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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

SRC Inauguration speech: 22 January 2005
2005-01-22

Campus Head (Prof Peter Mbati). Dean of Students (Dr Natie Luyt). Deputy Director: Student Affairs and my boss (Mr. Teboho Manchu), Members of the University executive and Academic staff members, SRC members, Leaders of trade Unions and Student organizations, Distinguished guests, Ladies and gentlemen, most importantly first entering students and Parents receive my heartfelt revolutionary greetings.

Let me extend my word of appreciation to our distinguished guests for adding value and dignity to this event. Your presence here means a lot to us. Program Director what I bring here with me, assisted by facts, and is therefore just the work of my imagination. Like a love letter addressed to a sweetheart miles away, even though you do not know how she feels, what she wants to hear, and do not even know how her face looks like.

To me a speech is just an honest and intimate conversation. That is why I got into the habit of establishing a dialogue, or a debate, with my acquaintances looking at their faces and trying to persuade them of what I am telling them.

Mr. Speaker and Madam Deputy Speaker of the Student Parliament we are gathering at this ceremony, significantly few weeks after the release of grade 12 results, with the exception of those from Mpumalanga because of fraud. The Grade 12 results also show that only 18% of Black learners matriculated with exemptions, as compared to 53, 6% of white learners. This is an indication that our education system needs an overhaul.

We are also gathered here significantly a day after the management retreat held in Bloemfontein, Masselspoort. The retreat discussed, among other things, the transformation agenda, and some possible solutions to challenges we are facing now.

Most regrettably, we are gathered here when the whole world morns the victims of Tsunami tragedy. Let me therefore tore the line and convey our deepest condolences, from the last robot of my heart, to the affected families. Our hearts and thoughts will always be occupied by this horrified tragedy.

Creating a new Institution

I would submit, for purposes of debate and discussions that this Institution should strive to specialize and excel in regional rural development studies. Since our higher education, institutions in South Africa are generally weak in rural development studies. Instead, most of them tend to have an urban orientation to their programmes. Training everybody for the cities, big business and the private sector. This is a big weakness in a country with such large rural areas and population trapped in poverty, disease and ignorance.

Women’s studies

Program Director, it is only a moron who can argue against the fact that for us to reposition the institution around the regional development challenge, we need to start first with women empowerment. It is a fact that in most of our poor communities and families, it is women who withstand the worst of poverty. They are the ones who daily have to wipe tears from children who are hungry. It is women who look after the sick, the elderly, those dying from AIDS and the jobless. They are the one who have to fetch water, make fire and cook. There can therefore be no rural development studies without women studies, in particular on how to empower them and assist in the provision of basic services, so that they are relieved from some of the burdensome task of the society.

Registration Process

Mr. Speaker and Madam Deputy Speaker of the Student Parliament let me indicate that the registration is a process and not an event, so it cannot be concluded overnight. This huge process demands for people to stay calm, as there is no crisis. People should stop being excited. At the same time, no organization should use its cheap popularity and unilaterally disrupt the continuous and smooth running of the registration process at hand.

Let me strongly indicate, madam deputy speaker, that I am on record for stating that I have forgiven all those who have wronged us. I harbour no bitterness towards the protagonists of our painful and unfortunate events of the past week. And we will overcome this process not by our own devices but by the help of Almighty God and the grace of our Lord Jesus Christ.

Concerning registration of first years, we have programs, concerning that of senior students, we have programs, regarding graduations we have programs, and concerning HIV\AIDS we have programs. So, there is no need for people to press panicking buttons.

Mr. Speaker and Madam Deputy Speaker of the Student Parliament let me be opportunistic and welcome the entire student body on Campus for the academic year 2005. May our lovely first entering students have a happy and momentous year as part of Qwaqwa Campus of University of the Free State. May your studies be fruitful and enjoyable.

Student years are generally the happiest years of your life, so please make the most of them. While you are doing, all your preparations bear in mind that University is not an opportunity, it is just creating opportunities for a person.

On behalf of SRC members, our people, our students and management members I would like to welcome you all. Even though your parents are far away, here at Uniqwa you have more brothers, more sisters and more parents. Since we will love you with the same love as if we are from one family, and I have no doubts that management members will love and care for you as if you are their own children. Should you encounter any problem while studying at the Qwaqwa Campus of University of the Free State do not hesitate to contact us at the SRC offices because we need to ameliorate any factor influencing you negatively while on campus. I wish you well in the attainment of your academic pursuit.

Senior Students: We are not faced with just a new year but another academic year where we all have to work together to achieve our common goal of building our Institution through the development of human power. I urge you to invest your whole selves in this SRC.

For quite some time now, a debate has been ranging as to, whether has there been any progress in this incorporation process, or we are just moving with no direction. This debate is important, but I hasten to add not essential. The SRC is also involved in this debate, but with definite shift in emphasis. For us it is not important to participate in the debate than it is in finding solutions for the challenges of this new chapter in the history of humankind.

To my colleagues: Comrades, we are leading this Institution with a sense of pride and duty, and I know very well that we lead men and women, students who are determined to ensure that we all reach our destination safely and on time.

I said in one of our meetings that there are more enemies on our way, more than we can imagine. I think you witnessed that during the course of this week. The excitement and unnecessary confusions caused by some confused and loosed charlatans bear testimony to my statements. We should not reveal our game plans unless we are ready to slam.

Let me also borrow from the words of the late Albert Lethuli when he said and I quote: “There remains before us the building of the new land, from the ruins of the old narrow groups, a synthesis of the rich cultural strains which we have inherited. The task is immense”. Lastly, a navy divided within its ranks will be vanquished and destroyed by the enemy, but a navy united in purpose and action, loyalty and commitment will not drawn but sail on to victory.

In conclusion, let me call upon all political structures, church denominations, developmental structures, clubs, societies and forums to put aside all their differences, ideological insinuations and forge unity towards transforming Qwaqwa Campus of University of the Free State into an institution that is seen playing vigilant role in developing students academically, politically, socially, spiritually, religiously, culturally and otherwise.

Program Director, let me end my speech by indicating that every drop of my blood is telling me that Uniqwa is my home. I firstly became a student here, I became an activist here, I became a leader here, I became a president here, I will become a graduant here and hopefully I will become an employee here. So never, doubt my commitment towards the community of this campus.

Please be informed, in a central University of Technology’s way, that if there is no UNIQWA in HEAVEN, then I am not GOING.

Let us broaden the social base.

Tello Titus Wa-Motloung President General

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