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Pozzolana cement, a breakthrough in the housing industry

Sat, 15 Oct 2005 Source: GNA

A GNA feature by Mrs Linda Asante Agyei

Accra, Oct.6, GNA - If houses were boxes which could be moved anyhow to anywhere at anytime, housing or accommodation would not be a headache for settlers in the urban areas who have come to seek so called greener pastures.

A drama by Osofo Dadzie, a popular drama group on Ghana Television a few years ago, aptly captured this problem in a play entitled "Edan entese adaka" meaning "a house is not like a box".

In the play, Kweku Darko, popularly known as Supper O.D, a famous actor of then Osofo Dadzie group, had a problem with a his landlord because he was unable to pay his rent which had been increased sharply by the landlord.

This sharp increase in the rent was too much for O.D. and he asked why he should come to the city to pay so much for just a single room whilst back in the village there were many empty houses.

He, in one of his exchanges with his landlord said, "If houses were to be like boxes, I would have carried one along with me to the city and you wouldn't have had the audacity to talk to me any how because back in my hometown, I am a respectable person and a landlord just like you." The landlord had the upper hand. He ejected O.D. who regretted coming to the city in search of better living conditions though back in his village he also owned a house if not houses.

Many people migrating from the rural to the urban cities in search for greener pastures have had similar experiences with their landlords and landladies and have had to come to terms with these difficulties because there is no other option.

Either you find the money to pay or leave. Yes, back in our villages and towns everybody has a place to stay. It is only in the urban areas that housing has become so critical that there is always an argument between tenants and landlord or landladies. In the urban areas, it is only the rich and affluent who can afford to build houses. Some people have turned it into business, building houses to rent.

Inadequate housing in the country has become very critical due to the increasing population.

The headaches and frustrations associated with securing a comfortable accommodation at a reasonable rent has been putting pressure on many people to own one house to prevent the confrontations with landlords and landladies which sometimes end up in the law courts. But this desire is hindered by the high cost of building a house. The cost of building materials such as cement, roofing sheets, wood, among others, has been increasing in leaps and bounds, and cost of paying for the construction has also been on the rise.

The price of cement and cement-based products, especially, has been increasing at an alarming rate. A bag of cement (50kg) leaped from 1,500 cedis in 1992 about 54,000 cedis today.

And this is in spite of the appearance of a second cement manufacturing company, Diamond Cement that broke the age-old monopoly of Ghacem.

Ghacem produces cement from imported clinker, hence the high cost of the product.

Now, the good news for Ghanaians is that the Building and Road Research Institute (BRRI) of the Council for Scientific and Industrial Research (CSIR) has conducted research and development activities on the evaluation and production of Pozzolana cement from local raw materials. Through laboratory trials, BRRI has successfully produced Pozzolana cement from bauxite waste and clay, which could be found almost in every district of the country.

The Pozzolana cement is selling at 25, 000 cedis for the same 50kg bag.

Pozzolana cement is not a new product on the world market. It is widely used in Europe, America and India for massive structures such as dams, bridges, roads and high-rise residential buildings.

The information is that structures built from natural pozzolanas centuries ago in Italy are still standing and looking very strong. Pozzolanas are defined as any siliceous or aluminous materials, which react with lime in the presence of water to form cement compounds. They occur either naturally from volcanic materials and tuff or are produced artificially from clays, shale, bauxite, water or fly ash. Ghana is very fortunate to be blessed with all the local materials it takes for the production of various types of cement in addition to ordinary Portland cement.

Records indicate that in the year 2003, Ghana imported about two million metric tonnes of clinker at the cost of 100 million dollars for the production of Ordinary Portland Cement (OPC).

If there are raw materials available in the country, which could be turned into composite cement, then government will not have to spend such huge sums of money to import clinker.

A visit to BRRI in Fumesua, Kumasi, by this reporter revealed many amazing things being undertaken by the Institute as well as other CSIR institutions throughout the country.

In an interview with Dr Kweku Amoah-Mensah, the Director of the Institute, told the Ghana News Agency (GNA) that the research programme to develop pozzolana cement started in the 70s and the idea was to reduce the construction industry's total dependence and government's annual expenditure on imported building materials since Ghana had in abundant the local raw materials for the production of pozzolana cement. He explained that there were two main types of pozzolana cement, bauxite waste and clay pozzolana cement.

With the bauxite waste, cement is produced when the bauxite is washed to get rid of loose earth and clayey part, which is often referred to as mud. The washings, called slime, are pumped through pipes into evaporated drying ponds and during drying, the mud then settles at the top.

This is then taken through processes to come out with the pozzolana cement.

According to Dr Amoa-Mensah, because bauxite was mined extensively at Awaso in the Western Region and mining activities were still in progress and expanding in capacity, large quantities of waste were being generated daily but the institute was currently focusing on the clay pozzolana cement.

He said laboratory trials have already been conducted and pozzolana cement has been successfully produced from clay and demonstration houses have been built. People have been living in these buildings for the past four years and results from the monitoring and assessments have indicated that it could withstand the Ghanaian weather without any defect.

According to Dr Amoa-Mensah, the clay pozzolana cement could be used to replace up to 40 per cent of the Portland cement masonry constructions and for non-structural masonry construction, including the production of sandcrete roofing tiles, internal and external walls, floor wet finishing and pavement bricks when used with the Portland cement.

"It can also be used with lime to stabilise marginal materials readily available in road corridors to reduce gravel haulage cost in road construction.

"It is also eligible for some investment concessions under the Ghana Investment Code and the internal rate of return of the project would be 70 per cent with a discounted pay back time of 24 years with an average equity coupled with other attractive financial indicators of the expansion project".

Production cost analysis also indicates that the selling price is currently about 50 per cent per lower than the OPC.

The Institute, with its small plant producing the cement on a pilot basis, aims at producing 3,000 metric tonnes of the cement annually. Currently, the maximum production is 12 bags a day and it supplies the building industry in Kumasi as well as individuals who have heard about it and shown interest.

The production process for the pozzolana cement is simple. It involves drying, milling, firing, sieving and bagging. The clay, which is just not any clay, undergoes laboratory tests, is air-dried and milled in a hammer mill to a fine size. The samples are afterwards mixed with ground palm kernel shells, which are also used as fuel and turned into nodules in a moduliser.

The product, after going through all the procedures, thus, becomes suitable to partly replace Portland cement in blocks and mortar for shelter construction.

Alternatively, fuel oil or LPG may also be used instead of the palm kernel shell but it is cheaper to use the palm kennel shells, which are easily accessed.

The cement is produced either by inter-grinding the pozzolana cement and clinker together at the manufacturing stage or blending the two materials on site during construction.

Though clay is in abundance in the country, it is not any type of clay that could be used.

Specific clay is selected and a series of tests are done to ascertain its potential to be used for pozzolana cement. According to Mr Amoah-Mensah, the promising prospects for a growing market for pozzolana products in the building construction industry represent bright opportunities for the proposed BRRI pilot plant for the production of pozzolana and its products not only in the Ashanti region but the country as a whole.

Mr Eugene Atiemo, Senior Research Officer, Pozzolana/Composite Cement Project of BRRI, explaining the economic benefits of the product if fully supported said the huge foreign exchange spent on the importation of clinker would be reduced considerably when pozzolana cement, produced locally, is used to supplement OPC as composite cement in the building construction industry.

He said the cost of cement was impacting negatively on housing delivery making production and use of durable local material very necessary. "But studies have shown that the production and use of pozzolana cement is a viable option", he added.

Mr Atiemo explained that most of the equipment used for pozzolana production are relatively simple and can be manufactured locally. "Setting up medium scale pozzolana plants in the country would create employment and generate revenue to the state and the economy would thus benefit considerably from its local production." He recommended that serious efforts should be made to promote the local production of pozzolana cement to support the building construction industry as well as creating more job opportunities for Ghanaians.

BRRI, not being selfish, is liaising with African Concrete Product (ACP Estates), a concrete and real estate developer, to produce pozzolana cement in a commercial base since they have bigger and sophisticated machines.

The pilot plant of BRRI would provide vital data and experience of the plant operation, product quality, market opportunities and consumer market perceptions to enhance the successful and profitable operation of the commercial plant.

Mr Joe Osae Addo, Head of Project Development, ACP Estates, in an interview later told the GNA that ACP was interested in developing new technologies and that they were trying to develop new housing type that would be affordable to the ordinary Ghanaian.

He said ACP Estates commended new technology by BRRI. He added that "this should not be seen as competing with Portland cement but as a complement to their products.

"Because of the new technologies coming up, we are opening up to new ideas and on behalf of new chairman I promise that ACP will be exploring this great initiative so that Ghana can also come out with something good which could be used locally and even export.

"I believe that with the introduction of pozzolana cement, it will reduce the problem of high cost in cement products and housing will be much more chea per and affordable for every Ghanaian", he added with smiles.

Government knowing the problems of accommodation facing Ghanaian workers is also making some efforts to solve the plight of Ghanaians. Mr. Hackman Owusu-Agyemang, Minister of Works and Housing, last month performed the groundbreaking ceremony for the commencement of a housing project at Borteyman, near the Nungua Commercial Farms, close to the eastern terminal of the Accra-Tema Motorway.

In all a total of 1,138 affordable housing units are expected to be completed at Borteyman, near Tema, to give accommodation relief to residents of the Accra-Tema metropolis by June 2006.

The units comprise 192 one-bedroom flats, 88 one-bedroom flats with shops, 608 two bedroom flats, 200 Type C one bedroom cluster of blocks and 50 Type C three bedroom cluster of blocks.

Modern amenities such as police stations, churches, primary and junior secondary schools, playgrounds, open spaces. Parking recreational and commercial centres are also to be provided to serve the neighbourhood. According to Mr Owusu-Agyemang one bedroom flat would cost 85 million cedis, while a two bedroom flat would cost not more that 110 million cedis, adding that, "we want to go down until one bedroom should cost 50 million cedis."

With the scanty salary structure of the average Ghanaian worker, and the high price of these houses, will the average Ghanaian ever own a house before retirement?

Ghana has the potential, the materials and human resource, let us use them and we will cut down cost on importation and rather export. The Francophone countries surrounding us are using composite cement why can't we also do the same to cut down cost. Let us give it a try and I believe that we will succeed to make Ghana proud.

Pozzolana is a product whose impact on the nation will be significant for a number of reasons, including lowering the cost of housing, accelerating the pace of national development. Perhaps, we are fast coming upon the day when the sight of Ghanaians sleeping in the streets because of the scarcity of housing options will be a thing of the past. Oct. 15 05

Columnist: GNA