Cement types — identification of white cement Portland cement manufactured from pure white chalk and clay and essentially free from iron oxide pigments is commonly called:

Civil Engineering Building Materials Difficulty: Easy
Choose an option
  • A
    Quick-setting cement
  • B
    Rapid-hardening cement
  • C
    White cement
  • D
    Low-heat Portland cement
  • E
    Portland pozzolana cement

Answer

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:

  • Raw materials: very low iron and manganese content to avoid gray coloration.
  • Manufacturing controls to prevent contamination from kiln and grinding media.
  • Application focus: decorative concrete, terrazzo, tiles, and colored mortars.

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:

  • Quick-setting and rapid-hardening cements (A/B): defined by setting/strength characteristics, not color.
  • Low-heat cement (D): formulated for mass concrete to limit temperature rise; again not color-driven.
  • PPC (E): blended with pozzolana, typically gray.

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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