Types of Portland Cement
Portland cements are hydraulic cements composed primarily of hydraulic calcium silicates. ASTM C 150, Standard Specification for Portland Cement, recognizes eight types of portland cement:
Type I and Type IA*
General purpose cements suitable for all uses where the special properties of other types are not required.
Type II and Type IIA*
Type II cements contain no more than 8% tricalcium aluminate (C3A) for moderate sulfate resistance. Some Type II cements meet the moderate heat of hydration option of ASTM C 150.
What's a Type I/II cement? Portland cements that meet Type II requirements also must meet all of the requirements of Type I cements, except those for compressive strength. Type I/II cements meet both the C3A requirements of Type II cement and the compressive strength requirements of Type I cements.
Type III and Type IIIA*
Chemically and physically similar to Type I cements except they are ground finer to produce higher early strengths.
Used in massive concrete structures where the rate and amount of heat generated from hydration must be minimized. It develops strength slower than other cement types.
Contains no more than 5% C3A for high sulfate resistance.