改性磷石膏在低气压环境下的试验研究*

为了利用改性磷石膏制备磷石膏制品用于墙体充填材料中，本文研究了不同低气压和低气压养护时间对磷石膏密度、抗压强度、吸水率及渗透性的影响。结果表明，养护3 d和28 d磷石膏砂浆的密度都在0.7 kPa时相对最小，随着低气压养护时间延长磷石膏砂浆密度降低；在3 d和28 d，低气压养护下磷石膏砂浆抗压强度均高于气压为1 kPa时的抗压强度，在28 d，磷石膏砂浆的抗压强度在0.7 kPa时表现出最大的趋势；不同低气压和低气压养护时间下磷石膏砂浆的抗压强度均满足砂浆MU5.0的要求，但对吸水率和渗透性的影响均较小。因此，磷石膏制品不仅能作为房屋装饰材料，也能作为房屋墙体填充材料，且能有效减轻其荷载进而提高抗震能力。

Experimental study of phosphogypsum in a low air pressure environment

In order to use modified phosphogypsum to prepare phosphogypsum products for use in wall filling materials, this paper investigates the effects of different low air pressure and low air pressure maintenance time on the density, compressive strength, water absorption and permeability of phosphogypsum. The results show that the density of phosphogypsum mortar is relatively minimum at 0.7 kPa for both 3 d and 28 d, and the density of phosphogypsum mortar decreases with the prolongation of low-pressure maintenance time; the compressive strength of phosphogypsum mortar is higher than that of the compressive strength when the air pressure is 1 kPa for both 3 d and 28 d under the low-pressure maintenance, and the compressive strength of the phosphogypsum mortar exhibits the maximum tendency at 0.7 kPa in 28 d; the compressive strength of phosphogypsum mortar at 0.7 kPa with different low-pressure and low-pressure maintenance times is higher than that at 1 kPa. compressive strengths of phosphogypsum mortar under low air pressure and low air pressure maintenance time all meet the requirements of mortar MU5.0, but the effects on water absorption and permeability are small. Therefore, phosphogypsum products can not only be used as decorative materials for houses, but also as filling materials for house walls, and can effectively reduce its load and thus improve the seismic capacity.