The aim of this study is to experimentally investigate the effect of drying on a shear wall, and to clarify the mechanism of the changes in the structural performance due to drying. Two sufficiently hydrated wall specimens are prepared. Then, one is loaded without drying, while the other is tested after sufficient drying until the shrinkage of concrete reaches an equi-librium state. The results show a reduction in the initial stiffness and little change in the ultimate shear strength in the dry specimen, in spite of an increase in the compressive strength. Reproduction numerical analysis using Rigid Body Spring-network Model (RBSM) coupled with a truss network model for moisture transport is conducted, and an ac-ceptable agreement is confirmed in the ultimate strength and the crack patterns. From the numerical results, it is revealed that two factors are balanced in the ultimate shear strength after drying in this experiment: 1) an increase in the com-pressive strength due to aging (material scale), and 2) a strength reduction due to lateral strain, which is evaluated using the formula suggested by Vecchio and Collins (1986) (member scale). This indicates that the wall reinforcement ratio and concrete shrinkage have the influence on the ultimate strength through increasing/decreasing the number of cracks and the crack width.

This paper investigates the behaviour of concrete failing under high stress levels and subjected to different types of loading. The aim of this investigation is to clarify the development of linear and nonlinear creep strains and how they relate to material damage and eventual failure. This research is supported on the results of a new experimental programme performed on concrete cylinders tested in uniaxial compression under varying strain and stress rates. The results of this programme allow investigating the influence of the loading history on the material response in terms both of its strength and deformation capacity. On this basis, a failure criterion related to the inelastic strain capacity of concrete is defined. Such failure criterion, showing consistent agreement for all types of loading histories, allows calculating in a simple manner the reduction of the strength for a long-term loading situation and also its associated deformation capacity. On that basis, a comprehensive method for predicting failure of concrete under different long-term loading patterns is proposed and validated.

To estimate the remaining life of existing RC bridge decks damaged by alkali silica reaction (ASR), multi-scale numeri-cal analysis with chemo-hygral model is integrated with visual inspection data at site. First, the applicability of the poro-mechanical models for ASR expansion in the multi-scale frame are examined with the experiments of the real scale RC slabs and the model is validated to bring about fair prediction of the 3D anisotropic expansion and the fatigue life of the slabs. Second, visually inspected cracks on bottom surfaces of RC decks are converted to space-averaged strains, and the magnitude of ASR is estimated from the vertical deformation, based on which the internal pre-stress and the damage fields are re-produced by numerical predictor-corrector cycles, and the remaining life of ASR damaged RC bridge decks is fairly estimated. By conducting sensitivity analyses in terms of ASR-gel volumes and cracks, allowable error range of site inspection data is clarified to meet the requirement of asset management.

For estimating remaining fatigue life of RC bridge decks subjected to traveling wheel-type loads, presented is the data assimilation procedure, i.e., coupled life-span simulation with inspection data at site. Multi-scale analysis with hygro-mechanistic models is used for the platform of data assimilation on which the visual inspection of cracking on the members’ surfaces and the acoustic emission (AE) tomography are numerically integrated. For verification, the wheel running load experiments of slabs were conducted with continuous data acquisition of both crack patterns and the acoustic emission data over the life till failure. Visually inspected cracks are converted to space-averaged strains, based on which the internal strains and damage fields are re-produced by numerical predictor-corrector cycles. The 3D field of elastic wave identified by AE tomography is also converted to the fracture parameter of concrete. Although no information on cracking is available, the proposed assimilation method successfully reproduces most probable internal cracks over the volume of analysis domains, and the remaining life of the deck slabs inspected was successfully estimated.