Alkali-silica Reaction In Concrete Research Articles

A Review Predictive Mathematical Modeling of Alkali-Silica Reaction in Concrete: evolution, current understanding and the knowledge gaps

Predictive mathematical models have been proposed in alkali-silica reaction (ASR). Predicting concrete degradation and its effects on mechanical properties is of interest given the long time until degradation becomes critical for intervention and recovery, and difficult structural access for predictive and corrective monitoring and treatment. The present paper presents a general overview of the evolution of the aforementioned predictive mathematical models, interrelating them to the maturation of the phenomenological state of the art associated with ASR. For this purpose, a systematic literature review was used, followed by bibliometric analysis and meta-analysis. In this study, 104 articles from 1974 to 2020 were selected, of which 31 articles were reviewed on the topic of mathematical modeling of ASR. The results of the method indicated the importance of the methodological approach of literature review to provide a comprehensive and chronological view of the evolution of ASR consolidated in the literature. It was found that the mathematical models have evolved considering the phenomenological approach of ASR.

Novel admixtures for mitigation of alkali-silica reaction in concrete

The objective of this study is to develop a new generation of alkali-silica reaction (ASR) inhibiting powder additives or liquid chemical admixtures for concrete. Throughout the paper, the word additive primarily refers to a powder while admixture primarily refers to liquid (pre-dissolved powder); otherwise, the two terms are used interchangeably. These additives are cheaper and more abundant than lithium admixtures, yet provide more consistency in terms of quality, supply, and performance in comparison with supplementary cementitious materials (SCMs). A methodical approach was developed to identify such additives that primarily mitigate ASR by reducing the pH of concrete pore solution. The mechanism of pH reduction was identified and the set of criteria that a potential additive must meet were developed. The suitable additives were screened using ASTM C1293 as well as mortar tests to estimate their impact on the performance of concrete. A final list of seven promising additives was identified.

Evaluation of the chemical index model for predicting supplementary cementitious material dosage to prevent the alkali-silica reaction in concrete

This study investigates the chemical index model effectiveness in predicting the minimum replacement of several types of Supplementary Cementitious Materials (SCMs) to mitigate the potential Alkali-Silica Reaction (ASR) in concrete. The experimental program results evaluating four natural aggregates (AF1, AF2, AF3, and AF4) and two Recycled Concrete Aggregates (RCA1 and RCA2), as presented here, were used in the model predictions. The SCMs used in this study consisted of fly ash class C (FA1), fly ash class F (FA2), ground granulated blast-furnace slag (SL), and silica fume (SF). For each SCMs, three levels of Portland cement replacements were used in the production of mortar bars: 15%-20%-25% for FA1-FA2; 20%-40%-60% for SL; and 5%-8%-10% for SF. The natural aggregates were tested according to the ASTM C1260 accelerated mortar bar test. For the RCA, an alternative preparation procedure was applied in the experimental phase to eliminate variability in the results given the RCA's high absorption.Further testing was then implemented for the aggregates classified as potentially reactive by evaluating different SCMs replacement levels to mitigate ASR using the accelerated mortar bar method, following the ASTM C1567. A Monte Carlo simulation was conducted to evaluate the chemical index prediction uncertainty, based on the model inputs statistical variation. The SCMs evaluated in this investigation were effective in mitigating ASR while used in sufficient proportion. The most effective SCMs in reducing ASR was silica fume, with a 10% replacement of Portland cement's weight, fly ash class F was next (15–25%), and finally ground granulated blast-furnace slag (40–60%). The chemical index has proven to give good results when predicting the minimum replacement of supplementary cementitious materials required to suppress ASR based on its chemical composition.

Microstructural Analysis of Concrete Using Cow Bone Ash for Alkali-Silica Reaction (ASR) Suppression

Concrete pavements are prone to microstructural changes and deterioration when exposed to Alkali-Silica Reaction (ASR). ASR results in strength reduction, cracking, spalling and other defects in the concrete if left unchecked. Supplementary Cementitious Materials (SCMs) such as Cow Bone Ash (CBA) however can be used to improve concrete performance, hence its use in this study. Concrete samples were prepared at replacement levels of 0%, 5%, 10%, 15%, 20% and 30% of cement with Cow Bone Ash. The concrete samples were then subjected to petrographic and Scanning Electron Microscopy (SEM) analysis. Petrographic examination shows that the minimal and least amount of ASR gels and micro cracking were observed at 15% CBA replacement of cement in the concrete samples. Scanning Electron Microscopy (SEM) analysis shows that changes in the elemental composition of the concrete samples is related to the effect of CBA which enhances adhesion in the concrete. SEM analysis show that, in general, the change in microstructure in the concrete was mainly due to the change in the arrangement of the C-H-S compounds. The microstructure analysis indicates that CBA in concrete influences the densification of the concrete at the transition zone, resulting in a much lower porosity. This results in the concrete having a tightly bound layer that repels ingress of water and thereby inhibiting cracks and gel formation as water is a contributing factor to the ASR in concrete.

Eco-Friendly Mitigation of Alkali-Silica Reaction in Concrete Using Waste-Marble Powder

AbstractWith several countries halting coal combustion in favor of clean and renewable energy production, there is need for alternative mineral additions that can substitute for fly ash in concrete...

Non-destructive non-invasive assessment of the development of alkali-silica reaction in concrete by spectral induced polarization: Evaluation of the complex electrical properties

The distress caused by alkali-silica reaction (ASR) to concrete structures can occur long time after the reaction has been triggered. We propose to use spectral induced polarization (SIP) as a non-destructive method for early detection of ASR reaction before the damage is apparent. Our research deals with monitoring the difference between the electrical behaviour (phase lag, bulk resistivity, relaxation time, total chargeability) of non-reactive (NR) and reactive (RC) concrete samples affected by ASR. Laboratory measurements of complex resistivity were done in the frequency range 1.43 mHz-20 kHz. A Debye decomposition (DD) model was used to determine the DC bulk resistivity (ρ0), and the distribution of the chargeability as a function of the relaxation time. The total chargeability (Σm) and the mean relaxation time (τmean) were computed as DD parameters to characterize the ASR development. While ρ0 was strongly dependent on the electrical conductivity of the solution (water, NaOH) with a constant change with time, both concrete mixtures saturated with the same solution showed an increase ρ0 due to the development of the matrix skeleton over time. In this work, ρ0 did not play a significant role to characterize the ASR development. For the samples affected by ASR, a significant evolution of Σm and τmean was found compared to the non-affected mixtures (RC, NRC-H2O), specially over the low frequency range [1.48 mHz < f < 5.86 Hz]. The RC-NaOH samples displayed a strong linear correlation between normalized chargeabilty and imaginary conductivity. This observation could be associated with an increase in surface conductivity of the Stern layer at reactive grain surface or the evolution of specific surface area due to production of ASR silica gel, or both. Based on our conceptual electrochemical model of RTD presented in this work, an evolution of chargeability peak was observed at relatively long relaxation time τ>102 s that could be associated with the polarization of aggregates affected by ASR.

The Attack of Alkali Silica Reaction on The Strength of Sea Water Resistance Concrete Pavement

Aggregate is the main material in concrete slab for rigid pavement. Quality of the aggregate should be eligible for the rigid pavement. Roads with rigid pavement structure can be damaged by non-technical factors including the effect of tidal flood. That damage due to the attack of alkali silica reaction in concrete. So, it required a research to select the type of aggregate that is more resistant to alkali silica reaction that will produce concrete more resistant to sea water. The method used is this research is experimental one, some sample in alkali silica reaction test using mortar bar of (25x25x285) mm dimensions. For the testing compressive strength and flexural strength of concrete using a cube-shaped test specimens of 150mm x 150 mm and a beam shape (150x160x600)mm. For testing performed after the age of concrete 28 days for normal conditions and after a concrete immersed fresh water 28 days, then soaked in seawater 13 days, and 26 days for testing the effect of sea water on the concrete strength. The test was performed using aggregates from PT. Armada Hada Graha, Magelang and PT. Panca Dharma Puspawira, Surakarta. The conclusion at this experiment is aggregate basalt (Surakarta) is more resistant to alkali silica reaction that caused by sea water than the aggregate andesite (Magelang).

The use of calcium sulfoaluminate cement to mitigate the alkali silica reaction in mortars

The mitigation of the alkali silica reaction in concrete has been the interest of many studies by using low-alkali cement or supplementary cementitious materials. In this paper, calcium sulfoaluminate cement, characterized by its low alkali content and low pH, is used as a mean to reach this goal.Therefore, the main objective is to verify if the composition of a sulfoaluminate cement paste can mitigate the alkali silica reaction compared to that of a Portland cement. The reactive flint aggregate from north of France was used to initiate the alkali silica reaction phenomena with two types of cements: Portland cement CEMI 52.5 N from Holcim, and calcium sulfoaluminate cement Alpenat from Vicat. Alkalis were added by introducing NaOH or NaCl in the mortar mixing solution; six mortars were made. Two references – with Portland or sulfoaluminate cement – without addition of extra amount of alkali, and the four other mortars with either NaOH or NaCl. The results show that, for the reference mortars non expansion/alteration has been detected during the test duration of 140 days. For Portland cement mortar, with same alkali content but coming from two different sources (NaOH or NaCl), the expansion is almost the same. The expansion measurements show that the using of calcium sulfoaluminate cement can mitigate the alkali silica reaction in mortars by reducing its expansion 7 times compared to that of Portland cement mortars. This result was confirmed by the microstructural observations, where the frequency of the alterations – due to the alkali silica reaction – is much less in sulfoaluminate based mortars than the one of the alterations in Portland based mortars.

A Literature Review on Alkali Silica Reactivity of Concrete

Deterioration of concrete structures with time is well understood. One of the major reasons of deterioration is reaction between cement paste and reactive siliceous aggregates which is known as alkali silica reaction (ASR). This article reviews the studies on ASR in concrete. Although a vast literature is available on mechanisms and preventive measures against ASR, however there are still a lot of deficiencies regarding the test methods to detect the ASR potential in concrete. The aim of this article is to discuss different factors affecting ASR, consequences of ASR and different challenges encountered by researchers in the detection of ASR. The study revealed that alkali content of cement, aggregates grading, mineralogical combinations, testing methods and testing conditions are all the challenges, researchers face during evaluation of ASR potential in concrete.

Effect of Lithium Based Admixtures on Alkali Silica Reaction in Concrete and Flexural Behavior of Reinforced Concrete Rectangular Beams

In recycling of lithium-ion batteries, lithium is a challenging element, which possesses great threat to the environment. The disposal of electronic waste is a major problem, which our country is currently facing, whereas, the lithium is one of the compound in electronic waste which challenges the recycling of lithium-ion batteries. If lithium is properly extracted, it can be used for structural engineering purpose. Lithium, if used in concrete, it controls the cracks due to alkali silica reaction (ASR), resulting in increased strength and durability of the concrete. Lithium based admixtures are effective in suppression of alkali silica reaction and delayed ettringite formation, if the dosage added in concrete is appropriate. The main objective of this paper is to assess the effectiveness of LiNO3 at various dosage levels in concrete. In this paper, the effect of LiNO3 on the mechanical properties of concrete, ASR gel formation and the flexural behavior of reinforced concrete rectangular beams are studied. The mechanical properties of concrete was investigated for six mix proportions comprising of control mix, lithium nitrate at 0.6M, 0.65M, 0.7M, 0.75M, 0.8M. LiNO3 not only prevents the ASR gel formation, but also it has great influence on mechanical properties of concrete. The results indicate that the concrete with 0.75M LiNO3 has higher strength values. SEM analysis has been performed for 0.75M and control mix to study the micro characteristics of concrete. The ASR gel formed in 0.75M has been suppressed as compared to that of concrete without lithium nitrate as an admixture. The durability studies are performed in concrete for water permeability, water absorption and rapid chloride penetration characteristics. The analytical study of flexural behavior of reinforced concrete rectangular beam is done using the software ANSYS 16.0.

Field Evaluation of Concrete using Hawaiian Aggregates for Alkali Silica Reaction

Alkali Silica Reaction (ASR) occurs in concrete when the alkali hydroxides (Na+, K+ and OH-) from the cement react with unstable silica, SiO2, in some types of aggregate. The resulting gel will expand when it absorbs water, potentially leading to cracking and overall expansion of the concrete. Concrete aggregates available in Hawaii have not demonstrated a history of ASR, however, results of accelerated laboratory tests using ASTM C1260 indicated a potential for ASR with some aggregates. In order to assess the accuracy of the laboratory test results, a long-term field study of the potential for ASR in concretes made with Hawaiian aggregates was initiated in 2011. Forty concrete specimens were constructed of various concrete mixtures using aggregates from all Hawaiian aggregate sources, and some US mainland aggregates known to exhibit ASR expansion. The specimens are located in an open field site in Manoa valley on the Hawaiian Island of Oahu, exposed to relatively high humidity and frequent rainfall. A weather station at the site records the ambient conditions on a continual basis. This paper describes the field evaluation program and presents the results after six years of monitoring. Comparisons are made between the field observations and accelerated laboratory tests.

Influence of Exposure Conditions on the Efficacy of Lithium Nitrate in Mitigating Alkali Silica Reaction

Lithium nitrate is known to have the highest potential to inhibit alkali silica reaction in concrete. It is well soluble in water and does not increase the pH of concrete pore solution. The extent to which the alkali silica reaction is mitigated is affected by the amount of the applied lithium ions, exposure conditions and by the kind of reactive aggregate. It is known that some lithium compounds such as lithium carbonate or lithium fluoride, when used in insufficient amount, may increase expansion due to alkali silica reaction. This effect was not detected in the presence of lithium nitrate. The aim of this study was to determine the effect of lithium nitrate on alkali silica reaction in mortars exposed to different conditions. Expansion studies were conducted in accordance with the accelerated mortar bar test (ASTM C1260) and the standard mortar bar test (ASTM C227). It was observed that the long-term expansion results are different from the values obtained in the accelerated mortar bar test. Lithium nitrate does not reduce ASR-induced expansion when mortars are stored under conditions specified in ASTM C 227. The microstructure of the mortar samples exposed to different conditions was examined and X-ray microanalysis was performed. The microstructure and compositions of the alkali-silica reaction products varied. The amount of alkali silica gel in mortars with lithium nitrate in which the expansion was high was greater than that in the mortar bars tested by accelerated method.

Cement Type Influence on Alkali-Silica Reaction in Concrete with Crushed Gravel Aggregate

Alkali-silica reaction is one of the chemical reactions which have a significant influence for durability of concrete. During alkali and silica reaction, silicon located in aggregates of the concrete, reacts with high alkali content. This way in the micropores of concrete is forming hygroscopic gel, which at wet environment, expanding and slowly but strongly destroying concrete structures. The goal of this paper- to determine the influence of cement type on alkali-silica reaction of mortars with crushed gravel. In the study crushed gravel with fraction 4/16 mm was used and four types of cements tested: CEM I 42.5 R; CEM I 42.5 SR; CEM II/A-S 42.5; CEM II/A-V 52.5. This study showed that crushed gravel is low contaminated on reactive particles containing of amorphous silica dioxide. The expansion after 14 days exceed 0.054 %, by RILEM AAR-2 research methodology (testing specimen dimension 40×40×160 mm). Continuing the investigation to 56 days for all specimens occurred alkaline corrosion features: microcracking and the surface plaque of gel. The results showed that the best resistance to alkaline corrosion after 14 days was obtained with cement CEM I 42.5 SR containing ash additive, and after 56 days with cement CEM II/A-V 52.5 containing low alkali content. The highest expansion after 14 and 56 days was obtained with cement CEM I 42.5 R without active mineral additives.

Relationship between Degree of Deformation in Quartz and Silica Dissolution for the Development of Alkali-Silica Reaction in Concrete.

This paper presents research on the influence of quartz deformation in aggregates for the development of the alkali-silica reaction in concrete and its relationship with silica dissolution. The study also compares these characteristics with the field behavior of such rocks in concrete. The paper proposes parameters to classify the different degrees of deformation of quartz. Transmission electron microscopy showed the presence of walls even in slightly deformed quartz, which indicate the presence of the internal paths available to react with the alkaline concrete pore solutions and point to the potential development of an alkali-silica reaction. The presence of the deformation bands in the quartz grains leads to the alkali aggregate reaction occurring more rapidly. The visible spectrophotometer test was performed to evaluate the dissolution potential of the different samples of deformed quartz, which confirmed that the reactivity of the quartz increases as the deformation of the crystalline structure increases. The parameters established in the present study could be verified by analyzing the behavior of reactive and innocuous aggregates from the buildings.

Literature review of modelling approaches for ASR in concrete: a new perspective

The assessment of concrete structures affected by alkali–silica reaction (ASR) is a complex problem due to the multiscale nature of this long-term phenomenon. The reaction starts within the concrete constituents and developed at aggregate level by inducing swelling and deterioration of concrete material, which eventually affect the capacity of the structure. Due to this multiscale nature of the phenomenon, the problem is studied by various researchers in numerous manners. In this paper, a literature review of the main modelling approaches for ASR in concrete is presented within a new perspective. The models are categorised on the basis of their input and output parameters, instead of adopting the classical classification on the base of the scale (e.g. micro, meso and macro). The main aim of the review is to understand to which extent the available models are able to describe the deteriorating impact induced by ASR in concrete material and if the approaches can ultimately be extended to structural analyses.

Fracture properties of the alkali silicate gel using microscopic scratch testing

We carry out a multi-scale investigation of the fracture properties of the gel produced by the alkali-silica reaction in concrete. Milimeter-sized alkali gels are tested via scratch tests at the micrometer level. Scanning electron microscopy reveals curved fracture surfaces produced during the scratch test, warranting a fracture mechanics analysis. By application of a nonlinear fracture mechanics model to the recorded load and depth data, we estimate the fracture toughness of ASR gel to be Kc=0.62 MPam. In turn, by combining micro-indentation and scratch tests, we can estimate the fracture energy Gf=11.2 J/m2. These experimental results are important for the multi-scale modeling of the alkali-aggregate reaction.

Examination of the Alkali Silica Reaction on Existing Roads with Use of Cements with Different Alkali Equivalent

In the paper two existing roads in Austria were examined on the focus of alkali silica reaction of concrete. The two roads have different ages. One is more than 50 years old one is round about 20 years old. The exposition was ordinary highway and countryside highway in the mountains. As next the examination takes the stones from the origin and uses different types of cement to examine the background of the alkali silica guidelines for performance tests of alkali silica reaction. The results are very interesting because most of the performance tests are use test cements with ordinary alkali equivalent. Often the used stones not meet the maximum value of loss of mass under the condition of alkali-load. By using alkali reduced cement the results are less than the maximum value of loss of mass under the condition of alkali-load. One of the targets of the examination was the determination of good load conditions for examination of the alkali silica reaction of stones for use in concrete for road structures. The final paper shows all the examinations and the results between the compared cements and the compared test procedures.

Alkali-Silica Reaction in Concrete with Previously Inert Aggregates

AbstractAlkali-silica reaction (ASR) is a persistent issue and has evaded eradication for nearly 80 years. The problem stems from a lack of standardized testing of aggregates. Cases occur when changes in material properties lead to potentially reactive aggregates reacting with higher alkali cements. A research program was established at the University of Arkansas to investigate cases of ASR, which occurred in combination with previously inert aggregates. In addition, locally available fly ashes were evaluated to determine replacement rates required to minimize the risk of ASR. A field monitoring program was established to evaluate deterioration mechanisms and mitigation measures. A concrete barrier wall located near the University of Arkansas was diagnosed with ASR that had considerable variation in the damage between sections of the wall. Deterioration ranges from minimal visible deterioration to severe damage or complete failure. The testing program reveals that certain aggregates that were previously d...

Influence of the Alkali-Silica Reaction on the Mechanical Degradation of Concrete

The alkali-silica reaction (ASR) is an important problem that has yet to be completely understood. Owing to the complexity of this phenomenon, a number of studies have been conducted to characterize its kinetics, its impact on the material, and its structural consequences. This paper focuses on the deteriorating impact of ASR on concrete material, not only in terms of concrete swelling but also in consideration of the induced mechanical degradation. The relationships between concrete expansion and various engineering properties, which are key parameters in structural assessments, are investigated. First, new mechanical test results are presented. Second, available literature data on the evolution of engineering properties of ASR-affected concrete under free-expansion conditions are collected and statistically analyzed. The elastic modulus was found to be the best indicator for identifying the progression of ASR in concrete. Conversely, the evolution of compressive strength was observed to potentially mask damage resulting from the ASR. The tensile behavior of the affected concrete was better represented by the splitting tensile test.

Potential alkali silica reactivity of various rock types in an aggregate granite quarry

Generally, alkali–silica reaction (ASR) is considered as an internal chemical reaction between the alkaline components in the cement and active silica–silicate based mineral constituents of some aggregates. The use of aggregates susceptible of ASR in concrete can cause a severe degradation of the concrete structures because of several reasons e.g. high humidity and sea saline water. Utilization of potentially alkali–silica reactive aggregates needs to conduct reliable tests for evaluating their alkali–silica reactivity. The objective of this study is to identify the potential alkali–silica reactivity of several aggregate rock types. To achieve this objective, a granite quarry which is operated to produce aggregates was selected and investigated. Six samples of five igneous rock types were collected from the mentioned site and an extensive laboratory tests consisting of petrographic examination and accelerated Bar Mortar test were conducted on these samples to assess the potential alkali–silica reactivity. According to ASTM C 1260 suggested method, three Bar Mortar tests were performed on each sample. Based on the obtained results, it was found that five samples of all six samples were considered as innocuous due to their average expansion rates which are less than 0.1%. Only one sample which was collected from the fault zone considered as reactive with average expansion rate of 0.2404% which is more than 0.2%.