Electronic Theses and Dissertation

Penelitian mengenai pemanfaatan pasir diatomae sebagai bahan pozzolan telah banyak dilakukan, terutama pada kandungan silika tinggi yang berpotensi meningkatkan kinerja mekanik mortar. Namun, sebagian besar penelitian sebelumnya belum secara spesifik mengkaji pengaruh variasi suhu kalsinasi dalam durasi waktu yang konstan terhadap kuat tekan mortar. Penelitian ini bertujuan untuk menganalisis pengaruh variasi suhu kalsinasi pasir diatomae terhadap kuat tekan mortar, dengan waktu kalsinasi tetap selama 6 jam. Penelitian dilakukan menggunakan satu campuran tanpa subtitusi pasir diatomae dan tiga campuran subtitusi pasir diatomae sebesar 10% dari 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 16% hingga 18,5%, sehingga seluruh campuran masih memiliki tingkat kelecakan yang relatif sama. Nilai kuat tekan mengalami peningkatan seiring bertambahnya umur pengujian dan suhu kalsinasi. Kuat tekan tertinggi diperoleh pada mortar dengan pasir diatomae yang dikalsinasi pada suhu 800°C pada umur 28 hari, dengan peningkatan sebesar 43,7% dibandingkan benda uji tanpa subtitusi pasir diatomae. Hasil analisis varian menunjukkan bahwa variasi suhu kalsinasi, umur pengujian, dan interaksi keduanya memberikan pengaruh signifikan terhadap kuat tekan mortar. Sementara itu, hasil regresi menunjukkan bahwa peningkatan suhu kalsinasi dan umur mortar memiliki hubungan positif terhadap nilai kuat tekan. Berdasarkan hasil tersebut, kalsinasi pasir diatomae pada suhu 800°C selama 6 jam dengan umur pengujian 28 hari merupakan kondisi paling optimum untuk meningkatkan kuat tekan mortar. Dengan demikian, penelitian ini menegaskan bahwa suhu kalsinasi yang tepat dapat mengoptimalkan pemanfaatan pasir diatomae sebagai bahan substitusi semen pada mortar.

Research on the utilization of diatomaceous sand as a pozzolanic material has been widely conducted, particularly regarding its high silica content which has the potential to improve the mechanical performance of mortar. However, most previous studies have not specifically examined the effect of calcination temperature variations at a constant duration on the compressive strength of mortar. This study aims to analyze the effect of calcination temperature variations of diatomaceous sand on mortar compressive strength, with a fixed calcination duration of 6 hours. The study was conducted using one mixture without diatomaceous sand substitution and three mixtures with 10% diatomaceous sand substitution by cement weight, calcined at temperatures of 400°C, 600°C, and 800°C. Tests performed included the flow table test and compressive strength testing at ages of 7, 14, 21, and 28 days using cubic specimens measuring 50 mm × 50 mm × 50 mm. Compressive strength data were analyzed using descriptive analysis, two-way analysis of variance, and multiple linear regression. The results showed that flow values ranged from 16% to 18.5%, indicating that all mixtures maintained a relatively similar workability level. Compressive strength increased with both increasing testing age and calcination temperature. The highest compressive strength was obtained in mortar with diatomaceous sand calcined at 800°C at 28 days, representing an increase of 43.7% compared to the specimen without diatomaceous sand substitution. The analysis of variance results indicated that calcination temperature variation, testing age, and their interaction had a significant effect on mortar compressive strength. Meanwhile, the regression results showed that increases in calcination temperature and mortar age had a positive relationship with compressive strength values. Based on these findings, calcination of diatomaceous sand at 800°C for 6 hours with a testing age of 28 days represents the most optimum condition for improving mortar compressive strength. Thus, this study confirms that the appropriate calcination temperature can optimize the utilization of diatomaceous sand as a cement substitution material in mortar.