Effect of Partial Replacement of Cement with Coconut Shell Ash on Concrete Performance ; Pengaruh Penggantian Sebagian Semen dengan Abu Tempurung Kelapa terhadap Kinerja Beton

Green concrete is environmentally friendly concrete made using waste or residual materials. Green concrete is made using alternative materials to partially replace cement or aggregate. Coconut shell is a solid waste from coconut processing that has not been utilized optimally so that coconut shell ash needs to be tried to replace some of the cement. The cement substitution with coconut shell ash used was 2.5%, 5.0%, 7.5%, 10%, 12.5%, 15%, 17.5%, 20%, and 22.5% by weight of cement. There are 3 concrete cylinder specimens for each variation and a total of 30 specimens. The tests carried out were slump testing for fresh concrete and compressive strength testing for hard concrete after 28 days. From the research results obtained: coconut shell ash has a high silica content so that it can be used as a pozzolan. Increasing the percentage of cement substitution with coconut shell ash decreases the slump value. The substitution of cement with coconut shell ash increases the compressive strength of concrete. Increasing the percentage of cement substitution with coconut shell ash reduces the compressive strength of concrete. The substitution of cement with coconut shell ash had no significant effect on the volume weight of the concrete. ; Beton hijau adalah beton ramah lingkungan yang dibuat dengan menggunakan limbah atau bahan sisa. Beton hijau dibuat menggunakan bahan alternatif untuk menggantikan sebagaian semen atau agregat. Tempurung kelapa merupakan limbah padat dari hasil pengolahan kelapa yang belum dimanfaatkan secara maksimal sehingga abu tempurung kelapa perlu dicoba untuk menggantikan sebagian semen. Substitusi semen dengan abu tempurung kelapa yang digunakan adalah 2,5%, 5,0%, 7,5%, 10%, 12,5%, 15%, 17,5%, 20%, dan 22,5 % terhadap berat semen. Benda uji berupa silinder beton sebanyak 3 buah setiap variasi dan dengan jumlah total 30 buah. Pengujian yang dilakukan berupa pengujian slump untuk beton segar dan pengujian kuat tekan untuk beton keras setelah berumur 28 hari. Dari hasil penelitian didapat: abu ...