EFFECT OF COMPRESSIVE STRENGTH, WATER ABSORPTION, AND WEAR RESISTANCE USING FLY ASH AS A CEMENT SUBSTITUTION IN PAVING BLOCK MIXTURES WITH 50% COPPER SLAG AGAINST THE SAND

Hasil limbah industri berupa fly ash dan copper slag perlu dikelola secara baik agar tidak menyebabkan pengaruh buruk terhadap lingkungan. Oleh karena itu diperlukan inovasi bahan alternatif pada pembuatan paving block dimana fly ash digunakan pengganti sebagian semen dan copper slag pengganti sebagian pasir diharapkan dapat berpengaruh terhadap kualitas, efisiensi dalam pengerjaan serta ekonomis. Penelitian ini bertujuan untuk mengetahui pengaruh dan persentase yang tepat penggunaan fly ash pengganti sebagian semen pada komposisi campuran paving block dengan 50% copper slag terhadap uji kuat tekan, uji penyerapan air, dan uji ketahanan aus berdasarkan SNI 03-0691-1996. Penelitian ini menggunakan variasi fly ash sebesar 0%, 5%, 7.5%, 10%, 12.5%, dan 15% terhadap berat semen dan 50% copper slag terhadap berat pasir. Pengujian benda uji paving block dilakukan pada umur 28 hari. Hasil penelitian menunjukkan adanya pengaruh penggunaan fly ash terhadap paving block bahwa terjadi peningkatan dan penurunan nilai uji kuat tekan, uji penyerapan air, dan uji ketahanan aus. Hasil dari ketiga pengujian pada variasi 2 dengan penggunaan substitusi fly ash sebesar 5% terjadi peningkatan namun penggunaan substitusi fly ash lebih dari 5% terjadi penurunan. Penggunaan substitusi fly ash 5%, 7.5%, dan 10% masih berada di atas hasil nilai kontrol fly ash 0%. Sedangkan hasil nilai substitusi fly ash lebih dari 10% di bawah nilai kontrol fly ash 0%. Hasil penelitian menunjukkan bahwa persentase optimum terjadi pada variasi 2 atau substitusi fly ash 5% dengan nilai uji kuat tekan sebesar 20.913 MPa, uji penyerapan air sebesar 6.004%, dan uji ketahanan aus sebesar 0.064 mm/menit.

Kata kunci: Fly ash, copper slag, kuat tekan, paving block

The results of industrial waste in the form of fly ash and copper slag need to be managed properly so as not to cause adverse effects on the environment. Therefore, it is necessary to innovate alternative materials in the manufacture of paving blocks where fly ash is used to replace part of cement and copper slag part of sand is expected to have an effect on quality, efficiency in workmanship and the economy. This study aims to determine the effect and appropriate percentage of the use of fly ash as a partial cement replacement on the composition of the paving block mixture with 50% copper slag on the compressive strength test, water absorption test, and wear resistance test based on SNI 03-0691-1996. This study used variations in fly ash of 0%, 5%, 7.5%, 10%, 12.5%, and 15% of the weight cement and 50% copper slag to the weight of sand. Testing of paving block specimens was carried out at the age of 28 days. The results showed that there was an effect of using fly ash on paving blocks that there was an increase and decrease in the value of the compressive strength test, water absorption test, and wear resistance test. The results of the three tests in variation 2 with the use of fly ash substitution of 5% increased, but the use of fly ash substitution of more than 5% decreased. The use of fly ash substitution of 5%, 7.5%, and 10% is still above the result of the fly ash control value of 0%. While the results of the fly ash substitution value are more than 10% below the fly ash control value of 0%. The results showed that the optimum percentage occurred in variation 2 or 5% fly ash substitution with a compressive strength test value of 20.913 MPa, a water absorption test of 6.004%, and a wear resistance test of 0.064 mm/min.

Keywords: Fly ash, copper slag, compressive strength, paving block