WETFIX BE

Wetfix BE is Adhesion promoter for hot and warm mix, and for cold and warm mix based on soft bitumens or cut-backs. 
Wetfix BE is Adhesion promoter and coating aid for foamed asphalt cold mix.

Wetfix BE is liquid bonding agent for passive adhesion with good temperature stability at reasonable prices


Benefits and features of Wetfix BE
• Versatile product: Wetfix BE provides both active and passive adhesion and finds use in a wide range of asphalt mixtures and spray applications
• Value for money: Wetfix BE is a concentrated product with consequent low dosage and low treatment costs
• Heat stability: The performance is maintained after storage in hot bitumen
• Low volatility: The product does not contain solvents and has low volatility at hot mix temperatures
• Easy to use: The product has lower viscosity than other concentrated anti-strips

Dosage
Adhesion promoter for hot and warm mix:  0.1-0.5% basis binder
Adhesion promoter for patch mix and soft bitumen mix : 0.1-1.0% basis binder
Compaction aid for hot mix : 0.3-0.5% basis binder

Wetfix BE: Fatty acids, C18 unsaturated, reaction product with ammoniaethanolamine reaction by-products
Wetfix BE is Heat-Stable Adhesion Promoter for Bituminous Binders


Specification
Acid value, mgKOH/g <10 VE 2.013
Amine value, mg KOH/g 160-185 VE 2.018

Physical properties
Appearance at 25°C:  liquid
Flash point, °C : >218 (>424°F)
Pour point, °C : <-20 (-4°F)
Density, g/cc at 20°C: 0.98
Density, lbs/U.S. gal at 20°C: 8.18
Viscosity, mPa s (cP) at 20°C: Brookfield Spindle SC4-18 538
Physical properties are typical data based on our own measurements or derived from the literature. They do not constitute part of the delivery specification.

WHY DO WE NEED WETFIX BE ?
Drivers for improving adhesion
Growth in passenger and goods transport
Increased focus on durability of Asphalt Pavement due to demand for extended warranty times and Long Term Contracts
Varying aggregate and bitumen quality
Limited funds for road construction/maintenance
Environmental impact, paving operations consume a lot of energy and create emissions

Asphalt
Detailed description
Heat-Stable Adhesion Promoter for Bituminous Binders

Functions
Adhesion Promoter
Applications
Hot Mixes


Why
Bitumen is a hydrophobic or “oily” substance

Aggregate surfaces are hydrophilic
Aggregate surfaces prefer to be in contact with water rather than bitumen


The effect of water
Bitumen cannot displace moisture from a surface and so will not adhere to wet aggregates


Asphalt may seem like a fairly waterproof material…
…but water can enter the voids through various means
Percolation, Permeation
Surface water can penetrate asphalt
Capillary action
Water from sub-grade can rise up through asphalt
Water vapour
Moisture in the air can enter voids in asphalt and condense
Pumping action of traffic accelerates passage of water


Cationic adhesion promoters
Cationic adhesion promoters are fatty amine, amidoamine orimidazoline surfactants (surface active agents)
Hydrophobic tail
Fatty alkyl carbon chain
Hydrophilic (Cationic) head group “Amine”


Surfactants go to the interphase between hydrophobic (oil/bitumen) and hydrophilic (water/aggregate)


Adhesion promoter effect: 
Active adhesion
Aggregates are normally hydrophilic
Under normal circumstances, aggregates have a higher affinity for water than on oily substance such as bitumen
Active adhesion promoters decrease the contact angle between bitumen and aggregate allowing the bitumen to coat the aggregate – even in the presence of water

Wetting of bitumen to aggregate
Adhesion promoters decrease the contact angle between bitumen and aggregate allowing the bitumen to coat the aggregate – even in the presence of water


Adhesion promoter effect: 
Passive adhesion
Over time, water can displace bitumen from an aggregate surface – this is called stripping
Passive Adhesion Promoters strengthen the bond between bitumen and aggregate preventing stripping


Why use Adhesion Promoters?
Legislation
Adhesion to dry and wet aggregates
Prolong the life of asphalt pavements
Allows a wider selection of aggregates
Minimal additional cost

Asphalt Concrete Mix Performance-Wearing Course (AC-WC) using Concrete Waste as Course Aggregate with the Addition of Wetfix-Be 
Nailil Khairini Departement of Civil Engineering, Politeknik Negeri Bandung, Jawa Barat, Indonesia Corresponding author. 

ABSTRACT 
The impact of high rainfall and uncontrolled traffic loads, it is necessary to conduct research on the use of concrete waste materials as a substitute for coarse aggregates in order to reduce the limitations of natural aggregates and wetfix-be additives with the aim of increasing performance, strength, durability, stability, and AC-WC mixed resistance. 
This research was conducted using variations of 0%, 40%, 80% and 100% concrete waste. 
Variations of additives are 0.15%, 0.25%, 0.35% and 0.45% by weight of asphalt. 
The value of normal asphalt content obtained was 5.35% and the optimum asphalt content of 100% concrete waste was 5.60%. 
Marshall characteristic values include stability, flow, density, VFA and VIM, namely the variation using 100% concrete waste and wetfix-be additives (1322,617 kg, 3,883 mm, 2,222 gr / ml, 49,731 %, 12,225 %). normal variation (998.23 kg, 3,311mm, 2.455 gr / mm, 77,519 %, 3,672 %). 
Based on the results of the analysis, the variation of the mixture of 100% concrete waste and the addition of 0.25% wetfix-be has good durability.
Keywords: Concrete waste, wetfix-be, marshall characteristic, durability

Based on the results of research on the use of concrete waste as a substitute for coarse aggregate and wetfix-be additives on stability and durability of the AC-WC hot asphalt mixture using Pertamina Pen 60/70 asphalt, the Bandung State Polytechnic Laboratory can be taken as follows: 

1. Composition of normal asphalt mixture using 100% natural aggregate and 0% concrete waste with an optimum asphalt content of 5.35%. 
A variation mixture that uses 100% concrete waste and 0% natural aggregate, with an optimum asphalt concrete waste content of 5.6%.

2. Marshall characteristics of all variations in the mixture of KAO conditions, namely for the normal AC-WC variation, the initial stability value is 998.23 kg, the flow value is 3,311 mm, the dencity value is 2.455 gr / ml then the modified AC-WC variation mixture using 100% concrete waste and 0.25% wetfix-be with a stability value of 1322,617 kg, a flow value of 3.883 mm, a dencity value of 2.222 gr / ml. 
So that the parameters of the stiffness, strength and flexibility numbers of all mixture variations meet the requirements of the 2018 General Bina Marga Specifications.

3. The level of resistance and durability of the mixture to the effects of water undergoes a series of immersion periods, at a duration of 30 minutes, 1 day (24 hours), and 2 days (48 hours). Based on the results of the analysis, the variation of the mixture of 100% concrete waste and the addition of 0.25% wetfix-be has good durability. 
This is due to the nature of the wetfix-be itself, which is to minimize the damage caused by water


THE STUDY OF OPERATING CAPACITY OF ASPHALT CONCRETE MODIFIED WITH AN ADDITIVE WETFIX BE. 
The problem of increasing the operating capacity of asphalt pavements is very urgent. 
The practice of road construction shows that after the start of the operation there is rut formation on an asphalt surface and various defects and deformations, one of the main reasons for that is unsatisfactory adhesion of bitumen with a paving stone. 
One of the applied solution methods is the introduction of various modified additives in organic astringent. 
This paper presents the results of the study of the main physical, mechanical and operational properties of bitumen and asphalt concrete modified using an adhesive additive Wetfix BE. 

Results. 
The paper presents a theoretical review of ways to increase the deformation stability of asphalt surface in high temperatures suggested by the authors. 
The results of the experimental studies are shown according to the estimation of the influence of adhesive additive Wetfix BE to physical, mechanical and operational properties of the bitumen SRC 60/70 and hot thick asphalt concrete BTN C12,5. 

Conclusions. 
The results of the experimental research allow one to make a conclusion that application of an adhesive additive Wetfix BE bitumen adhesion with paving stone improves, the deformation stability of asphalt surface in high temperatures increases.

A significant positive effect was identified using an adhesive additive Wetfix BE in number of 0,2% on the bitumen mass for an increasing the operating capacity of asphalt pavements.
 

Storage and handling 
Wetfix BE may be stored in carbon steel tanks. 
Bulk storage should be maintained at 10-40°C (50-105°F). 
Avoid heating above 65°C (150°F). 
It is also recommended that the products packaged in IBC/drum are stored at the above recommended temperatures. 
If they are subjected to temperatures below the recommended range, they should be warmed to the recommended temperatures and mixed well before use. 
Wetfix BE contains amines and may cause severe irritation or burns to skin and eyes. Protective gloves and safety goggles must be used when handling this product. 
For further information consult the Safety Data Sheet.


Build long-lasting roads with Wetfix
Adhesion promoters for the asphalt industry

In 2008, we asked ourselves: how can we show the longlasting effect of using Wetfix? 
To demonstrate this, we conducted a durability study on the condition of 16-year-old asphalt that was treated with Wetfix. 
Adhesion promoters based on our Wetfix amine surfactants have been used for many years to enhance the bond between bitumen and aggregate in asphalt mixtures and other bituminous applications. 
Lab tests and anecdotal evidence from the field shows that Wetfix is effective as an adhesion promoter, but hard, measureable confirmation on long-term effectiveness is hard to come by. 
Industry experts and clients rightly demand definite proof, so we, along with the Swedish authorities, undertook a study to validate the effectiveness of Wetfix over the long term


Durability study at Swedish airport The study was carried out in 2008 on a Swedish airport site where the asphalt was laid in 1992. 
Rigorous lab tests at the time of installation showed there was a need to include our Wetfix product in the binder to meet durability specifications. 
The ratio of stiffness modulus at 10°C, before and after conditioning (10 x -20/+20°C freeze thaw cycles and 5 days soaking at 60°C) was determined, the so called ITSM ratio*. 
16 years later, cores were taken from the airport pavement and tested under exactly the same conditions as before. 
The results in figure 1 clearly show the initial gain in ITSM ratio that was obtained and that the same level of enhanced resistance to the elements is still present after all the years in service.

This study therefore provides clear evidence that amine adhesion promoters fortify the bond between bitumen and aggregate over the long term, significantly improving the durability of asphalt throughout its life. 
The addition of a small amount of Wetfix adhesion promoter to the binder, at little extra cost to the formulation, enables road constructors to produce asphalt with better long-term durability and a longer life cycle


WETFIX BE
Heat-Stable Adhesion Promoter for Bituminous Binders
Application WETFIX BE is a liquid additive, specially designed for hot-mixed asphalt where good heat stability is required.
WETFIX BE may be stored in hot bitumen for up to 5 days at temperatures up to 170ºC without significant loss of activity.

Dosage The dosage of WETFIX BE depends on the type of bitumen and aggregate used. Normally between 0.2 and 0.5% is added to the binder.

Physical
Properties
Appearance at 20ºC Brown, viscous liquid
Density at 20ºC, kg/m³ 980
Pour point, ºC <0
Flash point, ºC >100
Viscosity at 20ºC, cP 3000
Viscosity at 50ºC, cP 400
Note: Above values are average and subject to minor variations. 

Passive adhesion
Over time, water can displace bitumen from an aggregate surface – this is called stripping
Passive Adhesion Promoters create a chemical bond between bitumen and aggregate preventing stripping throughout the service life of the asphalt

The purpose of asphalt binder as a significant binder in road constructions is to permanently bind aggregates of different compositions and grain sizes. 
The asphalt binder itself does not have suitable adhesiveness, so after a period of time, bare grains can appear. 
This results in a gradual separation of the grains from an asphalt layer and the presence of potholes in a pavement. 
Adhesion promoters or adhesive agents are important and proven promoters in practice. 
They are substances mainly based on the fatty acids of polyamides which should increase the reliability of the asphalt’s binder adhesion to the aggregates, thus increasing the lifetime period of the asphalt mixture as well as its resistance to mechanical strain. 
The amount of a promoter or agent added to the asphalt mixture is negligible and constitutes about 0.3% of the asphalt’s binder weight. 
Nevertheless, even this quantity significantly increases the adhesive qualities of an asphalt binder. 
The article was created in cooperatation with the Slovak University of Technology, in Bratislava, Slovakia, and focuses on proving the new AD2 adhesive additive and comparing it with the Addibit and Wetfix BE promoters used on aggregates from the Skuteč - Litická and Bystřec quarries.

Keywords
Asphalt binders
Additives
Adhesion promoters
Adhesion assessment

Properties of Bituminous Binders Exposed to Ageing Process
Remisova, Eva; Holy, Michal
Abstract
During the production technology of asphalt mixture and road pavement construction, the bitumen binder is exposed to the influence of oxygen, and the oxidative aging of bitumen occurs.
Changes of bitumen as a result of phenomena associated with evaporation and oxidation changes express in hardening. 
To improve the quality of bitumen and asphalt mixtures, an organic and inorganic additive are added. 
The paper reviews the change in the properties of paving grade and polymer modified bitumen by the effect of aging and the change of bitumen properties with the Licomont BS100 and Wetfix BE additives. 
Additive Wetfix BE, improving adhesion between bitumen and aggregate, had little influence on the empirical properties of tested bitumens. 
The Licomont BS100 additive caused an increase of the softening point and reduced the viscosity at higher temperatures of 120 to 180 °C, which allows reducing the working temperatures during the production, laying and compaction of the asphalt mixtures. 
The results confirmed the hardening of the binder after both short and longterm aging, which was reflected by a decrease in penetration and an increase in the softening point. 
The effect of aging by RTFOT generally showed an increase in bitumen viscosity without and with the additives. 
The greatest increase in viscosity was for bitumen PmB 45/80-75, the smallest change in values was for bitumen 50/70. 
Additives added to bitumen decreased the viscosity, except for Wetfix BE in bitumen 35/50. 
By comparing the bitumen viscosity results after aging without and with additives, the effects of additives on the bitumen viscosity are less prominent than those of bitumen without aging. 
Only with the Wetfix BE additive in bitumen 50/70, the viscosity change of the aged binder was greater than that of the unaged one.


AkzoNobel Wetfix and Diamine products are a range of nitrogen (amine) and phosphorus based surfactant adhesion promoters that are added to the bitumen at levels of 0.3 to 0.5% w/w

For Hot Mixed Asphalt (Passive Adhesion with some active)
Wetfix BE
Wetfix AP17
Wetfix  AP55

For colder* applications (Active and passive adhesion)
Wetfix N422
Diamine OLBS
* Foam mix, patching mixtures, spray applications


AKZO-NOBEL Wetfix adhesives and Redicote emulsifiers are used for the production of bituminous emulsions, for asphalt in road construction and bituminous emulsions acting as preservation for buildings, among others.

Application / Product    Note
Primers
Redicote E-27    Emulsifier specially developed for primers and tack coats (meets DIN 52046)
Redicote E-4875    Liquid emulsifier (CSS) for mixing with fine-grained or reactive grit
Contact adhesives / tack coats
Redicote EM-44    Liquid emulsifier for emulsions (hard binders) with small particle size and low sedimentation (non-sticky tack coat).
Redicote E-9    Universally applicable, paste at reasonable prices
Redicote E-27    Emulsifier specially developed for primers and tack coats (meets DIN 52046)
Redicote 103    Paste for producing viscous emulsions. Co-emulsifier for Redicote E-9.
Surface dressing
Redicote E-9    Pasty emulsifier with good adhesion (antistripping effect) at reasonable prices
Redicote EM-44    Efficient, readily processable liquid emulsifier for low-viscose emulsions
Redicote EM-22    Liquid emulsifier (CRS) for emulsions (with low viscosity and) with low breaking index BI
Redicote RM 007    Liquid emulsifier (CRS) for quickly breaking emulsion with high viscosity
Redicote 103    Paste. Alone or as co-emulsifier for high-viscose emulsions
Cold recycling / cold recycling mixes
Redicote E-11(-HF)    Liquid emulsifier. First choice for recycling mixes with and without cement. Also for soil stabilisation.
Redicote E-4875    Liquid emulsifier for very slowly breaking emulsions (CSS) for solvent-free, stable mixes (see also cold mix, grave emulsion)
Redicote EM-33    Liquid to pasty emulsifier based on polyamine
Redicote 611    Liquid non-flammable emulsifier for slowly breaking emulsions (CSS, open-graded cold mix)
Grave emulsion Soil stabilisation Dense-graded cold mix
Redicote E-4875    Liquid emulsifier for very slowly breaking emulsions (CSS) for solvent-free, stable mixes
Redicote EM-33    Liquid to pasty emulsifier based on polyamine
Slurry seal
Redicote E-11(-HF)    Liquid emulsifier (CSS) for mixes, a somewhat longer pot life allows manual work
Redicote 404    Liquid emulsifier for slowly breaking emulsions (CSS)
Thin layers with cold placement (DSK) / Slurry surfacing micro-surfacing
Redicote 404    Liquid emulsifier for slowly breaking emulsions (CSS) for mixes with or without cement
Redicote E-11(-HF)    Liquid emulsifier (CSS) for mixes, a somewhat longer pot life allows manual work, retarder for processing on site
Redicote 611    Liquid non-flammable emulsifier for slowly breaking emulsions (CSS, retarder for processing on site)
Product    Note    Storage stability in bitumen approx. 150 °C
Hot Mix
Wetfix AP 17    Liquid, low-odour bonding agent for passive adhesion with excellent temperature stability    5 - 7 days
Wetfix AP 40    Liquid, low-odour bonding agent for passive adhesion with excellent temperature stability    5 - 7 days
Wetfix BE    Liquid bonding agent for passive adhesion with good temperature stability at reasonable prices    3 - 5 days
Wetfix N 422    Universally applicable, liquid bonding agent for active and passive adhesion with good temperature stability    3 - 5 days
Cut-back bitumen, flux bitumen / Soft bitumen mixes, cut-back
Wetfix BE    Liquid bonding agent for passive adhesion with good temperature stability at reasonable prices    3 - 5 days
Wetfix N 422    Universally applicable, liquid bonding agent for active and passive adhesion with good temperature stability    3 - 5 days
Diamine HBG    Solid bonding agent (in bags) for active adhesion, favourable for manual feeding    < 24 hours
Diamine OLBS    Liquid bonding agent with excellent active adhesion    < 24 hours
Foamed bitumen / Foam mix
Wetfix N 422    Universally applicable, liquid bonding agent for active and passive adhesion with good temperature stability    3 - 5 days
Wetfix N    Liquid bonding agent for active and passive adhesion with good temperature stability    3 - 5 days
Diamine OLBS    Liquid bonding agent with excellent active adhesion    < 24 hours
Diamine HBG    Solid bonding agent (in bags) for active adhesion, favourable for manual feeding    < 24 hours
Surface dressing
Diamine OLBS    Liquid bonding agent with excellent active adhesion    < 24 hours
Diamine HBG    Solid bonding agent (in bags) for active adhesion, favourable for manual feeding    < 24 hours
Wetfix N    Liquid bonding agent for very good active and good passive adhesion with high temperature stability    3 - 5 days
Wetfix N 422    Universally applicable, liquid bonding agent for active and passive adhesion with good temperature stability, recommended for dosing in the depot or at the refinery    3 - 5 days
Pre-coating
Diamine OLBS    Liquid bonding agent with excellent active adhesion    < 24 hours
Wetfix N 422    Universally applicable, liquid bonding agent for active and passive adhesion    3 - 5 days
Emulsions
Diamine OLBS    Liquid bonding agent with excellent active adhesion for emulsions of the highest quality    < 24 hours
Wetfix N    Liquid bonding agent for active and passive adhesion with good temperature stability    3 - 5 days
Wetfix N 422    Universally applicable, liquid bonding agent for active and passive adhesion with good temperature stability    3 - 5 days


Road damages commonly found in Indonesia include surface damages that occur too early, as indicated by surface exfoliation, surface rutting, particle discharge and cracks. 
Based on a laboratory-scaled study at the Road and Bridge Research and Development Center in 2009, local aggregates of Central Kalimantan in Lupu, Runtu and Bukit Sintang quarries generally meet the requirements of road pavement materials. 
However, as part of asphalt mixtures, these aggregates fail to meet the requirement as they produce only 80 percent asphalt-aggrate adhesion, and Marshall’s stability index of 40 percent. 
Adhesion of up to 95 percent and residual stability index of 90 percent require a particular type of additives. 
This research was conducted in a laboratory by implementing Marshall method. 
The objective of this research is to identify the characteristics of surface layers of HRS-WC mixture at optimum bitumen content levels. 
Shell asphalt was used with a penetration of 60/70, coarse aggregates and fillers (rock ash) from Hampangen, fine aggregates from Tangkiling, and the anti-striping Wetfix Be additive. 
The results show that for an asphalt concrete surface layer (HRS-WC) with the addition of Wetfix Be of up to 0.2 percent the optimum bitumen content is 6.60 percent, with Wetfix BE of 0.4percentthe optimum bitumen content is 6.65 percent, and with Wetfix Be of 0.6 to 0.8 percent the optimum bitumen content is 6.7 percent. 
The stability index shows that the higher the of Wetfix Be content is, the lower the stability index will be. 
The highest stability index,that is 1370 kg, is obtained without any addition of Wetfix Be, while the lowest stability index,namely 1170 kg, is obtained by adding Wetfix BE as much as 0.8 percent of the mixture.
A series of void in mixture (VIM) tests without the addition of Wetfix BE resulted in a 3.80-percent absolute density and adding Wetfix Be up to 0.8 percent of the mixture resulted in a 3.60-percent absolute density. 
The result of tests on the HRS-WC durability show that without the addition of Wetfix Be the retained stability index is 86 persent, which does not meet the requirement (that is < 90 percent). 
Adding Wetfix Be of 0.2 percent increases this index to 91 percent, adding Wetfix Be of 0.4 percent increases this index to 97 percent, and adding Wetfix Be of 0.8 percent increases this index to 95 percent. 
This suggests that the HRS-WC mixture using local aggregates from Hampangen and Tangkiling sand requires Wetfix Be additive to meet the durability requirements of HRS-WC mixture.

Stripping of an asphalt mixture is reached when the interaction between bitumen and aggregate weakens by effect of water. 
The identification of bitumen–aggregate pairs with higher adhesion is key to obtain pavements that are more resistant to stripping. 
In order to research the adhesion and debonding processes further, several bitumen and aggregate combinations were prepared and their compatibility was estimated by means of surface energy measurements. 
Additionally, the water susceptibility of the proposed bitumen–aggregate combinations was mechanically tested by means of loss in storage modulus of samples exposed to water. 
It was found that the compatibility of water to bitumen and aggregate describes the mechanical behaviour of the asphalt mixture. 
One of the features of this study is the evaluation of the effect of physicochemical properties of bitumen and aggregates on the striping susceptibility of the given combinations and the corresponding correlation to the field performance of an asphalt mixture. 
Keywords: bitumen–aggregate compatibility; moisture damage; asphalt mixture; dynamic modulus; surface energy


Introduction Moisture damage is a failure mode that affects a large number of pavements throughout the world. 
The process starts in the bottom of the asphalt layer, by weakening the adhesive bond between bitumen and aggregate, and the cohesive bond of the asphalt mastic (Das, Baaj, Kringos, & Tighe, 2015). 
The progression of moisture damage in a pavement is reflected in the stripping of bitumen, ravelling of aggregates, proneness to deformation and cracking, among others (Canestrari, Cardone, Graziani, Santagata, & Bahia, 2010; Caro, Masad, Bhasin, & Little, 2008; Cho & Kim, 2010; Hicks, Santucci, & Aschenbrener, 2003; Meor, Muhammad-Rafiq, & Mohd-Rosli, 2015). 
Therefore, the consequences of moisture damage might be as severe as the total loss of the asphalt mixture (Airey & Choi, 2002). 
From a broader perspective, moisture damage can be considered as a distress affecting society in many ways. 
Economically, moisture damage costs millions of dollars in terms of required maintenance and rehabilitation of the affected pavements (Abuawad, Al-Qadi, & Trepanier, 2015). 
Furthermore, in many cases, additional investments are required to prevent damage such as the use of antistrip agents (Hicks et al., 2003). 
The resulting distresses from moisture damage reduce the durability of roads, which impacts the *Corresponding author. 
Baldi-Sevilla et al. quality of life of users, and in the overall perception of the national infrastructure which can severely impact a country’s competitiveness.
Consequently, it is imperative to characterise the moisture susceptibility of asphalt mixtures, as well as to predict the sensitivity of a particular mixture to deteriorate in the presence of water. 
Therefore, the main objective of this study is to estimate the bitumen–aggregate compatibility in hot mix asphalt by means of physicochemical measurements, and to relate the results to the mechanical changes in the mixture associated with moisture-induced damage. 
Background Mechanical evaluation of moisture damage susceptibility 
An asphalt mixture exposed to moisture experiences several physical and chemical processes that deteriorate its fundamental properties. 
Such processes occur simultaneously by means of mechanisms which are not fully understood. 
As a result, achieving a mechanical test that reasonably simulates these distresses has become a challenge to many researchers. 
In this sense, the dynamic modulus of the asphalt mixture has shown good correlation to the observed rutting and fatigue cracking in field tests (Witczak, Kaloush, Pellinen, El-Basyouny, & Von Quintus, 2002), and has been recommended as a primary material characterisation test in a hot mix asphalt (Solaimanian, Bonaquist, & Tandon, 2007). 
For such reasons, determination of dynamic modulus might represent an enhancement in moisture susceptibility evaluation of specimens subjected to severe humid conditioning (Vargas-Nordcbeck, Leiva-Villacorta, Aguiar-Moya, & Loria-Salazar, 2016). 
The loss in strength of an asphalt mixture due to the effect of water might be related to the weakening in adhesion and cohesion of the asphalt mastic. 
It has been observed that mixtures with poor adhesion characteristics show poor mechanical performance, and that the presence of moisture in the mastic reduces its flexibility and binding properties (Das et al., 2015). 
In addition, other mixture properties such as high void content and large water diffusion coefficients (Castillo, Caro, Darabi, & Masad, 2016), as well as the ageing of the asphalt mixture (Tong, Luo, & Lytton, 2015), have shown to increase the susceptibility of mixtures to moisture-induced damage. 
Therefore, the failure of an asphalt mixture by effect of water cannot be related to a singular process. 
However, by characterising the properties of materials involved, the water resistance of a certain mixture can be approximated and related to its final field performance. 
Compatibility between bitumen and aggregate The bitumen and the mineral aggregates are two different materials which do not tend to adhere spontaneously at room temperature. 
The reason for such behaviour goes beyond the high viscosity of bitumen, which impedes its ascension by capillarity into the pores of the aggregate. 
More accurately, it is a matter of chemical compatibility. 
During hot mix asphalt production, the bitumen and the aggregate are forced to combine by increasing the temperature. 
Once the mix returns to typical ambient temperatures, the adhesive bond between bitumen and aggregate is defined by their compatibility: a bitumen–aggregate pair with good compatibility is believed to have better adhesion properties and to be less prone to collapse in the presence of water. 
Therefore, it is imperative to improve the quality of the interaction between bitumen and aggregate by improving their compatibility. 
This could be achieved by the proper selection of materials to be used in the asphalt mix design. 
By accounting for the physicochemical surface characteristics of bitumen and aggregate (i.e. surface energy), it is possible to estimate the blend’s compatibility. 
The surface energy is a Road Materials and Pavement Design 3 property inherent to all materials and is defined by the nature and magnitude of the chemical interactions occurring at the surface. 
By definition, the total surface energy (γ T or simply γ ) is the sum of dispersive (γ LW), acidic (γ +) and basic (γ −) interactions (Equation 1) (Van Oss, Chaudhury, & Good, 1988). γ T = γ LW + 2(γ +γ −) 1/2 . 
(1) The surface energy of the individual components such as bitumen, aggregate and water is also useful to estimate the interactions taking place in a hot mix asphalt, such as adhesion (denoted as work of adhesion, WAB) (Equation 2) and stripping potential of the bitumen in the presence of water (denoted as work of debonding, Wwet) (Equation 3). 
WAB = γA + γB − γAB, (2) Wwet = γAW + γBW − γAB, (3) where the subscripts A, B and W refer to aggregate, bitumen and water, respectively; γ AB, γ AW and γ BW are the energies (in mJ/m2) of the aggregate–bitumen, aggregate–water and bitumen– water interfaces, respectively. 
A bitumen–aggregate pair with good compatibility will exhibit higher values of work of adhesion. 
However, simultaneous to the bitumen–aggregate adhesion process, water is also competing to reach a thermodynamic favourable condition in detriment of the adhesive bond between bitumen and aggregate. 
In order to avoid the latter, the work of debonding must be as low as possible. 
Since the adhesion–debonding processes occur simultaneously, the energy ratio parameter (ERP) (Equation 4) acts as a convenient parameter to estimate the resistance of the bitumen–aggregate interface to collapse in the presence of water. 
The higher the ERP of a given blend, the more resistant it will be to develop moisture-induced damage (Bhasin, Little, Vasconcelos, & Masad, 2007). ERP = WAB − WBB WWET , (4) where WBB in Equation (4) refers to the internal cohesion of bitumen, which can be defined as per Equation (5) (Little & Bhasin, 2006). WBB = 2γB


WETFIX BE prevents stripping of asphalt from aggregate.
Abstract
Stripping of an asphalt mixture is reached when the interaction between bitumen and aggregate weakens by effect of water. 
The identification of bitumen–aggregate pairs with higher adhesion is key to obtain pavements that are more resistant to stripping. 
In order to research the adhesion and debonding processes further, several bitumen and aggregate combinations were prepared and their compatibility was estimated by means of surface energy measurements. 
Additionally, the water susceptibility of the proposed bitumen–aggregate combinations was mechanically tested by means of loss in storage modulus of samples exposed to water. 
It was found that the compatibility of water to bitumen and aggregate describes the mechanical behaviour of the asphalt mixture. 
One of the features of this study is the evaluation of the effect of physicochemical properties of bitumen and aggregates on the striping susceptibility of the given combinations and the corresponding correlation to the field performance of an asphalt mixture.

Bu internet sitesinde sizlere daha iyi hizmet sunulabilmesi için çerezler kullanılmaktadır. Çerezler hakkında detaylı bilgi almak için Kişisel Verilerin Korunması Kanunu mevzuat metnini inceleyebilirsiniz.