As the main equipment for mixing concrete, the mixing performance and operation of the concrete mixer have a greater impact on the quality of concrete, such as the correct charging sequence. So what is the correct feeding order of concrete mixer?
First, what is the correct feeding order of concrete mixer?
The correct feeding order of concrete mixer is: (1) coarse aggregate; (2) cement; (3) fine aggregate; (4) water.
In concrete, sand and gravel act as a skeleton, called aggregate; cement and water form a cement paste that coats the surface of the aggregate and fills its voids. Cement paste acts as a lubricant before hardening and makes the mixture easy to work with. After the cement paste hardens, the aggregate will cement into a strong whole.
Before mixing, the ingredients should be mixed according to the requirements of the mixing ratio to control the weighing error. The order of adding ingredients and mixing time have influence on the quality of concrete, and should be strictly controlled to make the parts mix evenly.
Second, choose the concrete mixer according to the construction conditions
Concrete mixer according to the production method, appearance, structure is divided into JS type forced concrete mixer and JW type forced concrete mixer, JZC self-fall mixer.
According to different construction requirements and conditions, concrete can be mixed at the construction site or mixing plant. Concrete mix with good mobility can be used as self-falling mixer; for concrete with low mobility or dry and hard concrete, forced mixer can be used for mixing.
Third, the two feeding methods of concrete mixer.
1. The first feeding method.
This is a widely used method, which puts sand, stone and cement into the hopper in turn, and then enters the mixing drum with water for mixing. This method is simple and easy to operate. When using a self-falling mixer, the usual feeding order is to pour the stones first, then add the cement, and add the sand after mixing.
2. Secondary feeding method.
The secondary feeding method can be divided into ready-mixed cement mortar method and ready-mixed cement slurry method. Ready-mixed cement mortar method means that cement, sand and water are put into the mixing drum and mixed for 1-1.5 min, and then stones are added and mixed for another 1-1.5 min. Ready-mixed cement slurry cleaning method means that water and cement are put into the mixing drum for 1 / 2 mixing time, and then sand and gravel are added for mixing to the specified time.
The quality of concrete produced by concrete mixer is affected by many factors, among which the way of adding materials and the order of adding materials are some of the influencing factors. Therefore, the correct feeding method and sequence should be selected during the mixing process.
