Experiment and validation of local bearing capacity for reactive powder concrete confined with high-strength spirals

In this study, ten reactive powder concrete (RPC) specimens confined by high-strength spirals loaded over a limited area are used to investigate their behaviour and determine their local bearing capacity. The crack, wedge, and failure characteristics of RPC are discussed based on tests and simulation. The index of pressure versus deformation is used to evaluate the loading stages. The ratio of the cracking load to the ultimate load varies from 34 to 60%. A wedge pyramid is formed ahead of the bearing plate when approaching the ultimate load; thereafter, it slips downward, splitting the concrete below. The high-strength spirals did not yield even under the ultimate load. According to the test data, all the existing models for predicting the local bearing capacity are nonconservative. In this case, the effect of the actual stress caused by high-strength spirals is considered to further modify the existing calculation models when high-strength spirals are used, and a simple empirical equation for calculating the local bearing capacity of the RPC is developed. The equation and the models modified as described are verified experimentally.