Latest News Archive

Please select Category, Year, and then Month to display items

Green Engineering: How UFS’s Green concrete can be an alternative to OPC cement

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

UFS awards honorary doctorates during its centenary week

2004-10-07

The University of the Free State (UFS) will award 12 honorary doctorates on Thursday 14 October 2004 to a diverse group of outstanding South Africans and international experts.

This will be the last in a group of 18 honorary doctorates that the UFS will be awarding in its centenary year.

The awards comprise of a number of well-known language experts and writers, experts in higher education, first-time awards in community service and development studies, as well as music.

“This reflects quality and also diversity, a spectrum of convictions as well as the recognition of persons who played a major role in changing society in the last couple of decades, “ says Prof Frederick Fourie, Rector and Vice-Chancellor of the UFS.

The awards can be grouped in the following categories:

Language and literature:

Mr Karel Schoeman (D Litt (hc)) – well-known Afrikaans author and former student of the UFS. Some of the awards he has received include the Hertzog prize for prose (1970, 1986 and 1995), the CNA prize (1972 and 1994), the Old Mutual prize (1985 and 1991), the SABC prize for best television drama in 1990, the M Net book prize in 1997 and the State President award (former President Nelson Mandela: Order for Excellent Service – silver) in 1999. It is an honor for the UFS to have this gifted and creative person among its former students. This conferment is a fitting recognition of his status as leading South African writer.

Ms Antjie Krog (D Litt (hc)) – well-known South African poet and former student of the UFS. Her popularity as poet is evident in her piercing honesty and unequalled power of expression. Some of the awards she has received include the Eugéne Marais prize in 1973, the Rapport prize in 1987, the Hertzog prize in 1990 and the RAU prize in 2000. Her writing has been translated into seven languages. She has also received numerous honors for her involvement in and journalistic documentation of the Truth and Reconciliation Commission’s (TRC) proceedings. It is therefore an exceptional privilege for her alma mater to honor her with an honorary doctorate.

Prof Jaap Steyn (D Litt (et phil) (hc)) – recently, Prof Steyn again distinguished himself as biographer whose thorough research is apparent in the published biographies of illustrious writers such as NP van Wyk Louw and MER. The numerous awards, among which the Stals prize from the South African Academy of Science and Art for the Van Wyk publication, are a matter of record. He conducted the research for this great prize-winning work as honorary professor at the UFS.

Prof Jakes Gerwel (D Phil (hc)) – Chancellor of the University of Rhodes and Director of Naspers, Old Mutual, Gold Fields and Brimstone. His doctoral thesis was published in The Netherlands under the title Literatuur en apartheid. Konsepsies van “gekleurdes” in die Afrikaanse roman tot 1948 (1983). He received an honorary doctorate from Clark College ( Atlanta), the City University of New York and Missouri in the USA, the University of the Western Cape, the University of Cape Town, the University of Natal, Rhodes University, the University of Stellenbosch and the University of the Witwatersrand. He is also outstanding professor in the Humanities at the University of the Western Cape, honorary professor in the Humanities at the University of Pretoria, and was the chairman of the Human Sciences Research Council (HSRC).

Development Studies:

Dr Frederick van Zyl Slabbert (D Phil (hc)) – for his academic achievements, his endeavors for bringing about a peaceful transition in South Africa and his demonstration of the social investment role of the corporate sector. Dr Van Zyl Slabbert has received honorary degrees from the University of Natal and the Simon Fraser University in Canada. He has published seven books and various academic articles.

Community Service:

Prof Robert G Bringle (D Phil (hc)) – from the Indiana University-Purdue University Indianapolis (IUPUI) in the USA. He is currently Chancellor’s Professor of Psychology and Philanthropic Studies at the IUPUI and also Director of the IUPUI’s Centre for Service Learning. He is honored for his exceptional contribution to several of the UFS’s community service projects as well as his role in the advancement of a multi- and inter-disciplinary approach to academic development and the integration of service learning within the faculties of the UFS. He has also made a valuable contribution to the conceptual framework of the UFS’s unique community service policy and more recently to the advancement of a research culture regarding community service.

Higher education:

Dr Khotso Mokhele (D Phil (hc)), President of the National Research Foundation (NRF) is honored for his contribution to the South African higher education sector. He has also made a substantial contribution to the development of the research capacity of universities and technikons in South Africa. Dr Mokhele was born in Bloemfontein and matriculated at the Moroka High School in Thaba Nchu.

Prof Saleem Badat (D Phil (hc)), the Chief Executive Officer of the Council on Higher Education (CHE). Prof Badat has devoted himself to transforming and building South African higher education, and has constantly challenged the higher education sector to retain the moral basis of higher education and tackle its challenges with intellectual honesty, ingenuity, creativity and courage. He is honored for his intellectual leadership in the development of a equitable, just and quality higher education system in South Africa.

Law:

Prof HA (Boelie) Wessels (D Legum (hc)) – for his contribution to the fields of Roman Law, Legal History at the UFS. He is currently a part-time lecturer at the UFS’s Faculty of Law.

Medicine:

Prof CJC Nel (D Phil (hc) Posthumous) – for the way in which he strived for the advancement of excellent medical education in the country. Prof Nel also did pioneering work in the field of transformation in higher education. Under his guidance the School of Medicine at the UFS became one of the first medical schools to adopt a parallel-medium system of instruction.

Music:

Prof Leo Quayle (D Mus (hc)) – for the significant contributions he has made to the development of music – not only in Bloemfontein, but also on national level and abroad. His initiative, enthusiasm and dedication contributed to the eventual founding of the Free State Musicon, as well as the first symphony orchestra and the first string quartet in Bloemfontein. Prof Quayle is a former head of the Department of Music at the UFS.

Prof Jack de Wet (D Mus (hc)) – well-known for his exceptional contribution to violin tuition in South Africa. As pedagogue of international stature, he still moulds violinists who compete at national and international level. At an advanced stage of his career, he still actively conveys his knowledge, experience and distinctive insight in his field of speciality to yet another new generation of young violin teachers. Today the symphony orchestras in Bloemfontein and Port Elizabeth also stand on the foundations laid by him.

Media release
Issued by: Lacea Loader
Media Representative
Tel: (051) 401-2584
Cell: 083 645 2454
E-mail: loaderl.stg@mail.uovs.ac.za
7 October 2004

Back

Economic and Management Sciences

Education

Health Sciences

The Humanities

Law

Natural and Agricultural Sciences

Theology and Religion

Open Distance Learning

Business School

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