Influence of steel fiber content to the creep of ceramsite concrete beams
To explore the influence law of steel fiber content on the creep of ceramsite concrete beams,the creep performance of ceram-site concrete beams with different steel fiber content was studied by means of long-term deformation observation test,theoretical derivation analysis and finite element modeling.Firstly,the creep deflection of ceramsite concrete beams with 4 steel fiber content was observed for 180 days,and the creep deflection loading time relationship curve and the influence law curve of steel fiber content on creep deflection were obtained.Then,referring to ACI209 creep coefficient calculation formula and ACI435 creep calculation formula,the creep calculation formula of ceramsite concrete beam considering steel fiber content was established.Finally,the finite element numerical analysis model was established according to the test beam parameters.The results show that the creep of ceramsite concrete beams increases rapidly in the early stage of loading,and the creep growth rate gradually slows down with the passage of time,and tends to be stable after 120 days of loading.The steel fiber content had a significant impact on the creep of ceramsite concrete beams.The influence of steel fiber content on the creep of ceramsite concrete beams is obvious.When the steel fiber content is less than 0.5%,the influence of steel fiber content on the creep of ceramsite concrete beams is small;In the range of 0.5%to 1.0%,increasing the steel fiber content can effectively reduce the creep value under long-term load.However,when the content of steel fiber exceeds 1.0%,the effect of reduction is weakened.The calculated results of creep formula of ceramsite concrete beam are in good agreement with the measured values,which can well reflect the creep variation law of ceramsite concrete beam.The finite element simulation further verifies the influence law of steel fiber content on the creep of ceramsite concrete beams and the creep calculation formula.
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