Oxidized Bitumen 75/35 Description
Blown Asphalt 75/35 is an oxidized Bitumen produced by oxidizing a selected petroleum asphalts without adding the catalyst. Bitumen 75/35 has a high softening point, high flash point and it is highly stable during melting. This kind of Blown Asphalt is mostly using in the Mediterranean and especially the morocco market.
Blown Asphalt 75/35 is produced by the air-blowing of penetration grade bitumen. This is done at high temperatures, resulting in a material of a much higher penetration index.
Bitumen 75/35 is based on petroleum bitumen which is made by blowing bitumen 60/70 by very hot air. The designation of the Oxidised bitumen 75/35 refers to the midpoint of the softening point acceptance criteria.
Blown Asphalt is a solid or semi-black solid material and gradually liquid when heated. Oxidized Bitumen grades are blown or oxidized bitumen‘s which are produced by passing air through soft bitumen under controlled temperature conditions. This process gives the bitumen more rubbery properties than penetration or hard grade bitumens and a variety of uses in industrial applications.
Bitumen 75/35 is produced by either Continuous or Staggered Blowing Process. Heated Penetration Grade Bitumen under controlled environment is blown with air which controls the Oil Content in the Bitumen while it oxidized. The different grades for suited applications produced are designated by two numbers to indicate the mid-points of their softening point and penetration ranges.
As said before, Bitumen 75/35 is based on petroleum bitumen which is made by blowing bitumen 60/70 by very hot air. In addition, the numbers relate to the midpoint of the material’s softening point and penetration respectively. The softening point value measured by the Ring and Ball method as determined by ASTM D36. Also, the penetration value is in 1/10 mm as determined by IP49 or ASTM- D5.
Oxidized Bitumen 75/35 Applications
Blown Asphalt 75/35 grades are produced by passing air through soft bitumen under controlled temperature conditions. This process gives the bitumen more rubbery properties than penetration or hard grade bitumen and enables the product to serve a variety of uses in industrial applications. These grades are suitable for sealing saw cuts and joints where there is expected to be the minimum amount of moving in the joint. Their wide temperature range prevents bleeding in high-temperature applications. They can also be used for industrial applications such as pipe coating, roofing, waterproofing, flooring, mastics, sound damping, carpet backing, adhesive and electrical applications. Hard bitumen under controlled temperature conditions is widely used as an anti-slip layer compound in the piling industry, for the manufacture of roofing felts, the roofing and waterproofing industries, for sound dampening felts and undercarriage sealant in the automotive industry, electric cable joint protection, joint filling compound, sealant compound, and many others. Also used in sealing saw cuts and joints where expected movements are minimum.
Technical Advantages of Blown Asphalt 75/35
- Chemical Stability
Compared to paving grade bitumen:
- Reduced temperature susceptibility
- Exhibits a more ‘solid’ nature at ambient temperatures
- High penetration index
Recommendations for Handling / Storage
The heating of packaged bitumen is a critical phase in most of the final uses. Typically, the packaged material is heated and melted in boilers out on site.
However, control at the heating phase is very important in terms of health and safety as well as in maintaining the quality of the product.
A note must be taken of the maximum safe handling temperature of 230 C and this should not be abused. Bitumen is a poor conductor of heat, consequently, control of the heating phase is of paramount importance.
The Oxidized Bitumen material should be broken up prior to placement in the boiler. This exposes a larger surface area to the heat and encourages a more even heating regime. Without the larger exposed surface area, aggressive heating at the base and sides of the boiler may well result in localized overheating, altering the characteristics of the modified bitumen, and potentially causing thermal cracking of the bitumen, creating the release of low lash vapors. The flashpoint of the oxidized bitumen then becomes irrelevant; as these low flash vapors determine the fire risk.
Melted bitumen should not be left in the boiler and reheated from cold, as there is then a high potential for localized overheating around the heating area (lack of convection means poor heat transfer) and potential development of a pressurized pocket of low flash vapors.
Be aware of the placement of any temperature monitoring or control devices. As a result of the poor thermal conductivity of the bitumen, a thermometer in the bitumen some distance from the heat source could read significantly different (even hundreds of degrees) from the true temperature of the bitumen near the heat source.
For Health and Safety information, please make reference to the relevant MSDS.
Health & Safety
Workers should wear protective masks, gloves, and goggles during application. The asphalt can be removed from equipment and tools with kerosene or gasoline. Care should be taken when heating Blown Asphalt 75/35 to avoid overheating
Oxidized Bitumen 75/35 is a dark industrial bitumen. Petroleum residue modified by the oxidation process. In addition, Blown Asphalt is produced by passing air through bitumen under a controlled temperature state. Its stability ranges from highly viscous to solid. Blown Asphalt grade has technical advantages such as durability, flexibility, water-resistant and chemical stability. There is also a different grade of blown bitumen.
Blown Grade Asphalt shall be broken up into small pieces and heated slowly to the application temperature of 220ºC to 230ºC.
Packing of Oxidized Bitumen 75/35
Blown Asphalt 75/35 in various packing, including bitumen 75/35 is available in 20 & 50 kg Kraft Paper Bags / Poly Amide Bags, 25 kg Carton box, and 150, 180, 200kg Steel Drums. In addition, oxidized bitumen packing also palletize, 40 bags can stack on the pallet. 20 pallets can load to the 20ft container.
Technical Data Sheet of Blown Asphalt 75/35
|Bitumen 75/35||Test method||Unit||Specification|
|Specific gravity @25/25 C||ASTM D70||(Kg/m3)||1.05 approx.|
|Penetration @ 25°c||ASTM D5||mm/10||30/40|
|Softening point °c||ASTM D36||°C||70/80|
|Loss on heating(wt) %||ASTM D6||Wt. %||0.2 max|
|Flashpoint c||ASTM D92||°C||250 min|
|Solubility is CS2(wt) %||ASTM D4||Wt. %||99.5 max|
|Spot test||A.A.S.H.T.O 102||—||Negative|