Final answer:
Low-heat cement, also known as LH cement, is the term for Portland cement with reduced tricalcium aluminate content. It is used in situations where resistance to severe sulfate action is required.
Step-by-step explanation:
Portland cement with reduced tricalcium aluminate content, which lessens the need for gypsum, is known as low-heat cement or LH cement. LH cement is used in situations where resistance to severe sulfate action is required, such as in environments with high levels of sulfates. This cement is designed to minimize the risk of sulfate attack and ensure the durability of concrete structures.