Mixing Ratio Of Microsilica Fume And Concrete

The design of concrete mix ratio is essentially to determine the three proportional relationships between the four material amounts, that is, the proportional relationship between water and cement is expressed by water-cement ratio; the proportional relationship between sand and gravel is expressed by sand ratio; cement slurry The proportional relationship with aggregate can be reflected by the water consumption of 1 cubic meter of concrete. When these three proportions are determined, the mix ratio of concrete is determined.

　　 (1) Determination of water-cement ratio: The water-cement ratio that meets the strength requirements can be calculated according to the concrete strength formula based on the determined compound strength. The water-cement ratio that meets the durability requirements should be checked according to the maximum water-cement ratio and minimum cement dosage. The water-cement ratio determined according to the strength and durability requirements is sometimes different, and the smaller water-cement ratio should be selected.

　　 (2) Determine the water consumption: The water consumption shall be estimated with reference to the concrete water consumption reference table. Then try to mix the concrete mixture according to the estimated water consumption and measure its slump. If the slump does not meet the requirements, adjust the water consumption while keeping the water-cement ratio unchanged, and do the test again until it meets the requirements.

　　 (3) Determination of sand ratio: Generally, the method of determining the sand ratio can be estimated by experience or empirical charts, and then mix the concrete according to the preliminary estimated sand ratio, conduct a workability test, and determine it through adjustment.