6. Conclusions and Recommendations
It can be concluded from the present study that fiber-reinforced
geopolymer can significantly improve the bending strength of the matrix,
which makes the failure mode of the geopolymer change from brittleness
to ductility. Fiber acts as a bridge for geopolymer cracks, and
transfers stress from cracks to geopolymers, thereby reducing crack
propagation. Different fibers have different effects on matrix. Steel
fiber is helpful to enhance strength properties, while glass fiber is
conducive to eliminating microcracks and the ductility. In order to
obtain a composite fiber with comprehensive properties that are endowed
with all the benefits of strength, microcrack elimination, ductility,
and denser mix, steel and glass fibers can be used in the best
proportion of the composite fiber.
At present, the research mainly focuses on the influence of fiber type
and content on the performance of geopolymer, but the following factors
may also affect the geopolymer performance: the selection of geopolymer
matrix, interface strength, fiber extraction method, and fiber
treatment. Therefore, the following aspects remain to be further
explored:
- Most geopolymers are prepared by alkali activation, but it is actually
feasible to carry out acid activation as well. Studies on fiber
reinforced acid activated geopolymers should be taken into
consideration.
- The present research focuses on the influence of fiber type and
content on the geopolymer performance. Indeed, more emphasize can be
placed on the fiber treatment, extraction method, matrix-fiber
interface characteristics and pore structure of composite materials.
- There are few studies and applications on the influence of unique
properties of fibers such as light weight, heat preservation and heat
insulation on geopolymer, which requires further exploration.
- More academic attention should be paid to the special application of
geopolymer, such as 3D printing, insulation wall materials, etc.