For porous concrete pipe, which type of Portland cement may be used?

For porous concrete pipe, which type of Portland cement may be used?

• A. Type I
• B. Type II
• C. Type III
• D. Type IV

Answer: (B)

Type II cement is chosen because it balances heat of hydration with durability, which is important for porous concrete pipe. Porous pipes have a lot of surface area and need controlled curing so the internal heat from the cement does not cause thermal cracking that would seal pores and reduce permeability. Type II cement produces less heat than ordinary Portland cement (Type I), helping limit temperature rise in the thick sections of a pipe during curing. It also offers moderate sulfate resistance, which is helpful in soil or groundwater environments where sulfates may be present. Type III’s rapid strength gain comes with higher early heat, which can aggravate cracking in large pours, and Type IV’s very low heat is paired with very slow strength development, making it less practical for typical pipe installation timelines. Type I is more generic and can generate more heat, increasing cracking risk in porous pipe. So the best fit is Type II for this application.

Type II cement is chosen because it balances heat of hydration with durability, which is important for porous concrete pipe. Porous pipes have a lot of surface area and need controlled curing so the internal heat from the cement does not cause thermal cracking that would seal pores and reduce permeability. Type II cement produces less heat than ordinary Portland cement (Type I), helping limit temperature rise in the thick sections of a pipe during curing. It also offers moderate sulfate resistance, which is helpful in soil or groundwater environments where sulfates may be present. Type III’s rapid strength gain comes with higher early heat, which can aggravate cracking in large pours, and Type IV’s very low heat is paired with very slow strength development, making it less practical for typical pipe installation timelines. Type I is more generic and can generate more heat, increasing cracking risk in porous pipe. So the best fit is Type II for this application.