干湿循环条件下龙门石窟防渗灌浆材料耐久性试验研究

为评价龙门石窟灌浆材料在干湿循环条件下的耐久性,两组优选偏高岭土配合比MK001、MK002为研究对象,超细水泥配合比CXSN作为对比,体积、质量与强度等作为评价材料耐久性指标。结果表明:(1)在干湿循环后,三组配合比体积有所增长,以MK002增长率最大,为7.543%,而质量均有一定损失;(2)三组配合比强度在前期均有一定增长,MK001、CXSN配合比表现为前6次循环,MK002持续增长时间达到第12次;强度后期出现严重损失,但MK002强度仍大于原始强度,波速与强度变化规律相似,可相互校正;(3)MK001、MK002配合比的致密性明显下降,CXSN配合比的SEM图中,裂隙发育明显;(4)MK001、MK002配合比的易溶盐总量远小于CXSN配合比,且Cl-的含量较低,反应前后,离子含量变化较小,固离子性较好,三组配合比的p H均较高,有利于维持水泥水化产物的稳定性;(5)试样以物理破坏为主,化学作用较为微弱,材料的化学成分变化较小;(6)MK002配合比在干湿循环条件下的耐久性较好。

Experimental study on durability of impervious grouting material in Longmen Grottoes under dry-wet cycles

In order to evaluate the durability of grouting materials in Longmen Grottoes under wet and dry cycles,the two groups of optimized metakaolin formula were selected with MK001 and MK002 as the research object,the superfine formulation of CXSN as a comparison,and selecting the volume,quality and strength as the evaluation index of durability of materials.The results showed that:(1)after the dry-wet cycles,the volume of three groups formulations growth,the largest growth rate of MK002 is 7.543%,the quality of the sample has a certain loss;(2)the strength of three formulations has a certain growth in the early,the formulations of MK001 and CXSN mainly growth in the first cycles,then the growth duration of MK002 up to twelfth times.The strength of the samples appeared serious losses in the late period,but the MK002 strength is greater than the original strength,and velocity and strength similar to that of mutual correction;(3)the compact of MK001 and MK002 decreased obviously,and the crack of CXSN growth significantly in the SEM;(4)the soluble salt content of MK001 and MK002 formulations is far less than the CXSN formula,and the content of Cl-was low,as the favorable solid ion,the small change of ion,the stability of hydration products was maintained as the higher of thethree formulations;(5)the physical damage is mainly to the sample,and the chemical effect is relatively weak,which the chemical composition have small changes;(6)MK002 formulation has good durability under dry-wet cycles.