Bitumen Emulsion
Bitumen emulsion disperses bitumen in water, offering versatility in content (30%-70%) without heating requirements.
Overview
Understanding Bitumen Emulsion Properties and Application
In emulsions of oil-in-water, bitumen is typically dispersed in minute droplets of water and is a form of oil.
There can be a wide range of bitumen content to suit different requirements, often ranging between 30% and 70%. Bitumen Emulsion has its primary purpose the production of a product that doesn’t require heating, as is normally required when using cutbacks and paving grade bitumen.
The emulsifying chemical (emulsifier) in water is used to shear hot bitumen into emulsions with hot water. Dispersed bitumen (the dispersed phase) dispersed in water (the continuous phase) is produced through this process. Since the emulsifier is concentrated on the surface of the bitumen particles, the bitumen particles are stabilized in suspension and do not readily coalesce.
The water in a bitumen emulsion evaporates or separates from the bitumen during application depending on the surface the emulsion is applied to. We call this process breaking. In an emulsion, bitumen droplets tend to segregate slowly when stored, since the density of bitumen is slightly higher than water. When emulsions have been stored for a long time, they can usually be successfully regenerated by stirring gently to redisperse the bitumen droplets.
Uses of Bitumen Emulsions are:
- Bitumen emulsion UAE is used extensively in bituminous road construction. Other than this, they are used for maintenance and repair work.
- Emulsions can be used in wet weather even if it is raining.
- Is eco-friendly as it is water-based.
- Bitumen emulation is also used in soil stabilization in desert areas.
- It doesn't need extra heat while placing.
- There is no wastage in the placing and laying of bitumen.
- They possess anti-stripping properties.
- Rapid setting types of emulsions are used on the surface of roads.
- Medium setting types of emulsions are used in the premixing of bitumen emulsion and coarse aggregate.
- Slow setting types of emulsions are used with fine aggregates as the surface area is large and requires time for uniform mixing.
The Applications for Bitumen Emulsion
There are many different types of Bitumen Emulsions that can be applied for a variety of uses including:
- Light, medium & heavy traffic
- Asphalt Tack Coat
- Pavement Rejuvenation
- Dust Suppression
- Unsealed Road Binding
- Precoating of aggregate
- Crack Sealing
- Ingredient in the production of cold paving products e.g. Micro-Surfacing & Cold Mix Asphalt
Types of Bitumen Emulsion
Based on Setting Time
Bitumen emulsions are used for paving roads because they allow water to evaporate leaving behind droplets of bitumen. They spread on the surface of the aggregate and bind together to form a solid aggregate. By determining the setting time for the vitamin emulsion to evaporate the water and the time for the particles to separate from the water, it is possible to further classify bitumen emulsions into three categories:
- Slow setting emulsion: The emulsion is slowing the evaporation of water by using a special kind of emulsifier. Compared to other types of emulsifiers, this one shows relatively stable properties.
- Medium setting emulsion: In contrast with aggregate, this bitumen emulsion doesn't break when applied. Evaporation begins once the aggregate emulsion mix is mixed with a fine dust of minerals.
- Rapid setting emulsion: A bitumen emulsion of this type breaks down rapidly when it comes into contact with aggregate, giving a fast setting time and increasing the speed of curing.
Based on Surface Charge
- Anionic Bitumen Emulsion: Adsorption of cations by bitumen droplets causes the water to become negatively ionized during emulsion production. Fast setting emulsions have undeniably the most comprehensive range of applications.
- Cationic Bitumen Emulsion: Usually, fatty acid and resin acid-alkaline salts are used. Saponification of liquid resin, also known as Tall-Oil, results in these products. Paper pulp is a by-product of the pulp industry derived from resinous wood treated with sulphite. This by-product contains residual, distilled substances.
- Hydrophilic polar groups make up the Co2Na group. Soap molecules in continual solvent solutions become ionized; Na (or K) ions are adsorbed by the water, whereas the remaining molecules are adsorbed by the bitumen globules.
The characteristics of an emulsion are designated by the terms rapid (R), medium (M), and slow (S). The main grades for bitumen emulsions are classified as follows:
Electronegative recharging of the tiny bitumen droplets is present in anionic bitumen emulsion. The tiny droplets of bitumen in Cationic bitumen emulsion are electropositively charged. In general, cationic between emulsions are used as the average and most popular between emulsions. When the bituminous emulsion is used on aggregate that is silica-rich, the surface of silica is charging, and therefore cationic bitumen emulsion is selected, which aids in spreading and adhesion of bitumen with aggregates.
In this type of emulsion, a special type of emulsifier is used to slow the process of water evaporation. This type of emulsifier is relatively stable
| Cationic Emulsions | Anionic Emulsions | |||||
|---|---|---|---|---|---|---|
| Rapid Settings (RS) Type | CRS-1 | CRS-2 | RS-1 | RS-2 | ||
| Medium Settings (MS) Type | CMS-2 | MS-2 | ||||
| Slow Settings (SS) Type | CSS-1 | CSS-1h | Modified CSS-1h | SS-1 | SS-1h | Modified SS-1h |
What factors are important in grading bitumen emulsion?
Viscosity
As a prerequisite to grading bitumen emulsion, a high degree of viscosity must be achieved. Bitumen content determines the viscosity of the bitumen emulsion. The lower viscosity of bitumen emulsion is required for dense graded aggregates; however, higher viscosity of bitumen emulsion is required for open-graded aggregates. A higher viscosity will occur if an emulsion has a small droplet size and narrow distribution.
Ductility
An elongation test is used to determine the hardness of bitumen. In this test, samples of bitumen are stretched up to a certain length before they break. With a bitumen emulsion whose ductility exceeds 40 cm, the surface of the road is safe from heavy vehicles and won’t crack easily. Those with low ductility values may crack when exposed to cold weather.
Penetration
When a standard needle is inserted into bitumen, it displays its softness level. As the temperature rises, the harder the bitumen is, the better it performs. It is possible for bitumen emulsions of different grades to penetrate at different depths.
Storage stability
During storage, this parameter evaluates the stability of bitumen emulsion. A characteristic of bitumen emulsion droplets after manufacturing is storage stability, otherwise known as sedimentation. As part of the sedimentation test, a sample of bitumen emulsion is stored in a compressed cylinder at room temperature. The next day, we will collect two samples: one from the top and one from the bottom of the cylinder. The next step is to compare the weights of the two samples. One unit should not be different between the weights of the two samples. The viscosity level and the droplet size play a major role in bitumen emulsion storage stability. The risk of settlement is lower with bitumen that has smaller droplets. To know more about storage stability, contact top bitumen suppliers in the UAE.
Applications of Bitumen Emulsions in Bituminous (asphalt) Pavement Construction and Maintenance:
Tack Coat
The tacky coat (also called bond coat) is an asphalt emulsion application applied between hot mix asphalt layers in order to create an adhesive bond that won’t slip. The product can also be used as a sealing paint around patches or under porous layers. Unless tack sheets are applied to asphalt layers, these layers may separate, which could result in a reduction of road structural integrity as well as water penetration. Depending on the country, tack coat emulsions might differ. As a general rule, slow-setting emulsions are used in the USA and diluted with water before application. Several European countries use undiluted cationic rapid setting or specially formulated medium viscosity, low viscosity emulsions for this purpose.
Prime Coat
The primer coat helps reduce dust and protects the granular base during construction. Priming is necessary when a hot mix layer is to be applied over the surface or if a chip seal is to be used to reinforce a low-volume driveway. Otherwise, the seal would tend to delaminate from the surface beneath it. Emulsion primes are more environmentally friendly than cutback asphalt primers. Asphalt emulsions (diluted with water before being applied) with slow setting characteristics are appropriate. Often, with dense or stabilized granular bases, scarifying is needed before application in order to maximize penetration.
Uses of emulsion
| Anionic | Cationic | |||||
| RS | MS | SS | RS | MS | SS | |
| Plant Mixes | ||||||
| Open-graded | ||||||
| Dense-graded | ||||||
| Reclaimed asphalt pavement (RAP) | ||||||
| Stockpile mix | ||||||
| Pre-coated chips | ||||||
| Mix Paving | ||||||
| Open-graded | ||||||
| Slurry | ||||||
| Slurry for capeseal | ||||||
| Micro surfacing | ||||||
| In-Place Mixes | ||||||
| RAP | ||||||
| Dense-graded | ||||||
| Soil stabilization | ||||||
| Spray Applications | ||||||
| Chipseal | ||||||
| Fog seal–cement curing | ||||||
| Tack coat | ||||||
| Prime | ||||||
| Dust palliative | ||||||
| Mulch | ||||||
| Penetration macadam | ||||||
| Other | ||||||
| Waterproofing coatings | ||||||
| Driveway and footpath sealers | ||||||
Get in touch
Your Gateway to Top-Quality Bitumen
Elevate your projects with Gulf Bitumen’s superior quality and expertise. Contact us now to access top-notch bitumen solutions tailored to your needs.