Hard work is paying off for Nokuthula Mazibuko, a candidate engineer, with the Technical Excellence Academy at the South African National Roads Agency SOC Limited (SANRAL). She will present her case study on Binder Rise with Bubbles in Chip Seals this week to the Society of Asphalt Technology (SAT) in Pretoria.
Mazibuko responded to a request from the SAT when members were asked to provide an abstract of their research. The paper she submitted to SAT is on the investigation of the premature failure of a portion of reseal on National Route 2. She wants to inform industry players of this occurrence which could be costly to repair, and which can be mitigated in future.
The SATBinderrr 2022 conference will take place at the CSIR International Convention Centre in Pretoria from the 21 to the 22 September 2022.
“I was given an opportunity to do research on a reseal that had failed prematurely, where I lead a team from SANRAL’s materials training laboratory to collect samples of the reseal to determine the cause of the premature failure.
“Bitumen bubbles were observed on the surface, and the team was curious as to the cause of the bubbles because they had led to the bleeding of the seal. During the research I created a model to understand at what temperature and how much water causes the binder to ascend to the surface in the form of bubbles, effectively leading to the bleeding. We successfully simulated the above scenario, which I will present at the 2022 SAT conference,” Mazibuko said.
She is currently working as an assistant resident engineer on SANRAL’s R67 section 5 upgrade from the Swart Kei River Bridge to Queenstown. Her role and responsibilities include quality assurance, that is ensuring that the contractor produces pavement layers in accordance with the design specifications.
“My experience on site has been an eye-opener to the reality that designs are not always easy to construct on site due to available materials and the skills levels of staff,” she explained.
She joined the TEA in March 2020, at the beginning of the pandemic. She graduated from the University of Stellenbosch with a BEng (Civil Engineering) degree in 2014 and completed her Master’s degree in Civil Engineering in April 2020, with some industry experience in the intervening years.
“My experience with the SANRAL TEA has been a blessing where I have received opportunities to learn the deep art of engineering design and providing engineering solutions in the sub-disciplines of geometry, hydrology, hydraulics, and pavement engineering. I learned from my well-versed mentors and was encouraged to do some independent problem solving. I am currently getting great exposure to the industry at large from design to construction and will soon get the opportunity to learn about project management, the SANRAL way,” she said.