Analisis Kuat Tekan dan Karakteristik Mikrostruktur Material Bata dengan Densitas Tereduksi Berbasis Vermiculite dan Fiberglass

Muhammad Naufal Reinaldo, Angga Fajar Setiawan, S.T., M.Eng., Ph.D.

2026 | Skripsi | TEKNIK SIPIL

Pembangunan infrastruktur yang terus berkembang mendorong kebutuhan material dinding yang tidak hanya ringan namun tetap memiliki kekuatan struktural yang memadai. Vermiculite sebagai agregat ringan berpotensi menurunkan berat jenis material tetapi cenderung menurunkan kuat tekan, sehingga perlu dikombinasikan dengan fiberglass sebagai serat penguat. Kajian yang secara khusus menggabungkan keduanya dalam formulasi bata dengan densitas tereduksi dan menganalisis hubungan antara berat jenis, kuat tekan, serta karakteristik mikrostrukturnya secara simultan masih terbatas. Penelitian ini bertujuan mengkaji kuat tekan, karakteristik mikrostruktur, hubungan antara berat jenis dan kuat tekan, serta pengaruh penambahan vermiculite dan fiberglass terhadap berat jenis bata.

Penelitian menggunakan 5 variasi campuran dengan kadar vermiculite 0%–30?n kadar fiberglass 8%, dengan benda uji berupa kubus 50×50×50 mm. Pengujian yang dilakukan meliputi uji kuat tekan, uji berat jenis menggunakan metode displacement air raksa, dan analisis mikrostruktur menggunakan Scanning Electron Microscopy (SEM).

Hasil penelitian menunjukkan bahwa kuat tekan material bata yang dihasilkan berkisar antara 21,68 MPa hingga 24,34 MPa, dengan nilai tertinggi diperoleh pada variasi MV-2. Penambahan vermiculite menurunkan berat jenis hingga 1.810 kg/m³ (lebih rendah 18,10%), sedangkan penambahan fiberglass memberikan pengaruh yang relatif kecil terhadap berat jenis. Hubungan antara berat jenis dan kuat tekan mengikuti model regresi dengan R² = 0,712. Analisis SEM menunjukkan bahwa peningkatan kadar vermiculite menyebabkan peningkatan porositas dan dominasi bond crack, sedangkan kondisi FITZ serat fiberglass tergolong cukup kompak yang mengindikasikan mekanisme crack bridging berlangsung efektif. Komposisi campuran optimal diperoleh pada variasi MV-2 dengan kadar vermiculite 20?n fiberglass 8%, yang memenuhi SNI 8640:2018 dengan syarat kuat tekan ? 2 MPa.

The growing demand for construction materials that are both lightweight and structurally adequate has driven interest in the development of lightweight brick. Vermiculite, as a lightweight aggregate, effectively reduces material density but tends to decrease compressive strength, necessitating the incorporation of fiberglass as a reinforcing fiber. However, studies specifically combining both materials in a single brick formulation and simultaneously analyzing their compressive strength, specific gravity, and microstructural characteristics remain limited. This study aims to investigate the compressive strength, microstructural characteristics, the relationship between specific gravity and compressive strength, and the effect of vermiculite and fiberglass addition on the specific gravity of brick material. 

The study employed 5 mix variations with vermiculite contents ranging from 0% to 30% and fiberglass contents 8%, using 50×50×50 mm cube specimens. Tests performed included compressive strength, specific gravity testing using mercury displacement method, and microstructural analysis using Scanning Electron Microscopy (SEM). 

Results showed that the compressive strength of brick material ranged from 21,68 MPa to 24,34 MPa, with the highest value obtained at variation MV-2. Vermiculite addition reduced specific gravity to as low as 1.810 kg/m³ (a reduction of 18,10%), while fiberglass addition had a relatively minor effect on specific gravity. The relationship between specific gravity and compressive strength followed a regression model with R² = 0,712. SEM analysis revealed that increasing vermiculite content led to greater porosity and dominance of bond crack, while the fiberglass-matrix interfacial transition zone (FITZ) was found to be moderate, indicating that crack bridging mechanisms operated effectively. The optimal mix composition was identified at variation MV-2 with 20% vermiculite and 8% fiberglass, satisfying the SNI 8640:2018 with a minimum compressive strength of 2 MPa.

Kata Kunci : material bata, vermiculite, fiberglass, kuat tekan, berat jenis, Scanning Electron Microscopy