Construction World November 2016

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SANRAL will adopt new specifications for the asphalt design mix and for bitumen. The new specifications are more geared towards a paradigm of scientific knowledge in comparison to the South African mechanistic pavement design method. The new methodology that the agency is adopting will rely on temperature isotypes or temperature gradient regions in conjunction with the four classes of traffic volume over road surfaces to determine the bitumen design specifications. Bitumen is an essential product in road construction and repair. The major benefit of pairing the bitumen with the specific require- ments of the climatic area and the traffic loading is that the longevity of the bitumen and subsequently, the road surface, can be better under- stood. From this understanding comes the ability to build roads that can last longer, which will save tax payers’ money in the long run. SANRAL will also introduce a new asphalt design method. “Historically, we have drawn on the empirical method. However, we have now put a lot of time into understanding the finite elements, and the new mix design method will be more scientifically-orientated,” said Sean Strydom, SANRAL southern region materials specialist. The ability to analyse and predict what will happen in a structural element over time is the very basis of structural design. This ability is now within reach of the pavement engineer and the design of asphalt layers from the same principles as structural design will result in more cost effective road layers being constructed. “SANRAL will introduce software drawing on the insight generated by sophisticated mathematical models for every material layer in the pavement, from the lower-level granular layers to the more expensive upper layers which is cement and bitumen stabilised layers. Up until now we have never looked at how these layers interact with each other,” Strydom said. “The software will also allow us to conduct an HDM4 analysis or analysis of the lifecycle costs,” he said. SANRAL also announced in March this year the opening of a new engineering materials laboratory that will see road materials from across the Eastern Cape now being tested in Port Elizabeth. The South African National Roads Agency SOC Limited (SANRAL) has announced the adoption of two new road materials engineering specifications for the construction of the national road network and other roads under its jurisdiction. > Adoption of NEW SPECIFICATIONS

NATIONAL SAFETY AWARDS WINNER

This outstanding achievement is the result of the exceptional attention to detail and meticulous care taken by Liviero site teams in their work areas, comments Brad Boertje, managing executive of Liviero Building. “Our construction teams’ commitment to constantly striving for the safest sites sets them apart, and this dedication is reflected in our latest results in the MBSA’s prestigious, annual industry competition,” he states. Liviero’s Eskom Wilge site took top honours in Category H, for contracts between R300 and R500-million, while the contractor’s Jelf Taylor Crescent site won Category F, for contracts between R75 and R150-million. Liviero’s Pavilion team took first place in the competition’s Category E, for contracts between R25 and R75-million. Liviero was also among the top achievers in Categories D and G. The company’s Midlands Medical Centre site secured third place in Category G, for contracts between R150 and R300-million, and its KwaMnyandu Pedes- trian Bridge contract took fourth place in Category D, for contracts between R10 and R25-million. The MBSA National Safety Competition follows on from regional events in which Liviero also excelled, Boertje reports. The company’s KwaZulu-Natal sites won five regional awards in this stage of the competition. In addition to the many site-related awards, Liviero Plant was placed second in the regional competition for plant and storage yards. The annual MBSA safety awards ceremony was held at the International Convention Centre in Durban, during the MBSA’s annual congress. “We at Liviero are extremely proud of the efforts of all staff and stake- holders in consistently setting the highest standards in occupational health and safety,” Boertje concludes. From left: Itumeleng Leshoedi (MBSA occupational health and safety manager), Gift Shumba (Liviero site agent), Stephen Mayeza (Liviero senior safety officer), and Neil Cloete (MBSA president). Liviero Building was the proud winner of three awards in the 2016 Master Builders South Africa (MBSA) National Safety Competition. >

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Sean Strydom, SANRAL southern region materials specialist (right), and Yanga Mshweshwe of SANRAL’s Centre of Excellence determine the theoretical maximum density of asphalt. world-class road infrastructure network. We are also excited by the new research being undertaken by Nelson Mandela Metropolitan University in terms of adding non-homogenous agents such as recycled tyre rubber in combination with polymer particles into the design mix,” he said. The facility will double up as a skills development centre where graduate engineers in SANRAL’s experiential learning programme can get exposure to, and focus on, materials engineering. The civil engineering materials testing lab enables SANRAL to test the properties of construction materials used in road maintenance activities as well as in development and upgrading of the national roads. In addition it will give SANRAL a second-tier quality assessment tool through comparative or correlation tests done independently from, but concurrently with, the tests of site material labs conducted on conven- tional road engineering projects in the province. “Road materials engineering remains a critical part of ensuring a

CONSTRUCTION WORLD NOVEMBER 2016