Electronic Theses and Dissertation

Beton merupakan material konstruksi yang paling banyak digunakan di indonesia, namun memiliki kelemahan berupa kekuatan tarik rendah dan rentan terhadap retakan. teknologi self-healing concrete (shc) hadir sebagai solusi yang memungkinkan beton memperbaiki retakan secara mandiri melalui aktivitas mikroorganisme. studi ini bertujuan untuk menganalisis pengaruh penggunaan bakteri staphylococcus sp. sebagai self-healing agent terhadap sifat fisis (workabilitas, densitas, absorbsi, dan keausan) pada uhpc. metode studi bersifat pengujian terhadap 20 benda uji kubus 5 cm x 5 cm x 5 cm dengan variasi bakteri 0%, 0,5%, 0,6%, dan 0,7% dari berat semen. bakteri dienkapsulasi menggunakan tanah diatome untuk menjaga tetap hidup dalam lingkungan beton yang sangat basa dan padat. pengujian sifat fisis beton dilakukan sesuai dengan standar sni dan astm pada umur 7, 14, dan 28 hari kecuali uji keausan yang hanya diuji pada umur 28 hari. uji workabilitas (slump flow test) untuk mengetahui tingkat kelecakan beton segar, uji densitas untuk mengukur kepadatan beton keras, uji absorbsi untuk mengetahui kemampuan beton menyerap air sebagai indikator porositas dan durabilitas, dan uji keausan (los angeles abrasion test) untuk mengukur ketahanan permukaan beton terhadap abrasi. nilai flow menurun secara linear seiring meningkatnya kadar bakteri, dengan penurunan tertinggi sebesar 4,8% pada variasi 0,7%. pengaruh terhadap densitas, absorbsi, dan keausan menunjukkan pola yang tidak linear, di mana kondisi terburuk terjadi pada variasi 0,6% dengan penurunan densitas sebesar 4,9%-5,6%, peningkatan absorbsi sebesar 39,6%-50,4%, dan peningkatan keausan sebesar 12,79% terhadap kontrol.

Concrete is the most widely used construction material in Indonesia, yet it has fundamental weaknesses including low tensile strength and susceptibility to cracking. Self-healing concrete (SHC) technology has emerged as a solution that enables concrete to repair cracks autonomously through microbial activity. This study aims to analyze the effect of Staphylococcus sp. bacteria as a self-healing agent on the physical properties (workability, density, absorption, and abrasion resistance) of Ultra-High-Performance Concrete (UHPC). The experimental method involved 20 cubic specimens of 5 cm × 5 cm × 5 cm with bacterial concentration variations of 0%, 0.5%, 0.6%, and 0.7% by cement weight. The bacteria were encapsulated using diatomaceous earth to maintain their viability in the highly alkaline and dense concrete environment. Physical property tests were conducted in accordance with SNI and ASTM standards at ages of 7, 14, and 28 days, except for the abrasion test which was performed only at 28 days. The workability test (slump flow test) was conducted to determine the flowability of fresh concrete, the density test to measure the compactness of hardened concrete, the absorption test to assess the concrete's ability to absorb water as an indicator of porosity and durability, and the abrasion test (Los Angeles Abrasion Test) to evaluate the resistance of the concrete surface to abrasion. Flow values decreased linearly with increasing bacterial content, with the highest reduction of 4.8% observed at the 0.7% variation. The effects on density, absorption, and abrasion resistance exhibited a non-linear pattern, where the worst performance occurred at the 0.6% variation, with a density reduction of 4.9%-5,6%, an absorption increase of 39,6%-50,4%, and an abrasion increase of 12.79% compared to the control