Hasil penelitian menunjukkan bahwa variasi 10% abu sekam padi memberikan kuat tekan tertinggi yaitu 20,82 MPa dan masuk dalam mutu B
(pelataran parkir). Variasi 20% menghasilkan nilai daya serap sebesar 9,99-9,73% yang masuk kategori mutu C (pejalan kaki), sedangkan variasi 30% menunjukkan nilai daya serap tertinggi sebesar 16,08% sehingga hanya memenuhi mutu D (taman). Uji sorptivity memperlihatkan bahwa semakin tinggi kadar abu sekam padi, semakin besar kemampuan penyerapan air, meskipun pada umur 91 hari nilainya menurun karena reaksi hidrasi semen lebih sempurna. Secara keseluruhan, variasi 10% abu sekam padi merupakan campuran yang paling optimal karena
mampu memberikan keseimbangan antara kuat tekan, daya serap, dan sorptivity. Pemanfaatan abu sekam padi serta air laut tidak hanya ramah lingkungan, tetapi juga berpotensi sebagai solusi pemanfaatan limbah pertanian dan sumber daya lokal untuk bahan bangunan.
The research results showed that a variation of 10% rice husk ash provided the highest compressive strength, namely 20.82 MPa and was included in quality B (parking lot). A 20% variation produces an absorption capacity value 0f 9,99-9,73% which is in the C quality category (pedestrian), while a 30% variation shows the highest absorption capacity value of 16,08% so it only meets D quality (garden).
The sorptivity test showed that the higher the rice husk ash content, the greater the water absorption capacity, although at 91 days the value decreased because the cement hydration reaction was more complete. Overall, the 10% variation of rice husk ash is the most optimal mixture because it is able to provide a balance between compressive strength, absorption capacity and sorptivity. The use of rice husk ash
and sea water is not only environmentally friendly, but also has the potential to be a solution for utilizing agricultural waste and local resources for building materials.