In order to reduce the influence of impurities in hemihydrate phosphogypsum(HPG)on the environment and improve the workability of HPG,the effects of the content of quicklime and types of biopolymer(hydroxypropyl methy...In order to reduce the influence of impurities in hemihydrate phosphogypsum(HPG)on the environment and improve the workability of HPG,the effects of the content of quicklime and types of biopolymer(hydroxypropyl methylcellulose,xanthan gum,sodium polyacrylate(PAANa))on the compressive strength,softening coefficient and ultrasonic velocity of HPG were evaluated.When the content of quicklime was 1.5%and the content of PAA-Na was 0.2%,HPG had the best mechanical properties and workability,its water retention rate can be increased by 5.8%,and unconfined compressive strength of 3 days increased by 10.3%and 7 days increased by 13.1%.Through the analysis of scanning electron microscope and X-ray diffraction,it was found that the hydration reac-tion of HPG was more sufficient,the pores size and number decreased,the number of impurities on the crystal surface decreased obviously,and CaF2 and other substances were formed by the reaction after the addition of quicklime.After adding quicklime and PAANa,the indicators of gypsum self-leveling mortar prepared by HPG meet the requirements of the standard.展开更多
Since antiquity, man used to stock up materials and products existing in his close surroundings to build his house, which provides him shelter and comfort. Within the present work, mixtures of plaster and dune sand ha...Since antiquity, man used to stock up materials and products existing in his close surroundings to build his house, which provides him shelter and comfort. Within the present work, mixtures of plaster and dune sand have been studied with the aim of valorization of locally abundant materials. The tests showed that with the addition of dune sand and the compaction, an optimal mixture (67% plaster and 33% dune sand) can be used as a carrier element for construction of up to three levels;since significant increase of the mechanical strength has been observed. The element obtained offers an acceptable thermal insulation with a decrease in the thickness of the outer wall construction. The use of this gypsum’s mortar block as a carrier element in a structure not exceeding three levels, also enables a considerable savings especially in areas where sand and plaster are abundant and relatively inexpensive.展开更多
基金This study was financially supported by National Natural Science Foundation of China(GrantNo.51834001)Fundamental Research Funds for the Central University(Grant No.FRF-BD-20-01B).
文摘In order to reduce the influence of impurities in hemihydrate phosphogypsum(HPG)on the environment and improve the workability of HPG,the effects of the content of quicklime and types of biopolymer(hydroxypropyl methylcellulose,xanthan gum,sodium polyacrylate(PAANa))on the compressive strength,softening coefficient and ultrasonic velocity of HPG were evaluated.When the content of quicklime was 1.5%and the content of PAA-Na was 0.2%,HPG had the best mechanical properties and workability,its water retention rate can be increased by 5.8%,and unconfined compressive strength of 3 days increased by 10.3%and 7 days increased by 13.1%.Through the analysis of scanning electron microscope and X-ray diffraction,it was found that the hydration reac-tion of HPG was more sufficient,the pores size and number decreased,the number of impurities on the crystal surface decreased obviously,and CaF2 and other substances were formed by the reaction after the addition of quicklime.After adding quicklime and PAANa,the indicators of gypsum self-leveling mortar prepared by HPG meet the requirements of the standard.
文摘Since antiquity, man used to stock up materials and products existing in his close surroundings to build his house, which provides him shelter and comfort. Within the present work, mixtures of plaster and dune sand have been studied with the aim of valorization of locally abundant materials. The tests showed that with the addition of dune sand and the compaction, an optimal mixture (67% plaster and 33% dune sand) can be used as a carrier element for construction of up to three levels;since significant increase of the mechanical strength has been observed. The element obtained offers an acceptable thermal insulation with a decrease in the thickness of the outer wall construction. The use of this gypsum’s mortar block as a carrier element in a structure not exceeding three levels, also enables a considerable savings especially in areas where sand and plaster are abundant and relatively inexpensive.
