Electronic Theses and Dissertation

Pasir diatomae merupakan material alami yang memiliki kandungan silika tinggi dan berpotensi dimanfaatkan sebagai bahan pozzolan alternatif dalam campuran mortar. Penelitian ini bertujuan untuk menganalisis pengaruh variasi suhu kalsinasi pasir diatomae selama 4 jam terhadap workability dan kuat tekan mortar, serta menentukan suhu kalsinasi yang paling optimum. Penelitian dilakukan secara eksperimental dengan menggunakan satu campuran kontrol dan tiga campuran substitusi pasir diatomae sebesar 10% terhadap berat semen yang dikalsinasi pada suhu 400°C, 600°C, dan 800°C. Pengujian yang dilakukan meliputi flow table test dan uji kuat tekan pada umur 7 hari, 14 hari, 21 hari, dan 28 hari menggunakan benda uji kubus berukuran 50 mm × 50 mm × 50 mm. Data kuat tekan dianalisis secara deskriptif, analisis varian dua arah, dan regresi linear berganda. Hasil penelitian menunjukkan bahwa nilai flow berada pada kisaran 15,75% hingga 18,25%, sehingga seluruh campuran masih memiliki tingkat kelecakan yang relatif serupa. Nilai kuat tekan meningkat seiring bertambahnya umur pengujian dan kenaikan suhu kalsinasi, dengan kuat tekan tertinggi diperoleh pada mortar dengan diatomae hasil kalsinasi 800°C pada umur 28 hari, kuat tekan meningkat 30,2% dari benda uji kontrol. Hasil analisis varian menunjukkan bahwa variasi suhu kalsinasi, umur pengujian, dan interaksi keduanya berpengaruh nyata terhadap kuat tekan mortar, sedangkan hasil regresi menunjukkan bahwa suhu kalsinasi dan umur mortar memiliki hubungan positif terhadap kuat tekan. Dengan demikian, kalsinasi pasir diatomae pada suhu 800°C umur 28 hari selama 4 jam merupakan kondisi yang paling optimum untuk meningkatkan kuat tekan mortar.

Diatomaceous earth is a natural material with high silica content and has the potential to be used as an alternative pozzolanic material in mortar mixtures. This study aims to analyze the effect of variations in the calcination temperature of diatomaceous earth for 4 hours on the workability and compressive strength of mortar, as well as to determine the most optimum calcination temperature. The research was conducted experimentally using one control mix and three mixes with 10% diatomaceous earth substitution by weight of cement, calcined at temperatures of 400°C, 600°C, and 800°C. The tests carried out included a flow table test and compressive strength tests at the ages of 7, 14, 21, and 28 days using cube specimens measuring 50 mm × 50 mm × 50 mm. The compressive strength data were analyzed descriptively, using two-way analysis of variance, and multiple linear regression. The results showed that the flow values ranged from 15.75% to 18.25%, indicating that all mixtures still had a relatively similar level of workability. The compressive strength increased with both testing age and calcination temperature, with the highest compressive strength obtained in mortar containing diatomaceous earth calcined at 800°C at 28 days, showing a 30.2% increase compared to the control specimen. The analysis of variance showed that variations in calcination temperature, testing age, and the interaction between both factors had a significant effect on the compressive strength of mortar, while the regression results indicated that calcination temperature and mortar age had a positive relationship with compressive strength. Thus, calcining diatomaceous earth at 800°C for 4 hours is the most optimum condition for improving the compressive strength of mortar.