灰渣改良压实混合赤泥的力学性能研究

Studies on Mechanical Properties of Compaction Mass of Red Mud Mixture by the Improvement of Fly-ash

以中铝贵州分公司生产的拜耳法赤泥、烧结法赤泥和灰渣为对象,对拜尔法∶烧结法=1∶1和拜尔法∶烧结法∶灰渣=50∶50∶15两种配比混合赤泥进行了击实试验。以击实试验所得的最优含水量和最大干密度为依据制作试验样品,研究了掺灰渣与不掺灰渣两种配比混合赤泥在90%和95%两种压实度情况下、最优含水量和浸水饱和两种状态时的抗剪性能和压缩性。研究得出:1添加灰渣混合赤泥滤饼的最大干密度较未加灰渣的略大,最优含水量略小;2添加灰渣可提高最优含水量状态混合赤泥的抗剪强度,但添加灰渣的混合赤泥浸水饱和后的抗剪强度较未添加灰渣时降低;3添加灰渣的混合赤泥的压缩模量较未加灰渣的高得多,并且提高压实度能显著提高掺灰渣混合赤泥的压缩模量,而对未加灰渣的混合赤泥,在压实度提高时,压缩模量增加并不显著;4添加灰渣可改善混合赤泥的抗剪性能和压缩性能,但宜在最优含水量状态下工作,并建议添加灰渣混合赤泥用于筑坝时应做好防渗措施。

Taking Bayer red mud,Sintered red mud and fly-ash from Guizhou branch of China aluminum industry company as the sample object of study,two kind of mixing red mud were compounded to test compaction index,namely Bayer red mud：sintered red mud equaling to 1∶1 and Bayer red mud：Sintered red mud：fly-ash equaling to 50∶ 50∶ 15.Based on the optimal water content and the maximum dry density from compaction test,two kind of mixed red mud above which compaction rate is 90％ and 95％ were prepared for studying their shear behavior and compression performance in condition of optimal water content and saturating water content two state,and water content of all samples compounded should be controlled close to optimal water content.Analyzing results from study above,the conclusion are as follows.①Maximum dry density of mixing red mud with fly-ash is higher than that of mixing red mud without fly-ash,and for optimum water content,the formr is smaller.②In addition of optimal water content,the shear strength of mixed red mud with fly-ash can be improved obviously,but in saturated state,after adding fly-ash,the shear strength of mixed red mud reduced.③After adding fly-ash,compression modulus of mixing red mud increased obviously,and raising the degree of compaction can significantly improve the compression modulus of mixing red mud with fly-ash,but for mixing red mud without fly-ash,increasing compaction degree,increment of compression modulus is not significant.④After adding fly-ash,shear properties and compressive properties of mixing red mud can be improved,but they should work at optimum water content state.So,anti-leakage measures should be taken while mixing red mud with fly-ash is used to build red mud dam.