Damage evolution law and damage characteristics of fly ash recycled concrete under high temperature
Using fly ash,sodium hydroxide,slag and sodium silicate as raw materials,the damage evolution law and damage characteristics of fly ash recycled concrete under high temperature are studied,and the results show that when the fly ash content is the same,the residual compressive strength ratio of the specimen gradually decreases with the increase of temperature.Under the natural cooling,after the high temperature of 455 ℃ and 655 ℃,the residual compressive strength of fly ash content in 25％and 15％concrete increased,which was 6.73％and 32.68％higher than that at room temperature,respectively.The concrete with a content of 35％has a compressive strength lower than that at room temperature at 255 ℃.When the dosage is 45％and 55％,the strength is significantly smaller than the 0 dosage.Under natural cooling,the residual compressive strength is generally higher than that under spray cooling,and the residual compressive strength under natural cooling is 1.716 times the maximum strength under spray cooling.In addition to room temperature and 455 ℃,the peak stress of ordinary concrete is greater than the peak stress of corresponding fly ash concrete.At the same temperature,the sound velocity value and rebound value of various fly ash content concrete gradually decrease with the increase of fly ash content.Under spray cooling and natural cooling,the sound velocity value and rebound value of fly ash concrete are less affected.
high temperaturefly ashrecycled concretedamage evolutiondamage characteristics
万方数据
维普
