Study on the improvement of the waterproof and mechanical properties of hemihydrate phosphogypsum-based foam insulation materials

Hemihydrate phosphogypsum was used as a raw material to investigate the effects of different water-proofing agents (three organic agents and slag) and fibers (polypropylene (PP) and polyvinyl alcohol (PVA)) on the waterproofing and mechanical properties of hemihydrate phosphogypsum-based foam insulation materials (HGFMs), and HGFMs with low density, high strength and good water resistance were successfully prepared. The results show that the three organic waterproofing agents have no effect on the waterproofing performance of the HGFMs, but a small amount of slag can effectively improve the waterproofing performance and softening coefficient of the HGFMs. Both the PP and PVA fibers can increase the mechanical properties of the HGFMs, but the PVA fibers improve the mechanical properties more effectively. In addition, short fibers have a better effect on the compressive strength of the samples but a worse effect on the flexural strength of the samples compared with samples containing long fibers. (C) 2019 Elsevier Ltd. All rights reserved.