Bitumen materials are road, roofing and building. Due to the simplicity of use and low cost of bitumen, it is widely used in waterproofing work. This makes him attractive for private construction. Bitumen consists of three main components. Resins (18 – 48%) and mineral oils (40 – 65%) give it plasticity, and asphalons (13 – 30%) – hardness. To create a waterproofing layer, the most suitable brand 70/30 is the most suitable. Its softening temperature is 70 – 72 degrees. Such bitumen can be distinguished by the fact that, with mechanical exposure (impact), it beats on pieces, without forming fragments. One of the advantages of this bitumen – it sticks well to the surfaces of any material (high adhesion).
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However, any bitumen has some disadvantages. For example, over time, it acquires rigidity and fragility. This is a consequence of the gradual loss of light oil fractions. That is why when creating or repairing the waterproofing layer, experts recommend using bitumen mastic, and not bitumen in its pure form. It is good to use it if rolled materials, for example, roofing material are used to create a waterproofing layer. It is convenient to glue and glue stripes with mastic.
Bitumen mastic is a mixture of molten bitumen and filler. They may be small asbestos (10% of the total mass) or rubber crumb (7%). In addition, the “development” of machine oil is added. It plays the role of plasticizer, that is, gives mastic plasticity.
If we compare mastic with pure bitumen, then it is much more preferable. It is characterized by high heat – and frost resistance, elasticity, adhesion and durability. Mastic can be used not only for gluing and gluing, but also as a sealant for shaking gaps or seams. You can cook it yourself.
Method of preparing bitumen mastic
The process is that the molten bitumen is mixed with the filler. They can be: asbestos, peat crumbs, wood sawdust, finely chopped mineral wool. The filler is necessarily sifted through a sieve with cells of 3×3 mm and is well dried. During mixing, it is necessary to add a waste engine oil. About 1 liter of oil is taken on a bucket of bitumen, which is previously filtered. The approximate ratio of components for 5 kg of mastic: 4 kg of pure bitumen, 0.5 kg of filler and 250 g of oil.
Bitumen heating
When heating bitumen, when it begins to foam, releasing impurities should be removed from its surface. This is usually done with a tin can with a broken hole. When bitumen stops foaming, it is stopped heating. The surface of the bitumen should be mirrored, and the whole mass looks homogeneous. It must be borne in mind that it is impossible to overheat bitumen, as coke can form. Signs of overheating: the formation of greenish-yellow smoke and the appearance on the surface of the bubbles. When heated more than 240 degrees, the mass may light up.
After cooking bitumen, they continue to mix, adding dry filler and oil to it in small portions. It must be taken into account that mastic is used only in hot form. Therefore, it should be prepared only before the work on waterproofing. This composition is prepared as a “one -time”, therefore the number of components is selected from this calculation.