Utilization of marine waste enteromorpha prolifera powder to prepare sustainable lightweight cementitious materials

This study innovatively used enteromorpha prolifera powder (EPP) to prepare lightweight cementitious materials. The effect of EPP on the physical properties, mechanical strengths, and microstructure of mortar was tested and discussed. The results indicated that the density and thermal conductivity of mortar were significantly reduced after adding EPP, but the water absorption and porosity were increased accordingly, resulting in a significant loss of mechanical strength. Surprisingly, the density and thermal conductivity of mortar incorporated with 8 % EPP was only 855.00 kg/m³ and 0.28 W/m•K (reduced by 57 % and 83 % respectively compared with plain mortar), and the 28 d compressive strength was still as high as 1.90 MPa. The results of thermogravimetric analysis and X-ray diffraction showed that as the EPP content increases, the Ca(OH)₂ content decreases, and the CaCO₃ content increases. This was due to the increase in porosity causing CO₂ in the environment to enter the interior of the matrix. This study not only proposed new material for preparing sustainable lightweight cement mortar but also found a new way to utilize large amounts of waste enteromorpha prolifera resources.