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Critical Reasoning: Conclusion Weakening Questions

Due to oxidation, the iron components that are utilized in structures formed with reinforced concrete can potentially lose their strength over time, especially in coastal areas with high humidity levels. This phenomenon can be prevented by coating the iron components with a robust secondary substance, such as a polymer with anti-oxidant properties. Therefore, it is certain that buildings constructed in areas with high humidity using reinforced concrete that contains uncoated iron components will suffer structural damage in the form of corrosion due to oxidation.

Which of the following, if true, undermines the author's conclusion?

Incorrect.

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This answer choice neither weakens nor strengthens the conclusion because it deals with the cost of the coating materials (fairly expensive) while this issue is not discussed in the argument.

Incorrect.

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This answer choice neither weakens nor strengthens the conclusion. Since expenses are not discussed in the argument, budgets and costs of the coating material are irrelevant. The issue is whether or not the coating is vital.

Incorrect.

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This answer choice strengthens the conclusion while you're required to weaken it. By highlighting the harsh conditions that buildings close to the sea experience, we are led to believe that those that do not have coated iron components in their concrete are indeed likely to be damaged.

Incorrect.

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This answer choice strengthens the conclusion while you're required to weaken it. By describing a situation where a coating is vital in protecting the iron components, this statement clearly supports the importance of the coating.

Superb work!

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This answer choice tells us that only when a mistake is made are the internal iron parts exposed to the air. Therefore, the conclusion that buildings with uncoated parts will suffer structural damage is undermined since only those built incorrectly will have cracks that are necessary for the iron parts to become damaged.

Only when reinforced concrete is mixed disproportionately does it experience a more dramatic chemical reaction, leading to the release of abnormal amounts of heat, and as a consequence, becomes cracked, exposing its inner iron structure to the atmosphere.
A range of polymer products with anti-oxidant properties are readily available from suppliers of construction equipment, but are almost always fairly expensive due to the chemical processes and patents required to produce such products commercially.
Because of harsher conditions such as above-average moisture levels, strong winds, and higher exposure to sunlight, building materials tend to suffer structural disintegration at much higher rates in coastal areas than in areas that are further inland.
Cracking is an inevitable result when concrete is used in large volumes, but if the inner iron components are protected by an epoxy or zinc phosphate layer, and if the cracks are treated early enough, serious weakening of the structure should not not take place.
Building projects constructed in coastal areas are usually highly lucrative, and accordingly have higher budgets and the financial potential to invest in superior materials, such as coated iron components for structures built with reinforced concrete.