Long bridges sometimes expand up to a meter in hot weather, like the Golden Gate Bridge at the start of the chapter, or the Benjamin Sheares Bridge in Singapore. Without allowance for expansion, such structures are at risk of damage in very hot weather. Bridges and metal girders on building have expansion gaps or a free end resting on rollers to allow for expansion. In this way, when the weather is very hot, the will not be damaged.
That's the first one, so we need gaps to allow expansion on a bridge. Let's see the second one:
Excessive expansions on very hot days can cause roads or pavement to crack, or tiles to pop out. To get around this problem, the tiles on pavements and walls are laid with expansion gaps.Without gaps:
With gaps:
