Nanostructured zonolite–cementitious surface compounds for thermal insulation

Abstract This paper investigates the effect of zonolite loadings on the thermal resistivity and indirect tensile strength of nanostructured cementitious compounds. The main objective of this research is to develop a structural lightweight compound that can be used on building skins and cores for pre fabricated structural insulated panels (SIPs). The application of this compound is intended to improve the thermal resistivity of the building envelope with suitable mechanical performances. The zonolite dosage was added to the cement-nano clay blend at different dosages up to 40% by weight. The nano clay reinforcement used is montmorillonite clay (Hydrated sodium calcium aluminum silicate). The mixes were prepared using water of consistence. The wet compounds were molded in PVC cylindrical molds, having 50 mm inside diameter and 27 mm height, and left for 24 h, then demolded and cured in humid air (20 ± 1 °C&100% RH) for 28 days. The samples were then dried at 105 ± 5 °C for 24 h before testing using a forced convection oven. The thermal resistivity and indirect tensile strength of the different compounds were evaluated. Results demonstrate that the thermal resistivity at 40% zonolite loading enhanced by about 2.9 folds compared to the control samples. An increase of more than 30% in the indirect tensile strength was also achieved when a 0.5% by weight of polycarboxylate superplasticizer was used.