A petrol vibrator is a portable construction machine used to compact and remove air bubbles from freshly poured concrete. It is powered by a petrol (gasoline) engine, making it suitable for sites without electricity. The machine typically consists of a small engine, a flexible shaft, and a vibrating head (needle or poker). It is widely used in building construction for columns, beams, slabs, and foundations to ensure strong and durable concrete.

Operation
When the petrol engine is started, it drives the flexible shaft, causing the vibrating head to rotate and produce rapid vibrations. The operator inserts the vibrating head into freshly poured concrete. The vibrations reduce air pockets and allow the concrete particles to settle closely together, improving density and strength. The operator moves the vibrator slowly from one point to another to ensure even compaction. After sufficient vibration, the head is removed carefully, and the process is repeated until the entire concrete area is properly compacted.