Reflections on future needs in concrete durability research and development

Abstract

There is no doubt that, over the past two decades, we have made enormous advances in the understanding and practice of concrete durability. Spurred by the often experienced early deterioration of reinforced concrete structures, with high capital investment for repair and rehabilitation, conceptions of design for durability have gained an increasingly higher level of importance in recent years. Durability design is beginning to be considered of equal importance as design for safety and serviceability. Nevertheless, durability concerns remain and early deterioration still attracts much expenditure. This paper is aimed at identifying important developments made in the field of concrete durability during the past two decades. Based on current design practice and current knowledge, future research and development needs are discussed, focusing on the influences of constituent materials, deterioration prevention methods, service life modelling of reinforced concrete structures, and performance-based test methods.far from settled and the need for continuing research and development remains. This paper therefore presents some reflections on the future research needs in concrete durability. Much of this discussion relies on observations of the extent to which researchers have addressed some of the 1 INTRODUCTION

Durability performance of binary and ternary blended cementitious systems with calcined clay: a RILEM TC 282-CCL, review

“…The influence of concrete mixture proportioning on MK concrete's water sorptivity index was studied at three w/b (0.4, 0.5 and 0.6) and MK dosage was varied as 0, 10, 15, 20% [80]. The sorptivity index (a measure of resistance to moisture uptake as per [81]) reduced with an increase in MK dosage even for concrete prepared at a higher w/b of 0.6 [80], in line with pore refinement across w/b observed in [63]. Similarly improved performance was found for ternary mixture with lower grade calcined clay-limestone in [24].…”

Non-Contact Measurement to Detect Steel Rebar Corrosion in Reinforced Concrete by Electrochemical Impedance Spectroscopy

“…The DC voltage applied to SE1 and SE2 was set at 0 V, and an AC voltage of 10 mV was applied to SE1. The following parameters were used for simulations: conductivity of concrete σ c = 0.4 mS m −1 , 16 relative permittivity of concrete ɛ c = 20, 17 thickness of passive film d = 10 nm, conductivity of passive film σ p = 0.1 nS m −1 , relative permittivity of passive film ɛ p = 40, 18 conductivity of steel rebar σ s = 10 MS m −1 , and relative permittivity of steel rebar ɛ s = 1. Calculations were performed using the voltage and current obtained at 0.1 Hz.…”