High-profile industrial sealants

Joint sealants and auxiliary products supplied by abe Construction Chemicals, part of the Chryso Southern Africa Group, have recently been specified for several high-profile projects in Gauteng and KwaZulu-Natal (KZN).

Firstly, Dowsil 890-SL silicone joint sealants, for which abe is the sole South African distributor, was specified as sealant of the external concrete hardstand area at DSV Park, a massive new warehouse complex near OR Tambo International Airport in Kempton Park for the major logistics company, DSV South Africa. Dowsil (formerly Dow Corning), which produces its wide range of acclaimed sealants in Belgium and the USA, is widely recognised as a global leader in its field.

For the construction of DSV Park, Dowsil 890-SL sealant was applied by abe-approved applicator, Safrispec, to the joints at an external concrete hardstand area of about 150 000m2. A total of 65 000 linear metres of the highly-regarded sealant had to be applied between 200mmthick concrete surface panels that cover 2 300m2, says Jeandré Myburgh, abe technical sales consultant, based at the company’s Boksburg head office.

Among the sealant’s features that influenced its selection by specifying engineers, MVW Consulting and the flooring contractor, RCR Flooring Applications, are:

• Self-levelling.

• Movement capability of 100% for extension and 50% compression.

• UV stability and weather-resistance.

• Flows into irregular joint widths and does not require special application tooling.

• No heating or special preparation required.

• Short skin-over time of an hour or even less at standard conditions.

• Dowsil’s 15-year warranty on the 890- SL’s performance.

Jeandré says abe also supplied various sizes of ultra-flexible abe dura.cord preformed joint filler, (manufactured from low-density, closed cell polyethylene), which form part of the material to seal the concrete joints.

The main contractor for the construction of DSV Park, completed in March this year, was WBHO.

Dowsil 890-SL was also among the products supplied by abe for repairs to existing joints and sealants at the Gautrain Midrand bus depot. Grant Furrows, abe technical sales consultant, who collaborated with Myburgh for this project, says the sealing of about 40 000 linear metres was required for this project, being handled by Con-Solve Civils and scheduled for completion in November 2021.

“Abe is also supplying dura.rep FMC cement-based concrete grouting for the joint repairs at the bus depot. This popular product is non-shrinking, with aggregate and additive content that prevents segregation during application, as well as improved strength and low permeability,” explains Grant. “Abe’s epidermix 344 epoxy adhesive, with its exceptional strength and bonding capacity, is also being used for the refurbishment of the depot’s concrete surfaces.”

(Top): DSV Park.

Gauteng Bus Depot joints repaired and sealed.

Finally, 22 000 linear metres of Dowsil 890-SL joint sealant, which can also effectively be applied to seal joints on high-traffic roads, has been specified for the N2 concrete highway’s realignment at the northern ends of the Umhlali and Umvoti bridges in KZN. The aim of the long-awaited SANRAL project is to flatten sharp corners to increase safety on the busy highway and reduce the high number of accidents that have occurred in the past in the areas under realignment.

Darryl Laycock, technical sales consultant at the abe KZN branch, is assisting the specialist sub-contractor, Duncan Civils, in a supervisory capacity with the application of abe concrete repair products (dura.rep ZR Primer, epidermix 345 wet-to-dry epoxy and dura.rep FR), used specifically on the bridge structures, as well as Dowsil 890SL highway sealant and the dura.cote WB coating system, for this project.

The overall contract was awarded to Raubex KZN, which appointed abeapproved applicator Duncan Civils.

Sealant application at DSV Park.

The Gauteng Bus Depot depot hardstand area.