How to calculate the mixture ratio of concrete mortar? What is the calculation principle?

Assume that the bulk density of mortar is 2 120kg/m3, the standard deviation is 2.5Mpa, and the actual strength of cement PO42.5 is 52.6MPa.

Second, the mixture ratio calculation:

1, determine the trial intensity:

fm，0 = F2+0.645σ= 10+0.645×2.5 = 1 1.6 MPa

2. Calculate the cement dosage:1000 * (11.6+15.09)/3.03 * 52.6 =167kg/m3.

3. Because the calculated cement dosage is small, the cement dosage of the benchmark mixture ratio is 3 19kg/m3, and the cement dosage is increased or decreased by 10%.

4, calculate the contrast mixture ratio:

For a water-cement ratio of 0.86, the dosage of each material:

Cement: fine aggregate: mixing water = 319:1530: 274 =1:4.80: 0.86.

For a water-cement ratio of 0.95, the dosage of each material:

Cement: fine aggregate: mixing water = 287:1530: 283 =1:5.33: 0.95.

For a water-cement ratio of 0.70, the dosage of each material:

Cement: fine aggregate: mixing water = 351:1530: 245 =1:4.36: 0.70.

Third, fitting adjustment:

For the trial mixing test results of various water-cement ratios, see "Concrete (Mortar) Mix Ratio Test Records (I), (II) and (III)".

See "Test Report on Compressive Strength of Concrete (Mortar) Test Specimen" for theoretical mix strength test.

Four, the mixture ratio is selected:

According to the test results of each mixture ratio, the water-cement ratio of 0.86 is determined as the theoretical mixture ratio of the laboratory.

Preparation principle: improve workability and enhance adhesion.