进行了经历不同高温以及在不同冷却方式下混凝土经过不同养护方式后强度恢复试验,养护方式反映了外部水分补给到混凝土内的含量差异。试验表明,外部补给到高温后混凝土内的水分须达到一定含量,才有利于混凝土强度恢复。经过合适养护后,经历600℃高温后的自然冷却混凝土28 d时完全可达到甚至超过未经高温的原始强度,同样情况下的水冷却混凝土60 d时至少可达到原始强度的85%以上。虽然高温后水冷混凝土初期强度远低于自冷混凝土,但在合适养护后,相对于高温后初始强度而言,水冷混凝土强度恢复幅度高于自冷混凝土。经合适养护的混凝土强度恢复幅度随温度增高而增加。经历过高温度(750℃)后,水泥和砂石损伤过大,混凝土强度恢复机理比较复杂,需要进一步研究。
Experiment of concrete strength recovery by different curing way after different high temperature and by different cooling way is made.Curing way reflect water content into concrete experienced high temperature.Experiment indicates that, the water content into concrete experienced high temperature must be reach to a lever, which is beneficial for concrete strength recovery.The proper curing way may make concrete experienced 600 ℃ and by natural cooling recover or even exceed original strength before high temperature at 28 days, and that by water cooling recover above 85% of original strength at 60 days.Though earlier strength of concrete by water cooling is lower than that by natural cooling, the lever of strength recovery of the former is higher than the latter by right curing way, relative to origi- nal strength after high temperature.Higher the temperature experienced, the more concrete strength recovery is by right curing way.Because cement and sand stone damage is too damage,mechanism of concrete strength recovery experienced too high temperature (750 ℃ )is com- plex, and need to research forever.