为分析标准养护(20℃)、高温养护(70℃)对超高性能混凝土(ultra-high performiance concrete,UHPC)力学性能的影响规律,在不同养护方式与养护龄期(3、7、28 d)下对不同配合比制备的UHPC进行抗压、抗折、抗拉及弹性模量试验,测试UHPC的力学性能.结果表明:高温养护能有效改善UHPC的力学性能,抗压强度增长均匀,抗折强度增幅显著,养护7 d时UHPC的抗压、抗折强度的增幅均最大,养护28 d时UHPC的抗压与抗折强度增大缓慢;UHPC抗拉强度及弹性模量的增大规律基本一致,养护7 d时达到最大抗拉强度与弹性模量,养护28 d时,抗拉强度与弹性模量不再增大或略有下降.选择在(70±2)℃进行高温养护,养护龄期为7 d.
The influence of maintenance temperature on the mechanical properties of UHPC
To analyze the influence of standard maintenance(20 ℃)and high-temperature maintenance(70 ℃)on the mechanical properties of ultra-high performance concrete(UHPC),compressive tests,rupture tests,tensile strength tests,and elastic modulus tests are conducted on UHPC samples with different mix proportions under different maintenance methods and maintenance ages(3,7,28 days).The results indicate that high-temperature maintenance effectively improves the mechanical properties of UHPC.The increase in compressive strength is uniform,with a significant increase in rupture strength.The greatest increase in compressive and rupture strength of UHPC is observed at 7 days of maintenance,while the increase of that is slower at 28 days.The trends for the increase in tensile strength and elastic modulus of UHPC are consistent,reaching their peak at 7 days of maintenance,and stabilizing or slightly decreasing at 28 days of maintenance.The maintenance temperature is(70±2)℃,with a maintenance age of 7 days.
UHPCstandard maintenancehigh temperature maintenancestrengthelastic modulus
万方数据
维普
