Dr Wibke de Villiers follows father’s advice and finds her niche

“I had no idea what I wanted to study after Matric,” says Dr Wibke de Villiers, one of the Faculty’s PhD December 2019 graduates. “My father suggested that I study civil engineering as he thought it was a good qualification to have. I always loved Mathematics and Science and because I did not have a better proposition, I decided to follow my father’s advice. Everything worked out well and I enjoyed it immensely, especially the structures field.”

Her father may have been a tad biased towards a qualification in civil engineering, but who can blame him? He is the late prof Peter Dunaiski, one of the Faculty of Engineering’s most-beloved and highly-respected professors.

It is evident that civil engineering is indeed her niche for she obtained distinctions in both her BEng (in 2006) and master’s (in 2008).

She continues: “I always had the idea in the back of my mind that I might enjoy an academic career, but I wanted to gain industry experience first and joined Aurecon for a few years. In 2011, when an opportunity arose to enter academia, I joined Stellenbosch University as a lecturer in the Department of Civil Engineering.

The title of her PhD thesis was Computational and experimental modelling of masonry walling towards performance-based standardisation of alternative masonry units for low-income housing. (See summary below.)

Dr De Villiers elaborates: “When I tackled my PhD, the premise was to identify more sustainable housing solutions for low-income housing. However, I soon realised that the social acceptability of such systems was low, because beneficiaries want houses made of bricks and mortar. Another important factor is that government-subsidised houses are meant to be “starter homes” (of about 40m2) to which recipients can add rooms themselves. If the starter home is not constructed in the same manner, namely bricks and mortar, it is extremely difficult to add rooms to the house. I therefore decided on alternative masonry units since it is still a brick and mortar system and extensions are added far more easily.

“There are already a few alternative masonry units available on the market, but these do not fit the standards we have for bricks and concrete blocks. So I decided to investigate how we could develop performance-based criteria against which we could measure other types of masonry units.

“I have a 5/8ths post, which enables me to try and maintain a healthy balance between my career and my family life. Doing a doctorate is a challenge in itself. In addition, I had two babies during the period I did my PhD. This is not something I would recommend to anybody!”

When asked about her long-term plans, she does not hesitate to answer: “I am here to stay! On the research side there are many things I still want to pursue. During my PhD studies many questions arose that I feel need to be answered. I was on sabbatical in 2019 and in my capacity as a lecturer I really look forward to teaching again in the new year.”

Dr De Villiers is married to Richard, a chartered accountant, and they have two children, Anja (5 years) and Heinrich (3).

Title: Computational and experimental modelling of masonry walling towards performance-based standardisation of alternative masonry units for low-income housing.

Summary: For the widespread uptake of alternative, energy-efficient masonry units in low-income housing, material non-specific performance-based criteria must be established. Meso-scale nonlinear finite element analyses are performed on representative, single-storey, unreinforced masonry walls, based on the National Building Regulation’s deemed-to-satisfy provisions, using concrete, geopolymer, compressed-stabilised earth and adobe masonry materials, representing a spectrum of strength and stiffness. The analyses reveal a significant shortfall for the resistance against wind and seismic loading, even for the conventional concrete masonry walls. These results preclude immediate derivation of performance-based criteria but indicate that a review of the deemed-to-satisfy provisions is necessary.

Photograph: Dr Wibke de Villiers.