Self-Healing Concrete Using Alginate Encapsulation of Bacillus Megaterium Bacteria
Muhammad Hafizh (a), Luthfi Muhammad Mauludin (a*), Ambar Susanto (a), Keryanti (b), Gandhi Widiarnoko (c)

a) Civil Engineering Department, Politeknik Negeri Bandung, Jl. Gegerkalong Hilir, Bandung Barat, Indonesia
*luthfi-mm[at]polban.ac.id
b) Chemical Engineering Department, Politeknik Negeri Bandung, Jl. Gegerkalong Hilir, Bandung Barat, Indonesia
c) PT. Bintang Solusi Bersama, Jakarta Selatan, Indonesia

Abstract

Self-healing concrete is a concrete technology that is mixed using microorganisms in the form of bacteria so that the concrete can repair itself when cracks occur. Making self-healing concrete is a preventive measure to repair small cracks so they don^t become bigger. This also functions as an action to reduce the use of epoxy injection materials which are toxic to the environment and human life. The research method used in this research is a trial/experimental method using Bacillus Megaterium bacteria as a healing agent and microcapsule material made from alginate as a coating for the bacteria (encapsulation). The test object made is in the form of a block with dimensions of 500 x 100 x 100 mm. The percentage of added microcapsules used was 1%, 2%, and 3%. Flexural strength tests were carried out when the concrete was 7 and 28 days. Mechanical testing on microcapsules is also carried out to see the strength of the microcapsule material that will be used. The results obtained from this research were that the highest flexural strength occurred with the addition of a variation of 2% alginate microcapsules, namely 13.5 MPa on day 7 and 16 MPa on day 28. The tensile strength of alginate microcapsules was 0.02365 MPa with plate specimens measuring 65 x 27.45 x 5 mm. From the results of visual observations, healing process in the concrete began to occur on the 7th day after the bending test. After 28 days of curing, the specimens were tested again for the second time to determine the return to strength of the concrete that had been tested for flexural strength. From the test results, the greatest return to strength was obtained when 3% microcapsules were added to the concrete. The strength gain was 102%. The optimum percentage level of microcapsules to be added to concrete is 2% because it has a sufficiently increased flexural strength value and has a recovery ability of 92%.

Keywords: Encapsulation, Bacillus megaterium, Alginat, Flexural Strength, Self-healing concrete

Topic: Materials Science