Durability Study on High-Performance Fiber-Reinforced Mortar under Simulated Wastewater Pipeline Environment

Abstract

The acid–alkaline-inducd corrosive environments inside wastewater concrete pipelines cause concrete structural deterioration and substantial economic losses all over the world. High-performance concrete/mortar (HPC) was designed to have better resistance to corrosive environments, with enhanced service life. However, the durability of HPC in wastewater pipeline environments has rarely been studied. A high-performance mortar mixture (M) reinforced by supplemental materials (including fly ash and silica fume) and polyvinyl alcohol (PVA) fibers, together with a mortar mixture (P) consisting of cement, sand and water with similar mechanical performance, were both designed and exposed to simulated wastewater pipeline environments. The visual appearance, dimensional variation, mass loss, mechanical properties, permeable pore volume, and microstructure of the specimens were measured during the corrosion cycles. More severe deterioration was observed when the alkaline environment was introduced into the corrosion cycles. Test results showed that the M specimens had less permeable pore volume, better dimensional stability, and denser microstructure than the P specimens under acid–alkaline-induced corrosive environments. The mass-loss rates of the M specimens were 66.1–77.2% of the P specimens after 12 corrosion cycles. The compressive strength of the M specimens was 25.5–37.3% higher than the P specimens after 12 cycles under corrosive environments. Hence, the high-performance mortar examined in this study was considered superior to traditional cementitious materials for wastewater pipeline construction and rehabilitation.

Effect of Microstructure on the Dimensional Stability of Extruded Pure Aluminum

“…Moreover, the temperature disturbance caused by the cycle of the four seasons or the alternation of day and night is inevitable for the material. The thermal cycling is the prime environmental factor for the dimensional stability of materials [8][9][10].…”

Increasing the Corrosion Resistance and Durability of Geopolymer Concrete Structures of Agricultural Buildings Operating in Specific Conditions of Aggressive Environments of Livestock Buildings

“…It is conditionally possible to divide the studies conducted by other authors by grouping them into several groups of factors. For example, some authors [12,15,[18][19][20][23][24][25]34,36] were engaged in research aimed at improving the corrosion resistance of cement-based concrete, which are the most traditional type of concrete in current construction but are not environmentally friendly and cheap, leaving a high carbon footprint and not in line with the modern ESG agenda. Other authors [7][8][9][10][11]22,27,29,31,35] were engaged in developing compositions of geopolymer concrete aimed at improving the mechanical properties of such concrete: their strength and improvement of deformation properties.…”

“…In Ref. [24], the authors carried out experimental and information modeling to optimize the mechanical properties of an alkali-activated solution made with different concentrations of fly ash, granulated blast-furnace slag, and nano-silica from waste glass.…”

Effect of high‐temperature, high‐pressure, and acidic conditions on the structure and properties of high‐performance fibers

“…[ 2 ] The presence of these substances combined with free water can cause severe corrosion problems in oil and gas pipelines, even in fiber‐reinforced composites. A study of fiber‐reinforced mortar has shown that the component responsible for corrosion failures appears to be the fibers rather than the resin, [ 3 ] with the resin playing a protective role by shielding the fibers from the corrosive environment. In composites where the peripheral matrix material was damaged and the fibers were exposed to a corrosion environment, [ 4 ] corrosion spread rapidly throughout the material leading to complete failure of the composite.…”