Difficulty: Easy
Correct Answer: White cement
Explanation:
Introduction / Context:Different cements are formulated to achieve specific color or performance objectives. When architectural aesthetics call for light or colored finishes, a special low-iron formulation is used to produce a white product.
Given Data / Assumptions:
Concept / Approach:The absence of coloring oxides (primarily Fe2O3) yields a white clinker which, when ground with gypsum, becomes white cement. Performance is comparable to ordinary Portland cement, but color control is paramount; white pigments can be added without muddying.
Step-by-Step Solution:
Select high-purity limestone (chalk) and kaolin with minimal iron.Use kiln refractories and grinding media that do not introduce dark contaminants.Grind clinker with gypsum and test for whiteness index and strength.Verification / Alternative check:Colorimetric tests (whiteness index) and chemical analysis confirm low iron content; compressive strength tests verify structural suitability.
Why Other Options Are Wrong:
Common Pitfalls:Assuming white cement is always weaker or only decorative; it can meet structural grades but is more expensive due to stringent raw materials and processing.
Final Answer:
White cement
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