What is the ratio of cement sand and gravel in concrete hollow blocks?

The typical ratio of cement, sand, and gravel in concrete hollow blocks is often around 1:2:3, meaning one part cement, two parts sand, and three parts gravel. However, this can vary depending on specific requirements and block designs, with some mixes using a ratio of 1:1.5:3.5 or similar variations to achieve desired strength and workability. It's essential to adjust these ratiOS based on local materials and structural needs.