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SCIENCE & INNOVATION20 SCIENCE & INNOVATION AAC WORLDWIDE %u2022 2.2026Integration of nanotechnology into construction materialsOptimizing Nanofibrillated Cellulose Content for Improved Mechanical Properties of AACToday, traditional building materials are increasingly being replaced by alternative materials that are lighter, improve energy efficiency and are environmentally friendly. Autoclaved aerated concrete (AAC) offers high thermal and acoustic insulation performance with low density. In recent years, the integration of nanotechnology into construction materials has produced promising results, particularly in improving mechanical and thermal properties [1-3]. NanoFibrillated Cellulose (NFC) is considered a re,markable additive for these properties due to its derivation from renewable resources and its characteristics such as high specific surface area and high water-retention capacity [4-6]. Within the scope of this study, the potential use of NFC as an admixture in AAC production was investigated and effects on performance were evaluated. Experimental studies were conducted by incorporating NFC into the AAC mixture at dosages of 0.1%, 0.3%, and 0.5% by weight. The results indicated that adding 0.3% NFC increased compressive strength by up to 13.5% and flexural strength by up to 23.55%.Cellulose is an organic biopolymer compound obtained from biomass and annual production ranges between 1010 and 1011 tons. It is widely used in industry, including sectors such as paper, textiles, materials and chemical industry [4]. Despite cellulose chemical composition, the physical and morphological structure of natural cellulose in plants is complex. NFC consists of cellulose nanocrystals, cellulose nanofibers and bacterial nanocellulose [5]. The abundant availability of plant biomass and the superior mechanical properties of cellulose such as high specific surface and high water-retention have made NFC a desirable reinforcing material for a variety of materials [6-8].The use of NFC derivates with a low carbon footprint as additives in cement-based mortars and concretes has been investigated and studies have observed improvements in mechanical performance and durability [7-9]. Kamasamudran et al. [10] investigated the influence NFC fibers in portland cement as a function of water to solid ratio. They reported improved setting behavior and an increase in flexural strength up to 75% at a water to solid ratio of 0.35 whereas this effect disappeared when the ratio was increased to 0.45. Lisboa et al. [11] conducted a study by incorporating microcrystalline cellulose at dosages ranging from 0.1% to 1% and reported that the highest flexural strength was achieved at a 0.2% addition ratio.In this study, the aim was to produce high-performance AAC by incorporating NFC which modifies the hydration products and microstructure of the AAC matrix, leading to a denser structure and improved mechanical performance.MethodsExperimental SetupThe mix design for the AAC was developed to achieve a density in the range of 300 %u2013 350 kg/m3. According to AAC production scheme shown in Fig. 1, NFC premixed separately for 1 minute, was then combined with the main raw materials and the foaming agent before being poured into the molds. NFC was added M.Sc. Eng. Yunus Ion Grecu, Dr. Eng. Ezgi Bi%u00e7er and M.Sc. Eng. Emre Fenerci, Nuh Yap%u0131 %u00dcr%u00fcnleri R&D Center, Kocaeli, T%u00fcrkiye