Alkali–silica reaction in plain and fibre concretes in field conditions

Abstract

This paper presents an experimental study on the effects of alkali-silica reaction (ASR) in concrete blocks placed outdoors, exposed to weather conditions. To promote different reaction kinetics and damage levels, the size of the reactive aggregates, the alkali content and incorporation of different fibre types (steel, polymer) were the variables considered. Expansions, crack patterns and air permeability were monitored for more than 3 years. In addition, standard expansion, compression and flexion tests were performed. The volume of concrete involved in ASR enhances the development of expansions and cracking; in the blocks different expansions were measured in vertical or horizontal directions and important cracks were observed. While the prisms expansions were attenuated after the first 12 months, in the blocks the damage by ASR continues growing for more than 3 years. Although the incorporation of macrofibers does not inhibit the development of ASR, it led to benefits such as reduction in cracking and deformations. Keywords Alkali-aggregate reaction Á Concrete Á Degradation Á Fibre reinforcement Á Mechanical properties Á Microcracking Abbreviations ASR Alkali-silica reaction CMOD Crack mouth opening displacement E Modulus of elasticity FRC Fibre reinforced concrete f c Cylinder compressive concrete strength f L Limit of proportionality f R1 Residual flexural tensile strength corresponding to CMOD = 0.5 mm f R3 Residual flexural tensile strength corresponding to CMOD = 2.5 mm 1 Introduction The study of alkali-silica reaction (ASR) has great interest around the world as it is one of the important

Effects of Fibres on the Flexural Behaviour of Sound and Damaged RC Beams

“…It can be seen that after near 3 months R and FR show expansions greater than 0.04%, while in the reference mixtures (P and FP) the dimensional changes did not exceed 0.01%. It can be seen that ASR expansions are smaller in FRC; although the incorporation of fibres cannot inhibit ASR, it leads to some benefits such as a decreases in expansions and, even more important, reductions in the width and length of cracks [16].…”

Contribution of steel fibers to the flexural and shear behavior of RC beams damaged by alkali‐silica reaction

“…Although the incorporation of fibers cannot inhibit ASR, it leads to some benefits such as decreases in expansions and, even more important, reductions in the width and length of cracks. 60 F I G U R E 1 Geometry and reinforcement details of the RC beams (in mm) and lever arm system for long-term loading tests.…”

Study of Some Durability Properties of Self-compacting Concrete Containing Waste Polyethylene Terephthalate

“…This is by reducing the quantity and width of the cracks, even in high alkalinity solutions where the fiber-containing concrete showed better results than plain concrete. Also, the impact of ASR on blocks of fibers reinforced concrete left outdoors and exposed to climate changes was studied by Giaccio et al [10]. Their concrete prisms were left in the laboratory at 20°c and monitored for expansion, crack patterns, and air permeability for three years using different types of aggregate (reactive and nonreactive).…”

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