Analysis of Concrete Failure on the Descending Branch of the Load-Displacement Curve

Abstract

In this paper, load-displacement and stress-strain diagrams are considered for the uniaxial compression of concrete and under three-point bending. It is known that the destruction of such materials occurs on the descending branch of the load-displacement diagram. The attention of the presented research is focused on the explanation of this phenomenon. Fracture mechanics approaches are used as a research tool. The method for determining effective stresses and modulus of elasticity of concrete based on the results of uniaxial compression tests has been substantiated. The ratios necessary for the calculation were obtained without any assumptions about the reinforcement of concrete and the mechanical properties of its components. However, the effect of these properties is considered indirectly, using the stress and strain peaks determined by standard concrete compression tests. It was found that the effective stresses increase both on the ascending branch and on the descending branch of the load-displacement diagram. This explains the destruction of concrete on the descending branch of the load-displacement diagram. The results of determining the stresses and modulus of elasticity under uniaxial compression are comparable with the results obtained in experiments known in the literature.

A Damage Model to Trabecular Bone and Similar Materials: Residual Resource, Effective Elasticity Modulus, and Effective Stress under Uniaxial Compression

“…Within the framework of this work, it is appropriate to note that since the porous bone material contains mineralized components [6,18], and therefore shows the properties of a brittle or quasi-brittle material, some other porous mineral materials exhibit similar loaddisplacement patterns in compression tests. For example, the load-displacement curves for uniaxial concrete compression [27,28] are similar to the patterns in Figure 1. This means that the models of damage and destruction of concrete and other brittle materials [29] can be adapted to analyze the evolution of bone tissue damage.…”

“…In this case, it is assumed that the value d A is proportional to the change in energy, as shown in the ratio (3). Thus, it can be declared that the result of (13) was obtained using the energy criterion At the same time, the result of [36] was obtained using a simplified (strain) approach based on the assumption that the value is proportional only to the strain [27], i.e., the elastic strain energy was ignored, which led to differences in the coefficients 2.718 and 1.396. In this case, the advantage of the energy criterion mentioned above can be explained by analogy with the advantages of the known energy theory of strength compared to the historically first strength theories [37].…”

“…Since bone tissue contains organic and mineral components, we can predict that the developed models ( 1)-(16a) can be adapted for studies of concrete, frozen soil [27], rocks, and other brittle materials. The features of other models are studied in [35,40].…”

Damage Function of a Quasi-Brittle Material, Damage Rate, Acceleration and Jerk during Uniaxial Compression: Model and Application to Analysis of Trabecular Bone Tissue Destruction

“…The model proposed above can be used to analyze not only trabecular bone tissue, but also some other quasi-brittle materials. For example, the previous version of the proposed model (similar to the Furamura model [42,43]) was used for the analysis of low-and highstrength concrete (30 and 70 MPa) [44]. However, the details of the answer require separate consideration in another article.…”

Numerical Study of Concrete

“…The numerical results indicate that the maximum hoop stress position of the HFRC shaft lining presents a transition trend from the inside surface to the outside surface; the hoop strain of shaft lining concrete is always compressive, and the inside surface is greater than the outside surface. Kolesnikov [2] presents the load-displacement and stress-strain responses of concrete under uniaxial compression as well as three-point bending. The non-destructive test (NDT) method was proposed by Lim et al [3] for the measurement of concrete's compressive strength.…”