Bitumen emulsion is mainly composed of bitumen, surface active agent, adhesive additives and water.
Factors affecting the stability of bitumen emulsion are closely related to raw materials, equipment and production process, such as bitumen, emulsifying agent, water quality, stabilizer,defoamer, antifreezer, production temperature, storage temperature, etc.
1.Addition amount of emulsifier
Usually in the appropriate addition amount of the range, the more emulsifier, the smaller the bitumen emulsion particle size.
It is generally believed that before reaching the optimum mixing amount, micelle concentration increases with the increase of adding amount. The more the single-body capacity increases in micelles, the less the free monomer liquid decrease, and the smaller the monomer droplets.
When the admixture continues to increase beyond the optimal amount,a large number of free micelles agglomerate, which leads to the increase of particle size and the decrease of stability.
2. Selection and addition amount of the stabilizer
Traditional single stabilizer such as cellulose has poor compatibility with the system,the main performance is demulsification fast, difficult to maintain long-term stability.It associated with cellulose shortcoming ,such as poor mildew resistance, poor temperature resistance and poor PH tolerance,have to use multiple combinations to solve such problems. In the admixture test, it is found that when stabilizer is too less, bitumen particles and water will be close to each other and the surface tension will be too large which lead to the separation of oil and water(demulsification). When the stabilizer is too much, the variation of soap viscosity will lead to difficult shear and stability decrease.
The data show that the addition amount of stabilizer in the system should not be higher than 3‰.
3.Selection and addition amount of defoamer
The selection of defoamer should follow the variety suitable for addition to the formula, high concentration and low addition.
Excessive mixing amount will seriously affect the storage stability, even if it does not affect the storage stability, the surface of the product maybe honeycomb, thus affecting the dispersion and fluidity of bitumen emulsion.
4. Weather ability（propanol）
Bitumen emulsion’s thermodynamical system is unstable.When the storage temperature over 40°C or lower than -10°C, the bitumen emulsion may occur demulsification, condensation phenomenon, thus cannot be used.
Our Bitumen emulsion added low-grade fatty alcohol without adding diesel oil or kerosene and other diluents not only shorten the time of water volatilization, accelerate the hardening rate of the mixture, but also improve the frost resistance. It will not freeze at - 5 ℃~- 25 ℃, and also maintain the original asphalt cohesiveness and other excellent properties, avoiding low-temperature shrinkage cracking or freeze-thaw loosening of t
