Abstract
Reactive powder concrete (RPC) was confined by the circular steel tube to obtain the required ductility. The axial compression test results of 139 columns from different scholars were collated and compared to study the axial compression and bearing capacity of a reactive powder concrete-filled circular steel tube, of which the confining coefficient is 0.057–2.312 and the RPC strength is 76.6–178.2 MPa. Load-displacement curves have been categorized into four stages: (1) elastic; (2) elastic-plastic; (3) descending; and (4) strengthening. The failure mode can be divided into three types according to the different confining coefficients as (1) wall buckling; (2) diagonal shear; and (3) drum-shaped. The confining coefficient, core RPC strength, steel fiber volume, steel tube D/t ratio, and loading mode on the ultimate bearing capacity were analyzed. The results showed the confining coefficient to be the main factor affecting ultimate bearing capacity. The equation for determining ultimate bearing capacity was established based on the limit equilibrium theory, with the lateral confining coefficient of RPC (k) determined to be 2.86, less than that of normal concrete at 4.1. Based on the experimental analysis results and China’s “Design and Construction Code for Concrete-Filled Steel Tube Structure” (CECS 28-2012), the design proposal for an RPC-filled steel tube was recommended.
Highlights
The equation for determining ultimate bearing capacity was established based on the limit equilibrium theory, with the lateral confining coefficient of Reactive powder concrete (RPC) (k) determined to be 2.86, less than that of normal concrete at 4.1
RPCFT axially compressed experiments conducted in past studies found that the vertical stress and strain of the steel tube and core RPC gradually increased with increasing axial load due to pressure, and the core RPC was compressed in three directions because of constraints placed by the steel tube
The ultimate bearing capacity of RPCFT increased between 2%
Summary
Reactive powder concrete (RPC) is the direction for further development of high-strength concrete (HSC) and ultrahigh performance concrete (UHPC), with a relatively new type of cement-based composite material successfully developed by Richard in 1993, which has ultrahigh strength, good volume stability, and excellent durability [1, 2]. The successful application of steel tube RPC in the construction of the Sherbrooke Bridge, Quebec, Canada, demonstrated its superior mechanical properties and economic benefits [7]. Both RPC and NC are cement-based composite materials, their water/binder ratios, composition of raw materials, and mechanical properties differ considerably [8]. RPC strengths in the range of 76.6 MPa–178.2 MPa were affected by the RPC water/binder ratio (0.16–0.26), RPC steel fiber content (0%–2%), and curing methods (standard curing, 90°C steam curing, and curing in an autoclaved reactor with a maximum temperature and pressure of 200°C and 1.3 MPa, respectively).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
