Performance Analysis and Admixture Optimization of GBFS-HPMC/Fiber Pervious Concrete.

Area of Science:

• Civil Engineering
• Materials Science
• Environmental Engineering

Background:

• Permeable pavements reduce stormwater runoff, mitigating urban flooding and heat island effects.
• Pervious concrete is a key material for sustainable urban infrastructure, but its mechanical properties require optimization.
• Incorporating supplementary cementitious materials and fibers can enhance concrete performance.

Purpose of the Study:

• To investigate the impact of granulated blast-furnace slag (GBFS), hydroxypropyl methylcellulose (HPMC), and polypropylene plastic textile fiber (PPTF) on pervious concrete.
• To analyze the effects of these admixtures on mechanical properties (compressive, tensile, flexural strength) and water permeability.
• To optimize admixture proportions using gray correlation analysis for improved performance.

Main Methods:

• Orthogonal experimental design was used to systematically vary admixture proportions.
• Mechanical properties (cubic compressive, ultimate tensile, flexural strength) and water permeability were measured.
• Microstructural analysis was performed using Scanning Electron Microscopy (SEM) and Energy-Dispersive Spectroscopy (EDS).
• Gray correlation analysis was applied for admixture optimization.

Main Results:

• Pervious concrete with GBFS, HPMC, and PPTF achieved high mechanical strengths: 25.22 MPa (cubic compressive), 3.36 MPa (tensile), and 5.39 MPa (flexural).
• Microstructural analysis revealed enhanced bonding due to GBFS-derived calcium-silicate-hydrate (C-S-H) gel and improved matrix stability from PPTF.
• Optimized admixture proportions led to significant improvements: 7.2% increase in cubic compressive strength, 2.1% in splitting tensile strength, and 2.5% in flexural strength.

Conclusions:

• The combined use of GBFS, HPMC, and PPTF effectively enhances the mechanical properties and water permeability of pervious concrete.
• GBFS hydration products and PPTF reinforcement play crucial roles in improving the concrete matrix and interfacial transition zone.
• Admixture optimization through gray correlation analysis provides a viable strategy for maximizing the performance of pervious concrete for sustainable construction.