Mechanical Properties of Fiber-Reinforced Permeable Geopolymer Concrete

Abstract

In this paper, permeable geopolymer concrete with high compressive strength and permeability is prepared using alkali-activated metakaolin as a slurry, and its mechanical properties are reinforced by adding steel fibers. The influencing factors of the strength, porosity and permeability coefficient of the fiber-reinforced permeable geopolymer concrete, as well as its microstructure and curing mechanism, are determined by conducting an unconfined compressive strength test, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. The test results show that, under the water permeability required to meet the specification conditions, when the alkali activator modulus is 1.4 and the activation-to-solid ratio is 0.9, the effect of metakaolin activation is the most obvious, and the unconfined compressive strength of the permeable geopolymer concrete is the highest. Moreover, the paste formed via the alkali activation of metakaolin contains a large number of silica–oxygen and aluminum–oxygen bonds with a dense and crack-free structure, which enables the paste to tightly combine with the aggregates; the strength of the permeable geopolymer concrete is early strength, and its strength at a curing age of 3 days is the highest. The strength at a curing age of 3 days can reach 43.62% of the 28-day strength; the admixture of steel fiber can effectively improve the strength of the permeable concrete, and with an increase in the amount of admixture, the strength of the fiber shows a trend of increasing, and then decreasing. Under the conditions of this test, a volume of steel fiber of 0.3% enables the optimum unconfined compressive strength to be reached.

Structure and Properties Improvement by Recipe Factors of Geopolymer Basalt Fiber Reinforced Concrete for Building Enclosing Structures

“…In itself, this method is already quite effective, a proven option for changing the characteristics and structure of geopolymer concrete, giving it a different nature of destruction, more viscous, as well as the entire mechanics of the structure made from such concrete. This is in good agreement with the works of other authors who used various types of fiber in geopolymer concrete technology [36][37][38][39][40][41].…”

“…Geopolymer concrete, as a construction conglomerate, is no exception in terms of the prospects of reinforcing it with fiber. For example, in a study [36], the introduction of 0.3% steel fiber into the composition of geopolymer concrete made it possible to achieve the best compressive strength values. In studies [37][38][39][40][41], reinforcing geopolymer composites with glass, polypropylene, basalt, and steel fibers in optimal amounts improved their physical and mechanical properties.…”