What does AASHTO M 85 (ASTM C 150) provide guidelines for?

AASHTO M 85, which is equivalent to ASTM C 150, provides guidelines for cement types based on their chemical composition. This specification categorizes portland cements into various types according to the proportions of their ingredients, which is crucial for ensuring the correct performance characteristics for different concrete applications. Understanding the chemical makeup of the cement helps inform engineers and concrete inspectors about the expected behavior of the cement when mixed with aggregates and water, influencing factors such as strength, durability, and setting time. This is particularly important in construction projects where specific performance requirements must be met based on environmental conditions and structural demands.

While the other options pertain to related aspects of concrete and cement, they do not accurately capture the primary focus of AASHTO M 85, which is specifically centered around the classification of cement by its chemical constituents.