Question

how can expansion joints help prevent the cracking of asphalt due to thermal expansion? they put pressure on different parts of the asphalt. they put more pressure on the asphalt to stop it from expanding. they give the asphalt more room to expand as it heats up.

Explanation:

Thermal expansion causes materials like asphalt to expand when heated. Expansion joints are designed to accommodate this expansion. If there is no space for expansion (due to pressure or lack of room), cracking occurs. The first option about putting pressure is incorrect as pressure would exacerbate cracking. The second option of adding more pressure to stop expansion is also wrong because it goes against the principle of thermal expansion (materials expand when heated, and trying to stop it with pressure causes stress). The correct principle is that expansion joints provide space (room) for the asphalt to expand as it heats up, preventing cracking due to unaccommodated expansion.

Answer:

They give the asphalt more room to expand as it heats up.