Using local materials with low environmental impact is essential in building living spaces, combining energy efficiency, environmental respect, and user well-being. However, despite advances in using natural materials, few studies have focused on integrating spathe fibers into earth bricks to optimize their thermal, mechanical, and hydric performance. The study aims to develop an innovative approach to using spathe fibers as natural reinforcement in manufacturing soil bricks while analyzing their impact on thermal, mechanical, and hydric properties. Several soil bricks reinforced with spathe fibers at different concentrations (0%, 1%, 2%, 3%, 4%, and 5%) were developed. Thermal performance was assessed using the hot disk method, while mechanical strength was measured in compression and flexure with capillary absorption tests. Based on fiber content, the brick density ranged from 1719.75 to 1247.6 kg/m3. The thermal conductivity of the materials ranges from 0.621 to 0.327 W/m. K, indicating good insulating performance. Maximum capillary water absorption values range from 170 to 287%, revealing a difference in water permeability depending on fiber content. Compressive strengths range from 1.4 to 3.6 MPa, and flexural strengths range from 1.6 to 1.91 MPa, suggesting potential for structural applications. Physico-chemical and geotechnical analyses confirm the suitability of the soil for the production of spathe fiber-stabilized bricks. This study offers an alternative to conventional bricks, contributing to the promotion of ecological and sustainable building materials suitable for arid and semi-arid climates.

Volcanic eruption at La Palma island (Tajogaite, 2021) has produced tons of volcanic ash as natural sediments spread all around the island covering existing crops, roads, embankments, buildings, etc., by that way producing damage to environment. For the rehabilitation and reconstruction of island, and its application to adjacent areas, it is practical and economical to employ these volcanic ashes as construction material being encountered in abundant volume, and by that way could be considered as a resource material instead as a waste material, reducing necessary volume of landfills for its deposition. This paper defines the investigation of chemical, mineralogical and geotechnical properties of these deposited materials for its possible reuse by that way providing solution for its recovery. These young volcanic ashes are studied in its fresh natural state, prior to consolidation and cementation has taken place for its chemical, mineralogical and geotechnical characterization. Volcanic ash of Tajogaite is of a poorly graded sandy nature having difficulties for its compaction, having low improvement of relative density by the application of standard compaction methods. Mineralogy analysis indicates it is rich in silica, iron, calcium and alumina oxide, although being necessary the addition of mineral additives for its alkali-activation. Geotechnical characteristics of different samples vary depending on the sampling site, being resistance parameters determined by direct shear test (friction angle 30 degrees degrees to 34 degrees) degrees ) and deformational properties defined by one-dimensional consolidation test considered low values as of loose sand materials (deformation modulus range from 20 to 40 MPa).