Properties evolution and aging assessment of panel concrete under high and low temperature cycles

Abstract

To investigate the performance evolution and aging of concrete panels of rockfill dams under high and low temperature cycles, the mechanical property evolution of panel concrete under 5~85℃ was investigated, while it was reinforced with steel fibers to improve its cracking resistance. In addition, the aging level of panel concrete after deterioration was evaluated. The result show that the incorporation of steel fibers reduces the loss of compressive and tensile strength of concrete under high and low temperature cycles. Compared to normal(Type O) panel concrete, the rate of loss of compressive and tensile strength of steel fiber reinforced(Type S) panel concrete was reduced by 3.89% and 9.32% after 450 cycles of high and low temperature cycles. The compressive strength aging grade of O-type panel concrete after 450 cycles of high and low temperatures could reach grade 4, while that of S-type panel concrete only reached grade 3. The aging level of tensile strength of O-type panel concrete after 360 cycles of high and low temperature cycles have reached 4, and the aging level of S-type panel concrete after 450 cycles of high and low temperature cycles has also reached 4, indicating that the degradation of tensile strength caused by high and low temperature cycles is more significant. The aging problem caused by long-term high and low temperature cycles will make the panel concrete unable to bear the design load and may cause building safety problems.

Keywords

panel concrete / high and low temperature cycles / steel fiber / property evolution / aging assessment