scholarly journals Assessing the Effect of Nano Hydrophobic Silane Silica on Aggregate-Bitumen Interface Bond Strength in the Spring-Thaw Season

2019 ◽  
Vol 9 (12) ◽  
pp. 2393 ◽  
Author(s):  
Wei Guo ◽  
Xuedong Guo ◽  
Jilu Li ◽  
Yingsong Li ◽  
Mingzhi Sun ◽  
...  
Keyword(s):  
Shear Strength ◽  
Bond Strength ◽  
Moisture Damage ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Modified Asphalt ◽  
Bonding Failure ◽  
Interface Bond Strength ◽  
Hydrophobic Silane ◽  
Interface Bond

In the asphalt–aggregate system, the aggregate-bitumen interface cohesive and adhesive bond determine the mechanical properties of asphalt pavement. The presence of moisture leading to adhesive failure at the binder-aggregate interface and/or cohesive failure within the binder or binder-filler mastic is the main mechanisms of moisture damage in the spring-thaw season. In order to evaluate the effect of nano hydrophobic silane silica (NHSS) on aggregate-bitumen interface bond strength in the spring-thaw season, an aggregate-bitumen interface bond strength test was proposed to quantify the interface bond strength of base asphalt and NHSS modified asphalt. Then, the effect of temperature, freeze-thawing cycles and moisture on aggregate-bitumen interface shear strength of base asphalt and NHSS modified asphalt was also discussed. The results illustrated that the shear failure dominated the aggregate-bitumen interface bonding failure in the spring-thaw season, and temperature and moisture had a significant effect on interface shear strength of modified and unmodified asphalt. Moreover, the addition of NHSS could increase the aggregate-bitumen interface shear strength under any working conditions. Furthermore, the moisture damage model of aggregate-bitumen interface shear strength of base asphalt (BA) and NHSS modified asphalt was established based on a research method combining numerical calculations and laboratory tests.

Effects of Tack Coat Application on Interface Bond Strength and Short-Term Pavement Performance

2017 ◽  
Vol 2633 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Ramendra Das ◽  
Louay N. Mohammad ◽  
Mostafa Elseifi ◽  
Wei Cao ◽  
Samuel B. Cooper
Keyword(s):  
Shear Strength ◽  
Bond Strength ◽  
Pavement Performance ◽  
Interface Bonding ◽  
Short Term ◽  
Surface Type ◽  
Tack Coat ◽  
Interface Bond Strength ◽  
Interface Bond ◽  
Coat Material

The objectives of this study were to evaluate the effects of pavement surface type, tack coat material, and application rate on the interface bond strength between a hot-mix asphalt overlay and underlying pavement layers in the field. The effects of interface bonding on short-term pavement performance were also investigated. Three field projects that included 14 in-service test sections were constructed with four types of emulsified tack coats applied at different residual application rates. Specimens were cored from the test sections, and the interface shear strength (ISS) was measured at different service times with a direct shear test device, the Louisiana interlayer shear strength tester. The results of the study showed that, with respect to surface type, the ISS was largely dependent on the type of pavement surface receiving tack coat materials and surface texture. With respect to tack coat material type, the use of a nontracking (rapidly setting) tack coat resulted in a greater ISS than the use of slowly setting (SS-1 and SS-1H) tack coats, a result that was primarily attributed to the stiffer base asphalt cement used in the nontracking tack coat material. With respect to the effects of service time, the interface bonding strength increased with service time in all field projects and for all surface types. This phenomenon was primarily attributed to tack coat curing, which was more pronounced with slowly setting tack coat materials. Laboratory ISS test results correlated well with short-term field performance. All test sections except those that did not meet the minimum ISS threshold of 40 psi, recommended by NCHRP Project 9-40, exhibited satisfactory cracking performance.

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.

Influence of revision arthroplasty on bone/cement interface shear strength

1987 ◽  
Vol 20 (8) ◽  
pp. 824
Author(s):  
J.E. Bechtold ◽  
Y. Dohmae ◽  
R.E. Sherman ◽  
R.B. Gustilo
Keyword(s):  
Shear Strength ◽  
Bone Cement ◽  
Revision Arthroplasty ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Cement Interface

scholarly journals Skewness and Kurtosis: Important Parameters in the Characterization of Dental Implant Surface Roughness—A Computer Simulation

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Karl Niklas Hansson ◽  
Stig Hansson
Keyword(s):  
Surface Roughness ◽  
Shear Strength ◽  
Roughness Parameter ◽  
Interface Shear Strength ◽  
Interface Shear ◽  
Implant Surface ◽  
Bone Response ◽  
Dental Implant Surface ◽  
Skewness And Kurtosis

The surface roughness affects the bone response to dental implants. A primary aim of the roughness is to increase the bone-implant interface shear strength. Surface roughness is generally characterized by means of surface roughness parameters. It was demonstrated that the normally used parameters cannot discriminate between surfaces expected to give a high interface shear strength from surfaces expected to give a low interface shear strength. It was further demonstrated that the skewness parameter can do this discrimination. A problem with this parameter is that it is sensitive to isolated peaks and valleys. Another roughness parameter which on theoretical grounds can be supposed to give valuable information on the quality of a rough surface is kurtosis. This parameter is also sensitive to isolated peaks and valleys. An implant surface was assumed to have a fairly well-defined and homogenous “semiperiodic” surface roughness upon which isolated peaks were superimposed. In a computerized simulation, it was demonstrated that by using small sampling lengths during measurement, it should be possible to get accurate values of the skewness and kurtosis parameters.

Investigation into Shear Experiment on Interface between Asphalt Pavement and Concrete Bridge Deck

2011 ◽  
Vol 197-198 ◽  
pp. 1435-1442
Author(s):  
Hong Fu Liu ◽  
Jian Long Zheng ◽  
Guo Ping Qian ◽  
Yun Yong Huang
Keyword(s):  
Shear Strength ◽  
Asphalt Pavement ◽  
Adhesive Layer ◽  
Interface Shear ◽  
Contact State ◽  
Modified Asphalt ◽  
Interface Contact ◽  
Concrete Bridge Deck ◽  
Sbs Modified Asphalt ◽  
Concrete Deck

This paper describes the laboratory measurement of shear interface properties between asphalt pavement and concrete bridge deck using the shear test. The main factors affecting shear strength are interface frictional resistance and adhesive stress from material of waterproof layer. Firstly, we simplify the whole system by considering the asphalt pavement as an elastic layer and the cement concrete deck a rigid base. And make a sensitivity analysis on interface contact state and the material modulus of waterproof layer. The maximum shear stress increases as interface contact state changes from continuous to smooth and as modulus of waterproof layer material decreases. Secondly, an interface shear experiment is conducted with the application of portable shear apparatus. With interface shear strength as evaluation indicator, shear strength of different interface treatments is arranged in descending order, i.e. cleaning up laitance and spreading aggregate between layers; only cleaning-up laitance; leaving the surface untreated. While the descending order for shear strength of different waterproof materials can be listed as follows: SBS modified asphalt, penetration grade of 70 asphalt. Therefore, based on the laboratory test results, it is recommended that before applying waterproof adhesive layer, laitance and dust on concrete deck surface should be cleaned up and keeping it dry. And the material for waterproof adhesive layer should be SBS modified asphalt with one-size aggregate of 4.75mm-9.5 mm spreading on.

scholarly journals Influence of Ageing on Flexible Pavement Interface Bond under Repeated Shear Stresses

2020 ◽  
Vol 2 (2) ◽  
pp. 462-475
Author(s):  
Saad Issa Sarsam ◽  
Samah Abdulrazzaq AL Nuaimi
Keyword(s):  
Shear Strength ◽  
Permanent Deformation ◽  
Research Work ◽  
Application Rate ◽  
Shear Stresses ◽  
Interface Shear ◽  
Concrete Core ◽  
Application Rates ◽  
Tack Coat ◽  
Interface Bond

The durability of interface bond was not sufficiently taken into consideration, and the research work in this field is scares and scattered. The interface bond usually practices dynamic shear stresses throughout its service life while ageing due to volatilization provide stiffness at the interface. In this investigation, an attempt has been made to assess the durability of the interface bond in terms of resistance to ageing under repeated shear stresses. Two types of tack coat (Rapid Curing cutback RC-70 and Cationic Medium setting emulsion CMS) and three application rates have been implemented in the preparation of two layers slab samples (base overlaid by binder, and binder overlaid by wearing) courses using roller compactor. Asphalt concrete core specimens were obtained from the roller compacted slab samples and subjected to long term ageing, then the specimens were subjected to 1200 repeated shear stress cycles. The accumulation of permanent deformation was monitored. Afterwards, the specimens were tested for interface shear strength at 20 °C. Control specimens were also tested for comparison. It was concluded that ageing reduces the total microstrain for RC-70 tack coat by (43.6, 25.6, and 29.5) % and (50, 51.3, and 30.2) % for (binder-base) and (wearing-binder) interfaces for the application rate of (0.15, 0.33, 0.5) l/m2  respectively. However, ageing reduces the total microstrain for CMS tack coat by (37, 35.5, and 40.3) % and (45.2 , 49, and 46.8) % for (binder-base) and (wearing-binder) interfaces for the application rate of (0.1, 0.23, 0.35) l/m2  respectively. Ageing increases the interface bond shear strength by a range of (8-27)% for various interfaces, tack coat type and application rates.

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