Electronic Theses and Dissertation

Foamed concrete merupakan salah satu material beton ringan yang dihasilkan melalui proses pembentukan gelembung udara stabil ke dalam campuran semen dan air sehingga membentuk struktur berpori dengan densitas yang lebih rendah dibandingkan beton konvensional. karakteristik tersebut menjadikan foamed concrete sebagai material yang berpotensi diaplikasikan pada wilayah rawan gempa, seperti provinsi aceh, karena berat jenisnya yang rendah. foamed concrete mampu mengurangi massa struktur akibat beban gempa. namun, tingginya penggunaan semen portland dalam campuran foamed concrete menyebabkan biaya produksi menjadi lebih tinggi selama proses produksi. penelitian ini bertujuan untuk mengembangkan foamed concrete yang lebih berkelanjutan melalui optimasi rancangan campuran menggunakan metode specific gravity serta mengurangi penggunaan semen portland dengan memanfaatkan supplementary cementitious materials (scms) berupa pasir kuarsa dan kaolin lokal aceh. material scms digunakan dalam dua kondisi, yaitu sebelum dan sesudah aktivasi termal melalui proses kalsinasi, untuk mengevaluasi pengaruhnya terhadap karakteristik material dan kinerja foamed concrete. karakterisasi scms dilakukan melalui pengujian sifat fisis berupa berat jenis, serta pengujian sifat kimia dan mineralogi dengan menggunakan x-ray fluorescence (xrf), x-ray diffraction (xrd), dan scanning electron microscopy–energy dispersive spectroscopy (sem–eds). kinerja foamed concrete dievaluasi melalui pengujian pada kondisi segar yang meliputi slump flow dan densitas, serta pada kondisi beton keras yang meliputi kuat tekan, kuat tarik belah, kuat tarik lentur, absorpsi, porositas, dan analisis mikrostruktur. hasil penelitian menunjukkan bahwa penggantian semen portland sebesar 10% menggunakan pasir kuarsa lokal yang dikalsinasi pada suhu 600°c menghasilkan karakteristik fisis, kimia, dan mekanis yang paling optimum. pemanfaatan pasir kuarsa hasil aktivasi termal terbukti mampu meningkatkan kualitas mikrostruktur dan kinerja mekanis foamed concrete sekaligus mengurangi penggunaan semen portland. berdasarkan hasil penelitian yang dilakukan menunjukkan bahwa pasir kuarsa dan kaolin lokal aceh memiliki potensi yang besar sebagai scms pada foamed concrete. pemanfaatan kedua material tersebut tidak hanya meningkatkan kinerja beton ringan, tetapi juga berpotensi menurunkan biaya produksi, mengurangi dampak lingkungan, serta mendukung pengembangan material konstruksi yang berkelanjutan dan lebih tangguh terhadap beban gempa.

Foamed concrete is a lightweight cement-based material produced by incorporating stable preformed air bubbles into a cement–water mixture, resulting in a porous structure with a lower density than conventional concrete. This characteristic makes foamed concrete a promising construction material for earthquake-prone regions, such as Aceh Province, Indonesia, because its low density reduces the structural mass and consequently minimizes the effects of seismic loading. However, the high Portland cement content required in foamed concrete mixtures increases production costs during the manufacturing process. This study aims to develop a more sustainable foamed concrete by optimizing the mix design using the Specific Gravity (SG) method and reducing Portland cement consumption through the utilization of lokally available Supplementary Cementitious Materials (SCMs), namely quartz sand and kaolin from Aceh, Indonesia. The SCMs were incorporated into the foamed concrete in two conditions, namely before and after thermal activation through the calcination process, to evaluate their effects on the material characteristics and the performance of foamed concrete. The SCMs were characterized by evaluating their physical properties through specific gravity measurements, while their chemical composition and mineralogical characteristics were analyzed using X-ray Fluorescence (XRF), X-ray Diffraction (XRD), and Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy (SEM–EDS). The performance of foamed concrete was evaluated in both fresh and hardened states. Fresh properties were assessed through slump flow and density tests, whereas hardened properties were evaluated through compressive strength, splitting tensile strength, flexural strength, water absorption, porosity, and microstructural analyses. The experimental results showed that replacing 10% of Portland cement with lokally sourced quartz sand calcined at 600°C produced the optimum physical, chemical, and mechanical properties. The incorporation of thermally activated quartz sand significantly improved the microstructural quality and mechanical performance of foamed concrete while reducing Portland cement consumption. The findings demonstrate that lokally available quartz sand and kaolin from Aceh possess significant potential as Supplementary Cementitious Materials (SCMs) for foamed concrete. The utilization of these lokal mineral resources not only enhances the performance of lightweight concrete but also has the potential to reduce production costs, minimize environmental impacts, and support the development of sustainable and earthquake-resilient construction materials