인천대학교 인디고클랫폼 인천대학교 기술지원허브

The present invention relates to the development of a sulfuric acid-resistant, high-durability composite mortar incorporating Graphene Nanoplatelets (GNPs) and Multi-Walled Carbon Nanotubes (MWCNTs). The deterioration of concrete is linked with the liberation of sulfuric acid (H2SO4) in the presence of microorganisms in sanitary wastewater resources. This damage, which is often referred to as “microbial induced concrete corrosion” (MICC), is commonly observed in concrete pipes and results in substantial damage. The anaerobic digestion of sewage results in the liberation of hydrogen sulfide (H2S) gas, which metabolizes with oxygen by aerobic bacteria, thereby producing H2SO4 solution. During MICC, the sulfate ions (SO42− ) react with the binder products (mainly CH, C–S–H, and monosulfate) and produce gypsum and ettringite, as shown in equation 1-3. The formation of these products is accompanied by an increase in volume and pressure in concrete, leading to internal cracking that can result in structural failure. The current solutions on improving the resistance of concrete against chemical and biogenic attacks include the modification of concrete mix using pozzolanic materials, sulfate-free aggregates, polymeric fibers, and adoption of special surface treatment and curing methods. This innovative composite mortar is designed to perform effectively in chemically aggressive environments by significantly enhancing both mechanical, durability and microstructural characteristics. The incorporation of GNPs and MWCNTs results in a denser microstructure, improved interfacial bonding, and reduced porosity, which collectively contribute to increased resistance against acid attack, particularly from sulfuric acid solutions with low pH levels (Ph=1-2). The invention employs optimized dispersion techniques, such as high-shear mixing or ultrasonication, to ensure uniform distribution of the nanomaterials within the cementitious matrix. As a result, the mortar demonstrates improved compressive strength, residual compressive strength lower mass loss, and reduced formation of harmful products like gypsum and ettringite after acid exposure. This makes it highly suitable for use in sewer systems, industrial floors, chemical storage areas, and other structures exposed to harsh acidic conditions. The invention offers a sustainable, high-performance solution for long-term durability in infrastructure subjected to chemical degradation.