Effect of Emulsion Type on Bond Behavior of Asphalt Concrete Layers in Cold Regions

2019 ◽  
Vol 2673 (2) ◽  
pp. 368-378
Author(s):  
Laura Stasiuk ◽  
Haithem Soliman ◽  
Ania Anthony
Keyword(s):  
Bond Strength ◽  
Asphalt Concrete ◽  
Failure Surface ◽  
Type B ◽  
Cold Regions ◽  
Modes Of Failure ◽  
Peak Shear Stress ◽  
Tack Coat ◽  
Interlayer Shear Strength ◽  
Term Performance

Tack coat materials, which are typically emulsified bituminous products, are used to provide a sufficient bond between asphalt concrete (AC) layers/lifts. Owing to construction limitations and severe temperature variations in cold regions, agencies are investigating the use of fast curing and non-tracking emulsions as tack coat materials. The objective of this study is to evaluate the performance of various tack coat products in cold climates. Several tack coat products were installed during a field study in Saskatchewan, Canada. The tack coat products included slow setting, medium setting, and three proprietary fast curing/non-tracking emulsions. Core samples were collected three weeks after construction to evaluate the initial interlayer shear strength (ISS) for typical construction conditions in cold regions. Although the ISS values for all of the products, except one SS-1 section, varied in a narrow range, this does not indicate that all products will have a similar long-term performance. The modes of failure for the bond strength samples were classified into two types according to the shape and location of the failure surface: type A and type B. Failure type B indicates that the tack coat material can successfully provide sufficient bond strength to make the two AC lifts behave as one thick homogenous layer. The results showed that the failure mode should be included as an evaluation criterion in addition to ISS. The results showed that the energy required to reach peak shear stress is a comprehensive parameter that should also be considered when evaluating tack coat materials.

scholarly journals Assessing the Influence of Moisture Damage under Repeated Load on Multilayer Interface Bond Strength of Asphalt Concrete

2020 ◽  
Vol 26 (11) ◽  
pp. 21-42
Author(s):  
Samah Abdul razzaq Alnuami ◽  
Saad Issa Sarsam
Keyword(s):  
Bond Strength ◽  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Moisture Damage ◽  
Application Rates ◽  
Tack Coat ◽  
Interface Bond Strength ◽  
Repeated Load ◽  
Moisture Conditions ◽  
Interface Bond

The performance and durability of the asphalt pavement structure mainly depend on the strength of the bonding between the layers. Such a bond is achieved through the use of an adhesive material (tack coat) to bond the asphalt layers. The main objective of this study is to evaluate the effect of moisture in conjunction with repeated traffic loads on the strength of the bonding between asphalt layers using two types of tack coats with different application rates. Using the nominal maximum size of aggregate (NMAS), the layers were graded (25/19) and (19/9.5) mm. The slabs of multilayer asphalt concrete were prepared using a roller compactor using two types of tack coats to bond between layers, namely rapid curing cut back asphalt (RC-70) and cationic medium setting emulsion (CMS), with different application rates.  Six extruded cores with a diameter of 116 mm each form the prepared slab has been obtained. Core specimens were subjected to moisture damage according to the American Association of State Highway and Transportation Officials (AASHTO), after which repeated bond shear stresses and monotonic tests are practiced. It is concluded that permanent deformation increased with moisture-induction under repeated load for both interfaces and tack coat types. The (CMS) as a tack coat had less permanent deformation values than RC-70 for both interface types and all application rates. In contrast, the interface bond strength (IBS) value was higher than that for (RC-70) in both interface types after moisture conditions. The trend of the results illustrates that (IBS) decreased with moisture conditions under repeated load, as compared to samples under repeated load only.

scholarly journals Influence of Surface Texture on Interface Bond Shear Strength of Asphalt Concrete

2020 ◽  
Vol 1 (3) ◽  
pp. 8-14
Author(s):  
Saad Issa Sarsam
Keyword(s):  
Shear Strength ◽  
Bond Strength ◽  
Surface Texture ◽  
Asphalt Concrete ◽  
Maximum Size ◽  
Application Rate ◽  
Application Rates ◽  
Tack Coat ◽  
Base Course ◽  
Interface Bond

The bonding strength provided by the tack coat between asphalt concrete layers at the interface is considered as an essential issue in the performance of the flexible pavement throughout its service life. However, the surface texture of the pavement surface exhibits another essential issue in the bond strength. In this investigation, three layers of asphalt concrete (base, binder and wearing) courses with (25, 19, and 12.5) mm of nominal maximum size of aggregates have been prepared using roller compactor. Rapid curing cutback RC-70 and cationic medium setting emulsion CMS have been implemented as tack coats with three application rates. The slab specimens were subjected to mean texture depth determination using sand patch method. Core specimens of 102 mm diameter were obtained from the prepared slab samples and subjected to interface bond strength test with the aid of a special manufactured mold. Test results were analyzed and compared. It was concluded that when RC-70 tack coat was implemented, asphalt concrete binder course laid on base course exhibited the highest shear strength of 1600 kPa at an application rate of 0.33 liter/m2 when compared to other application rates. Asphalt concrete wearing course laid on binder course exhibited the highest shear strength of 1515 kPa at an application rate of 0.15 liter/m2 when compared to other application rates. When CMS tack coat was implemented, asphalt concrete binder course laid on base course exhibited the highest shear strength of 1620 kPa at an application rate of 0.23 liter/m2 when compared to other application rates. Finally, the asphalt concrete wearing course laid on binder course exhibited the highest shear strength of 2272 kPa at an application rate of 0.23 liter/m2 when compared to other application rates.

Interfacial Nanoleakage and Bonding of Self-Adhesive Systems Cured with a Modified-Layering Technique to Dentin of Weakened Roots

2013 ◽  
Vol 38 (5) ◽  
pp. E154-E165 ◽  
Author(s):  
E Mobarak ◽  
R Seyam
Keyword(s):  
Bond Strength ◽  
Repeated Measures ◽  
Adhesive Systems ◽  
Root Canals ◽  
Root Region ◽  
Modes Of Failure ◽  
Group A ◽  
Post Hoc ◽  
Vertise Flow ◽  
Self Etch

SUMMARY Objective The purpose of the study was to evaluate the nanoleakage and bond strength of different self adhesive systems cured with a modified-layering technique (MLT) to dentin of weakened roots. Methods Twenty-one maxillary incisors were decoronated and then root canals were instrumented and obturated with the cold lateral compaction technique. Weakened roots were simulated by flaring root canals until only 1 mm dentin thickness remained. Teeth were distributed into three groups. The canals were backfilled with Vertise Flow (VF group), a self-adhering system, following a modified-layering technique using two light-transmitting posts, sizes 6 and 3. DT Light Post size 2 was cemented using the same material. Remaining roots were prepared and cured in the same way as the VF group. However, in the TS/MF group, Clearfil Tri-S Bond (TS) adhesive and Clearfil Majesty Flow (MF) composite were used, while in the ED/PF group, ED primer II (ED)/Panavia F2.0 (PF) were used. After one week of storage, each root was sectioned to obtain six slices (two slices from each root third: coronal, middle and apical) of 0.9 ± 0.1 mm thickness. Interfacial nanoleakage expression was analyzed using a field emission scanning electron microscope (FEG-SEM), and the micro push-out bond strength (μPOBS) was measured at different root regions. Modes of failure were also determined using SEM. Data were statistically analyzed using two-way analysis of variance with repeated measures and Tukey post hoc test (p≤0.05). Results With MLT, all adhesive systems showed nanoleakage. For μPOBS, there was a statistically significant effect for adhesive systems (p<0.001) but not for root region (p<0.64) or for their interaction (p=0.99). Tukey post hoc test revealed that the bond strength of the VF group was significantly higher than the TS/MF and ED/PF groups for all root regions. Conclusion All of the tested self-adhesive systems cured using MLT had slight nanoleakage and were not sensitive to root regional differences. Self-adhering systems had higher bond strength than self-etch adhesives.

A Review on Role of Aluminum Matrix Materials, Failure Causes and Optimization Techniques

2021 ◽  
Vol 6 (3) ◽  
pp. 1-11
Author(s):  
Tilahun Y ◽  
◽  
Mesfin G ◽  
Keyword(s):  
Failure Modes ◽  
Matrix Material ◽  
Aluminum Matrix ◽  
Ductile Failure ◽  
Failure Surface ◽  
Optimization Techniques ◽  
Alloy Matrix ◽  
Modes Of Failure ◽  
Causes Of Failure

Aluminum is a metal matrix material which is widely used in different industrial as well as engineering applications.it has a great advantage due to its remarkable properties like less density, formability, and light in weight, recyclability and other properties. but, failure of aluminum matrix materials are the main problems in aluminum industries now a days.in this review role of aluminum and its alloys as matrix materials, their failure modes, causes of failure and optimization techniques to minimize this failure modes and causes of failure are discussed. Sources are reviewed which are from 2005 to recent one. Consequently, most modes of failure, causes of failure and most optimization techniques of aluminum and its alloy matrix materials are found. most modes of failure are mechanical related like fatigue failure, surface cracking, ductile failure, porosity formation, and stress related like stress corrosion cracking, surface weakness due to repeated stresses and other factors are summarized.in causes of failure mostly like corrosion formation, wear formation and poor mechanical properties are discussed.

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