可再分散乳胶粉对软岩相似材料性能的影响

The Influence of Redispersible Latex Powder on Similar-Materials Properties of Soft Rock

为研制软岩的相似材料,本文选用铁精粉、重晶石粉和石英砂作为骨料,分别以石膏以及水泥和粘土混合作为胶凝剂,设计了以可再分散乳胶粉掺量为变化参数的单因素影响试验。结果表明:(1)在石膏胶结类型相似材料中,掺入2%以内的可再分散乳胶粉可提高其密度以及抗压强度,但超过2%后,上述指标呈下降趋势,其中密度表现得更明显;变形模量始终呈下降趋势,在2%后越显著;(2)水泥和粘土胶结的相似材料密度、抗压强度及变形模量线性降低,抗压强度最大降幅约35%,(3)随该掺量增加,石膏胶结的相似材料呈现明显的弹、塑性阶段,破坏形式转变为软岩常见的X状共轭破坏;(3)水泥和粘土胶结的相似材料在6%时才开始表现出这一性质。结论可为软岩大型边坡工程或地下结构围岩工程的稳定性分析。

In order to develop similar-materials of soft rock,iron powder,barite powder and quartz sand as aggregate,gypsum,cement and clay are mixed as gelling agent,a single factor test with redispersible latex powder dosage as variable parameter was designed.The test results show that the density and compressive strength of similar gypsum cementing materials can be improved when the redispersible latex powder content less than 2%,but the above indexes show decreasing trend when the ratio exceeds 2%;among them,density is more obvious.The deformation modulus of this group always shows a downward trend,and the change becomes more significant after 2%.The density,compressive strength and deformation modulus of similar-materials of cement and clay bonding also decreased linear significantly,and the maximum compressive strength reduction is about 35%.In addition,with the increase of the redispersible latex powder,the similar-materials of gypsum cement show obvious elastic and plastic stages,and the failure form gradually converts to the common X-shaped conjugate failure of soft rock.Similar materials for cement and clay bonding starts to show this property at 6%.The conclusion can be used to simulate the stability of large scale slope engineering or underground structure surrounding rock engineering of soft rock.