养护条件对水泥石早期电通量的影响

摘要

研究了养护环境(保湿环境、干燥环境及干燥-保湿混合环境)、养护时间(10、14、21、28 d)及掺合料取代水泥量(0~60%)对水泥石电通量的影响.研究结果表明:(1)无论何种养护环境,不掺矿物掺合料的水泥石抗氯离子渗透性能最差;(2)0~10 d是水泥石抗氯离子渗透性能养护的最佳龄期,在此期间保湿养护越充分,越有利于水泥石28 d抗氯离子渗透性能;水泥石在该阶段短暂缺水养护后及时保湿,能够最大程度降低28 d抗氯离子渗透性能受损的风险;(3)10~21 d是水泥石抗氯离子渗透性能发展的快速时期,此期间保湿养护时间越长,抗氯离子渗透性能发展越快;(4)引入掺合料能够明显提升水泥石抗氯离子渗透能力,过量引入掺合料能够一定程度弥补水泥石由养护湿度不足而引起的抗氯离子渗透性的降低,但是弥补效果随干养时间的延长而变差.%In this paper,electric-flux of hardened cement paste replaced mineral admixture of cement were tested under different curing conditions and curing time.The results of experiment show that 28 d resistance to chloride ion permeability of hardened cement paste without mineral admixture is weak whether to change curing conditions.Curing time within 10 day is the optimum stage for resistance to chloride ion permeability property development of hardened cement paste mixed with mineral admixture under the condition of wet maintenance.In this stage,resistance to chloride ion permeability of hardened cement paste under dry condition can be recovered as far as possible when wet maintenance is taken timely.Curing time from 10 day to 21 day is the rapid development stage for resistance to chloride ion permeability property development of hardened cement paste mixed with mineral admixture under the condition of wet maintenance.In comparison with hardened cement paste without mineral admixture,resistance to chloride ion permeability of hardened cement paste mixed with mineral admixture could be improved obviously regardless of curing condition and curing age.With the increasing of the dosage of mineral admixture,resistance to chloride ion permeability of super mineral admixture hardened cement paste could be repaired under the condition of dry curing and loss of wet curing.However,the repair effect is weaker and weaker along with the prolonging of dry curing.