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• An inverse analysis algorithm considering local response was proposed. • Complete load-CMOD curve was accurately reproduced and the σ-w curve was evaluated. • Tri-linear model was recommended after considering the accuracy and convergence. • Applicability to various materials and specimen configurations was investigated. This study presents an inverse analysis algorithm for deriving the softening relationship of concrete. The algorithm can not only reproduce the influence of local response on the σ - w curve by introducing additional load criteria but also reduce the dependence of optimization results on the initial guesses by combining global best-fitting with the automatic parameter updating technique, improving the prediction accuracy and lowing the possibility of obtaining pseudo-solutions. Then, the fracture tests were carried out on the wedge splitting specimens. The validity and versatility of the algorithm were verified using experimental data. The findings show that the simulation responses agree well with the test ones in all regions of the load-CMOD curve, and the values of fracture energy determined by the load-CMOD and σ - w curves are consistent. The derived σ - w curve is independent of the initial guesses of parameters. The widely used bi-linear σ-w curve tends to overestimate the load in the post-peak of load-CMOD, and the tri-linear model is recommended after considering the accuracy, computation time, and convergence. The tensile strength evaluated by the inverse analysis method is 75% of the splitting tension test and 91% of the fracture theory method. Further, the proposed algorithm exhibits outstanding versatility, applying to various concrete materials and specimen configurations. [ABSTRACT FROM AUTHOR]

The inconsistency in strength parameters between full-graded dam concrete and wet-sieved concrete is primarily attributed to variations in curing conditions, member size, and aggregate size. To ensure more reliable strength parameters for the structural analysis of the Baihetan Dam, comprehensive strength tests were conducted on site-casting full-graded and wet-sieved concrete. Full-graded concrete specimens and a portion of wet-sieved concrete specimens underwent natural curing on site or in close proximity to the laboratory, while the remaining wet-sieved concrete specimens were cured in seven large environmental chambers with controlled temperatures and relative humidity. The quantitative effects of curing conditions, specimen size and maximum aggregate size on the compressive and splitting tensile strength of dam concrete were obtained through strength tests. Subsequently, based on the test results, by introducing the equivalent age-adjusted coefficient C ea , the member size-adjusted coefficient C ms and the aggregate size-adjusted coefficient C as , a strength determination method for full-graded concrete that can consider the above three factors was proposed and validated. Finally, according to the measured temperature and relative humidity history of the dam concrete and ambient environment, the real strength parameters of the full-graded concrete of Baihetan dam were determined by the proposed method. The validation and practical application of the proposed method indicate that this method can meet the actual use requirements of the Baihetan dam project, and can provide more reliable full-graded concrete strength parameters for dam structure analysis than traditional methods. • Curing conditions, specimen size and aggregate size effects on dam concrete strength should be considered. • The equivalent age, member size and aggregate size adjusted coefficients are derived. • A strength determination method for dam concrete is proposed and validated. • The strength determination method meets Baihetan dam's application requirements. [ABSTRACT FROM AUTHOR]

• Restrained cracking for concrete is determined by stress and strain together. • The restrained cracking has a lower failure stress and larger failure strain. • A combined stress–strain failure criterion for concrete restrained cracking. The failure behavior of restrained cracking induced by temperature and/or shrinkage differs from that of direct tensile failure. To study the restrained cracking behavior and criterion, a self-developed temperature stress testing machine (TSTM) was utilized and found to have good performance when examining concentric deformation and reproducibility. Restrained cracking experiments were performed considering different mixtures, temperature histories, shrinkages, and loading ages. The results indicated that concrete would crack when the restrained tensile stress exceeded 76% of the direct tensile strength, while the failure strain was 103%–137% of the tensile strain capacity. A combined stress–strain failure criterion was proposed under the assumption of linearity, and the prediction errors range from −7.61% to 12.89%. The proposed criterion will aid evaluations of the safety of restrained concrete. [ABSTRACT FROM AUTHOR]