Bitumen Mastic Definition
Bitumen Mastic is a type of asphalt composed of suitable graded mineral and asphaltic cement, also to take in proper proportion to consistent mass solid or semi solid form. when it is heated it is in fluid form and then becomes solid.
Mastic asphalt (MA) is a dense mixture consisting of coarse aggregate, and/or sand, and /or limestone fine aggregate, and/or filler and bitumen, which may contain additives (for example polymers, waxes). The mixture is designed to be of low void content. The binder content is so adjusted that the voids are completely filled and that even a slight excess of binder may occur. Mastic asphalt is pour-able and able to be spread in its working temperature condition. It requires no compaction on site.
On the other hand asphalt mastic – abbreviation AM – is a term used in Europe to describe a mix of sand (that is, without aggregates > 2 mm), and/or limestone fine aggregate, and/or filler and bitumen that is used specially for waterproofing in a variety of applications.
The formulation of the mixture is chosen as a function of
– field of application
– mechanical load
– thermal load
– chemical load
– climatological influences.
Bitumen mastic is a thick, adhesive, waterproofing material made primarily from bitumen, combined with fillers and other additives to enhance its properties. It is used in construction for sealing, bonding, and waterproofing purposes. Bitumen mastic is typically applied as a paste or thick liquid that hardens upon cooling, creating a durable and flexible seal.
Properties of Bitumen Mastic
– Waterproofing: Provides excellent resistance to water infiltration, making it ideal for damp-proofing and waterproofing applications.
– Adhesion: Strongly adheres to various surfaces, including concrete, metal, wood, and masonry.
– Flexibility: Remains flexible even after curing, allowing it to accommodate structural movements and temperature variations without cracking.
– Durability: Resistant to weathering, chemicals, and mechanical wear, ensuring long-lasting performance.
– Ease of Application: Can be applied with a trowel, spatula, or specialized spray equipment, depending on the formulation and the application area.
Applications of Bitumen Mastic
– Roofing: Used for sealing roof joints, flashings, and repairs to prevent water ingress.
– Damp-Proofing: Applied to foundation walls and basements to protect against moisture penetration.
– Joint Sealing: Used in expansion joints and construction joints to provide a watertight seal.
– Road Repairs: Employed in filling cracks and joints in asphalt pavements and concrete roads.
– Pipe Coating: Used for coating and protecting pipelines from corrosion and water ingress.
Bitumen mastic is valued in construction for its versatility, strong adhesive properties, and excellent waterproofing capabilities, making it a reliable solution for various sealing and protection needs.
Bitumen Mastic Applications
Bitumen mastic has a wide range of applications in construction and maintenance due to its excellent waterproofing, adhesive, and flexible properties. Here are some common applications:
- Roofing:
– Sealing roof joints, flashings, and edges.
– Repairing leaks and damaged areas on roofs.
– Providing a waterproof layer on flat and sloped roofs. - Foundation Waterproofing:
– Coating foundation walls and basements to protect against water infiltration and dampness.
– Serving as a damp-proof membrane to prevent rising damp in walls. - Joint Sealing:
– Filling and sealing expansion joints in concrete structures.
– Sealing construction joints in buildings, bridges, and other structures. - Road and Pavement Repairs:
– Filling cracks and joints in asphalt pavements and concrete roads to prevent water penetration and further damage.
– Patching potholes and other surface irregularities in roads. - Pipe Coating:
– Coating and protecting underground and above-ground pipelines from corrosion and water ingress.
– Providing an additional protective layer for pipe joints and fittings. - Waterproofing Structures:
– Coating and sealing water tanks, reservoirs, and other water-retaining structures.
– Protecting underground structures like tunnels and culverts from water seepage. - Soundproofing and Vibration Damping:
– Used in buildings and vehicles to reduce noise and vibration due to its damping properties. - Bridge Deck Waterproofing:
– Applying a waterproof layer on bridge decks to protect against water and chemical damage, and to enhance the longevity of the structure. - Protective Coatings:
– Providing a protective coating for steel structures and metal surfaces to prevent corrosion and rust. - Flooring:
– Used as a base layer for flooring in wet areas such as bathrooms and kitchens to prevent moisture damage.
Bitumen mastic is chosen for these applications due to its versatility, strong adhesion, and durability, making it a reliable material for waterproofing, sealing, and protecting various structures and surfaces.
Bitumen Mastic Production Process
The production process of bitumen mastic involves several steps to ensure that the final product has the desired properties for its various applications. Here is an outline of the typical production process:
1. Raw Material Selection:
– Bitumen: The primary component, typically selected based on its grade and quality to match the required performance characteristics.
– Fillers: Materials such as limestone, sand, or mineral powders that enhance the mastic’s mechanical properties.
– Additives: Polymers, plasticizers, and other chemicals that improve flexibility, adhesion, and other specific properties.
2. Heating and Mixing:
– Heating Bitumen: The bitumen is heated in large tanks to reduce its viscosity, making it easier to mix with other components. This is usually done at temperatures between 160°C and 180°C (320°F to 356°F).
– Mixing Fillers and Additives: The heated bitumen is then mixed with fillers and additives in a controlled manner. The mixing process ensures a homogeneous blend, with consistent dispersion of all materials throughout the bitumen.
3. Cooling:
– The mixture is allowed to cool down to a manageable temperature, typically below 100°C (212°F), while continuously stirring to maintain homogeneity.
4. Quality Control:
– Samples of the bitumen mastic are taken for testing to ensure that it meets the required specifications for properties such as viscosity, adhesion, flexibility, and waterproofing.
– Adjustments are made as necessary to the formulation or process based on the test results.
5. Packaging:
– Once the bitumen mastic has been verified for quality, it is packaged in containers suitable for its intended application. These can range from small buckets for manual application to large drums or bulk containers for industrial use.
6. Storage and Distribution:
– The packaged bitumen mastic is stored in appropriate conditions to maintain its quality until it is distributed to the end-users.
Detailed Process Flow
Raw Material Preparation:
– Ensure all raw materials are ready and within specification.
Pre-Heating:
– Pre-heat the bitumen in a bitumen Melter or pre-heater.
Mixing Tank:
– Transfer the heated bitumen to a mixing tank equipped with agitators.
– Gradually add the fillers and additives while maintaining continuous mixing.
– Monitor temperature and mixing speed to ensure uniform consistency.
Homogenization:
– Use high-shear mixers or homogenizers if necessary to achieve a fine and uniform dispersion of all components.
De-Aeration:
– The mixture may be passed through a de-aeration stage to remove any trapped air bubbles, ensuring a dense and uniform mastic.
Final Quality Check:
– Conduct final checks for consistency, viscosity, and other critical properties before packaging.
Considerations
– Safety: Ensure that all heating and mixing equipment is operated safely, as working with hot bitumen involves risks of burns and fire.
– Environmental Controls: Implement measures to control emissions and waste, complying with environmental regulations.
By following these steps and maintaining stringent quality control throughout the process, manufacturers can produce high-quality bitumen mastic suitable for a wide range of construction and maintenance applications.
In the past, that means approximately until 1970, mastic asphalt was often manufactured in mobile cookers (usually at the work site) that were filled with the various components. By slowly heating them, the components were brought to the right temperature, where the mix-ing device (then mostly a horizontally rotating mixer shaft) served to make sure that the mix was homogeneous for processing. Of course, in this way no high production rates could be achieved.
Nowadays mastic asphalt is manufactured in (specially designed) stationary industrial plants. These are designed to proportion the materials, dry the mineral aggregates and mix them in a heat controlled environment. Application specifications control the temperatures at which material is produced. Typically, in the past, mastic asphalt production temperatures were in the range of 230 to 270 ºC. However in the recent years considerable research and investments have been done (and are still ongoing) to lower these temperatures beneath 230 ºC – in some countries even below 200 °C.
Packing of Bitumen Mastic
Bitumen Mastic is available in 25 Kg Carton Box & 20 Kg new steel drum.
Technical Data Sheet of Bitumen Rubber Mastic Sealant
| PROPERTIES | VALUES | TEST STANDARDS |
| Color | Black | – |
| Form | Paste | – |
| Solid content, [%] | >80 | ASTM D 2939 |
| Slump | Nil | – |
| Density, [g/cc] | 1.1 ± 0.05 | ASTM D 1475 |
| Initial set @ standard condition, [hours] | 24 -48 | |
| Full cure @ standard | 14-21 days | |
| condition, [days] | (10mm) | |
| Chemical resistance | Sea water, chlorides and sulphate ions. | ASTM D 543 |
