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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

Top class musicians appointed for UFS Odeion String Quartet
2008-01-29

 
The three new members of the Odeion String Quartet are, from the left: Jeanne-Louise Moolman (alto violinist), Denise Sutton (leader and first violinist), and Sharon de Kock (second violinist).
Photo: Lacea Loader
 

Top class musicians appointed for UFS Odeion String Quartet

The University of the Free State (UFS) has recently appointed three top class musicians for the Odeion String Quartet. The quartet, which was formed in 1991, is the only resident quartet at a South African university.

The new persons who were appointed are: Denise Sutton, first violinist and leader of the string quartet, Jeanne-Louise Moolman, alto violinist, and Sharon de Kock, second violinist. The post of cellist was recently advertised and applications can be submitted at the UFS until 29 February 2008.

The new appointments follow after three former members of the quartet retired or left Bloemfontein at more or less the same time. Michael Haller, longtime cellist of the quartet, will also be retiring at the end of 2008.

These developments means that the Odeion String Quartet will literary be brand new. It also implies that opportunities exist for learners and students to be taught by excellent new lecturers. The new players will also strengthen the Free State Symphony Orchestra to a large extent.

“The Odeion String Quartet is a flagship of the UFS and it symbolises our commitment to the arts. It also plays an important strategic role in the development of symphony orchestra music and classical music training in the Free State. This is why a real attempt was made to obtain top class musicians. We are pleased that such a strong group could be appointed,” said Prof. Frederick Fourie, Rector and Vice-Chancellor of the UFS and chairperson of the String Quartet’s management committee.
Most string quartets abroad are affiliated with a higher education institution, which enables a higher level of playing as there is more time for preparation and to study the repertoire. “We appreciate the university’s confidence in us and for the opportunity to explore the intricacies of ensemble playing. We hope that we can produce inspiring performances for our audiences and students,” said Denis Sutton, new leader of the string quartet.

Denise Sutton studied at the University of Stellenbosch (US) and obtained the degree B.Mus. with distinction. After this, she studied in Amsterdam with Theo Olof and Nap de Klijn, as well as in London. She was leader and second violinist in the Scottish Chamber Orchestra and did a successful audition for the English Chamber Orchestra. In South Africa she had a long career as concert master and leader of symphony orchestras. From 1980 she was concert master of the TRUK Orchestra for almost twenty years and from 2000 until 2005 she was member of the Johannesburg Festival Orchestra and the Chamber Orchestra of South Africa (COSA). She was also a founding member and leader of the Rosamunde String Quartet, one of the leading string quartets in the country. Denise had a very successful parttime teaching practice at the University of Pretoria (UP) and at a number of schools. She was also involved in postgraduate training. Her students include various competition winners and a number of them are playing professionally.

Jeanne-Louise Moolman studied at the UP under Prof. Alan Solomon where she obtained the B.Mus and B.Mus.Hons. degrees with distinction. She won among others the ATKV Forté and the Oude Meesters competitions and in 1985 she was the first winner of the prestigious 75th Commemorative Prize of the University of Natal. She has about twenty years experience as head alto violinist of various professional orchestras in Gauteng. Until her appointment at the UFS she was leader of the alt violinists in the Johannesburg Philharmonic Orchestra and COSA. She is an experienced chamber musician who regularly performs in various combinations with some of South Africa’s leading musicians. This includes Gerard Korsten, Phillipe Graffin, Jürgen Schwietering, the pianists Lamar Crowson and Albie van Schalkwyk, as well as clarinet player Robert Pickup. Jeanne-Louise was also a founding member of the Rosamunde String Quartet. She lectured on a part time basis at the UP and the Pro Arte Music School.

Sharon de Kock obtained the degrees B.A. Mus. and M.Mus. at the College-Conservatory of Music (CCM) of the University of Cincinnati in the United States of America (USA) in 2002 and 2004 respectively. Some of her teachers include the well-known concert violinist Chee-Yun Kim, Prof. Kurt Sassmannshaus and Piotr Milewski, all alumni of Julliard. From 2004 to 2006 she was violinist lecturer at two universities and a music conservatorium in Puebla, Mexico. She was also violin lecturer at a music school in Costa Rica and was associated with the Hugo Lambrechts Centre in Cape Town since 2007. Her orchestra participation includes among others the Opera Orchestra in Trujillo, Peru, the Sinfonica Nacional de Costa Rica in Costa Rica, as well as the Kentucky Symphony Orchestra, the Richmond Symphony Orchestra and the Dayton Philharmonic Orchestra. She also participated in the Luca Music Festival in Italy, the Grandin Music Festival in Portugal, the Pacific Music Festival in Japan and the Aspen Music Festival in the USA. Sharon performed regularly abroad as soloist and received various awards. This includes among others the CCM chamber music competition 2003 and the Baur Orchestral Competition and Heermann competition winner for violin at the CCM in 1995. In 1990 she won the first prize in the Sanlam competition.

The first official performance of the “new” Odeion String Quartet will be in May this year in Bloemfontein. Hopefully the new cellist will be appointed by this time. Members of the quartet will however perform on Friday, 1 February 2008 together with Albie van Schalkwyk and guest cellist Marian Lewin at 19:30 in the Odeion, as well as in the upcoming Spanish Music Festival held in February and March 2008. In May 2008 the quartet will participate in Zimbabwe in the Bulawayo Festival.

Media Release
Issued by: Lacea Loader
Assistant Director: Media Liaison
Tel: 051 401 2584
Cell: 083 645 2454
E-mail: loaderl.stg@ufs.ac.za
29 January 2008
 

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