Abstract
Improving the thermal insulating performance of porous building materials is of great practical significance for building energy conservation. In this work, silica aerogels (SA) with ultralow thermal conductivity were proposed as an appropriate candidate to be integrated with autoclaved aerated concrete (AAC) to produce novel SA-AAC composites with higher thermal insulating performance by physical solution impregnation method. The pore-structures, mechanical and thermal properties of the SA-AAC composites were probed by various experimental tests. According to the microscopy and porosimetry results, SA were observed to adhere to the surface walls of the AAC holes, thus reducing the amount of macro-sized pores. In addition, the improved thermal insulating performance of AAC was successfully achieved with the relative improvement depending on the porosity of the pristine AAC. At the mass fraction of SA of ~7%, the highest relative improvement was found to be ~30% The results of this work exhibited a great potential of this novel SA-AAC composite in engineering applications.
Highlights
With growth of energy crises and global warming, energy conservation and emission reduction have become more and more critical in the building field
The thermal conductivities were measured by the transient plane source (TPS) technique via Hot Disk TPS 3500, whose thermal conductivity range is 0.005-500 (W/myK) while the measurement accuracy is 3%, which was subjected to considerable research [24]
The scanning electron microscope (SEM) image of SA-aerated concrete (AAC) composites under 7000× magnification is shown in Fig.2 (e), some irregular groups with size of 2-5 μm are clinging on the sheet-shaped tobermorite pore surface
Summary
With growth of energy crises and global warming, energy conservation and emission reduction have become more and more critical in the building field. There are some novel thermal insulation materials such as binderless cotton stalk fiberboard (BCSF) [3], vacuum insulation panels (VIP) and aerogels[4], indicating better thermal insulation performance, which is likely to reduce the overall building energy consumption[5][6]. Many attentions have been paid on the modification of typical building materials such as concrete [7], wood [8] and xonotlite-type calcium silicate [9] to reduce their thermal conductivity and increase thermal insulating performance [10][11]. The physical doping method recently exerts a tremendous fascination on researchers, for it is not needed supercritical drying technique, which was utilized in this work [19][20]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
