Model-based design, synthesis and use of thermally insulating mortar formulations for energy conservation in buildings

Internally structured porous calcium-silicate-hydrate (CSH) particles were made by a sol-gel process using natural rubber as template. These particles were formulated in cement to produce mortar with excellent thermal insulation properties. The synthesis of CSH and its formulation in cement were comparatively optimized using response surface models based on central composite design (CCD) of experiments and artificial neural networks (ANN). CSH samples produced using a range of rubber/silica mass ratios (0.2-2.0) and hydrothermal processing temperatures (120-210 degrees C) were used to make CSH-mortars with various CSH/cement mass ratios (0.0-2.0). Thermal insulation capability of the different CSH-mortars was determined. Models based on CCD and ANN both achieved similar accuracy in predicting the insulating response. This notwithstanding, the ANN model identified optimal conditions for making a CSH-mortar that was cheaper and had nearly the same thermal insulation capacity as the optimal product predicted by the CCD-based model. The novel internally structured CSH particles were confirmed to greatly (similar to 3.4-fold) improve the thermal insulation performance of the CSH-mortars relative to controls. (C) 2020 Elsevier Ltd. All rights reserved.