What is the concrete mixing ratio in 4 inch concrete hollow blocks?

The typical concrete mixing ratio for 4-inch concrete hollow blocks is usually 1 part cement, 2 parts sand, and 3 parts gravel (1:2:3). However, some variations may include using a 1:1.5:3 ratio for better strength. It's important to adjust the mix based on specific requirements, including block strength and local material characteristics. Always consult local building codes for precise specifications.