In this article, we are going to talk in detail about the effects of gilsonite in asphalt paving
As you know, natural asphalt is a natural hydrocarbon that is extracted from the mines of the Middle East . Natural asphalt has a very effective role in various industries. It is also widely used in the asphalt production industry .
The melting point of Gilsonite is about 180-205 degrees Celsius . gilsonite prevents the softening of asphalt, especially in the tropics. Natural asphalt is provided in the form of mass and powder. Therefore, it is very effective in beautifying asphalt.
GILSONITE BENEFITS IN ASPHALT PAVEMENT
The University of Nevada-Reno conducted a study on natural asphalt in 2015. They proved that gilsonite-modified bitumen significantly increases the service life of asphalt pavement. This is good news for companies looking to cut costs.
Also companies that are thinking about long-term maintenance of road pavements.
This experiment showed that Gilsonite-modified adhesives show great improvement in the following cases:
Addition of natural asphalt increases the tensile strength of road asphalt.
modified Bitumen with natural asphalt has a significant improvement in compressive strength
Predicted pavement life with Gilsonite modified adhesives is 1.5 to 5 times longer.
Gilsonite-modified binders increased projected pavement life. adding Natural asphalt yielded a ten-fold increase.
Asphalt powder reduces material and saves money .
The lifespan of Gilsonite modified asphalt is twice that of an unmodified mixture.
Also, the high modulus provided by Natural asphalt allows the base and binder courses to be up to 20% thinner .
so, it has shown the same efficiency and makes less materials needed for this.
According to research conducted by researchers,
natural asphalt can increase the viscosity of asphalt well. so, the road is well resistant to climate change, oxidation and deformation. Hence natural asphalt is a cheap mineral.
Gilsonite can also be compatible with SBS polymers. It therefore acts as an enhancer alongside SBS polymers.
Because it significantly increases the useful life of asphalt pavement. It also allows pavement materials to be reduced to produce the asphalt needed.
Gilsonite Powder is superior for recycling asphalt
Gilsonite is a good choice for creating quality asphalt pavements. Because it can stabilize it well. this making recycled asphalt as strong and durable as new. In this process . so, the molecules of the polymer-modified binders can be bonded to a matrix through each other . at result recycled binder cannot bond with leaving pavement vulnerable to breakdown . benefits of Natural asphalt as the best additive
- Superior deformation resistance
- Safe and environmentally responsible
- High strength and fatigue resistance Increased resistance to water stripping
- Reduced pavement thickness
- Reduced temperature susceptibility
Gilsonite has many advantages in the production of asphalt, which we will mention .
In this case, you can reduce the cost of repairing and replacing asphalt by 70% . Experts usually use gilsonite to compensate for poor mix designs
Natural asphalt is very resistant to road deformation. So, using Natural asphalt greatly increases the life of the road.
Gilsonite is well resistant to water and road oxidation
Gilsonite can also greatly reduce the risk of fractures at low and cold temperatures..
Natural Asphalt is proven to perform
Natural asphalt can perform very well against climate change,
especially high temperatures, and does not deform . at result you can added directly at the hot mix plant without extra equipment.
Gilsonite strengthens roads and increases the life of asphalt
Natural asphalt has a stronger bond that can last 25 years.
so, sbs polymers are so expensive that they cost more than three times as much as natural asphalt. A more cost-effective solution is to combine Natural asphalt and SBS polymers to achieve the desired grade
Asphalt with Gilsonite resists rutting
(This is in contrast to other RAP-based modifications)
Natural asphalt increases the viscosity of asphalt.
so, roads are resistant to fatigue as well as deformation. Even in conditions of temperature changes
natural asphalt outperforms other bitumen modifiers
- Gilsonite with its unique properties, resists oxidation well and makes asphalt last longer.
- Ideal softening point for bitumen modification
- Unique source with high purity deposits
- Extracted with little contamination
Specialists performed their experiments based on adding Gilsonite to 60/70 pure bitumen
and Gilsonite-modified bitumen concluded that:
- This mineral asphalt can reduce the penetration of 60/70 pure bitumen
- Natural asphalt powder increases the hardening rate of pure bitumen
- bitumen powder increases the viscosity of pure bitumen by 60/70
- Natural asphalt powder increases the thermal sensitivity index of pure bitumen
- Gilsonite powder also does not affect the ignition rate of pure bitumen, which is a very positive point.
Beautiful roads with long life
Gilsonite is a naturally occurring hydrocarbon resin . so that adds tremendous strength, durability, and longevity to asphalt roads. Natural asphalt is a low-cost mineral that improves asphalt performance. Gilsonite modified asphalt improve strength, reduce slipperiness and crack asphalt. Experts have used Natural asphalt as an additive to increase the performance of asphalt pavements for many years.
Key points of the study
The evaluation was conducted under rigorous standards:
The researchers prepared and presented two samples of Gilsonite modified asphalt :
* PG76-16, This sample is for Gilsonite modified asphalt from 76 to 16 degrees Celsius.
* PG64-28 This sample is for Gilsonite modified asphalt at 64 ° C to 28 ° C;
All asphalt connectors follow the specifications of state highway agencies with the Super Pave PG system.
> The researchers measured the properties of asphalt in their OBCs. This study can be seen in the E * curve of the dynamic module
> Asphalt mix performance tester (AMPT) was used for this study.
The experts used the Superpave volumetric mixture design method. This design was to study asphalt mixtures and the optimal content of binders
> Specialists evaluated the asphalt mixture using the following characteristics:
Resistance to loosening, resistance to cracking and breakage. Also fatigue resistance
Natural asphalt has long been used to increase the performance of asphalt binders. Now, the respected study has documented its advantages.
Superpave PG used in testing uses the rheological properties of the asphalt binder to identify its performance
You can see the characteristics of the connectors used in the experiment in the table below
According to the evaluations, adding mineral asphalt to PG 76-16 mixture causes asphalt binders . this mixture is less susceptible to short-term and long-term aging.
The industry standard
Experts typically use Superpave Performance Grading in different countries for asphalt binders properties.
Tests showed that the OBC was comparable to control samples and asphalt modified samples.
PG Mixtures 64-28 should be hydrated with lime to improve performance. (to meet moisture sensitivity specifications)
Gilsonite modified binders cause improvement in both tensile strength (TS)
also cause unconfined compressive strength (UCS) .
optimum binder contents and lime contents,
The properties of UCS as well as TS conditioning of different mixtures are summarized:
Dynamic modulus (E*) represents strength and stability
AASHTO uses the dynamic modulus (E*) master curve as the engineering property of
the asphalt concrete layer to test the structural response of asphalt pavement. this test is under various combinations of traffic loads , speed, and environmental conditions.
According to the experiment, the higher E * property indicates a stronger and more stable composition of asphalt
this mix leads to lower stresses generated in the asphalt pavement
under given loading and environmental conditions. According to the main curve data in the figure below you can see that:
the Natural asphalt mixture compared to the control mixtures over the entire range of loading frequency :
exhibit significantly higher E* properties
Capturing a range of variables
You can see different combinations of load frequency and temperature in the dynamic module curve
Feature E * Mixtures at 10 Hz loading frequency
here truck traveling at 60 mph (108 kph) . The 104° F (40° C) and 70° F (21° C) temperatures . You can see that they are the critical temperature of relaxation as well as fatigue, respectively. Natural asphalt helps reduce rutting Gilsonite increases the viscosity of asphalt . Gilsonite modified asphalt withstands temperatures that are very high and easily deformed.
Resistance to rutting
You can see the roughness models of the mixtures in the figure below, which they have compared. so the Natural asphalt mix would offer higher resistance to rutting. The modified mixture with asphalt powder PG 76-16 showed a higher roughness model at 40 ° C than the mixture .
You can see that adding gilsonite to the PG76-16 mixture causes:
The current increases by 66% at 60 ° C
. The addition of asphalt powder to the PG64-28 mixture resisted the tertiary flow at 48°C (118°F). so modified Gilsonite mixtures are more resistant to grooving at high pavement temperatures.
Number of flow mixtures:
Relevant sample preparation
Since rutting is an early pavement life failure, the mixtures for the flow number test were only short-term aged.
Resistance to thermal cracking
specialists measured the temperature at which fracturing occurred .
also they checked out the stress required to start fractures .
( To determine an asphalt mixture’s ability for withstand low temperatures without cracking ).
In the PG64-28 samples:
both the control and the gilsonite modified binders exceeded cold temperature specifications . so were not expected to crack .
PG 76-16 sample of natural asphalt caused cracking at 2 ° C warmer than the specification. so the calculated crack initiation energy was 20% higher than the control. at result it would not be expected to crack under normal conditions. Investigated mixtures and thermal cracking properties
Resistance to fatigue cracking
experts evaluated The resistance of the various mixtures to fatigue and cracking . so, the researchers measured the initial flexural stiffness in the 50th cycle with the studies performed. Fatigue failure was defined as the number of cycles corresponding to a 50% reduction in the initial stiffness. You can see a comparison of the fatigue models of the mixtures below. According to studies, cycle-to-failure tests have provided traceable results
In the PG64-28 mixtures:
the control sample exhibited slightly higher fatigue relationships than the asphalt mixture. For higher E * in Gilsonite modified asphalt the calculated values are not calculated.
Specialists in PG76-16 and PG64-28 mixtures tested fatigue crack models at 21.11 ° C
As a result, the proper time for cracking is fatigue and thermal cracking after about five years. The experimental mixtures were aged accordingly.
This analysis examines the effect of real conditions
Also to sophisticated laboratory tests, the university’s evaluation included mechanistic analysis. A lab test designed to the fatigue cracking models of two asphalt mixtures .
this test assesses the relative behaviour of the mixtures on pavement life
It should be noted that its main benefit is the combination with the asphalt mixture (E *).
The evaluated analysis :
thin pavements – <4”
(AC) layer and 8” crushed aggregate base (CAB) layer
and thick pavements – 6” AC layer and 12” CAB layer.
Dynamic conditions included the heavy load imposed by a legally loaded 18-wheeler traveling at 60 mph (96 kph)
a travell without any braking, and traveling at 10 mph (16 kph) with braking.
In theory and in practice
Mechanistic analysis completes the picture begin with lab testing.
Vertical and horizontal forces affecting pavement life
Natural asphalt works very well in areas with heavy traffic and prevents road wear in those areas.
Gilsonite modified asphalt resists well under the pressure of heavy machinery
When an 18-wheeler is in the free rolling condition, the vertical loads are distributed evenly among the various axles.
During braking :
During braking, there is a large distribution of vertical loads between the axles
and horizontal loads at the tire-pavement interface . . These horizontal loads increase the shear and vertical stresses within the AC layer . Distribution of truck axle loads in free braking conditions
Mechanistic analysis findings:
- so, PG 64-28 mixture is not made to withstand the truck braking performance in the thin structure of asphalt pavement .
- Modified gilsonite mixtures improved the performance of thick and thin roads . PG 64-28 and PG 76-16
- PG 76-16 natural asphalt mix makes asphalt pavement more durable. Thin asphalt in braking conditions as well as no braking. Bearing the load The mechanistic analysis shows which mixtures improved road life.
Specific conclusions and recommendations
the addition of Gilsonite to the
PG76-16 and PG64-28 polymer modified asphalt binders
cause unique characteristics . this can offer interesting alternatives in the following situations:
- this mixture provides high resistance to rutting and shoving in asphalt pavements.
Mixtures of PG 64-28 and PG 76-16 have high resistance to cracking as well as oxidation. they are suitable for use as the binder/base course of Perpetual asphalt pavements.
The PG64-28 mix can withstand severe braking of trucks and light vehicles on ramps.
Natural asphalt mined in the United States in recent years is well known to experts there. They have been using Gilsonite for many years to repair their roads.
That is why the roads of the highways as well as the asphalt around the houses and parks there are very beautiful and durable. After the discovery and extraction of Natural asphalt in the Middle East,
various countries became acquainted with this mineral product
and used this mineral to improve asphalt.
. As a result, they are very satisfied and ues natueral asphalt or gilsonite
Addition of Natural asphalt can significantly increase the useful life of asphalt pavement. Gilsonite modified asphalt lasts more than twice as long as unmodified mix. Also, Natural asphalt allows the road to be up to 20% thinner while still offering the same level of performance. So, Gilsonite makes it possible to use less material. Gilsonite can also act as a performance enhancer in mixtures including SBS polymers.
This, in turn, reduces costs.
As a result Gilsonite has been proven to be economically viable.
We as ARYA GILSONITE :
We have the opportunity to offer Gilsonite to modified asphalt producers at a base price.
dear Gilsonite suppliers in different countries! modified asphalt producers ! contractors and road builders! Arya Gilsonite Co is in the middle east and is ready to cooperate with you dear ones. So with giving gilsonite by a base price, it will make your job as easy as you need it to be. As a result, you will be satisfied as a representative of your country and your customers. We offer high quality Gilsonite to customers in different countries at a quality of 5 to 25% ash.
Arya Co as one of the oldest and most reliable suppliers of Gilsonite in the Middle East
offers Gilsonite modified asphalt as follows:
- 25kg ± 5% Laminated Bags
- 25kg ± 5% Multilayer Paper Bags
- 1 ton QBAG
- 1 ton Jumboobag
dear Gilsonite suppliers in different countries! modified asphalt producers ! contractors and road builders! We have gilsonite for modified asphalt . Any amount you need. If you have any questions about natural asphalt, you can also contact us . We will guide you better and it will be our honor to meet you