Experimental Study on the Road Performance of High Content of Phosphogypsum in the Lime–Fly Ash Mixture

Abstract

Phosphogypsum (PG), as a by-product of the production of phosphoric acid, faces the problems of large annual output and difficult treatment. There is a large demand for fillers in the process of road paving, which may be an effective method for the utilization of PG resources. In this study, three proportions of phosphogypsum–lime–fly ash (PLF) mixture were designed, first, according to orthogonal tests. The comprehensive performance of the PLF mixture was tested by the compression rebound modulus test, unconfined compressive strength test, flexural tensile strength test, dry shrinkage test, and temperature shrinkage test, respectively. The results show that adding crushed stone to the PLF mixture can effectively improve the compression rebound modulus, unconfined compressive strength, and flexural tensile strength. The high content of PG in the mixture can also improve the dry shrinkage and temperature shrinkage properties of the mixture. According to the road layer requirements, the optimum proportion of the PLF mixture is recommended, which may benefit the road construction and PG resources.

Application of the Industrial Byproduct Gypsum in Building Materials: A Review

“…As shown in Figure 8, microscopic analyses revealed that the formation of calcite after the Currently, there is a high demand for materials in the road-paving process. Three different proportions of PG-lime-fly ash blends were tested for their various performances [47]. The results show that the compressive resilient modulus of the specimens increased slowly with time, but the growth rate decreased, and at the same time, the compressive resilient modulus decreased with the increasing PG content.…”

Research on the hydration process of solid waste–based cementitious materials and application in roadbase

“…Fly ash, as an additive to concrete, improves the plasticity and fluidity of concrete and increases its strength and durability (Grabias-Blicharz and Franus, 2023). In recent years, some studies have been conducted on the mechanism of shrinkage and enhancement behavior of desulfurization gypsum-slag-cement cementitious material for stabilized macadam (Li et al, 2017;Ju et al, 2019;Ou-Ming et al, 2019;Deng et al, 2020;Qing-qing, 2021;Qian et al, 2022). The results show that gypsum can promote the hydration reaction of slag.…”