Difficulty: Easy
Correct Answer: Petroleum distillation
Explanation:
Introduction / Context:
Asphalt is the dark, viscous binding material used in road pavements, roofing felts, and waterproofing membranes. This question tests the basic materials source knowledge: whether asphalt is primarily derived from crude oil refining or from some other process.
Given Data / Assumptions:
Concept / Approach:
In petroleum refineries, fractional distillation separates lighter fractions (gases, petrol, kerosene, diesel) from the heavier residuum. The non-volatile bottom residue, after possible air blowing or further processing, is asphalt/bitumen used for paving and industrial applications.
Step-by-Step Solution:
Verification / Alternative check:
Road construction specifications worldwide treat asphalt as a refinery product. Natural asphalts (lake/asphaltite) exist but are niche compared to refinery output.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing terminology (asphalt vs bitumen). In many regions, the terms are used interchangeably for the refinery residue used as binder.
Final Answer:
Petroleum distillation
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