Concrete users are aware of the need to use in line with national recognition, which is for the safety of building products and whom. But believe that many users do not know the term "concrete slump" is not very clear that concrete slump is used to determine the quality of concrete construction is a good standard. Then the role of concrete slump on the concrete is: If the collapse of the larger easy to cause the separation of the mixture, if too small to the construction of the difficulty, you can not change the water-cement ratio to change the amount of aggregate, Or add the cement slurry to change. Simply said: the concrete slump is too large, easy to segregation, stratification, easy to work very poor, and sometimes bad construction, resulting in blocking pump, running pulp, Ma face and other issues, the intensity and its disadvantage. Such as too small, poor mobility, is not conducive to the construction, resulting in empty, honeycomb, not vibrant dense, but also against the strength. Since the slump of concrete is so important, why is it that the slump of concrete (concrete) produced in the same proportion is not the same, then what are the factors that cause the slump difference? You have a detailed answer.
First, the different raw materials lead to:
The difference between the raw material of sand and gravel, the difference of the amount of water containing the amount of mud, the height of the agent, the control of the operator and so on will cause the slump difference. In this also suggested that you concrete manufacturers, try to keep the original material, do not arbitrarily to replace the supply.
Second, the old and new products lead to:
Not only concrete mixers, but also other concrete mixing plant
facilities may also lead to slump differences. So it is necessary to carry out regular maintenance, but also to regulate the operation. Most of the concrete mixing plant manufacturers, the production of commercial concrete to C30 majority. C30 standard ratio of the following concrete samples 28 days standard curing strength> 30Mpa, C30 concrete ratio: 1: 1.44: 3.14: 0.48 cement (P.O42.5): 396Kg sand: 571Kg gravel: 1243kg water: 190kg
Third, the performance of concrete mixer
Mixers due to long hours of work, the output of concrete will be different from the past, which is the cause of slump differences. Concrete mixer to be regularly maintained every day to clean up.
Fourth, the ratio of the instrument is not accurate lead to:
In the proportion of weighing when the middle of the replacement of measuring instruments, and instrumentation does not lead to the original imbalance. Then the production of concrete slump will be different, Yangzhou built in this proposal you concrete manufacturers, to regular maintenance, replacement to identify the brand with the company can not be free to replace. The specification of concrete slump is as follows:
According to "ready-mixed concrete"
Low plasticity concrete, slump ¡Ü 40mm, allowable deviation of ¡À 10mm;
Plastic concrete, slump in the 50 ~ 90mm, allowable deviation of ¡À 20mm;
Liquidity, slump ¡Ý100mm, allowable deviation of ¡À 30mm.