St Marys Portland Cement GU

Using the suggested proportions, one 40 KG (88 lb) bag of cement will produce about 3.5 ft3 (0.1 m³) of concrete mix, approximately.

Concrete must be fully cured (approximately 28 days) and dry before painting. Refer to paint manufacturer directions for application instructions.

Curing should take place for a period of seven (7) days.

Curing can be achieved using polyethylene (plastic) sheeting, spray-on curing compounds, or complete water saturation.

Concrete develops strength via a chemical process combining cement and water, called hydration. After placing and finishing, the concrete should be protected from drying out or freezing. Hydration continues until all cement particles react with water, or until cold temperatures slow or stop the chemical reaction.

The following proportions (by volume) are recommended:

•  1 part Portland Cement
• 2.5 parts concrete sand
• 2.5 parts ¾ in (19 mm) stone
• 2 to 3 parts water: 20 L to 23 L (4.5 US gallons to 5 US gallons) per bag of cement.

The key to producing high-quality concrete is the proportion of cement to water used. For this reason, use only as much water as is required to make the mix workable. Any excess water will lower the durability and strength of the hardened concrete.

Mix and substrate temperatures should be maintained between +5 °C and +30 °C (40 °F and 86 °F) for at least 24 hours prior to and 48 hours after.