The mixing and transportation of hot mix bitumen mixture is a very important in the construction process. Every step must be strictly followed to ensure the quality of bitumen pavement construction. The following is a specific introduction to the mixing and the transportation of bitumen mixture.
Mixing of Bitumen Mixture
- The number of feeding bins of hot mix equipment must meet the requirements of aggregate types. The feeding bins must be separated from each other, and the mixing of mineral materials is strictly prohibited.
- Bitumen hot mixing equipment must be equipped with additional equipment for adding external admixtures such as cement or slaked lime powder.
- The bitumen hot mixing plant must be equipped with printing equipment so that the dosage and mixing temperature of bitumen and various mineral materials can be printed at any time during the mixing process. And equipped with dynamic data real-time transmission monitoring system.
- Before mixing, all kinds of aggregates should be fully dried. When mixing, each specification of aggregate, mineral powder and bitumen must be accurately measured according to the predetermined production mix ratio, and the error should be controlled within the specified range.
- The mixing time of bitumen mixture is determined by the test. The mixing time of each batch of ordinary bitumen mixture is not less than 45s, and the mixing time of each batch of modified bitumen mixture is about 60s.
- The aggregate can only be sent to the mixing tank when it is heated to a temperature of 170-190°C in the drying equipment.
- During the mixing process, it is necessary to print various parameters such as the amount of material measured by each sensor, the amount of bitumen mixture mixed, and the mixing temperature. The computer data needs to be saved, and the supervisory engineer needs to record and save the results.
- During the construction process, the uniformity of the mixture is checked by special quality inspectors at any time.
- The batch mixing plant from manufacturer should be equipped with a finished product storage bin with good thermal insulation performance. During the storage process, the temperature drop of the mixture should not exceed 10°C, and there should be no bitumen dripping. The storage time of ordinary bitumen mixture shall not exceed 24 hours; the storage time of modified bitumen mixture shall not exceed 3 hours.
Transportation of the bitumen mixture
- When the bitumen mixture is loaded, the transport truck should move back and forth to avoid segregation of the mixture during loading and rolling.
- The transport truck is tightly covered with cotton tarpaulin, and the sides of the carriage should be tightly covered with cotton quilts. When the mixture is transported to the construction site, the temperature should meet the requirements.
- The bottom and side panels of the transport truck must be clean and must not be stained with organic substances.
- The mixture that does not meet the temperature requirements or has formed agglomerates or has been wet by rain should be discarded.
When the material truck enters the paving site, the tires must not be stuck with dirt and other dirt that may pollute the road surface, otherwise a pool should be installed to wash the tires before entering the construction site.
Before loading the bitumen mixture, a thin layer of oil-water (1:3 diesel: water) mixture can be applied on the inner surface of the transport truck, but the remaining liquid should not accumulate at the bottom of the truck.
