As a leading supplier of construction materials and technical solutions, AfriSam was instrumental in the successful execution of a project in Spartan, Kempton Park. Working closely with contractor, DM Bodenstein Projects & Construction, AfriSam leveraged its expertise to create yet another concrete possibility the moment the lockdown ban was lifted on construction activity for essential services.
Appointed to undertake a project relating to the transport and distribution logistics for the client, DM Bodenstein Projects & Construction brought its experience on similar and, in fact, larger projects to the contract. The company is owner driven with a solid track record in delivering quality projects on time.
Phase 1 of the project was completed last year and comprised access and security structures. Phase 2, 3 and 4 comprise the construction of three surface beds in the storage yard to carry the static and dynamic loads of containers and heavy delivery vehicles, as well as the installation of fire hydrant lines and sleeving for all services and all paved walkways.
With heavily loaded forklifts with up to 98.17 tons on the front axle, the challenge was to design and construct concrete slabs to carry these loads. The surface beds are only 300 mm thick.
“We believe we secured this contract based not only on our experience and ability to offer a competitive price, but also because we were able, through our relationship with AfriSam, to offer technical solutions that would meet the specific application requirement,” Dewet Bodenstein, director of Bodenstein Projects & Construction says.
This solution was found in a modified AfriSam Surfacebed mix with the addition of Oxyfibre, supplied by CHRYSO Southern Africa. In consultation with the AfriSam Centre of Product Excellence and the technical team from CHRYSO Southern Africa, a high dosage rate of 3 kg Oxyfibre per cubic metre of concrete was determined as the optimum application for these surface beds.
“The project specification called for a 40 MPa concrete, 125 mm slump, with a 22.4 mm aggregate. The addition of the Oxyfibre, with a strand length of 40 mm, required careful monitoring of the slump at all times,” Bodenstein says.
The high density of fibre in the mix necessitated very thorough mixing of the concrete to ensure that the fibres were evenly dispersed. As AfriSam’s readymix plant in Spartan is less than 2 km from the construction site the concrete trucks arriving on site had to stand for another 10 minutes to complete the required mixing time.
Some 1 800 m2 of fibre reinforced concrete was placed using an AfriSam pump, and Bodenstein says that placing the pumped concrete is much easier and faster when the operator does not have to navigate steel reinforcing. In total all four phases will equate to about 7 000 m2.
“Another major advantage of using fibre instead of steel mesh is that the fibre disperses throughout the concrete matrix, facilitating a multi-directional plastic shrinkage cracking reduction matrix,” he explains.
Seven-day cube results achieved 29 MPa, and with appropriate curing the required 40 MPA specified strength at 28 days was achieved. While the cold weather and windy conditions have slowed down the curing process somewhat, it has had no detrimental effect on the placing of the concrete.
“The AfriSam readymix plant’s proximity to the site, coupled with AfriSam’s track record of excellent support service, made the company an easy choice,” Bodenstein says. “And their readiness to supply material at short notice once the lockdown was eased, and the support received from their Centre of Product Excellence and sales representative on site ensured that the project could proceed without a hitch.”
“This is our first experience using Oxyfibre at this scale, and having experienced the advantages and ease of use, we are confident that this is the way of the future for reinforcement.”
Queen Mabunda, territory sales manager at AfriSam concludes: “We pride ourselves on giving excellent service and building lasting relationships to ensure the successful execution of a project. Working with DM Bodenstein Projects & Construction on this project proved once again that supplying appropriate materials, supported by dedicated service is the AfriSam way.”