Research on the Flexural Performance and Degree of Composite Action of Precast Concrete Sandwich Panels With Concrete Ribs

ABSTRACT Five full‐scale precast concrete sandwich panels (PCSPs) with concrete rib connectors were designed and cast. The test research involved parameters of the spacing and arrangement of the connector, and 4‐point bending tests were conducted. The five specimens' flexural properties and composite action were analyzed, and formulas for calculating the cracking load and ultimate bearing capacity of such fully composite panels were proposed. Finite element models were established for parameter analysis, including the ratio of the total rib width of the connector ( b rib ) to the panel width ( b ) ( b rib / b ), the ratio of the rib width ( b 0 ) to spacing ( S ) of a single concrete rib connector ( b 0 / S ), and the ratio of the connector thickness ( t 2 ) to the panel thickness ( t ) ( t 2 / t ). The results indicated that b 0 / S has a significant impact on the composite action. The concept of design composite action (DCA d ) was proposed, and a formula for calculating the DCA d of these panels was established. In comparison with existing formulas that calculate the degree of composite action (DCA) based on experimental results, this formula directly determined the panel's DCA based on design parameters. The results of DCA calculation are of great significance for practical engineering design and construction applications. Finally, based on the proposed DCA d formula, formulas for predicting the cracking load and initial stiffness of these panels were presented.