Good design, quality materials key to effective sewerage systems
24 July 2020 | Web Article Number: ME202019725
EFFECTIVE sewerage systems are an essential element of infrastructure planning, development and maintenance. They ensure that communities live in hygienic conditions through the collection, conveyance, treatment, and disposal of wastewater in a non-hazardous manner to people and the environment.
That’s according to Rocla, a manufacturer of precast concrete and sewerage system products, which said a critical function of sewerage systems is to prevent water-borne diseases from becoming active.
“The success of such systems is dependent on the design of the system, good quality materials and products, good installation and construction practice and continuous monitoring and maintenance to ensure their effectiveness is not compromised during their service life,” the company said in a statement.
Rocla line of sewer reticulation products include reinforced concrete pipes with high-density polyethylene (HDPE) lining, which it says offer the advantages of a conventional concrete pipe as well as a plastic pipe in that it maintains its shape under load and is inert to acid attack.
“They are an ideal product for large diameter gravity pipelines in almost any condition. The standard HDPE lining is light green and 3mm thick. A HDPE capping strip is welded over the joints after installation to protect the exposed concrete at the joints from corrosive products.” These pipes are available from 750mm diameter pipes.
The company also makes reinforced concrete pipes with a sacrificial layer. The host pipe is manufactured from ordinary Portland cement (OPC) concrete with either dolomitic or siliceous aggregate and the sacrificial layer is manufactured with dolomitic aggregate in an OPC concrete or calcium aluminate cement (CAC) concrete.
Reinforced concrete pipes with Xypex BIO-SAN C500 are offered for 300mm to 600mm diameter pipes. “Xypex BIO-SAN C500 is a uniquely designed admixture for integral, long term protection of concrete in harsh sewerage conditions with high levels of H2S that causes microbial induced corrosion in pipelines,” the company said.
Supporting precast concrete sewerage accessories include: pipes with access hole; custom made bends of up to 30 degrees; HDPE lined manhole chambers, as well as reducer slabs and cover slabs.
Rocla products have been used in the Waterkloof Quarry and the Nellmapius Ext 22 housing project both in Pretoria, as well as for the Polokwane Eastern Ring Road and rehabilitation of the D528 in George’s Valley and the Great North Plaza in Limpopo.