Question

The basis for classification of ordinary Portland cement (OPC) as grade 33, 43 and 53 as per IS 10262 is:
1. setting time
2. 28 day compressive strength
3. fineness value and setting time
4. soundness value
5.

Answer 1

Correct Answer - Option 2 : 28 day compressive strength

Explanation:

• Ordinary Portland Cement (OPC) is the most widely used cement in the world for producing concrete, mortar, stucco, and non-specialty grouts.
• Ordinary Portland Cement has 3 grades based on its strength namely 33, 43, and 53 grade that indicates the compressive strength obtained after 28 days of setting.

​Different properties of OPC:

Physical Properties:

Grade	Average Compressive strength			Fineness in m2/kg	Soundness		Setting time
	At 3 days in Mpa	At 7 days in Mpa	At 28 days in Mpa		By Le Chatelier method	By autoclave test method	Initial setting time in min.	Final Setting time in min.
OPC 33	16	22	33	225	10 mm	0.8%	30	600
OPC 43	23	33	43	225	10 mm	0.8%	30	600
OPC 53	27	37	53	225	10 mm	0.8%	30	600