steamroller

A steamroller is a type of roller vehicle used for compacting road surfaces, soil, and foundations. Originally powered by steam engines, modern steamrollers are typically powered by diesel engines. They are characterized by their heavy weight and large, smooth cylindrical drums that apply pressure to the material being compacted. The weight of the roller is the primary mechanism for compaction, forcing loose materials together and reducing air voids.

Steamrollers are essential in modern construction, particularly in road building and infrastructure projects. They are used in various stages of construction, from preparing the subgrade to compacting asphalt or concrete layers. Different types of rollers exist for specific applications, including vibratory rollers, pneumatic tire rollers, and sheepsfoot rollers, each designed to achieve optimal compaction for different materials and conditions. The term "steamroller" is still widely used even for non-steam-powered machines due to historical association. In a figurative sense, "steamroller" can also refer to something or someone that is overwhelmingly powerful or insistent, crushing all opposition.