OPC stand for ordinary Portland cement and it doesn’t contain pozzolana mix. It can be used for all types of concrete works and construction activities. OPC comes in three grade as 33, 43 and 53, referring it’s compressive strength at 28 days. All three grade achieve 50% strength within 7days and 99.9% at 28days under well cured conditions. OPC has a faster rate of hydration which means its initial set is faster. However it generate more heat of hydration and leads to development of cracks in large concrete structure.
It can be ideally used for construction of buildings, retaining walls, pavements, culverts and other infrastructure with the lesser sectional area.
Whereas PPC stands for pozzolana Portland cement and it contain pozzolana materials such as fly ash and slag. PPC is more durable and has slower rate of hydration compare to OPC. Because of this property it is more suitable for structures that require long-term strength and durability, such as bridges, dams, and marine structures.
PPC also has a lower heat of hydration, which reduces the risk of cracking in large concrete structures. It is commonly used in the construction of precast concrete elements, pre-stressed concrete, and high-performance concrete.