阳离子表面活性剂对电沉积法修复混凝土裂缝的愈合效果的影响研究

就电沉积方法修复混凝土裂缝中,阳离子表面活性剂(十六烷基三甲基溴化铵)对愈合效果的影响进行了试验研究,测定了沉积过程中试件的表面覆盖率、裂缝愈合率及渗透系数,并对裂缝中的沉积物进行了XRD、SEM分析。结果表明:从表面覆盖率、裂缝愈合率和渗透系数这3个指标来看,十六烷基三甲基溴化铵有助于提升电沉积法修复混凝土裂缝的愈合效果。ZnSO_4、MgSO_4溶液中掺加2%CTAB作为电解质溶液时,试件的表面覆盖率及裂缝愈合率在开始5 d时变化最大,之后随着时间的增加而逐渐减小,另外试件在裂缝处和非裂缝处的渗透系数降低较大、尤其是裂缝处下降更为明显,且上述3项评价指标都随溶液浓度的增大而减小。添加十六烷基三甲基溴化铵后,试件裂缝里沉积物的成分不变,但微观结构发生改变,而且比未添加CTAB时更为致密。

Healing effect of cetyltrimethyl ammonium bromide on the formation of electrodeposits in the concrete cracks

The influence of cetyltrimethyl ammonium bromide on the electrodeposition effect was investigated,and three parameters,that is,rate of surface coating,rate of crack closure and penetration coefficient were measured.XRD and SEM microscopic test of electrodeposits in the cracks was analyzed.The results demonstrate that from the surface coating rate,crack closure rate and penetration coefficient of these three indicators,the addition of cetyltrimethyl ammonium bromide is helpful to improve the effect of electrodeposits in the concrete cracks.When 2%CTAB was added in ZnSO4 or MgSO4 solution as electrolyte solution,variations of surface coating rate and crack closure rate climaxed at the 5th day,after which it tended to decline gradually with time increasing.In addition,the penetration coefficient of test specimens at the cracks and non-cracks was greatly reduced,especially in the cracks,and the three evaluation indexes decreased with increase of solution concentration.Moreover,the electrodeposits become more denser and the microstructure varies with cetyltrimethyl ammonium bromide content,while the compositions of electrodeposits do not change.