Assessing the Strength Characteristics and Environmental Impact of Fly-Ash Geopolymer Mortar for Sustainable Green Patch Repair: A Pathway towards SDGs Achievement

¹ Department of Civil Engineering, Universitas Muhammadiyah Yogyakarta, Indonesia
² Department of Civil Engineering, Vocational College, Universitas Gadjah Mada, Indonesia
³ Department of Civil Engineering, Universitas Muhammadiyah Sumatera Barat, Indonesia
⁴ Department of Civil and Environmental Engineering, Saitama University, Japan

^* Corresponding author: pinta.astuti@ft.umy.ac.id

Abstract

The primary factor influencing the service life of building structures is concrete deterioration caused by steel bar corrosion, which holds significant impact. Implementing maintenance techniques is crucial for mitigating both environmental and economic ramifications, thereby aligning with the Sustainable Development Goals (SDGs) agenda. Patch repair emerges as a prevalent method for addressing degradation stemming from corrosion-induced cracking. This study introduces experimental investigations into the utilization of fly-ash geopolymer mortar as an environmentally sustainable option for green patch repair. Material properties, encompassing grain size distribution, specific gravity, mud content, water absorption, water content, and X-ray fluorescence, were thoroughly examined. The fresh properties of the mortar were evaluated through flow table testing, while compressive strength testing was conducted on the hardened mortar. The findings indicate that all mix proportions considered in this experimental inquiry are viable for use as patch repair materials for substrate concrete, achieving a maximum strength of 30 MPa. Notably, a minimum aggregate-to-binder ratio of 30% is deemed sufficient for ensuring adequate strength of the patch material. However, in cases where the substrate comprises high-strength concrete with 60 MPa, mix proportions with aggregate-to-binder ratios of 35% and 40% are recommended.