The Malta Independent 23 May 2024, Thursday
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Reinforced concrete residential buildings could potentially face problems after 50 years

Sabrina Zammit Sunday, 5 February 2023, 07:30 Last update: about 2 years ago

Concrete reinforced with steel has a shorter service life, usually of 50 years or less, meaning that many such buildings will either require expensive maintenance or need to be demolished, the president of the Chamber of Geologists, Peter Gatt said.

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In reply to questions by The Malta Independent on Sunday, Gatt said that concrete on its own can last for many decades, if not centuries. When the material is reinforced with steel it has a shorter service life “usually of 50 years or less depending on the surrounding environmental conditions which can be rather harsh in Malta”.

He added that this situation in itself is already creating a waste problem, which will become more acute in the long term.

Gatt was contacted to give comments on cement as one of the main sources of building materials usually used in the building of blocks of apartments on the island.

The geologist explained that the concrete mix consists of cement, aggregate and water. He said that cement is imported but that the other materials (water and aggregate) are dependent on the country’s geological resources, which are extracted by quarrying and water boreholes.

“These essentially geological materials make up 70 to 80% of the concrete and are both in short supply in Malta.”

He said that additionally, unlike other European countries, the regulatory framework concerning quarries in Malta “does not require the input of geologists and this results in long-term inefficiency in the use of our rock resources and compromises the sustainability of rock extraction.

The Malta Chamber of Geologists has requested the Minister for Public Works and Planning, Dr Stefan Zrinzo Azzopardi to recognise the professional role of the geologists, “but we do not have a tangible reply.

In explaining why concrete is being used in building projects, Gatt said that the raw materials to make cement are limestone and clay but that “expensive energy costs, to produce cement, affect the price of cement, whereas aggregate is a relatively cheap material we extract from quarries.

However, apart from the price of building material, the quality of the materials used in concrete is very important as it affects the strength and durability of concrete.

“In Malta we have problems with aggregate in terms of their strength, water absorption and shape of aggregate,” he said.

The geologist said that the country needs a National Geological Service to assess its limestone resources, from where  the aggregate is obtained, and to improve the processing of aggregate so that “we (Malta) have a sustainable industry that produces better quality material, which is an important consideration for public safety.

He said that Maltese aggregate needs to reach the levels of quality required by European standards, as currently, labelling of imported cement does not adhere to EN197, which regulates the classification of cement in the EU.

“The Chamber of Geologists has already made representations to the authorities about this issue and we hope that Malta will begin to conform to EN197."

Asked about what remedies the government can take in order to lessen the harmful effects of concrete, Gatt suggested recycling. However, he added that the concrete mix may include additives which may be harmful to the environment and humans.

In explaining how this could happen he said that additives might leak from the concrete or concrete batching plants.

“It is important that thorough geological studies are made in Environmental Impact Assessments of concrete batching plants,” he said.

He also said that the government needs to regulate and control potential toxic effects as airborne concrete dust is carcinogenic.

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