| Abstract [eng] |
In the past few decades, numerous studies have been carried out on LWSCCC incorporating several types of lightweight aggregates. Aerogel is a promising material featuring a very low density; it can be used in the production of very lightweight cementitious composites. While EGA is also a lightweight aggregate, it has a lower density. Yet, despite the lower density, aerogel is fragile in nature. Moreover, hydrophobic aerogel might exhibit weaker adhesion with cementitious materials, which would lead to a weaker strength of cementitious composites. The development of a lightweight self-compacting cementitious composite incorporating a combination of EGA and aerogel can be a promising material for building applications. A lightweight cementitious composite incorporating such low-density aggregate would be denoted by a lower density. Moreover, the use of such materials in a cementitious composite might lead to a decrease in the mechanical performance, and would increase the risk of water absorptions. A hydrophobic aerogel may also suffer from weaker adhesion problems, and further studies are required to extensively investigate the characteristics of cementitious composites incorporating aerogel and EGA in terms of their fresh, mechanical performances, microstructure, and water absorption capacity. Furthermore, problems related to aerogel and EGA aggregate-based cementitious composite should be eliminated. Moreover, most developed LWSCCs below the density of 1400 kg/m3 feature a lower compressive strength than the recommended value of ACI-213R-03 2003, ACI-213R-2014 and CEB/RILEM so that they could be used as structural applications. In this context, the current investigation is performed. To achieve the aim of the study, several cementitious composites have been developed by using the mixing and trial methods. Firstly, lightweight cement composites were prepared by using EGA and aerogel in order to identify their impact and probable problems regarding the lightweight cementitious composites. By the mixing and trail method, the mixing composition was optimized, and the self-compatibility factor was achieved. Such problems as higher water absorption, inferior mechanical performance, and weaker adhesion levels of aerogel with cementitious materials have been mitigated by using polymer coatings on LWA. Furthermore, mechanical performances and water absorption and ITZ between the aerogel and cementitious materials have been improved by using carbon nanotubes and graphene platelets. |
