, I. A., “Evaluation of Joint and Crack Sealants”, Report No. FHWA/OH-91/007, University of Cincinnati, Cincinnati, OH (1990).
21. Masson, J. F., Collins, P., and Légaré, P. P., “Performance of Pavement Crack Sealants in Cold Urban Conditions,” Canadian Journal of Civil Engineering, 26 (4) (1999) 395-401.
