Interview with dr. eng. Andreea HEGYI, scientific researcher grade III, INCD URBAN-INCERC, Cluj-Napoca Cluj-Napoca Branch

It is already well known that the educated population's appetite for natural building materials at the expense of non-environmentally friendly ones is steadily increasing. From your point of view, is the production and use of renewable natural materials advisable for use as building/insulation materials? Why?

Andreea HEGYI: Since the Brundtland Report (1987), development in all areas, not only construction and building materials, has been based on the criterion of sustainable development or, as it is also known, sustainability. It has therefore become increasingly apparent that there is an interest in producing sustainable materials and technologies that meet today's needs without compromising the possibility of harmonious development for future generations, while respecting the criterion of intergenerational equity. Sustainable development in the construction sector is possible in several directions:

• Producing materials that do not jeopardize renewable raw material resources, with the lowest possible energy consumption and environmental pollution impact - for example, buildings made of rammed earth or adobe bricks;
• recycling and reuse of waste products from either the demolition of buildings whose lifespan has come to an end or from technological manufacturing processes - for example, the production of recycled aggregates in concrete or self-compacting concrete
• the development of technologies that extend the life of structures and therefore, even if involving a higher initial investment, the benefits are found in higher durability, reduced need for maintenance and repair or even self-healing capacity - for example, the production and use of self-healing mortars and concretes or the use of corrosion-protected reinforcement by thermal galvanization.

Are standards and/or approvals for such materials in work or have you already developed them? For which materials and what would be their advantages/disadvantages?

A.H.: Within INCD URBAN-INCERC Cluj-Napoca Branch, experimental researches have been carried out in order to elaborate Test Reports and Technical Approvals for thermal insulating mats made of sheep wool and thermal insulating panels made of sheep wool, thermal insulation made of cellulose fibers.

The advantages of thermal insulation with sheep's wool mattresses or panels are:

• The raw material is abundant in our country;
• the insulation is permeable to water vapor, which allows the walls to "breathe", thus contributing to a healthy indoor environment with optimal humidity, without the risk of mold growth;
• the manufacturing process requires low energy consumption;
• insulation reduces the energy consumption needed to heat interior spaces;
• the insulation system involves no loss of material;
• application is quick and to the required dimensions.

The advantages of cellulose fiber insulation are:

• the raw material, cellulose fibers, are obtained by mechanically shredding newspaper pulp;
• the insulating material absorbs moisture from the atmosphere into the fibers, then quickly releases it
• it is also a recyclable product; it contains purely natural additives (boric salts);
• the manufacturing process requires low energy consumption;
• reduces the energy consumption needed to heat interior spaces;
• the insulation system involves no loss of material;
• application is quick and to the desired dimensions.

Possible disadvantages of using these materials may be:

• attack by insects or rodents - this disadvantage can be mitigated by specific treatments of the product before and/or after installation;
• vulnerability to fire - this disadvantage can be reduced by specific fireproofing treatments.

INCD URBAN-INCERC Cluj-Napoca Branch has elaborated the normative C 155-2013 on the production of lightweight aggregate concrete, which demonstrates the possibility of using recycled brick waste, and has participated in the elaboration of other norms and standards in the field of construction materials.

Read the full text in issue 1 / 2016 of Arhitectura Magazine