Electronic Theses and Dissertation

Cangkang tiram setelah dikalsinasi pada suhu > 8000c dapat merubah komponen caco3 menjadi cao, sehingga dapat meningkatkan mutu beton. abu cangkang tiram (osa atau oyster shell ash) masih belum dimanfaatkan secara maksimal sehubungan dengan sifat kimiawinya dan belum diaplikasikan ke dalam beton mutu tinggi. penelitian ini bertujuan untuk memanfatkan kalsinasi osa yang dikombinasikan dengan serat abaka dalam menghasilkan kuat tekan, kuat tarik, dan kuat lentur beton mutu tinggi. pengujian karakteristik osa serta sifat fisis dan mekanis pasta osa 5% dilakukan terlebih dahulu guna mendukung analisis kekuatan beton. penelitian dilakukan dalam 2 (dua) tahap, menggunakan metode taguchi dengan model percobaan l16(43). mutu beton yang direncanakan adalah 9000 psi atau 62 mpa. nilai optimum pengujian ditentukan melalui s/n, dianalisis dengan anova dan response surface methodology (rsm) melalui aplikasi design expert. tahap pertama menggunakan variabel: cement replacement (cr): 1%, 5%, 10%, dan 15%, calcined temperature (ct): 7000c, 8000c, 9000c, dan 10000c, dan ssa (specific surface area): 120 m2/kg; 276 m2/kg; 419 m2/kg; dan 4268 m2/kg. tahap kedua menggunakan variabel: cr: 0%, 5%, 10%, dan 15%, % of abaca (af): 0%, 0,15%, 0,30%, dan 0,45%, dan ratio of abaca (l/d): 50, 75, 100, dan 125. berdasarkan optimasi nilai s/n taguchi pada penelitian pertama, maka kuat tekan dan kuat lentur beton optimum diperoleh pada variasi: cr 5%, ct 900°c, ssa 276 m2/kg, yaitu: 81.38 mpa dan 8.93 mpa. sedangkan kuat tarik beton optimum diperoleh pada variasi: cr 5%, ct 700°c, ssa 4268 m2/kg, yaitu: 7.95 mpa. hasil penelitian tahap kedua menunjukkan bahwa kuat tekan beton optimum diperoleh pada variasi: cr 5%, af 0.15%, l/d 75, yaitu: 85.95 mpa. kuat tarik beton optimum diperoleh pada variasi: cr 5%, af 0.30%, l/d 125, yaitu: 9.11 mpa. sedangkan kuat lentur beton optimum diperoleh pada variasi: cr 0%, af 0.15%, l/d 100, yaitu: 8.90 mpa.

After being calcined at temperatures above 800°C, oyster shells can convert their CaCO₃ content into CaO, thereby enhancing the quality of concrete. Oyster shell ash (OSA) has not yet been optimally utilized, particularly due to its chemical properties and its limited application in high-performance concrete. This study aims to utilize calcined OSA in combination with abaca fiber to improve the compressive, tensile, and flexural strengths of high-performance concrete. An initial investigation was conducted on the characteristics of OSA, as well as the physical and mechanical properties of cement paste containing 5% OSA, in order to support the analysis of concrete strength. The research was carried out in two phases, employing the Taguchi method with an L16(4³) experimental design. The target concrete strength was 9000 psi or 62 MPa. Optimum test values were determined using Signal-to-Noise (S/N) ratios, and further analyzed through ANOVA and Response Surface Methodology (RSM) using Design Expert software. In the first phase, the variables examined included Cement Replacement (CR): 1%, 5%, 10%, and 15%; Calcination Temperature (CT): 700°C, 800°C, 900°C, and 1000°C; and Specific Surface Area (SSA): 120 m²/kg, 276 m²/kg, 419 m²/kg, and 4268 m²/kg. The second phase involved variables as follows: CR: 0%, 5%, 10%, and 15%; Abaca Fiber content (AF): 0%, 0.15%, 0.30%, and 0.45%; and Fiber Aspect Ratio (L/D): 50, 75, 100, and 125. Based on the optimization of S/N ratios from the first phase, the optimum compressive and flexural strengths were achieved with the following combination: CR 5%, CT 900°C, and SSA 276 m²/kg, resulting in 81.38 MPa and 8.93 MPa, respectively. The optimum tensile strength was obtained with CR 5%, CT 700°C, and SSA 4268 m²/kg, resulting in 7.95 MPa. In the second phase, the highest compressive strength was achieved at CR 5%, AF 0.15%, and L/D 75, reaching 85.95 MPa. The optimum tensile strength was obtained with CR 5%, AF 0.30%, and L/D 125, reaching 9.11 MPa. Meanwhile, the optimum flexural strength was found at CR 0%, AF 0.15%, and L/D 100, with a value of 8.90 MPa.