Study on the Permeability of Recycled Aggregate Pervious Concrete with Fibers

• Published in: Materials Vol. 13; no. 2; p. 321
• Main Authors: Zhu, Haitang, Wen, Chengcheng, Wang, Zhanqiao, Li, Lan
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.01.2020; MDPI
• Subjects: Aggregates; Cement; Coefficients; Composite materials; Compressive strength; Concrete; Diameters; Flexural strength; Image analysis; Particle size; Permeability; permeability coefficient; Physical properties; Polypropylene; Porosity; porosity tortuosity; recycled aggregate pervious concrete; Steel fibers; Tortuosity; Two dimensional analysis; Volumetric analysis; Water-cement ratio; permeability coefficient; porosity tortuosity; water-cement ratio; flexural strength; recycled aggregate pervious concrete
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma13020321

Pervious concrete is considered to be porous concrete because of its pore structure and excellent permeability. In general, larger porosity will increase the permeability coefficient, but will significantly decrease the compressive strength. The effects of water-cement ratio, fiber types, and fiber content on the permeability coefficient, porosity, compressive strength, and flexural strength were investigated. The pore tortuosity of the pervious concrete was determined by volumetric analysis and two-dimensional cross-sectional image analysis. The concept and calculation method of porosity tortuosity were further proposed. Results show that the permeability coefficient of the pervious concrete is the most suitable with a water-cement ratio of 0.30; the water permeability of the pervious concrete is influenced by fiber diameter. The permeability coefficient of pervious concrete with polypropylene thick fiber (PPTF) is greater than that with copper coated steel fiber (CCF) and the polypropylene fiber (PPF). The permeability coefficient is related to tortuosity and porosity, but when porosity is the same, the permeability coefficient may be different. Finally, general relations between the permeability coefficient and porosity tortuosity are constructed.