Steel siloThe relationship between storage conditions, storage time, and strength of steel plate storage of cement.
Research on cement storage conditions for different regions
(1) Northern Cement's Winter Storage
In northern regions of our country, the frost period halts outdoor construction and poses difficulties for cement sales. Leveraging the advantages of lower temperatures and drier air in the north, storing more cement during winter helps balance the supply and demand矛盾 between the off-season and peak season. This is a measure for northern cement companies to enhance efficiency by using steel silos and steel warehouses to store cement.
The cement factory believes, based on tests of physical strength, that in sealed drums, the stored samples for three months show no significant change in setting time and strength.Steel siloThe cement is stored in steel plate silos after being ground. Cement stored in steel plate silos for 3 months prior to dispatch does not undergo significant changes in its physical properties. Bagged cement is stored in the finished goods warehouse. For cement bags in contact with the atmosphere (such as surface bags or bags with holes), the setting time is extended, and the longer the storage time, the greater the impact on the final setting time. The strength of the cement gradually decreases, with a rapid and significant drop early on; the rate of strength decrease in the later stage is smaller compared to the early stage, and the strength of bags not exposed to the atmosphere does not show significant decline.
(2) Storage of Southern Cement
Bagged cement for storage tests at the cement factory indicates: there is minimal change in the standard consistency water content during the initial storage period, but as storage time extends, the standard consistency water content increases; the setting time is significantly prolonged; and the strength is not significantly affected within one month, but after three months, the strength declines rapidly.
2. Conditions for winter storage of cement
The tests on winter storage cement in the north indicate that steel silos are used during the winter and spring seasons in the northern region.Steel plate inventoryStore for 3-6 months without significant strength decline, provided that: it is stored in a sealed, dry steel silo or steel warehouse; not suitable for storage in warehouses with heating equipment; the low winter temperatures and dry air in northern regions create favorable conditions for cement storage, so within 3-6 months, northern steel silos,Steel plate inventoryWinter-stored cement is feasible.
3. The effect of cement storage time on concrete performance
According to the information provided, fresh cement experiences rapid early hydration and a high adsorption rate for admixtures within 12 days due to its high dryness, leading to reduced workability and increased water demand for concrete. This causes a quick loss of slump and shorter setting time. However, after 15 days, its performance tends to normalize. This study suggests caution when using cement in concrete engineering.
