CAJ | 학술논문

利用电脉冲加速外部硫酸根离子向砂浆内部迁移，研究了电脉冲作用下水灰比、侵蚀溶液种类以及电脉冲周期等因素对水泥砂浆硫酸盐侵蚀的影响，并利用扫描电镜观察受硫酸盐侵蚀后砂浆的微观结构．结果表明，硫酸钠溶液浸泡侵蚀180 d后，水灰比为0．3，0．4，0．5的砂浆抗折系数分别为1．03，0．98，0．94，抗压抗蚀系数分别为1．02，0．96，0．90；电脉冲作用下30 d后，各砂浆抗折系数分别变为0．98，0．95，0．90，抗压抗蚀系数分别为0．97，0．96，0．91，试件内部生成了大量的钙矾石，表明电脉冲加速了水泥砂浆的硫酸盐侵蚀．电脉冲作用下，在侵蚀溶液为硫酸镁的试件内部，部分水化硅酸钙（CSH）凝胶已转化为无胶凝性的水化硅酸镁（MSH），导致试件强度下降幅度大于硫酸钠侵蚀．此外，与周期为20 s的电脉冲相比，在周期为10 s的电脉冲作用下，试件受硫酸盐侵蚀的破坏程度更大．
이용전맥충가속외부류산근리자향사장내부천이，연구료전맥충작용하수회비、침식용액충류이급전맥충주기등인소대수니사장류산염침식적영향，병이용소묘전경관찰수류산염침식후사장적미관결구．결과표명，류산납용액침포침식180 d후，수회비위0．3，0．4，0．5적사장항절계수분별위1．03，0．98，0．94，항압항식계수분별위1．02，0．96，0．90；전맥충작용하30 d후，각사장항절계수분별변위0．98，0．95，0．90，항압항식계수분별위0．97，0．96，0．91，시건내부생성료대량적개반석，표명전맥충가속료수니사장적류산염침식．전맥충작용하，재침식용액위류산미적시건내부，부분수화규산개（CSH）응효이전화위무효응성적수화규산미（MSH），도치시건강도하강폭도대우류산납침식．차외，여주기위20 s적전맥충상비，재주기위10 s적전맥충작용하，시건수류산염침식적파배정도경대．
The effects of the water-cement ratio,types of attack solution and the period of pulse on sulfate attack on cement mortars subjected to electrical pulse were investigated through electrical pulse speeding up the migration of external sulfate ions into cement-based materials.The microstruc-tures of the damaged specimens were examined by scanning electron microscope.The results show that for the mortars with the water-cement ratios of 0.3,0.4 and 0.5,after immersion in the attack solution of Na2SO4for 180 d,the flexural coefficients are 1.03,0.98 and 0.94,respectively,and the compressive strength coefficients are 1 .02,0.96 and 0.90,respectively.However,after using electrical pulse for 30 d,the flexural coefficients are changed into 0.98,0.95 and 0.90,respective-ly,and the compressive strength coefficients are 0.97,0.96 and 0.91,respectively.A large amount of ettringite form in the damaged specimens,indicating that electrical pulse accelerates the erosion of cement-based mortars due to sulfate attack.When MgSO4 is used as the attack solution under electri-cal pulse,some calcium silicate hydrate (CSH)gel converts into non-cohesive magnesium silicate hydrate (MSH),resulting in greater strength loss of the specimens compared with that caused by so-dium sulfate attack.Moreover,the deterioration degree of the specimens subjected to electrical pulse with the period of 10 s is greater than that with the period of 20 s.