Pengaruh Variasi Pengganti Pasir dengan Crumb Rubber dan Serat Tandan Kosong Kelapa Sawit terhadap Karakteristik Light Pile

Abstract

Foundation light piles to overcome the problem of embankment are used when the subgrade under the building does not have sufficient bearing capacity to carry the weight of the building. Local wisdom of the archipelago often uses wood or bamboo known as cerucuk on the foundation of the building structure foundation. Fixed variable in this study, with mixed variations of 10%, 25%, 50%, 75%, 90%, and 100% while Crumb rubber and oil palm empty fruit bunches as a substitute for sand (filler) are independent variables in this study. The specimen test was made by adopting the mixed design of Standard ASTM C 109. The curing method is carried out by open air curing and immersion curing. Dimensions of the test specimen cube size (50 x 50 x 50) mm to calculate the specific gravity and tested for compressive strength. The FTIR test examination for industrial solid waste was carried out in the Research Laboratory, Faculty of Pharmacy, University of North Sumatra (USU). The results obtained from the processing of industrial solid waste that are pozzolanic are activated with NaOH solution to form pozzolanic activity as an additive for portland cement (OPC). The composition of fine aggregate as a substitute for sand, namely crumb rubber and oil palm empty fruit bunches, resulted in a decrease in linear compressive strength with a decrease in specific gravity which made the mortar lighter than normal mortar.

Tiang pancang (light pile) pondasi untuk mengatasi masalah timbunan yang digunakan apabila tanah dasar di bawah bangunan tidak mempunyai daya dukung yang cukup untuk memikul berat bangunan. Kearifan lokal Nusantara sering menggunakan kayu atau bambu yang dikenal sebagai cerucuk pada landasan pondasi struktur bangunan. Variabel tetap dalam penelitian ini, dengan variasi campuran 10%, 25%, 50%, 75%, 90%, dan 100% sedangkan crumb rubber dan serat tandan kosong kelapa sawit sebagai material pengganti pasir (filler) merupakan variabel bebas dalam penelitian ini. Pembuatan uji spesimen dilakukan dengan mengadopsi desain campuran Standard ASTM C 109. Metode curing dilakukan dengan curing udara terbuka dan curing direndam. Dimensi spesimen uji kubus ukuran (50 x 50 x 50) mm untuk menghitung berat jenis dan diuji kuat tekannya. Pemeriksaan uji FTIR dilakukan dilaboratorium Penelitian, Fakultas Farmasi, Universitas Sumatera Utara (USU). Komposisi agregat halus pengganti pasir yaitu crumb rubber dan serat tandan kosong kelapa sawit menghasilkan penurunan kuat tekan linier dengan penurunan berat jenis yang membuat mortar menjadi lebih ringan dari mortar normal.