Effect of Posidonia oceanica Fibers Addition on the Thermal and Acoustic Properties of Cement Paste.

What is it about?

The present work focused on the experimental study of the mechanical, thermal and acoustic properties of cement composite reinforced using Posidonia oceanica (PO) fibers. For this purpose, parallelepipedic specimens of dimensions 270 mm × 270 mm × 40 mm and cubic specimens of dimensions 150 mm × 150 mm × 150 mm were prepared with a water-to-cement ratio of 0.50 by varying the volume of fibers (Vf) from 0% to 20%. Properties such as compressive strength, thermal conductivity, thermal diffusivity, standardized level difference and sound transmission class were examined. The compressive strength of the specimens was determined using the rebound hammer test, while the thermal measurements were performed with the steady-state box method. The results showed that the addition of PO fibers improved the compressive strength of the mixtures and produced a maximum value of 33.60 MPa for a 10% volume of fiber content. Thermal conductivity and thermal diffusivity decreased significantly with the addition of fibers for all the mixtures. The experimental investigation also showed that the sound transmission class of PO-fiber-reinforced cementitious composites decreased as the fiber volume increased due to an increase in air voids in the mixtures.

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Why is it important?

The Mediterranean Sea is one of the areas in the world where the phenomenon of marine litter is the most important environmental problem (about 80% of which is plastic litter); the accumulation of this waste along coastal areas compromises the integrity of coastal ecosystems and represents a problem for economic activities (fishing, tourism, etc.). On the other hand, the deposits of PO, which represent a natural resource found on the beaches of the Mediterranean, can determine criticalities in tourism if they are not properly managed. Posidonia oceanica is found as small balls on the sea bed carried by waves. These balls can be effective natural fibers for enhancing the properties of concrete .Life cycle analysis shows that when Posidonia fibers are used as insulation, their environmental impact is very low. Today, many insulation materials are derived from crude oil, while there is growing market potential for renewable resources in Europe. The use of PO fibers represents an alternative solution to petroleum-derived products and, at the same time, guarantees energy-efficient insulation of buildings . In view of their ecological interest, it is guaranteed that these natural fibers will meet with growing success in the years to come. Compared with other natural fibers, seaweed clusters have an undeniable advantage, as they are not produced using agricultural or forestry processes and, therefore, will not compete with the food industry for use of available land. In addition, the materials produced from Mediterranean Posidonia are suitable for both thermal and acoustic insulation, are resistant to fire and mold, and therefore, do not require any chemical treatment . Natural fibers can be used as insulating materials in construction for environmental and economic reasons given their low cost, their biodegradability and their availability.

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