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23 June 2021 | Story Leonie Bolleurs | Photo Supplied
The Department of Engineering Sciences (EnSci) – under the leadership of Dr Abdolhossein Naghizadeh – is heading a collaboration of scientists to create a green concrete that will reduce the impact of cement on the environment.

Conventional cement production is responsible for more than 6% of the overall carbon emissions in the world, which ultimately affects global warming.

The Department of Engineering Sciences (EnSci) at the University of the Free State (UFS) – under the leadership of Dr Abdolhossein Naghizadeh – is heading a collaboration of scientists from universities in South Africa and abroad to create a green concrete that will reduce the impact of cement on the environment.

This product has the potential to be used as an alternative to conventional concrete in large-scale constructions such as residential buildings and infrastructure, as well as small-scale constructions such a pavements and brickworks. 

Dr Nagizadeh, whose passion is cement and green concrete, says the idea of eco-friendly concrete was considered by European researchers a few years ago; however, this technology is still in its initial stages and has not been researched and employed at industrial scale yet. He believes that it is due to the complexity of the preparation process, and the relatively aggressive chemicals used in green concrete mixtures.

Expertise and equipment 

With his knowledge and experience of the product, Dr Naghizadeh – who joined EnSci in 2020 – has been appointed project leader of a collaborative group of scientists from the Universities of Johannesburg, KwaZulu-Natal, Yaoundé in Cameroon, and the Erzurum Technical University in Turkey.  

“Since there are only a limited number of researchers in this field, EnSci is benefiting from the expertise of this international collaboration. The proficiency of this group of scientists are keeping the project current, based on the latest findings in the research area,” says Louis Lagrange, Head of the Department of Engineering Sciences. 

Based on this new capacity, the department decided to establish and equip a new laboratory facility dedicated to cement and concrete research, with a specific current focus on green concrete. 

In this laboratory, they want to create formulations of green concrete, based on user-friendly materials. Furthermore, they aim to simplify the preparation and mixing process. “This can introduce a more eco-friendly, desirable product that can easily be employed extensively in the construction industry,” says Lagrange.

Benefits and other advantages

Besides its ability to reduce the impact on the environment through reduced carbon emissions, the product is also described to perform at equal or even superior strength and durability compared to conventional concrete, with potentially substantial environmental and economic benefits. 

This product is also primarily made from waste materials or industrial by-products. Dr Naghizadeh explains it as follows: “Normal concrete consists of conventional (Portland) cement, sand, stone and water, while in green concrete the conventional cement part of the concrete mix is replaced by industrial wastes or by-products and alkali solutions. These alternative materials are mostly aluminosilicate materials such as fly ash (residue from coal burning process in power plants) and slag (waste material from iron extraction processes).”

“Using these waste substances as binding material in green concrete can, apart from the environmental benefits, also reduce waste and contribute to the circular economy. Annually, more than 36 million tons of fly ash are produced in South Africa alone, of which more than 90% is deposited at landfill sites. Reuse of these waste materials will moderate the related waste deposition issues, such as air and groundwater pollution.”

Production of green concrete

Currently, green concrete is mostly produced in two parts: a solid raw material and an alkali activation solution. With their project, the research group wants to develop green concrete in a powdered form, to be mixed with water, instead of a chemical. Dr Nagizadeh estimates that the construction industry will be able to benefit from their work in about two years’ time when they will have a user-friendly green concrete product ready. 

Apart from putting an eco-friendlier concrete on the market, this project is also establishing a brand-new research niche in the UFS Department of Engineering Sciences. According to Lagrange, this research has the ability to attract postgraduate students and other researchers. He is also looking forward to the international academic recognition that EnSci will receive through published articles in leading international journals, and the participation of researchers in accredited conferences arising from this project. 

Lagrange is pleased that the project is establishing EnSci as a research player of note in the engineering field, specifically in the green engineering field. 

News Archive

Inaugural lecture: Prof. Phillipe Burger
2007-11-26

 

Attending the lecture were, from the left: Prof. Tienie Crous (Dean of the Faculty of Economic and Management Sciences at the UFS), Prof. Phillipe Burger (Departmental Chairperson of the Department of Economics at the UFS), and Prof. Frederick Fourie (Rector and Vice-Chancellor of the UFS).
Photo: Stephen Collet

 
A summary of an inaugural lecture presented by Prof. Phillipe Burger on the topic: “The ups and downs of the South African Economy: Rough seas or smooth sailing?”

South African business cycle shows reduction in volatility

Better monetary policy and improvements in the financial sector that place less liquidity constraints on individuals is one of the main reasons for the reduction in the volatility of the South African economy. The improvement in access to the financial sector also enables individuals to manage their debt better.

These are some of the findings in an analysis on the volatility of the South African business cycle done by Prof. Philippe Burger, Departmental Chairperson of the University of the Free State’s (UFS) Department of Economics.

Prof. Burger delivered his inaugural lecture last night (22 November 2007) on the Main Campus in Bloemfontein on the topic “The ups and downs of the South African Economy: Rough seas or smooth sailing?”

In his lecture, Prof. Burger emphasised a few key aspects of the South African business cycle and indicated how it changed during the periods 1960-1976, 1976-1994 en 1994-2006.

With the Gross Domestic Product (GDP) as an indicator of the business cycle, the analysis identified the variables that showed the highest correlation with the GDP. During the periods 1976-1994 and 1994-2006, these included durable consumption, manufacturing investment, private sector investment, as well as investment in machinery and non-residential buildings. Other variables that also show a high correlation with the GDP are imports, non-durable consumption, investment in the financial services sector, investment by general government, as well as investment in residential buildings.

Prof. Burger’s analysis also shows that changes in durable consumption, investment in the manufacturing sector, investment in the private sector, as well as investment in non-residential buildings preceded changes in the GDP. If changes in a variable such as durable consumption precede changes in the GDP, it is an indication that durable consumption is one of the drivers of the business cycle. The up or down swing of durable consumption may, in other words, just as well contribute to an up or down swing in the business cycle.

A surprising finding of the analysis is the particularly strong role durable consumption has played in the business cycle since 1994. This finding is especially surprising due to the fact that durable consumption only constitutes about 12% of the total household consumption.

A further surprising finding is the particularly small role exports have been playing since 1960 as a driver of the business cycle. In South Africa it is still generally accepted that exports are one of the most important drivers of the business cycle. It is generally accepted that, should the business cycles of South Africa’s most important trade partners show an upward phase; these partners will purchase more from South Africa. This increase in exports will contribute to the South African economy moving upward. Prof. Burger’s analyses shows, however, that exports have generally never fulfil this role.

Over and above the identification of the drivers of the South African business cycle, Prof. Burger’s analysis also investigated the volatility of the business cycle.

When the periods 1976-1994 and 1994-2006 are compared, the analysis shows that the volatility of the business cycle has reduced since 1994 with more than half. The reduction in volatility can be traced to the reduction in the volatility of household consumption (especially durables and services), as well as a reduction in the volatility of investment in machinery, non-residential buildings and transport equipment. The last three coincide with the general reduction in the volatility of investment in the manufacturing sector. Investment in sectors such as electricity and transport (not to be confused with investment in transport equipment by various sectors) which are strongly dominated by the government, did not contribute to the decrease in volatility.

In his analysis, Prof. Burger supplies reasons for the reduction in volatility. One of the explanations is the reduction in the shocks affecting the economy – especially in the South African context. Another explanation is the application of an improved monetary policy by the South African Reserve Bank since the mid 1990’s. A third explanation is the better access to liquidity and credit since the mid 1990’s, which enables the better management of household finance and the absorption of financial shocks.

A further reason which contributed to the reduction in volatility in countries such as the United States of America’s business cycle is better inventory management. While the volatility of inventory in South Africa has also reduced there is, according to Prof. Burger, little proof that better inventory management contributed to the reduction in volatility of the GDP.

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