Role of Limestone Addition in Improving the Initial Compressive Strength of Geopolymer Concrete for Corrosive Environment Repair

Abstract

Geopolymer Concrete (GC) is highly durable in corrosive environments, making it a viable material for repair. However, its initial compressive strength was below the 7 megapascals required at one-day age. Adding fine limestone (45 micrometer) can improve GC's density and early strength. This study explores the effects of adding 0 percent, 3 percent, 5 percent, and 7 percent limestone and 1 percent sucrose superplasticizer to GC 16M. The compressive strength was tested at 1, 3, 7, and 28 days, along with slump, permeability, and resistivity tests to assess the durability. The results show that adding 5 percent limestone yields the optimal GC performance for repairing corrosive environments. The compressive strengths were 15.96, 28, 43, and 67.14 megapascals at 1, 3, 7, and 28 days, with a slump of 120 millimeters. The permeability and resistivity results were 0.128 × 10^-16 square meters and 57.87 kiloohm-centimeter, indicating normal corrosion levels. These findings confirm that GC with 5 percent limestone meets the durability and strength requirements of repair materials in corrosive environments.