Generally speaking, the main reasons for the low productivity are:
1: The low quality of the medium-sized concrete mixers itself. Because the production process of the mixer is relatively simple, some township enterprises with less perfect conditions can produce it, so its quality is difficult to guarantee. It is the product of a state-owned designated factory. There are also quality problems, the most prominent of which is that the mixture cannot be mixed well within the specified breaking time (the specification requires a 50-500L mixer to mix the mixture thoroughly: 45s for the self-falling type, and 35s for the forced type). . In order to solve this problem, the wrestling time had to be extended to 1.5~2min (self-falling type) and 1~1.5min (forced type), and the productivity of the mixer decreased accordingly.
2: It is difficult to use bagged cement to achieve the rated batching volume of the mixer. When using bagged cement to mix concrete, in order to save time, the batching is generally made according to the whole bag of cement, so that the mixing volume of each plate cannot reach the rated quantity of the machine. For example, the concrete mixing ratio of a bridge construction site is 1:1.84:2.93:0.41. JZ350 type mixer is used for mixing, and each plate is mixed with 2 bags of cement (100 kg). The volume of the mixed material is about 0.26m. While the rated mixing volume of this machine is 0.35m, the actual mixing volume is only the rated mixing volume.
3: The disrepair and out of warranty of the mixer caused more machine failures and decreased power.
4 :The construction organization was not strict in order to improve the production efficiency of the mixer. According to the above analysis, the following four aspects should be paid attention to: (D) When purchasing a mixer, be sure to choose products with reliable quality, and do not try to buy unqualified products from township enterprises at a low price.
To promote the use of bulk cement, the amount of cement used each time is calculated according to the following formula: WLlxyz In the above formula, w represents the amount of cement each time, and the unit is kg; the concrete mix ratio is 1:X:Y:Z. L is the mixer Rated discharge volume, the unit is m3. It is the density of concrete. If the concrete is less than 30Mpa, it will be calculated as 2250kg/m3, and if it is greater than 30Mpa, it will be calculated as 2350kg/m3. @ Reasonably organize the construction, avoid the loss of layoffs, shorten the intermittent time of the mixer, and improve the operator's productivity Proficiency, promote the use of automatic batching devices. (@Attention to equipment management, regular maintenance of machinery, keep the mixer in good working condition.
