Anti-Stripping Agent TOUGH FIX HYPER
Overview of TOUGH FIX HYPER
Tough Fix Hyper is additive which dramatically improves anti-stripping performance of asphalt mixture. Once the stripping problem starts eating in asphalt pavement, especially asphalt mortar, it grows into big deterioration, like ravelling, cracking, pothole. Above all, with acid/ neutral igneous/pluton rock like granite, rhyolite, andesite, and others, there are big risks that the stripping would easily occur.
≪Characteristics≫
(1) In case of using Tough Fix Hyper, adhesion between aggregate and asphalt is considerably improved.
(2) Tough Fix Hyper excel in heat resistant, and it can maintain the effects even in mixing and storing at high temperature of the asphalt and asphalt mixture.
(3) Tough Fix Hyper does not impact on the asphalt properties at the range of a prescribed additive amount.
(4) Solubility of Tough Fix Hyper to asphalt is very good.
(5) Purity of Tough Fix Hyper is 100%, it is safe to human body.
≪How to use Tough Fix Hyper≫
+) Tough Fix Hyper cost is higher, but amount is only 0.15%, so it’s reasonable, and exhibits an excellent effect in a small addition amount.
+) Additive amount of Tough Fix Hyper.
0.1%~0.3% (0.15% is normal) to asphalt weight. Small amount, but big effect.
75 grams for asphalt mixture of 1 ton if asphalt content is 5%
+) Additive method Tough Fix Hyper.
There are three methods available.
However, asphalt should be heated and kept to more than 140 °C in this case.
Method 1 Method 2 Method 3
Why is TOUGH FIX HYPER needed?
Asphalt mixture used for highway pavement, dam impervious wall, and Seawall is required to be durable. Asphalt mixture is a combination of aggregates on which asphalt film is coated. Adhesive of asphalt to aggregate surface would be impacted by the wetness of the aggregates surface and water content of aggregate.
There are some cases that asphalt film would be removed from the aggregates surface. Furthermore, if the water permeates between asphalt film and aggregates surface by rainfall and so on, it would be connecting to deterioration.
Because asphalt is nonpolar, adhesive strength between asphalt film and aggregates’ surface is generally smaller rather than the adhesive strength between water and aggregates’ surface. This means that asphalt has a potential risk for asphalt to be stripped from aggregates’ surface. There are many cases to use Polymer modified asphalt in which thermal plastic resin and/or rubber is contained to enhance the asphalt mixture strength for prevention of rutting and cracking, but this can’t reach to significant improvement of the antistripping problem.
The most important thing is to increase the adhesive strength between aggregate surface and asphalt to improve the problems with asphalt mixture. The just solution is anti-stripping agent, Tough Fix Hyper.
What kinds of countermeasure for stripping ?
Improving in the adhesion strength between asphalt and aggregates is very important to improve the asphalt pavement performance. There have been many kinds of countermeasure for antistripping proposed, however, the results are not enough to satisfy so far. The main countermeasure so far is as follows;
(1) To make use of the property of the additives which have adsorption orientation property by the electric property of polar group.
(2) To select the additive by considering the chemical composition/ properties of acidic aggregate and alkali aggregate.
(3) To activate aggregate surface by using hydrated lime together with calcium carbonate.
The countermeasure to stripping by Tough Fix Hyper is as follows;
(1) To add Tough Fix Hyper into asphalt
(2) To enhance the cohesive strength by Chemical molecular architecture of Tough Fix Hyper.
(3) To adhere solidly the interface between aggregate surface and asphalt regardless of the kind and property of aggregate.
Characteristics of TOUGH FIX HYPER
The merit of these antistripping agents is that the interface adhesion is never destroyed, even though water comes into the aggregate surface or the interface is subjected to big impact, because the property of the interface is changed and the interface is adhered solidly and chemically by Tough Fix Hyper.
Tough Fix Hyper is an additive for antistripping, which consists of amphoteric high molecular compound. The reason of antistripping effect by Tough Fix Hyper is as follows;
(1) The aggregate’s surface has “－OH” group in wet situation.
(2) Chemical bond is formed between the amphoteric high molecular compound and “－OH” group.
(3) In addition, Chemical bond is formed between the amphoteric high molecular compound and positive ion such as “Ca+”, too.
(4) As a result, the antistripping effect is very excellent.
Tough Fix Hyper prevents invasion of the water to the aggregate interface by water-repellent effect of the high molecular compound.
- Tough Fix Hyper is higher, but amount is only 0.15%, so it’s reasonable, and exhibits an excellent effect in a small addition amount.
1. Static Stripping Test Results (Coarse aggregate)
≪Test for static resistance to stripping with coarse aggregate≫
JPI (Japan Petroleum Institute) Method, 30 minutes in water at 80°C, Aggregate: Granite
2. Heat Resistant of Anti stripping Agent (Change in antistripping effect during staying at 160 °C)
Storage stability of Tough Fix Hyper is much better than other products. Therefore these agents can dissolve in asphalt beforehand. Even if the asphalt dissolving Tough Fix hyper is stored in an asphalt tank for 7 days, the anti-stripping effect lasts.
≪Aggregate: Granite, Asphalt: Straight asphalt 60/80≫
JPI (Japan Petroleum Institute) Method Static stripping test, 30 minutes in water at 80°C, Target Value: Max 15%
3. Influence of Antistripping Agent to Asphalt
Even though Tough Fix Hyper is employed with asphalt, it does not infect any properties of the original asphalt.
4. Stripping Test Results (Asphalt mixture)
Even if Granite in which SiO2 is contained at high ratio or Limestone consisting mainly of Ca were used, the resistance to stripping would be improved by giving Tough Fix Hyper to asphalt.
≪Marshall Residual Stability Test (ASTM D1559) ≫
Asphalt Mixture:
Dense-graded asphalt mixture (13)
Asphalt:
Straight Asphalt 60/80,
Coarse Aggregate:
Limestone, Granite, Andesite
≪Modified Lottoman Test (AASHTO T283) ≫
Asphalt Mixture:
Dense-graded asphalt mixture (13)
Asphalt:
Straight Asphalt 60/80,
Coarse Aggregate:
Limestone, Granite, Andesite.
5. Test for Resistance to Rutting of Asphalt Mixture.
The addition of Tough Fix Hyper does not adversely affect the resistance to rutting of asphalt pavement.
≪Wheel Tracking Test at 60 °C ≫ Asphalt Mixture: Dense-graded asphalt mixture (13)
Asphalt: Straight Asphalt 60/80, Coarse Aggregate: Granite
