A Wet Mix Macadam (WMM) plant, also known as a wet mix plant or wet mix macadam plant, is a type of construction equipment used to produce materials used in road construction, particularly in laying the base or sub-base layers of a road. The wet mix macadam process involves mixing graded aggregates and water with a binder (like cement or bitumen) to create a homogenous mixture that can be laid and compacted to form a stable foundation for roads.