Seismic Performance of Pretensioned Centrifugal Spun Concrete Piles with Combined Steel Strands and Deformed Steel Bars

Abstract

Pretensioned spun high-strength concrete piles usually use the traditional helical grooved steel bars as the main reinforcement, which leads to insufficient ductility. Replacing prestressing steel bars with steel strands can effectively overcome the problem. To further enhance the overall seismic performance of the piles, pretensioned centrifugal spun concrete piles with a combined use of pretensioned steel strands and nonprestressing deformed steel bars (PSRC piles) have been developed. This paper presents the experimental and numerical investigations into the seismic performances of PSRC piles. Three full-scale PSRC pile specimens have been tested under lateral cyclic loading with different axial compressive forces, and the results are analyzed in detail and discussed. The influence of incorporating the deformed steel bars on the cyclic behavior of piles is examined with comparison to the previous test results of the counterpart piles with only steel strands.A detailed finite element model of the PSRC pile specimens is developed and verified against the test results.2 Parametric analyses are then carried out using the validated model. The results show that the incorporation of non-prestressing deformed steel bars markedly improves the cracking behavior of the piles with much diffused crack distributions. The combined use of steel strands and deformed bars also results in better deformation capacity as well as higher load bearing capacity. By adjusting the concrete wall thickness and selecting a desirable ratio of prestressing steel strands and non-prestressing deformed bars, sufficient deformation and load bearing capacities can be ensured with the piles.

Investigation on Seismic Behavior of Prestressed Steel Strand Composite Reinforced High-Strength Concrete Column

“…Tian et al [10] have proposed a method with wide spacing and high-strength longitudinal bars, which simplifies the construction of node areas, reduces construction difficulties, and improves construction efficiency while ensuring construction quality. The widespread application of prestressing technology can draw insights from prefabricated prestressed bridge piers and prestressed steel strand piles [11][12][13][14][15]. Prestressed steel strands tackle issues related to the poor ductility of prestressed steel bars in ordinary prestressed piles, leading to compromised lateral resistance, flexural and shear ductility, and susceptibility to brittle failure.…”