Wyniki 1-1 spośród 1 dla zapytania: authorDesc:"François Modjabi-Sangnier"

Indeks kompatybilności - nowe ilościowe podejście kompatybilności napraw betonu DOI:10.15199/33.2017.06.21

  The aim of concrete repairs is to extend the useful service life of an existing structure, to restore its load-carrying capacity and stiffness, and/or to strengthen itsmembers [3]. The requirement for compatibility between the existing concrete and the repairmaterial has been addressed conceptually by various authors since the early nineties [1 ÷ 6]. Guidance on the approach can now be found in reference documents such as EN 1504, ACI 562, and report MERL-2014-87 issued by USBR [8]. The level of compatibility will generally determine whether a repair project is a success or a failure, and whether a repaired structure is durable. One of the main challenges to be faced now lies in evaluating quantitatively compatibility and determining what it requires under given circumstances (characteristics of the structure to be repaired and the environment). For the compatibility approach to be fully implemented in repair engineering design, adequatee characterization tests and design tools for concrete repair are needed. In the present paper, two approaches for quantitative evaluation of dimensional compatibility of repairs are presented. Compatibility index evaluation based on the restrained- -shrinkage ring test Restrained-shrinkage ring test. This paper presents the results of the large project on the quantitative relationship between the individual dimensional compatibility-related properties (notably elastic properties, creep, drying shrinkage) and the corresponding stress and strain values recorded in an annular restrained shrinkage test, commonly referred to as the ring test (Figure 1). While the actual deformation and stress gradients across the thickness of the specimens are considered in the calculations, the analysis of the results is based on the average stresses. The evolution of the average shrinkage-induced stress (σc avg.) over time can be calculated with equation 1, where εfs is the concre[...]

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