DAMS & RESER VOIRS The circular wall comprises 170 mm thick precast concrete panels that were prestressed vertically
The fourth precast concrete reservoir in Ekurhuleni Metropolitan Municipality is nearing completion.
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his reservoir will cater specifically to the anticipated doubling in demand for water due to several planned new large developments in the Pam Brink and Dal Fouche suburbs. Work on these developments will commence shortly after the finalisation of the construction of the Pam Brink reservoir and related infrastructure. Professional team • T he precast system was approved by Tango’s Consultants, which was appointed as the design engineer for the construction of the reservoir and to supervise the works programme. • Infinite Consulting Engineers collaborated with Tango’s Consultants in the design of the system and to ensure that the various aspects of the works integrated seamlessly, with no delays, and to approve and accept liability for the concrete structure.
• Anita Building was the principal contractor and was also tasked with the earthworks and site terracing, as well as the construction of the inlet and outlet chambers and all inter-related pipe work. The company was responsible for training a large group of subcontractors and locals from poor communities located within the project footprint to work on less onerous aspects of the works programme. • Corestruc assisted with concrete design and application as well as rigging and erection. • Coreslab and another approved manufacturer produced the various precast concrete systems. Concrete technology By harnessing precast concrete technology, the various trades were able to work simultaneously to save on construction time. The
By harnessing precast concrete technology, the various trades are able to work simultaneously to save on construction time
precast concrete elements were produced during the earthworks and construction of the floor. If conventional methods were used, work would first commence with the construction of the concrete floor slab and then the walls. The most complex and time-consuming aspect of the build – namely the reservoir roof – would be left as one of the last items in the construction programme, with work on its supporting columns only able to commence once the wall had reached a predetermined height. The roof and walls were erected in three months after the cast in situ floor, bases for the precast concrete roof structure and ring foundation for the prefabricated wall were completed. In order to assist with quality control, the precast elements were manufactured in the factory. Self-compacting concrete was used to manufacture elements that contain significant reinforcing where conventional vibrating pokers could not be used. Trial mixes were prepared and tested for strength and durability, while also taking into consideration the workability of the concrete. Working in a controlled environment, Coreslab was able to ensure the perfect dosages of admixtures in order to avoid overdosing that may delay early strength development. Early strength development was imperative for uninterrupted production. M A R/ A P R 2022
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