PPC has successfully finished a ZAR26m (US$1.54m) structural rehabilitation of a reinforced concrete duo-cell silo at its Hercules plant in Tshwane, Gauteng. The project, which took place between July and December 2025, restored the structural integrity and long-term performance of this critical storage facility without interrupting the plant’s daily operations.

Before the intervention, the silo suffered from vertical cracks that caused cement leakage and water ingress. Specialist civil engineering contractor Smart Civils and PT Systems, alongside consulting engineers Jones and Wagener, conducted a detailed assessment to develop a repair strategy. The resulting methodology combined crack injection, localised concrete repairs, and the application of protective coatings to prevent future deterioration.

A central feature of the project was the installation of an external post-tensioning system. This involved 176 rings of specialised UV-protected strands anchored at 352 points. To ensure even load distribution and limit lateral movement, four jacks were operated simultaneously during the stressing of each ring. This system provides vital circumferential restraint, significantly enhancing the load-carrying capacity of the silo wall.

Execution required careful coordination within an active industrial environment. The team managed continuous truck movements using segregated routes and physical barricades, while on-site generators mitigated the impact of power outages. Despite challenges like heavy seasonal thunderstorms, the project was completed on time and within budget. Notably, the project maintained a perfect safety record with zero incidents, thanks to dedicated safety personnel and strict working-at-heights protocols.

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