They then built the sand pit initially with bricks, covered the bricks with concrete and then put small stones into the concrete to keep the natural appearance.

然后就是用砖块做沙坑，为了保持自然形态，在砖头上浇注了混凝土并铺上小石子。

youdao

They were pouring concrete into the pit.

他们正往坑里倒混凝土。

youdao

Currently the asphalt concrete pavement pit slots and crack are patched by heating asphalt mixtures mostly and needs higher temperature.

目前对沥青混凝土路面坑槽、裂缝等病害的修补多采用热拌沥青混合料的形式，温度要求较高。

youdao

The operation came a day after workers plugged a highly radioactive water leak from a concrete pit connected to the number two reactor, using sodium silicate - known as ''water glass''.

BBC: Japan quake: Nitrogen pumped into nuclear reactor

He said there was some work being done in the pit by concrete workers at the time, who all escaped safely.

CNN: fire