Analisis Komposisi dan Struktur Kimia Beton Romawi Termodifikasi terhadap Variasi Abu Vulkanik melalui Raman Spectroscopy

Ghonia Millata Mallia Shofa, Dr.Eng. Fahrudin Nugroho, S.Si., M.Si.;Dr. Iman Santoso, S.Si., M.Sc

2023 | Skripsi | FISIKA

Telah dilakukan penelitian mengenai komposisi dan struktur kimia pasta beton yang merupakan modifikasi dari beton Romawi. Pasta beton dibuat dari campuran OPC (Ordinary Portland Cement), abu Gunung Merapi, kapur tohor (CaO), dan air laut. OPC disubstitusi dengan abu merapi dengan variasi 0%, 10%, 20%, 30%, 40%, dan 50% sedangkan kapur tohor dan air laut dibuat tetap. Hasil uji tekan menggunakan digital force gauge menunjukkan bahwa kuat tekan tertinggi dimiliki oleh pasta beton variasi 10% (10?u merapi–90% OPC). Faktor kekuatan tersebut diperjelas dengan hasil karakterisasi Raman Spectroscopy yang menunjukkan adanya pembentukan mineral fase C-S-H (calcium silicate hydrate) serta C-A-S-H (calcium aluminosilicate hydrate) berupa phillipsite dan Aluminium tobermorite.

We had done a study about composition and chemical structure of concrete pastes from modified roman concrete. Concrete pastes were made from a mixture of OPC, volcanic ash from Mt. Merapi, quicklime, and seawater. OPC was substituted with volcanic ash with variation of 0%, 10%, 20%, 30%, 40%, and 50%. The compressive test was done by digital force gauge. It showed that concrete paste with addition of quicklime had higher compressive strength for up to 10% substitution of OPC with volcanic ash. Raman spectroscopy analysis showed that the formation of C-S-H and C-A-S-H phase such as phillipsite and Al-tobermorite was the key to strength of concrete pastes.

Kata Kunci : beton,abu vulkanik,semen portland,air laut,Raman Spectroscopy