Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
29 November 2022 | Story Leonie Bolleurs | Photo Leonie Bolleurs
UFS green concrete
The Department of Engineering Sciences (EnSci) welcomes collaborations with other departments at the UFS. Pictured here are, from the left: Louis Lagrange, Head of EnSci, Prof Kahilu Kajimo-Shakantu, Head of the Department of Quantity Surveying and Construction Management, Dr Abdolhossein Naghizadeh, and Megan Welman-Purchase, analytical scientist in the Department of Geology.

More than 30 million tonnes of fly ash (residue from coal combustion in power plants) are generated in South Africa annually, with 96% of that being disposed of in landfills. There is thus more than enough of this key ingredient to produce green concrete. 

Green concrete, so called due to its environmentally friendly benefits, is an eco-friendly alternative to conventional concrete based on the Portland cement binder. During the production of green concrete, less carbon dioxide is released into the atmosphere than with the production of ordinary Portland cement (OPC). The latter accounts for up to 8% of all global carbon emissions.

Successful tests

In the Green Concrete Lab, established in 2021 within the Department of Engineering Sciences (EnSci) on the Bloemfontein Campus of the University of the Free State (UFS), Dr Abdolhossein Naghizadeh, Senior Lecturer, researcher, and engineer, is working on green cement and concrete projects.

He uses ‘geopolymer’ technology and a mix of waste materials, alkaline solutions, and recycled aggregates to form concrete mixtures that can provide properties similar to conventional concrete.

Besides being a synthesised inorganic material (not a petrochemical product), the geopolymer cement he introduced has the following properties: it is made from a reaction between aluminosilicate materials and strong alkalis (5-7% of the concrete mixture), it uses water and by-products as raw materials, it does not calcinate lime, thus giving it a low carbon emission, and it is also beneficial from a waste management point of view. 

The waste materials used can include waste from industrial and agricultural sources, such as fly ash, rice husk ash, sugar-cane bagasse, or corncob ash, as well as natural materials such as volcanic ash. In South Africa, sufficient amounts of industrial and agricultural waste are available. 

“So far, we have successfully tested various types of green concrete based on different waste materials,” says Dr Naghizadeh. 

Besides researching the green mixture proportions in the lab, Dr Naghizadeh and his students focused their attention on establishing the strength, durability, workability, and production cost of the product. 

They compared green concrete with conventional concrete. Green concrete’s workability is slightly lower (but he believes that with appropriate mix design it can be corrected), and it has a much higher compressive strength (50-90 MPa), a smaller carbon footprint, and comparable production costs to conventional concrete (depending on the mix design). A very high level of resistance against alkali-silica reaction (concrete cancer) is also present, as well as resistance to carbonation, sulphate attack, and acid attack.
So far, we have successfully tested various types of green concrete based on different waste materials.– Dr Naghizadeh. 

He explains, “The superior durability performance of green concrete is related to its chemical compositions and microstructure. For example, the lack of calcium content in the composition provides better resistance to alkali-silica reaction. At the same time, stronger bonds between elements and polymeric microstructure provide better resistance against acids and fire.”

With all the work and research of the past year and a half, Dr Naghizadeh says they are at the stage where they can prescribe green concrete production recipes for the industry parties based on the specified application and the materials they have.

Biggest accomplishments

“We transferred most of the experimental works to the Green Concrete Lab at the beginning of 2022, which improved our productivity tremendously. Since then, nine journal papers and three peer-reviewed conference papers have been published as outputs of the research projects. Currently, there are also multiple publications under review or in the development stages,” says Dr Naghizadeh.

In addition to him, there are three master's students and one research associate working on their own individual projects.

The department is very proud of its research outputs. Dr Naghizadeh was either author or co-author of all 12 research papers. The focus of these papers was mostly on the formulation of green concrete, based on locally available agricultural waste materials, the formulation of one-part geopolymer cement (when aluminosilicate raw material is replaced with pre-activated aluminosilicate material, water can be used instead of alkali solution), and the development of ambient-cured green concrete (replacing the aluminosilicate raw material with a blend of materials).

Dr Naghizadeh is also the project leader of a group of scientists from local and international universities who are researching sustainable construction materials. These institutions include the Universities of Johannesburg, KwaZulu-Natal, Yaoundé in Cameroon, Erzurum Technical University in Turkey, as well as Nelson Mandela University and the Central University of Technology, which recently came on board. 

 


 


News Archive

Position statement: Recent reporting in newspapers
2014-10-03

 

You may have read reports in two Afrikaans newspapers, regarding recent events at the University of the Free State (UFS). Sadly, those reports are inaccurate, one-sided, exaggerated and based not on facts, but on rumour, gossip and unusually personal attacks on members of the university management.

Anyone who spends 10 minutes on our Bloemfontein Campus would wonder what the so-called ‘crisis’ is about.

We are left with no choice other than to consider legal action, as well as the intervention of the South African Press Ombudsman, among other steps, to protect the good name of the institution and the reputation of its staff. No journalist has the right to launch personal and damaging attacks on a university and its personnel, whatever his or her motives, without being fair and factual. In this respect, the newspapers have a case to answer.

But here are the facts in relation to the reports:

  1. No staff member, whether junior or senior, is ever suspended without hard evidence in hand. Such actions are rare, and when done, are preceded by careful reviews of our Human Resource Policies, labour legislation and both internal and external legal advice. Then, and only then, is a suspension affected. A suspension, moreover, does not mean you are guilty and is a precautionary action to allow for the disciplinary investigation and process to be conducted, especially where there is a serious case to answer.
  2. At no stage was the Registrar instructed to leave the university; this is patently false and yet reported as fact. We specifically responded to the media that the Registrar does outstanding work for the university and that it is our intention for him to remain as our Registrar through the end of his contract in 2016.
  3. The Rector does not make decisions by himself. Senior persons, from the position of Dean, upwards, are appointed by statutory and other senior committees of the university and finally approved by Council. No rector can override the decision of a senior committee, and this has not happened at the UFS even in cases where the Rector serves as Chair of that committee. The impression of heavy-handed management at the top insults all our committee structures, including the Institutional Forum – the widest and most inclusive of stakeholder bodies at a university – which reports directly to Council on fairness and compliance of selection processes.
  4. In the case of senior appointments, Council makes the final decision. Council fully supports the actions taken on senior appointments, including a recent senior suspension. The fact that one Council member resigns just before the end of his term, whatever the real reason for this action, does not deter from the fact that the full Council in its last sitting approved the major staffing decisions brought before it. The image therefore that the two newspapers try to create of great turmoil and distress at the university, is completely unfounded.

Even if we wanted to, the university obviously cannot provide details about staffing decisions, especially disciplinary actions in process, since the rights of individuals should be protected in terms of the Human Resource Policies and procedures of the UFS. But that does not give any newspaper the right to speculate or state as fact that which is based on rumour or gossip, or to slander senior personnel of the university. For these reasons, we have been forced to seek legal remedy and correction as a matter of urgency.

Make no mistake, underlying much of the criticism of the university has been a distress about transformation at the UFS; in particular, the perception is created that white colleagues are losing their jobs. The evidence points in the opposite direction. Our progress with equity has been slow and we lag far behind most of the former white universities; that is a fact. More than 90% of our professors are white; most of our senior appointments at professorial level and as heads of department are still overwhelmingly white. Reasonable South Africans would agree that our transformation still has a long way to go and only the mean-spirited would contend otherwise. But based on the two Afrikaans newspaper reports, an impression is left of the aggressive rooting out of white colleagues.

In the past few years the academic standard of the university has significantly improved. We now have the highest academic pass rates in years, in part because we raised the academic standards for admission four years ago. We now have the highest rate of research publications, and among the highest national publication rate of scholarly books, in the history of the UFS. We have one of the most stable financial situations of any university in South Africa, with a strong balance sheet and growing financial reserves way beyond what we had before. We now attract top professors from around the country and other parts of the world, and we have the highest number of rated researchers, through the National Research Foundation, than ever before. And after the constant turmoil of a number of years ago, we now have one of the most stable campuses in South Africa. Those are the facts.

The UFS is also regarded around the world as a university that has become a model of transformation and reconciliation in the student body. The elections of our Student Representative Council are only the most visible example of how far we have come in our leadership diversity. Not a week goes by in which other universities, nationally and abroad, do not come to Kovsies to consult with us on how they can learn from us and deepen their own transformations, especially among students.

Rather than focus on what more than one senior journalist, in reference to the article in Rapport of 21 September 2014, rightly called ‘a hatchet job’ on persons and the university, here are the objective findings of a recent survey of UFS stakeholders: 92% endorse our values; 77% agree with our transformation; 78% believe we are inclusive; and 78% applaud our overall reputation index.  Those are very different numbers from a few years ago when the institution was in crisis.

This is our commitment to all our stakeholders: we will continue our model of inclusive transformation which provides opportunities for study and for employment for all South Africans, including international students and colleagues. We remain committed to our parallel-medium instruction in which Afrikaans remains a language of instruction; we are in fact the only medical school in the country that offers dual education and training in both Afrikaans and English for our students - not only English. We provide bursaries and overseas study opportunities to all our students, irrespective of race. And our ‘future professors’ programme is richly diverse as we seek the academic stars of the future.

We are not perfect as a university management or community. Where we make mistakes, we acknowledge them and try to do better the next time round. But we remain steadfast in our goal of making the UFS a top world university in its academic ambitions and its human commitments.

END

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept