Materials Bulletin: Alkali-Silica Reaction (ASR) Brief
ASR is a reaction between the alkali hydroxides in concrete and reactive forms of silica in the aggregate. The reaction forms a gel that swells when moisture is present. The two step process can be visualized as: 1. Alkali + Silica → Gel reaction Product 2. Gel reaction Product + Moisture → Expansion Factors Affecting ASR For the reaction ...
Alkali–silica reaction: Current understanding of the reaction
Alkali–silica reaction (ASR) is a major concrete durability problem, resulting in significant maintenance and reconstruction costs to concrete …
Alkali Aggregate Reaction Topic
Alkali-aggregate reactions can be either alkali-carbonate reactions (ACRs) or alkali-silica reactions (ASRs). In ACR, the reaction is between the alkalies (sodium and potassium) and certain carbonate rocks, particularly calcitic dolomite and dolomitic limestones, present in some aggregates. In ASR, the reaction is between alkalies and …
Alkali-Aggregate Reactivity
Alkali-Silica Reactivity (ASR) is a chemical reaction between alkalis in the cement fraction of concrete mortar and certain types of siliceous aggregates. Resulting in the expansion and cracking of the concrete. There are at least two types of interactions between cement components and aggregates that cause sim…See more on globalgilson
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Alkali-Silica Reaction: Causes and Solutions - Concrete …concreteconstruction
Alkali-silica reaction in concrete: Mechanisms, mitigation …
The ASR, identified in 1940 [6], is the chemical reaction between the reactive constituents of the cement aggregates and the alkali (K) and hydroxyl (OH) ions present in the interstitial concrete pore solution [2], [7], [8]. ASR involving rocks and minerals containing reactive silica forms are currently considered as the cause of early ...
Alkali-Silica Reaction (ASR) in Concrete Explained
Alkali-Silica Reactivity (ASR) is a chemical reaction between alkalis in the cement fraction of concrete mortar and certain types of siliceous aggregates. Resulting in the expansion and cracking of the concrete. There are at least two types of interactions between cement components and aggregates that cause similar damages from expansion and ...
(PDF) Quarry limestone dust as fine aggregate …
The inclusion of quarry dust in cement bound materials and its effect on various properties of cement such as transport, dimensional stability, alkali-silica reaction, the heat of hydration and ...
Alkali–silica reaction: Current understanding of the reaction
Alkali-silica reaction (ASR) is a chemical reaction between alkaline ions (Na +, K +), silicon phases and aluminum phases in the aggregate, causing volume expansion and cracking of the concrete, leading to a deterioration in the mechanical properties of the structure.In previous studies, microbially induced carbonate precipitation (MICP) …
MANAGING ALKALI-AGGREGATE REACTIVITY: NORTH …
1 INTRODUCTION. After Stanton's discovery of alkali-silica reaction in the late 1930s, significant research efforts have focused on elucidating the mechanisms of …
Alkali-Silica Reaction: Causes and Solutions
Alkali-Silica Reaction: Causes and Solutions. B. Erlin Cross-section of concrete cracks caused by alkali-reactive chert and strained quartz. Filling the cracks and air voids is white alkali-silica gel. Alkali-silica reactivity, better known as ASR, has openly been with us since the early1940s when it was discovered in California and publicized ...
(PDF) The Influence of Calcined Clay Pozzolan, Low-Cao
The influence of low CaO steel slag, calcined clay and granite dust on the alkali-silica reaction was investigated over a period of 35 days under accelerated curing conditions.
Alkali-Aggregate Reactivity
5.2 Types of Reaction (AAR = ACR + ASR) 5.2.2 Alkali Silica Reaction (ASR) In the presence of a high concentration of hydroxyl ions (OH-) silica tends towards dissolution (modified from Dent Glasser & Kataoka, 1981): first by neutralization of the silanol groups and then by attack on the siloxane groups
STRENGTH AND DURABILITY ASSESSMENTS OF …
Quarry dust (QD) is a waste obtained by crushing granite. It is mostly used as fine aggregate in concrete making. During quarrying crush rock into various sizes, dust is generated. ... in eradicating the challenge of alkali silica reaction [13]. Up till now, limited study has been done in assessing the effects of incorporating IFS and QD
Alkali-Aggregate Reaction
Alkali-silica reaction (ASR) is of more concern because aggregates containing reactive silica materials are more common. In ASR, aggregates containing certain forms of silica will react with alkali hydroxide in …
Influence of Water on Alkali-Silica Reaction: Experimental Study …
Alkali-silica reaction (ASR) is a concrete pathology due to chemical reactions involving reactive silica from reactive aggregates and the inner solution of concrete. ... F., Fasseu, P., and Van Overbecke, V. (2000). "Study on Tournai limestone in Atoing Cimescaut quarry petrological, chemical and alkali reactivity approach." Proc., …
Dolomite-Based Quarry-Dust As A Substitute For Fly-Ash
A reduction in workability was observed in fly ash alkali-activated geopolymer mixtures with increasing quarry dust content, especially at higher than 20% fly ash replacement by waste quarry dust ...
Alkali-silica reaction: understanding the phenomenon
Abstract. The alkali-silica reaction in cementitious composites occurs through the chemical association of the solution contained in the matrix pores, which is …
Mechanism and kinetics of expansion in the alkali- carbonate rock reaction
Alkali-silica reaction (ASR) can also contribute in the alkali-aggregate reaction (AAR) in carbonate rock, mainly due to micro- and crypto-crystalline quartz or clay content in carbonate aggregate.
Quantifying alkali-silica reaction in Pennsylvania
Quantifying alkali-silica reaction in Pennsylvania. As drivers, we take for granted the aggregates that makes up roads and bridges. To the majority of drivers hustling along roads and bridges, the possible occurrence of alkali-silica reaction – or ASR, as it is commonly known in the industry – on the concrete below them means little, if ...
Alkali Silica Reaction
9.8.7 Alkali–silica reaction. Alkali–silica reaction (ASR) is a chemical reaction that occurs between alkalis in PC and certain types of silica in aggregates. It causes the formation of expansive gels, which causes the concrete to crack. The cycle is repeated until the concrete is no longer usable.
Preventing Concrete Deterioration Due to Alkali …
Alkali-Silica Reaction This is the most common form of alkali-aggregate reaction and results from the presence of certain siliceous aggregates in the concrete found in some granites, gneisses, volcanic rocks, greywackes, argillites, phyllites, hornfels, tuffs, and siliceous limestones. The product of the alkali-silica reaction is a gel that absorbs
(PDF) ALKALI-SILICA REACTIVITY OF SOME …
Alkali-Silica reactions occur over time between alkaline cement paste and silica contained in rock aggregates as a result of the swelling due to the reaction of certain constituents in the rock ...
Alkali-Aggregate Reaction
Alkali-Aggregate Reaction. In most concrete, aggregates are more or less chemically inert. However, some aggregates react with the alkali hydroxides in concrete, causing expansion and cracking over a period of …
Alkali-Silica Reactivity Mitigation | SpringerLink
Alkali-silica reaction (ASR) results in random map cracking and attendant spalling concrete. Cracking initiates in areas with a frequent supply of moisture, …
A simple way to mitigate alkali-silica reaction
A possible practice to prevent disorders due to alkali-silica reaction (ASR) in concretes containing reactive aggregates is the use of chemical admixtures (lithium salts) or, more commonly, mineral admixtures such as fly ash, silica fume, ground granulated slag or metakaolin. An analysis of the literature concerning ASR revealed some papers …
Geological Study and Mining Plan Importance …
Alkali Silica reaction is slow chemical reaction in concrete due to reactive silica minerals in aggregates, alkalis in cement and moisture. ... This paper deals with geological study of any ...
Alkali-silica reaction (ASR) in concrete structures: …
Alkali-silica reaction (ASR) and its associated deformation are major durability problems in concrete structures and was reported as far back as the 1940s by …
Is alkali–carbonate reaction just a variant of alkali–silica reaction
Abstract. The mechanism of the alkali–carbonate reaction (ACR) has been recognized as being different from that of the more common alkali–silica reaction (ASR). However, the identification of alkali–silica gel in ACR concrete from Cornwall, Ontario, Canada by Katayama, in 1992 raised the possibility that ASR was at least playing a role …
Properties, compatibility, environmental benefits and future …
Quarry rehabilitation. Durability-Vulnerable to alkali-silica reaction-Limited long-term data-High permeability-May require quality control. Environmental Impact-High energy consumption-Limited research and adoption-Land degradation-Dust and noise pollution. Cost-Fluctuating prices-Initial setup costs may be high-Transportation costs-
An investigation on the effectiveness of quarry dust and …
From the study, 20% of quarry dust is found to be the optimum replacement level for river sand. The compressive strength of the 30% bagasse ash-20% quarry dust based heat cured alkali activated specimens is decreased 35.1% compared to the control specimens. Ambient-cured sugarcane bagasse ash-quarry dust based specimens …