Mechanical properties and modification mechanism of phosphogypsum stabilized soil

Abstract The red clay is widely distributed in Guizhou province, which characterized by high natural moisture content, difficult compaction and serious shrinkage crackingin, phosphogypsum discharged for 5 million tons every year province. For the sake of effectively reducing accumulation phosphogypsum, mixtures were prepared with cement as a curing agent mass ratios to 1:1, 1:2 1:3 (low content group) (high group). Unconfined compressive strength, expansion, dynamic characteristic tests conducted analyze behavior mechanical properties mixtures. modification mechanism was further explored XRD (X-ray diffraction) SEM (scanning electron microscopy). provided theoretical basis application highway engineering improved clay. results show that unconfined strength stabilized soil low group greater than group. When cement:phosphogypsum = 1:2.2–1:3, mixture maximum. 1:3, maximum shear modulus largest. absolute expansion rate linear are those cement: 1:1–1:3, 6.5–12.3%, 1.3–2%. clay:Phosphogypsum 0.2–4%, 1–1.5%. more smaller deformation mixture. It suggested 5%. Which can not only make full use solid waste, but also improve Article Highlights derived from comprehensive effect phosphogypsum. Due increment decline proportion clay, leading decrease hydrophilic minerals, characteristics changed. Considering characteristics, it recommended 5% 1:1 subgrade filler,