Application research of MgO expansive agent in crack control of super-long wall structure
The micro-expansion performance of MgO expansive agent in concrete can better compensate the early temperature drop shrinkage,and has a good crack control effect in the ultra-long wall structure.The monitoring data of the solid structure show that the internal temperature of the 300～400 mm thick wall structure reached the temperature peak at about 15～24 h under the curing condition of the wood formwork,and the cooling rate of the first three day after reaching the temperature peak was about 5.0～9.3 ℃/d.Early temperature drop shrinkage cracks would basically occur within 2～5 d,and the longer the length of the continuous straight wall of the super-long wall structure,the more the number of cracks.Compared with ordinary concrete,the micro-strain of shrinkage-com-pensating concrete prepared with magnesium oxide expansive agent increased by 80 με～134 με after temperature correction within 30 days in the engineering solid structure,and the comprehensive micro-strain value increased by 100 με～185 με.
万方数据
维普
