## 1 Introduction  
Today, there is already a wide range of applications for steel and concrete composite structures [1, 2, 3, 4, 5] and precast concrete structures [6, 7]. A new type of material has emerged based on steel and concrete composite structures and precast concrete structures-- incomplete prefabricated steel-reactive powdered concrete (PSRPC). Compared to traditional steel and concrete, PSRPC materials do not require the on-site tying of reinforcement, formwork and dismantling, which simplifies on-site construction processes, shortens the construction cycle, improves construction efficiency and reduces construction energy consumption. Refs. [8, 9] respond to the national concept of sustainable construction. Due to their superior performance, steel and concrete composite structures (SRC) have been widely used in high-rise buildings, large-span structures and offshore structures. Refs. [10, 11, 12] SRC structures have high strength and stiffness, and the concrete protects the steel sections from impact, fire damage and chemical attack. With the advancement of assembled construction, prefabricated SRCs (PSRCs) were born, initially in shopping malls and then in an increasing number of countries [13]. However, the high weight of PSRC materials, the difficulty of transporting and installing them, the dense arrangement of reinforcement and the complexity of the connections between the materials limited their use, which led to the creation of PSRPC materials. Partially precast composite structures have been studied by scholars in China. [PERSON] [14; 15] proposed a partially precast honeycomb section steel-concrete beam (CPSRC beam) and carried out tests on the bending and shear performance of CPSRC beams, finding that the precast section concrete of CPSRC beams could work in coordination with the cast-in-place section concrete and that the force performance did not differ much from that of cast-in-place beams. [PERSON] [16] studied the force performance of three different cross-sectional forms of partially precast section concrete beams (PPSRC beams, HPSRC beams, PPCSRC beams and PPCSRC beams) and established a calculation method for beam stiffness and deformation. [PERSON] [17] conducted shear performance tests on nine PPSRC beams, investigated the effect of precast shell strength and shear-to-span ratio on the shear bearing capacity of solid PPSRC beams and hollow PPSRC beams, and proposed a formula for calculating the shear bearing capacity. [PERSON] [18] studied the effects of eccentricity, heating time and concrete type on the damage pattern of PPSRC columns after fire exposure, testing six PPSRC columns under eccentric compression after fire exposure and one PPSRC column under eccentric compression at room temperature. The greater the eccentricity and the longer the heating time were, the lower the residual load capacity of the PPSRC column. In this study, a new type of PSRPC column is designed. The idea was to first fabricate a prefabricated RPC shell in the factory, which consisted of an external RPC, hoop reinforcement and an internal H-beam. Corrugated steel plates were welded to the flanks of the internal H-beam to form the internal cavity. The precast RPC shell was then maintained to the required strength, transported to the construction site and assembled before the internal RPC was poured to form the complete PSRPC column, thereby compensating for the complex assembly and poor integrity of conventional fully precast steel and concrete columns. In the PSRPC column, the precast shell is made of high-performance reactive powder concrete with good durability, while the internal cast-in-place concrete can be designed as a hollow section with plain concrete or uncast concrete. Research has been carried out on the performance of PSRPC beams and PSRPC columns after fire exposure, but less research has been carried out on the performance of PSRPC columns under static loads.