纤维和磷石膏对淤泥强度及饱和渗透系数的影响规律

Effects of Fiber and Phosphogypsum on Sludge Strength and Saturation Permeability Coefficient

为了将产生的淤泥重复利用,开展改良淤泥废土试验。以纤维和磷石膏为固化剂固化处理淤泥,进行不同养护龄期下不同掺量的纤维、磷石膏-淤泥混合土的无侧限抗压试验和渗透试验,探究不同纤维和磷石膏掺量下的力学性质以及饱和渗透系数变化规律。研究结果表明:聚丙烯纤维对强度的增强效果显著,且随着聚丙烯纤维掺量的增加,纤维固化淤泥土的强度逐渐提高。固化淤泥土的无侧限抗压强度随着磷石膏掺量增加呈现先增大后减小的趋势,磷石膏的最优掺量为1.84%(干重量之比)。磷石膏-固化淤泥土混合样的无侧限抗压强度随养护时间的增加而增大,14d之后趋于稳定。固化淤泥土的饱和渗透系数随着纤维和磷石膏掺量增加而提高。磷石膏-固化淤泥土饱和渗透系数随着养护龄期增加而提高,养护14d后其值趋于稳定。淤泥的饱和渗透系数均随着纤维和磷石膏掺量的增加而增加。

There is large sludge output in our country,which easily c cm tributes to accumulation pollutions.Using fiber and phosphogypsum as curing agents to solidify the sludge,unconfined compressive tests and permeability tests of mixed soil of fiber,phosphogypsum and sludge were carried out under different curing ages to investigate the mechanical properties and changes rules of saturation permeability coefficient under different filler and phosphogypsum contents.It was found that fiber has a significant effect on strength enhancement,and with the increase of fiber content,the strength of fiber solidified soil increased gradually.However,the unconfined compressive strength of the sludge increased firstly and then decreased with the increase of phosphogypsum content,and we found that the optimal content of phosphogypsum was 1.84%(dry weight ratio).The unconfined compressive strength of phosphogypsum sludge mixture increased with the increase of maintenance period,and tended to lie stable after 14 days.The saturated permeability of sludge increased with the addition of filler and phosphogypsum.In addition,the saturation permeability coefficient of phosphogypsum and sludge increased with the increase of maintenance period,and the value tended to be stable after 14 days of curing.