The strongest mix of sand and cement is typically a 3 to 1 ratio (3 parts sand to 1 part cement).
While a standard mix often involves a 4:1 ratio (sand to cement), reducing the sand content and increasing the cement results in a more robust and durable mixture. This stronger mix is suitable for applications requiring high compressive strength and resistance to wear and tear.
However, it's important to note that a very high cement content can also lead to issues like increased shrinkage and cracking. Therefore, while 3:1 represents a "strong" mix, it's crucial to consider the specific application and potential drawbacks of using excessive cement. A properly designed concrete mix will also incorporate aggregates other than sand, water and possibly admixtures to optimize strength, workability and durability for a particular purpose. The 3:1 mix mentioned above would be suitable for mortar, not concrete.
