Civil Engineering July 2021 | Vol 29 No 6

as slurry dust – are sourced from Raumix in Queenstown. Local permit holders in the area are also being supported, with a large por- tion of G1 material being sourced from a permit holder in Ngojini, as well as a portion of the G4 and G5 material. About 50 000 m 3 of fill is also being sourced from a local permit holder in the Tambo Village area. This allows the RBX / RMSC JV to support emerging businesses in the supply chain and provides access to material at both ends of the project route to optimise load-and-haul costs. The RBX / RMSC JV has a Structures Mentoring Programme in place to assist its SMME subcontractors working on cul- verts and this initiative is driven by sister- company EMPA Structures, which has an experienced specialist on site to facilitate skills transfer and quality construction. The mentoring approach is to be ‘in the trenches’ with the subcontractors. This guidance ensures that learning is effective and that high standards of work can be expedited within the planned time frames. The project will need only small quantities of asphalt, just for the bridge decks and large intersections, and this will be sourced from East London. NO STOP-AND-GO While 5 km of the route can be con- structed at full-width, the remaining 13 km has to accommodate traffic without using the stop-and-go traffic control method. To do this, a temporary 8 m widening has been constructed alongside the existing road. Side fills are put in place and G5 material is imported to create upper and lower selected layers; a 250 mm sub-base is then stabilised, which is covered with a 14 mm Cape Seal. This specification will ensure that the tempo- rary road is capable of safely carrying the busy traffic flow that is experienced on the R67 route, particularly on Fridays and pay-day weekends. Sections of the road are in the flood plain, requiring significant undercuts and side fills where unsuitable material has to be replaced with rock fill. It has been vital to adequately channel water from the road sides to protect the new road structure. Construction to date has had to deal with summer rainfall events that range from 20 mm of precipitation to as much as 70 mm to 80 mm in a single day – demanding a flexible approach that allows construction to continue wherever possible. The positive decision was to make an early start on the Swart Kei River Bridge where work on the footings was con- ducted between July and September 2020, well ahead of the rainy season. Improvements at various intersections are also included in the work package. This requires that certain existing gravel road intersections be relocated or upgraded. Some intersections will be provided with right-turn lanes and bell mouths, all contributing to higher levels of road safety. WELL RESOURCED Led by a core RBX / RMSC JV team of about 64 on-site employees, the project employs around 260 labourers and opera- tors from the local area. Other on-site human resources include 25 laboratory staff and 13 consultants, as well as 24 engineering technicians, interns and students arranged by SANRAL. Plant and equipment at work makes up a total of 88 items on site, including eight excavator load and haul teams (three 30 t and five 20 t units), five padfoot rollers, four dozer teams, four grader teams and a CAT RM500 recycler. The recycler plays an important role in the processing of G4 material to the widening sections, devia- tions, full and half width sections which are then cement-stabilised. For more information www.afrisam.com Facebook: @AfriSamSA Twitter: @AfriSam LinkedIn: AfriSam 8 July 2021 Civil Engineering Plant and equipment at work makes up a total of 88 items on site Led by a core group of RBX / RSMC JV team of about 64 on-site employees, the project employs about 260 local labourers and operators