For very high pavement temperature resistance (around 196°C) in taxiways and aprons, select the most suitable construction material.
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AAsphaltic concrete
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BRubberised tar concrete
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CPlain cement concrete
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DEpoxy asphalt concrete
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EAll of the above perform equally well at 196°C
Answer
Correct Answer: Epoxy asphalt concrete
Explanation
Introduction / Context:Aprons and taxiways near jet exhaust and frequent braking zones can face extreme thermal and fuel/oil exposure. Selecting a material that maintains stiffness and integrity at elevated temperatures is crucial to prevent rutting, bleeding, or softening.
Given Data / Assumptions:
- Target high-temperature resistance near 196°C (very severe).
- Materials compared: conventional asphaltic concrete, rubberised tar concrete, plain cement concrete, and epoxy asphalt concrete.
Concept / Approach:Softening temperature and binder rheology control high-temperature performance. Epoxy asphalt uses a thermoset epoxy-modified binder network that drastically improves high-temperature modulus and chemical resistance compared with conventional thermoplastic binders.
Step-by-Step Solution:
1) Conventional asphaltic concrete softens at far lower temperatures; susceptibility to bleeding/rutting increases.2) Rubberised tar may improve elasticity but does not approach epoxy asphalt’s high-temperature stability.3) Plain cement concrete has good high-temperature stability but is a different system; the prompt points to a specifically high softening point target associated with epoxy asphalt solutions for overlays/aprons.4) Epoxy asphalt concrete, with its cross-linked binder, is engineered for high-temperature and chemical resistance, making it the most suitable among the listed bituminous choices.Verification / Alternative check:
Compare binder softening points and dynamic modulus curves—epoxy asphalt remains serviceable where conventional asphalt becomes too soft.Why Other Options Are Wrong:
Options a/b lack sufficient high-temperature stability; option c is not the intended solution in the context of a high-temp bituminous choice; “all of the above” is incorrect because performance differs significantly.Common Pitfalls:
Assuming any asphalt will suffice; ignoring binder chemistry and thermoset vs thermoplastic behavior.Final Answer:
Epoxy asphalt concrete