Experimental identification of plastic shakedown behavior of saturated clay subjected to traffic loading with principal stress rotation

Because information collected in a site investigation is limited, it is not possible to obtain actual values for the mean, standard deviation, and scale of fluctuation for a soil property of intere...

Statistical characterization of random field parameters using frequentist and Bayesian approaches

This review article proposes the identification and basic concepts of materials that might be used for the production of high-performance concrete (HPC) and ultra-high-performance concrete (UHPC). Although other reviews have addressed this topic, the present work differs by presenting relevant aspects on possible materials applied in the production of HPC and UHPC. The main innovation of this review article is to identify the perspectives for new materials that can be considered in the production of novel special concretes. After consulting different bibliographic databases, some information related to ordinary Portland cement (OPC), mineral additions, aggregates, and chemical additives used for the production of HPC and UHPC were highlighted. Relevant information on the application of synthetic and natural fibers is also highlighted in association with a cement matrix of HPC and UHPC, forming composites with properties superior to conventional concrete used in civil construction. The article also presents some relevant characteristics for the application of HPC and UHPC produced with alkali-activated cement, an alternative binder to OPC produced through the reaction between two essential components: precursors and activators. Some information about the main types of precursors, subdivided into materials rich in aluminosilicates and rich in calcium, were also highlighted. Finally, suggestions for future work related to the application of HPC and UHPC are highlighted, guiding future research on this topic.

https://www.mdpi.com/1996-1944/14/15/4304/pdf

Materials for Production of High and Ultra-High Performance Concrete: Review and Perspective of Possible Novel Materials.

Experimental study on evolution of mechanical properties of CRTS III ballastless slab track under fatigue load

Shrinkage mechanisms and shrinkage-mitigating strategies of alkali-activated slag composites: A critical review

Effects of alkali dosage and silicate modulus on autogenous shrinkage of alkali-activated slag cement paste

Three-dimensional shakedown solutions for cohesive-frictional materials under moving surface loads

‘Shakedown’ is used to refer to a state of structures under repeated loading conditions at which the material behaviour becomes purely elastic after some initial plastic deformation. Residual stresses developed in a structure due to the initially occurred plastic deformation play an important role in helping the structure to reach the shakedown state. A better understanding of residual stresses in cohesive-frictional half-space under moving surface loads is urgently needed if shakedown theory is applied to solve pavement or railway problems. This paper is focused on residual stresses in cohesive frictional materials by using finite element analysis to investigate the development of residual stresses in a cohesive-frictional half-space under repeated moving surface loads. These numerical results illustrate how residual stresses affect the behaviour of cohesive frictional materials under repeated loading conditions.

Residual stresses and shakedown in cohesive-frictional half-space under moving surface loads

Previous work on three-dimensional shakedown analysis of cohesive-frictional materials under moving surface loads has been entirely for isotropic materials. As a result, the effects of anisotropy, both elastic and plastic, of soil and pavement materials are ignored. This paper will, for the first time, develop three-dimensional shakedown solutions to allow for the variation of elastic and plastic material properties with direction. Melan's lower-bound shakedown theorem is used to derive shakedown solutions. In particular, a generalised, anisotropic Mohr–Coulomb yield criterion and cross-anisotropic elastic stress fields are utilised to develop anisotropic shakedown solutions. It is found that shakedown solutions for anisotropic materials are dominated by Young's modulus ratio for the cases of subsurface failure and by shear modulus ratio for the cases of surface failure. Plastic anisotropy is mainly controlled by material cohesion ratio, the rise of which increases the shakedown limit until a maximum value is reached. The anisotropic shakedown limit varies with frictional coefficient, and the peak value may not occur for the case of normal loading only.

/pdf/three-dimensional-shakedown-solutions-for-anisotropic-1z5ecr8x2e.pdf

Three‐dimensional shakedown solutions for anisotropic cohesive‐frictional materials under moving surface loads

Experiments involving the application of moving-wheel loads to a series of two- and three-layered pavement systems, involving various soils and unbound granular materials, were used to determine the applied contact pressure ranges within which the structures may be assumed to have developed a ‘shakedown' condition. Shakedown implies that the pavement responds to loading in a resilient manner after some limited plastic deformation during the early load applications. The data were used to assess the validity of applying three-dimensional lower-bound shakedown theory to pavements as a basis for improving pavement design computations. The research indicated that this approach has considerable promise, and that further experimental validation work is desirable.

Juan Wang

Papers

Effects of alkali dosage and silicate modulus on autogenous shrinkage of alkali-activated slag cement paste

Three-dimensional shakedown solutions for cohesive-frictional materials under moving surface loads

Residual stresses and shakedown in cohesive-frictional half-space under moving surface loads

Three‐dimensional shakedown solutions for anisotropic cohesive‐frictional materials under moving surface loads

Validation experiments for lower-bound shakedown theory applied to layered pavement systems