The Effect of Curing Regime on the Dynamic and Static Mechanical Properties of Ultra-high Performance Concrete with Addition of Nano-SiO2
The influence of nano-SiO2 content on the static mechanical properties of ultra-high performance concrete(UHPC)under the curing regime of standard curing,steam curing,dry-heat curing and steam-dry heat combined curing was studied.The test results showed that compared with standard curing regime,both steam curing regime and combined curing regime could significantly improve the compressive and flexural strength of UHPC.Dry-heat curing regime could improve the compressive strength of UHPC but reduce the flexural strength.Under standard curing regime,the compressive and flexural strength of UHPC reached the highest when the content of nano-SiO2 is 5％.Under steam curing regime,dry-heat curing regime and combined curing regime,the best nano-SiO2 content is 3％.According to the results of static test,the dynamic compressive properties of UHPC with 3％nano-SiO2 content under different curing regimes were studied with 100 mm Split Hopkinson Pressure Bar.According to the results of dynamic test,the dynamic increasing factor of UHPC was fitted with the empirical formula and the constitutive model of dynamic strain-stress curve under different strain rates was constructed.The energy consumption capacity of UHPC under different curing regim was calculated.The results showed that under the same strain rate compared with other curing regimes,the dynamic increasing factor of UHPC under standard curing regime was the largest and the energy consumption capacity of UHPC under combined curing regime was the highest.
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