Magnesium oxide

The content of clinker magnesium oxide shall not exceed 4.5%.

Sulphur trioxide

The content of sulfur trioxide in cement shall not exceed 3.5%.

Fineness

0.080 mm square hole screen sieve should not exceed 10%.

Setting time

The initial condensate may not be earlier than 45 minutes, final condensate no later than 12 hours.

Stability

With boiling test, must be qualified.

strength

The corresponding order strength of each label shall not be lower than the values in Table 1:

Table 1

Cement label

Compressive strength, kg / cm 2

Compressive strength, kg / cm 2

3day

28day

3day

28day

325

120

325

30

60

425

170

425

35

65

525

220

525

525

40

70

10.whiteness

White cement minimum whiteness value of not less than 87.