Asphalt modifier
Gilsonite in Asphalt modifier
Use Gilsonite in Asphalt binder and recycled asphalt to build roads that last.
High-performance road surfaces have long been made possible with the use of Gilsonite. Gilsonite’s superior properties make it the go-to modifier for hot mix pavements and pavement sealers.
As it is practical to add Gilsonite to Slurry to make cheaper bitumen, Gilsonite can also be applied in asphalt application, making cheaper and enhanced asphalt. Applying Gilsonite to asphalt modifier is simple since it can be put directly into the hot mix at the factory or the project site. Gilsonite (natural Bitumen) content will react immediately with molecules and creates higher modules decreasing the thickness of asphalt while gaining superior properties. This will eventually result in having cheaper asphalt which easily passes the international standards.
Interesting Fact:
Researchers show applying Gilsonite in Asphalt Binder is successful in high-performance temperature while it does not affect in low-performance temperature.
Also while in North America a low ash content Gilsonite is used for this application, in China it has been proven that the asphalt binder can take up to Ash 20% Gilsonite with 80-100 mesh. However, at the moment the technology is limited to a single company only. Also, there has been successful testing of Ash 10% natural bitumen in India & Iran for asphalt modifier. In case the suppliers can prove their technical performance, Gilsonite as asphalt binder will be a very common and economical product worldwide. Considering the low Gilsonite Price from the mentioned sources and high ash content of the Gilsonite applied, this practice will result in elevated performance and is cost-effective as well.
Another Gilsonite application on asphalt is to make Pavement Sealer or generally called Gilsonite Sealer based on bituminous materials. This task is done in order to increase the lifetime of a pavement. The product is used at the consumer level and is sold in tool shops all over the American continent.
Among the components defining natural bitumen, there are Asphaltenes which can be found within the chemical structure. Since the route of Gilsonite is from Crude Oil, it is solvable in any oil matters which are tested by Solubility in TCE & CS2.
Gilsonite powder can be added into the hot mix or at the Asphalt manufacturing facility into the asphalt material and it can improve the asphalt on 3 levels: Base Course, Binder Course, and Wearing Course
Gilsonite is used as a performance-enhancing agent for asphalt mixes. Gilsonite-modified paving mixes achieve higher PG grades and incorporate perfectly into the asphalt blend with no need for high shear milling as is the case with many other modifiers. Gilsonite-modified asphalts have higher stability, reduced deformation, reduced temperature susceptibility and increased resistance to water stripping than non-modified asphalts. Gilsonite is also used to make both solvent-based and emulsion pavement sealers with superior appearance and weathering properties.
High-Strength, High-Performance roads that stand the test of time.
High-performance road surfaces have long been made possible with the use of Gilsonite. Gilsonite’s superior properties make it the go-to modifier for hot mix pavements and pavement sealers.
Gilsonite is used in asphalt mix as an agent for increasing the efficiency and productivity. The asphalt mixed with the high content of Gilsonite without adding any other balancing materials so that it becomes a highly solid material. Gilsonite as an additive in the total of or portion regarding value and cost can replace SBS polymers in asphalt modifiers. Asphalt modified by Gilsonite have a higher stability, lower shape changes, stability against low temperatures and higher resistance against water compared to asphalts void of Gilsonite. In fact, the main task of Gilsonite in this application is to improve the stability of pavements and their resistance against shape changes which increases the ability to withstand high applied load and it is used in areas under high pressure. There are almost 35 different replacements for Gilsonite, but since their ratios of cost to benefit are higher than Gilsonite’s, Gilsonite is more often used.
HOT MIX
As an asphalt modifier, the unique properties of Gilsonite make a road that is less susceptible to high-temperature and deformation performance issues. When these modified binders are used in recycled asphalt pavements, Gilsonite adds back what time has taken from the old asphalt, making it easier to use more of this recycled material. The Gilsonite-modified asphalt binder will produce a stronger road that can be thinner by nearly 20 percent compared with other pavements. As an aggregate modifier, Gilsonite can be added directly at the hot mix plant with no additional equipment. The excellent bonding properties of Gilsonite will produce a high-strength, high-performance pavement that also resists water stripping.
PAVEMENT SEALERS
Gilsonite’s proven properties make high-performance solvent-based and emulsion pavement sealers dry quicker, look better and last longer. Gilsonite is Naturally Better. As a natural antioxidant, it allows pavement sealers to stay blacker longer. Gilsonite’s unique molecular fractions rejuvenate the pavement being sealed. The strong bonding properties of Gilsonite help weatherproof the sealer. Making longer-lasting pavement helps the environment. By rejuvenating pavements with recycled asphalt instead of replacing them, there is a proven significant reduction in energy used as well as a reduction in required resources. For further information.
Advantages of Applying Gilsonite in Asphalt modifier:
- Applying Gilsonite in Asphalt modifier increases the bonding inside the asphalt.
- Reduced pavement thickness. It can decrease the thickness while preserving the specifications of the asphalt.
- High strength and durability; Gilsonite Binder increase asphalt life.
- Gilsonite Modifier can be used to make Gilsonite Sealer suitable for Pavement repairs.
- Gilsonite can be mixed with SBS polymers to obtain more economical combined grades.
- High strength and durability.
- Superior deformation performance.
- Reduced temperature susceptibility.
- Increased resistance to water stripping.
Formulation and Performance Characteristics of Gilsonite- Modified Asphalts
Gilsonite-Modified-Asphalts (GMAs) exhibit generally significantly improved high-temperature properties. Because Gilsonite addition changes the oil-to-asphaltene content the low and intermediate temperature properties may potentially be adversely affected. However, when using the modifier at levels ranging between 1 to 4% in conventional asphalts our research indicates that the natural balance of the various asphalt constituents is maintained.
Formulation and Performance Characteristics of Gilsonite- Modified Hot Mix Asphalt
- Improved Marshall Stability: addition of Gilsonite can dramatically raise the stability of pavement mix. 8% Gilsonite (a typical level of addition) will increase Marshall stability by approximately 25% to 40%. This converts a standard pavement into a high-performance pavement.
- Water Sensitivity: the use of Gilsonite offers another important benefit: reducing the water sensitivity of the mix. Tests were conducted with a granite gneiss known to be highly water sensitive. Marshall stabilities were tested both with a standard 30-minute immersion in 25°C water and with a 24-hour water immersion at 60°C. The data shown below indicates that the mix without Gilsonite never achieves an adequate wet stability level. Gilsonite addition, even at a modest 4% level, produces considerably higher wet stability values
- Dynamic Modulus Studies: Dynamic modulus testing shows that Gilsonite increases the complex module of hot mixes in a way that strongly suggests increased fatigue life in commercial practice. These tests evaluate the dynamic modulus of mixes modified with Gilsonite and with Gilsonite/polymer combinations. When used with polymers, Gilsonite appears to selectively increase modulus at high temperatures, which suggests an even higher level of improvement in pavement resistance to rutting and shoving.
- Fatigue Studies: The table below shows tests that were conducted at three temperatures and three frequencies, simulating fast-moving, moderate-moving and stop-and-go traffic conditions. From these data, an Asphalt Institute computer program was used to calculate estimated fatigue. While these calculations can only be considered a laboratory indicator of actual pavement performance under stressed conditions, the results are sufficiently encouraging to be reported. It is demonstrated how the pavement lifetime is forecast to increase approximately 25% due to Gilsonite modification. In commercial experience, the pavement lifetime increase is usually between 100% and 200% when rutting and shoving are the original causes of the pavement failure.
- Permanent Deformation Studies: Conventional binders were compared with polymer-modified and with systems modified with a combination of polymer and Gilsonite. Our wheel tracking results suggest excellent deformation resistance and superior overall pavement performance. The test conditions included a wheel load of 70 kilograms passing over the sample at 21 rpms for 60 minutes at 60°C.The test was performed on a matrix of binders containing Gilsonite, SBS, EVA and their respective combinations as shown in the table below. All blends, (except #10) utilized a 70-pen base asphalt. The wheel tracking data shows that best results were obtained with Blend #3 (8% Gilsonite) and Blend # 5 (6% Gilsonite and 2% SBS). The latter even outperformed the blend containing 4% SBS (# 6).
Laboratory Handling for Preparation of Gilsonite-Modified Asphalt
The asphalt should be heated to a temperature ranging between 190°C (374ºF) to 205°C (401°F). A paddle mixer is sufficient and no high shear blending is required. We recommend reacting the blend for a minimum of two hours at the above-mentioned temperature. No additional modification steps are generally required.
Purpose Of Gilsonite Modification Of Asphalt Pavement Mixtures
- Improved resistance to deformation
- Improved the economic performance of the road
- Improved resistance to stripping
- Improved resistance to fatigue
- Improved durability
- Compensation for poor mix design
- Compensation for poor aggregates
