1. Unreasonable discharge residual rate and blade design. From the internal structure of the mixing drum, the mixing drum of the concrete mixer truck relies on the rotating drum to drive the spiral motion generated by the two spiral blades, so that the concrete can obtain both "tangential" and "axial" composite motion, so that the mixing drum has the functions of mixing and unloading. Therefore, the relevant factors forming this spiral motion, such as the curve parameters of the spiral blades, The geometry and size of the mixing drum have an important impact on the discharge residual rate of the mixing truck. The excessive unloading residual rate means that there will be more surplus materials in the mixing tank after unloading, so it is more likely to stick materials in the mixing tank over time.
2. The transportation distance is too long. With the process of urbanization and the requirements of urban planning, more and more mixing plants are required to move to suburbs and suburban counties, which are farther and farther away from the urban area. Due to the particularity of concrete, any ready mixed concrete will enter the initial setting state from left to right within 1h without adding retarder. If the concrete pouring construction is carried out at this time, It not only affects the engineering quality of concrete, but also because the concrete loses fluidity, it is easy to condense on the mixing drum and blades, resulting in tank sticking. In serious cases, even the whole vehicle concrete sticks in the tank and causes damage to hydraulic equipment. Therefore, the transportation radius of ready mixed concrete by concrete mixer truck is controlled within 1h.
3. Unreasonable site construction design. During the construction of walls and columns on the construction site, the tower crane bucket truck will be used for pouring and tamping. Because the slump of the tower crane is lower than that of the pump, and because the construction time is long, it usually takes 2 ~ 4H to unload a truck of concrete. Some drivers stop the normal rotation of the mixing drum in order to save oil. In this case, it is particularly easy to cause tank sticking. Sometimes the tank sticking of the 9-square truck can reach 1t at a time, The situation is more serious in summer.
4. Improper use and maintenance. The driver of the concrete mixer truck fails to clean the residual concrete in the mixing tank and on the blades in time after the unloading of the mixer truck. During the return of the mixer truck to the station, the mixing tank does not rotate. The residual concrete will solidify on the mixing drum and blades after drying, and will gather more and more in the future, forming the phenomenon of tank sticking.
5. The working environment temperature of concrete mixer is too high. In summer, the ambient temperature often exceeds 30 ℃ around noon in the South during the day. In this case, when transporting concrete, it will be easier for the concrete to stick to the tank due to the rapid loss of concrete slump and the higher temperature around the tank relative to the center.