RPM continues to bolt on new pieces to its UK-based USL Group as it moves to ramp up involvement in larger infrastructure projects at home and abroad.

Medina-based RPM said Oct. 30 that it has acquired Sheffield, England-based EkspanĀ Holdings, a $10 million designer and installer of motion control products for bridges and major structures. Among its past projects is the London Tower Bridge.

Ekspan is the third acquisition in the past 15 months for the USL Group. In January, it bought Prime Resins, a $7 million manufacturer of specialty chemicals and equipment for infrastructure construction and repair. Last summer, it picked up Applied Polymerics Inc. and Marketing Associates Inc., a $14 million civil engineering group focusing on bridges, roads and major structures.

Among large manufacturing companies, RPM has a fairly unique approach to dealmaking. Over the past 30 years, the company has built itself into a $5 billion business through more than 170 acquisitions, many of them of small, entrepreneurial businesses. It then typically leaves management in place to run the operations, providing additional investment capital and leveraging other RPM businesses as needed to fuel growth.