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Zorluk: KolayInferences from the Text

Recent analyses of ancient Roman maritime structures have revealed that their exceptional durability stems from a post-curing chemical reaction triggered by seawater percolation. Unlike modern Portland cement, which degrades when exposed to saline intrusion, the Roman mortar—composed of volcanic ash (pozzolana) and quicklime—reacts with percolating seawater to dissolve volcanic minerals and precipitate interlocking crystals of aluminium tobermorite and phillipsite. Because these mineral crystals form within micro-cracks over decades rather than during the initial setting phase, they reinforce the concrete matrix over centuries instead of causing structural expansion and fracture. Consequently, submerged Roman breakwaters tend to gain structural cohesion over prolonged exposure to marine environments.

Based on the passage, which of the following statements can be logically inferred regarding Roman maritime concrete and modern Portland cement? (Select all that apply)

  1. Unlike Roman maritime concrete, modern Portland cement suffers structural degradation when penetrated by saline water.Cevap
  2. B
    Roman mortar requires several centuries of continuous seawater contact before it achieves sufficient structural stability to function as a breakwater.
  3. The long-term reinforcement of Roman maritime concrete relies on mineral precipitation occurring after the initial setting period.Cevap
  4. D
    Modern Portland cement produces higher initial compressive strength than Roman concrete due to differences in quicklime composition.
  5. E
    The growth of aluminium tobermorite and phillipsite crystals causes micro-cracks to expand and fracture the Roman concrete matrix.

Cevap

The statements confirming that modern Portland cement degrades when penetrated by saline water and that long-term reinforcement of Roman concrete relies on mineral precipitation after initial setting are logically inferred from the text.
The correct statements are directly entailed by the passage: the text explicitly contrasts Roman mortar with modern Portland cement by noting the latter degrades under saline intrusion, and it establishes that Roman concrete's long-term strength comes from post-curing mineral precipitation forming within micro-cracks over decades.

Adım Adım Çözüm

1
Analyze the passage's discussion of modern Portland cement and saline exposure.
The text directly states that modern Portland cement degrades when exposed to saline intrusion, making the comparison regarding its degradation fully supported.
Direct textual comparison establishes the factual basis for evaluating contrasting claims about modern cement.
2
Evaluate the timing and mechanism of crystal growth in Roman mortar.
The passage specifies that aluminium tobermorite and phillipsite crystals form over decades rather than during the initial setting phase, reinforcing the matrix over centuries.
This confirms that the long-term reinforcement depends on chemical processes occurring well after the initial curing phase.
3
Examine the remaining choices for unsupported leaps, contradictions, or outside knowledge.
Claims regarding centuries of mandatory delay before functional use, unmentioned initial compressive strengths, and crystal-induced fracturing directly contradict or exceed the passage text.
Valid reading comprehension inferences must strictly derive from the explicit boundaries of the stimulus.

Anahtar Kavram

Drawing Necessary and Direct Inferences from Comparative Text
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Inferences from the Text

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