Rapid hardening Portland cement possesses:a)Low percentage of (C3A)a...
Rapid hardening Portland cement is similar to ordinary Portland cement except that it is ground finer, possesses more (C
3S), and less (C
2S) than ordinary Portland cement.
Hence the correct answer is option C.
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Rapid hardening Portland cement possesses:a)Low percentage of (C3A)a...
The answer to the question is option 'C': Rapid hardening Portland cement possesses more (C3S) and less (C2S) than ordinary Portland cement.
Explanation:
Rapid hardening Portland cement (RHPC) is a type of cement that is specially designed to gain strength faster than ordinary Portland cement (OPC). RHPC is commonly used in construction projects where early strength gain is required.
The composition of RHPC differs from OPC, and the key difference lies in the percentages of the main chemical compounds present in the cement, namely tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and tetracalcium alumino ferrite (C4AF).
Here's a breakdown of the composition of RHPC and OPC:
Rapid Hardening Portland Cement (RHPC):
- Low percentage of tricalcium aluminate (C3A)
- More tricalcium silicate (C3S) than OPC
- Less dicalcium silicate (C2S) than OPC
Ordinary Portland Cement (OPC):
- High percentage of tricalcium aluminate (C3A)
- More dicalcium silicate (C2S) than RHPC
- Less tricalcium silicate (C3S) than RHPC
Reasoning:
Tricalcium silicate (C3S) is the main compound responsible for the early strength gain in cement. It hydrates and hardens rapidly, contributing to the early strength development of the concrete. Rapid hardening Portland cement contains a higher percentage of C3S compared to ordinary Portland cement, which results in faster strength gain.
Dicalcium silicate (C2S), on the other hand, hydrates and hardens at a slower rate than C3S. By having a lower percentage of C2S in RHPC, the cement can achieve faster setting and hardening, leading to early strength development.
Tricalcium aluminate (C3A) is responsible for the initial setting time of cement and can cause flash setting if present in high amounts. RHPC contains a low percentage of C3A to prevent rapid setting and allow for a reasonable working time.
In summary, rapid hardening Portland cement possesses more tricalcium silicate (C3S) and less dicalcium silicate (C2S) than ordinary Portland cement. This composition allows for faster strength gain and early hardening of the cement.