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Somnuk Tangtermsirikul - One of the best experts on this subject based on the ideXlab platform.
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effect and limitation of free lime content in cement fly ash mixtures
Construction and Building Materials, 2016Co-Authors: Adnan Nawaz, Parnthep Julnipitawong, Pitisan Krammart, Somnuk TangtermsirikulAbstract:This study emphasizes the limitation of free lime content in fly ash. A detailed experimental program was carried out in order to evaluate the extent to which free lime content in fly ash can be tolerated, particularly for fly ashes with different sulfur trioxide contents. Some basic and durability properties of fly ash mixtures with varied free lime contents were considered. Four distinct types of fly ashes were obtained from two different sources, and free lime was added to obtain overall free lime contents of 5%, 7% and 10% for each type of fly ash. Water requirement, initial and final setting times, compressive strength, autoclave expansion, alkali Aggregate Reaction (AAR), and sulfate resistance tests of fly ash mixtures, containing various free lime contents, with two fly ash replacement percentages (20% and 40%), were conducted. Experimental results revealed that an increase in the free lime content caused an increase in water requirement. Higher free lime content also lead to faster setting times, improved compressive strength, and higher autoclave expansion. Mixtures with 20% fly ash replacement and free lime content up to 10% as well as mixtures with 40% fly ash replacement and free lime content up to 7.72% experienced autoclave expansion within the specified limit of ASTM C618. Similar trends of expansion were observed in cases of alkali-Aggregate Reaction and sulfate resistance tests where fly ash mixtures with high free lime led to higher expansion. In alkali-Aggregate Reaction testing, the mixtures with 20% fly ash replacement and free lime content up to 7.95%, as well as mixtures with 40% fly ash replacement and free lime content up to 10%, expanded less than the cement-only mixtures. The effect of added free lime was more severe in the sulfate resistance test, as fly ash mixtures tend to expand more than cement-only mixtures, especially in the case of fly ashes with very high SO3 content (>5%). Test results also revealed that it is possible to utilize 20% of tested fly ash in a mixture as binder, with SO3 content <5% and free lime content up to 10% while not compromising the basic and durability properties. In the case of 40% fly ash replacement, tested fly ashes with SO3 < 5% and free lime content up to 4.23% can be utilized. In the case of high SO3 content in fly ash, i.e., 8.53% and 9.44% in this study, the limit of free lime content of fly ash is reduced to 5.31% and 3.73%, for 20% and 40% fly ash replacements, respectively to satisfy the durability requirements.
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effect of free lime content on properties of cement fly ash mixtures
Construction and Building Materials, 2013Co-Authors: Krittiya Kaewmanee, Pitisan Krammart, Pongsak Choktaweekarn, Taweechai Sumranwanich, Somnuk TangtermsirikulAbstract:Abstract This research aims to clarify the limitation of free lime content in fly ash according to EN-450. The form and existence of free lime in fly ash by SEM, EDX, and free lime content by a titration method, were observed. Some basic properties of fly ashes with various free lime contents and durability properties of mortar incorporating the fly ashes were also preliminary studied. It was found that free lime particles were mostly distributed outside the fly ash particles and that a minor amount of free lime was encapsulated inside the fly ash particles in the fly ash formation process, meaning that the originally high free lime and added free lime similarly affects properties of fly ash mixtures. A free lime addition method was selected by adding free lime to the originally collected fly ash in order to vary free lime content of the fly ash. The studied basic properties consisted of normal consistency, autoclave expansion, initial and final setting time, water requirement, and compressive strength. In terms of durability, alkali-Aggregate Reaction, carbonation, shrinkage, and chloride and sulfate resistances, were investigated. Test results revealed that physical properties such as normal consistency and water requirement were unaffected by free lime, and that a free lime content up to 4.51% had only slight chemical effects on fly ash–cement mixtures, i.e., faster setting, higher compressive strength, especially at early age, and higher autoclave expansion. However, the values of autoclave expansion were still within the standard limit. Regarding durability, mixtures with the high free lime fly ash led to higher expansion due to alkali-Aggregate Reaction. The expansion was smaller than that of a cement-only mixture. Carbonation depth, shrinkage, and chloride and sulfate resistances were only slightly affected by the added free lime.
Vera Castillo, Milary Jazmin - One of the best experts on this subject based on the ideXlab platform.
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Influencia de las características de los agregados de las canteras del sector el Milagro - Huanchaco en un diseño de mezcla de concreto, Trujillo 2017
Universidad Privada del Norte, 2017Co-Authors: Castro Pacheco, José Abel, Vera Castillo, Milary JazminAbstract:RESUMEN La presente investigación, se desarrolló con el objetivo de analizar la influencia de las características de los agregados de las canteras del sector El Milagro - Huanchaco; y así obtener las condiciones en las cuales se encuentran los agregados procedentes de las diferentes canteras que se utilizan para la construcción en la ciudad de Trujillo. Esta investigación se basa en la necesidad de obtener información de las características de los agregados fino y grueso ¾” extraídos de cuatro canteras, de las cuales dos son formales y dos informales, ubicadas en el Sector El Milagro - Huanchaco. Para analizar las características que cuenta cada agregado, se realizarán ensayos físicos, químicos y mecánicos de acuerdo con los parámetros establecidos por la Norma Técnica Peruana (NTP 400.037), basada en la norma de la Sociedad Americana de Prueba de Materiales (ASTM C33) como: humedad, peso específico, absorción, peso unitario, contenido de vacíos, arena equivalente, granulometría, cloruros, reactividad agregado/álcali, durabilidad a los sulfatos y abrasión. Tener la información acerca de las características de los agregados de las canteras será de mucha utilidad para los constructores, entidades públicas y usuarios particulares ya que conocerán la fiabilidad de los agregados empleados. Al realizar los ensayos básicos (físicos), se obtuvieron resultados desfavorables en todas las canteras estudiadas, los cuales no cumplían con los parámetros establecidos por la norma. Los problemas principales encontrados fueron el exceso del contenido de finos y alta cantidad de partículas con tamaño superior al máximo nominal de ¾”, para lo cual se realizaron modificaciones con la intención de optimizar el material, realizando una segunda etapa de ensayos, las modificaciones realizadas alteraron de forma positiva las características físicas y mecánicas de los agregados, cumpliendo con los requerimientos de calidad. Siendo la mejor cantera “Rubio - Jaén” para el agregado fino y “Calderón” para el agregado grueso, obteniendo los siguientes resultados: humedad 0.6% y 0.4%, absorción 1.5%, peso específico 2650 kg/cm³ y 2760 kg/cm³, peso unitario compacto 1780 kg/m³ y 1470 kg/m³ respectivamente para cada agregado, respecto a la granulometría el agregado fino se encuentra cercano a los límites del huso, con un módulo de finura de 2.9. Al analizar las características químicas se obtuvo que los agregados cumplen con los límites siendo 7.0% y 9.0% el ataque por sulfato de magnesio del agregado fino y grueso respectivamente y para el ensayo de reacción álcali-agregado por el método químico se obtuvo que son potencialmente deletéreos, según la clasificación de la norma NTP 334.099:2011. En el ensayo de abrasión por el método de desgaste Los Ángeles se obtuvo un 11% y 23% para el agregado grueso de ambas canteras.ABSTRACT The following report was developed with the objective of analyzing the influence of the characteristics of the Aggregates of the quarries of the El Milagro - Huanchaco sector; and thus obtain the conditions in which they are the Aggregates coming from the different quarries that are used for the construction in the city of Trujillo. This report is based on the need to get information on the characteristics of the fine and coarse Aggregates extracted from four quarries, of which two are formal and two informal, located in the Milagro – Huanchaco Sector. To determine the characteristics of each Aggregate, physical, chemical and mechanical tests shall be carried out in accordance with the parameters established by the Peruvian Technical Standard (NTP 400.037), based on the American Society for Testing Materials (ASTM C33) as: humidity, specific gravity, absorption, unit weight, void content, sand equivalent, chlorides, Aggregate / alkali reactivity, sulfate durability and abrasion. Having the information about the characteristics of quarry Aggregates will be very useful for builders, public entities and private users since they will know the reliability of the Aggregates used. When performing the basic (physical) tests, unfavorable results were obtained in all the studied quarries, which did not comply with the parameters established by the NTP. The main problems found the excess content of fines and high quantity of particles with a size greater than the nominal maximum of ¾ ", for this purpose, modifications were made with the intention of optimizing the material, in a second stage of tests, the modifications made a positive change in the physical and mechanical characteristics of the Aggregates, complying with the quality requirements. As the best "Rubio - Jaén" quarry for the fine Aggregate and "Calderón" for the coarse Aggregate, obtaining the following results: moisture 0.6% and 0.4%, absorption 1.5%, specific weight 2650 kg/cm³ and 2760 kg/cm³ weight unit 1780 kg/m³ and 1470 kg/m³ respectively for each Aggregate, with respect to the granulometry the fine Aggregate is close to the limits of the spindle, with a modulus of fineness of 2.9. When analyzing the chemical characteristics it was obtained that the Aggregates comply with the limits being 7.0% and 9.0% the attack by magnesium sulphate of the fine and coarse Aggregate respectively and for the test of alkali-Aggregate Reaction by the chemical method were obtained that are potentially deleterious, according to the classification of the norm NTP 334.099: 2011. In the Los Angeles abrasion test, 11% and 23% were obtained for the coarse Aggregate of amaba quarries
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Influencia de las características de los agregados de las canteras del sector el Milagro - Huanchaco en un diseño de mezcla de concreto, Trujillo 2017
'Dipartimento di Economia Universita di Perugia (IT)', 2017Co-Authors: Castro Pacheco, José Abel, Vera Castillo, Milary JazminAbstract:ABSTRACT The following report was developed with the objective of analyzing the influence of the characteristics of the Aggregates of the quarries of the El Milagro - Huanchaco sector; and thus obtain the conditions in which they are the Aggregates coming from the different quarries that are used for the construction in the city of Trujillo. This report is based on the need to get information on the characteristics of the fine and coarse Aggregates extracted from four quarries, of which two are formal and two informal, located in the Milagro – Huanchaco Sector. To determine the characteristics of each Aggregate, physical, chemical and mechanical tests shall be carried out in accordance with the parameters established by the Peruvian Technical Standard (NTP 400.037), based on the American Society for Testing Materials (ASTM C33) as: humidity, specific gravity, absorption, unit weight, void content, sand equivalent, chlorides, Aggregate / alkali reactivity, sulfate durability and abrasion. Having the information about the characteristics of quarry Aggregates will be very useful for builders, public entities and private users since they will know the reliability of the Aggregates used. When performing the basic (physical) tests, unfavorable results were obtained in all the studied quarries, which did not comply with the parameters established by the NTP. The main problems found the excess content of fines and high quantity of particles with a size greater than the nominal maximum of ¾ ", for this purpose, modifications were made with the intention of optimizing the material, in a second stage of tests, the modifications made a positive change in the physical and mechanical characteristics of the Aggregates, complying with the quality requirements. As the best "Rubio - Jaén" quarry for the fine Aggregate and "Calderón" for the coarse Aggregate, obtaining the following results: moisture 0.6% and 0.4%, absorption 1.5%, specific weight 2650 kg/cm³ and 2760 kg/cm³ weight unit 1780 kg/m³ and 1470 kg/m³ respectively for each Aggregate, with respect to the granulometry the fine Aggregate is close to the limits of the spindle, with a modulus of fineness of 2.9. When analyzing the chemical characteristics it was obtained that the Aggregates comply with the limits being 7.0% and 9.0% the attack by magnesium sulphate of the fine and coarse Aggregate respectively and for the test of alkali-Aggregate Reaction by the chemical method were obtained that are potentially deleterious, according to the classification of the norm NTP 334.099: 2011. In the Los Angeles abrasion test, 11% and 23% were obtained for the coarse Aggregate of amaba quarries.TesisRESUMEN La presente investigación, se desarrolló con el objetivo de analizar la influencia de las características de los agregados de las canteras del sector El Milagro - Huanchaco; y así obtener las condiciones en las cuales se encuentran los agregados procedentes de las diferentes canteras que se utilizan para la construcción en la ciudad de Trujillo. Esta investigación se basa en la necesidad de obtener información de las características de los agregados fino y grueso ¾” extraídos de cuatro canteras, de las cuales dos son formales y dos informales, ubicadas en el Sector El Milagro - Huanchaco. Para analizar las características que cuenta cada agregado, se realizarán ensayos físicos, químicos y mecánicos de acuerdo con los parámetros establecidos por la Norma Técnica Peruana (NTP 400.037), basada en la norma de la Sociedad Americana de Prueba de Materiales (ASTM C33) como: humedad, peso específico, absorción, peso unitario, contenido de vacíos, arena equivalente, granulometría, cloruros, reactividad agregado/álcali, durabilidad a los sulfatos y abrasión. Tener la información acerca de las características de los agregados de las canteras será de mucha utilidad para los constructores, entidades públicas y usuarios particulares ya que conocerán la fiabilidad de los agregados empleados. Al realizar los ensayos básicos (físicos), se obtuvieron resultados desfavorables en todas las canteras estudiadas, los cuales no cumplían con los parámetros establecidos por la norma. Los problemas principales encontrados fueron el exceso del contenido de finos y alta cantidad de partículas con tamaño superior al máximo nominal de ¾”, para lo cual se realizaron modificaciones con la intención de optimizar el material, realizando una segunda etapa de ensayos, las modificaciones realizadas alteraron de forma positiva las características físicas y mecánicas de los agregados, cumpliendo con los requerimientos de calidad. Siendo la mejor cantera “Rubio - Jaén” para el agregado fino y “Calderón” para el agregado grueso, obteniendo los siguientes resultados: humedad 0.6% y 0.4%, absorción 1.5%, peso específico 2650 kg/cm³ y 2760 kg/cm³, peso unitario compacto 1780 kg/m³ y 1470 kg/m³ respectivamente para cada agregado, respecto a la granulometría el agregado fino se encuentra cercano a los límites del huso, con un módulo de finura de 2.9. Al analizar las características químicas se obtuvo que los agregados cumplen con los límites siendo 7.0% y 9.0% el ataque por sulfato de magnesio del agregado fino y grueso respectivamente y para el ensayo de reacción álcali-agregado por el método químico se obtuvo que son potencialmente deletéreos, según la clasificación de la norma NTP 334.099:2011. En el ensayo de abrasión por el método de desgaste Los Ángeles se obtuvo un 11% y 23% para el agregado grueso de ambas canteras
Pitisan Krammart - One of the best experts on this subject based on the ideXlab platform.
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effect and limitation of free lime content in cement fly ash mixtures
Construction and Building Materials, 2016Co-Authors: Adnan Nawaz, Parnthep Julnipitawong, Pitisan Krammart, Somnuk TangtermsirikulAbstract:This study emphasizes the limitation of free lime content in fly ash. A detailed experimental program was carried out in order to evaluate the extent to which free lime content in fly ash can be tolerated, particularly for fly ashes with different sulfur trioxide contents. Some basic and durability properties of fly ash mixtures with varied free lime contents were considered. Four distinct types of fly ashes were obtained from two different sources, and free lime was added to obtain overall free lime contents of 5%, 7% and 10% for each type of fly ash. Water requirement, initial and final setting times, compressive strength, autoclave expansion, alkali Aggregate Reaction (AAR), and sulfate resistance tests of fly ash mixtures, containing various free lime contents, with two fly ash replacement percentages (20% and 40%), were conducted. Experimental results revealed that an increase in the free lime content caused an increase in water requirement. Higher free lime content also lead to faster setting times, improved compressive strength, and higher autoclave expansion. Mixtures with 20% fly ash replacement and free lime content up to 10% as well as mixtures with 40% fly ash replacement and free lime content up to 7.72% experienced autoclave expansion within the specified limit of ASTM C618. Similar trends of expansion were observed in cases of alkali-Aggregate Reaction and sulfate resistance tests where fly ash mixtures with high free lime led to higher expansion. In alkali-Aggregate Reaction testing, the mixtures with 20% fly ash replacement and free lime content up to 7.95%, as well as mixtures with 40% fly ash replacement and free lime content up to 10%, expanded less than the cement-only mixtures. The effect of added free lime was more severe in the sulfate resistance test, as fly ash mixtures tend to expand more than cement-only mixtures, especially in the case of fly ashes with very high SO3 content (>5%). Test results also revealed that it is possible to utilize 20% of tested fly ash in a mixture as binder, with SO3 content <5% and free lime content up to 10% while not compromising the basic and durability properties. In the case of 40% fly ash replacement, tested fly ashes with SO3 < 5% and free lime content up to 4.23% can be utilized. In the case of high SO3 content in fly ash, i.e., 8.53% and 9.44% in this study, the limit of free lime content of fly ash is reduced to 5.31% and 3.73%, for 20% and 40% fly ash replacements, respectively to satisfy the durability requirements.
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effect of free lime content on properties of cement fly ash mixtures
Construction and Building Materials, 2013Co-Authors: Krittiya Kaewmanee, Pitisan Krammart, Pongsak Choktaweekarn, Taweechai Sumranwanich, Somnuk TangtermsirikulAbstract:Abstract This research aims to clarify the limitation of free lime content in fly ash according to EN-450. The form and existence of free lime in fly ash by SEM, EDX, and free lime content by a titration method, were observed. Some basic properties of fly ashes with various free lime contents and durability properties of mortar incorporating the fly ashes were also preliminary studied. It was found that free lime particles were mostly distributed outside the fly ash particles and that a minor amount of free lime was encapsulated inside the fly ash particles in the fly ash formation process, meaning that the originally high free lime and added free lime similarly affects properties of fly ash mixtures. A free lime addition method was selected by adding free lime to the originally collected fly ash in order to vary free lime content of the fly ash. The studied basic properties consisted of normal consistency, autoclave expansion, initial and final setting time, water requirement, and compressive strength. In terms of durability, alkali-Aggregate Reaction, carbonation, shrinkage, and chloride and sulfate resistances, were investigated. Test results revealed that physical properties such as normal consistency and water requirement were unaffected by free lime, and that a free lime content up to 4.51% had only slight chemical effects on fly ash–cement mixtures, i.e., faster setting, higher compressive strength, especially at early age, and higher autoclave expansion. However, the values of autoclave expansion were still within the standard limit. Regarding durability, mixtures with the high free lime fly ash led to higher expansion due to alkali-Aggregate Reaction. The expansion was smaller than that of a cement-only mixture. Carbonation depth, shrinkage, and chloride and sulfate resistances were only slightly affected by the added free lime.
Marc-andré Bérubé - One of the best experts on this subject based on the ideXlab platform.
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alkali mass balance during the accelerated concrete prism test for alkali Aggregate reactivity
Cement and Concrete Research, 2003Co-Authors: Marc-andré Bérubé, Patrice Rivard, J P Ollivier, Gerard BallivyAbstract:The alkali mass balance was calculated in concrete specimens submitted to the storage conditions of the Canadian standard CSA A23.2-14A concrete prism test for expansion because of alkali-Aggregate Reaction (AAR). The alkali concentration of both the concrete pore solution expressed under high pressure and the water below specimens in storage pails (bottom water) was measured. Measurements were conducted over a 1-year period that corresponds to the length of the above test. Two reactive Aggregates were testes [Potsdam sandstone (PO) and Spratt limestone (SP)]. Each Aggregate was incorporated in two concrete mixtures (mass concrete and structural concrete), for a total of four batches. Significant alkali leaching occurred at 38 degrees centigrade while performing tests in high moisture storage conditions even though prisms were covered with plastic sleeves. After 52 weeks, the alkali loss ranged from 12% to 25% of the original Na(2)O(e) content of the concrete, depending on the mixture proportioning and the Aggregate type. After estimation of the proportion of alkalis fixed in cement hydrates, it appears that about 23% to 39% of the original alkalis released by the cement are quickly sorbed on Aggregate surfaces or have rapidly migrated inside Aggregate particles, which may have been incorporated with time in the AAR product. After 52 weeks at 38 degrees centigrade, the pore solution alkalinity expressed from mass concrete made with PO was 250 mmol/l, whereas the alkalinity was 270 mmol/l in mass concrete incorporating SP. Since prisms of both mixtures were still expanding at 1 year, these alkalinity values are above the thresholds required for sustaining AAR in these concrete mixtures.
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long term effectiveness of supplementary cementing materials against alkali silica Reaction
Cement and Concrete Research, 2001Co-Authors: Josée Duchesne, Marc-andré BérubéAbstract:Abstract The long-term effectiveness of six supplementary cementing materials (SCM) were tested according to the CSA-A23.2-14A Concrete Prism Method in the presence of two very alkali–silica reactive Aggregates from Canada. Three fly ashes, two silica fumes, and one ground granulated blast furnace slag (GGBFS) were selected based on their elemental composition in order to represent a wide range of composition. The performance of SCMs in suppressing expansion due to alkali–silica Reaction was compared with that obtained by a low-alkali cement. Pore solution composition of the mixtures was also determined. Results show that expansion curves flatten out after 2 years of curing. This phenomenon was due to alkali leaching from the concrete prisms and alkali binding by the alkali Aggregate Reaction products in the presence of the very reactive Aggregates used, which was supported by very low alkali ion concentrations measured on concrete samples at the end of the experiment. A 2-year expansion limit is then suggested when using the CAN/CSA-A23.2-14A method to evaluate mixtures containing SCM. The proportion of SCM and total alkali content of the concrete are very significant factors controlling concrete expansion.
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testing concrete for aar in naoh and nacl solutions at 38 c and 80 c
Cement & Concrete Composites, 1994Co-Authors: Marc-andré Bérubé, J FrenetteAbstract:Abstract Low-alkali and high-alkali concrete prisms were made with a water/cement ratio of 0·55 and two very alkali-silica reactive Aggregates, and tested at 38 and 80°C in 1 M NaOH and NaCl solutions, in water and in air at about 100% RH. The results obtained indicate, at least for the concretes tested, that: (1) ion migration by diffusion is relatively rapid between the immersion solution (alkaline solution or water) and the concrete pore solution; (2) in the presence of reactive Aggregates, two expansive mechanisms seem to superimpose when testing in 1 M NaCl, e.g. alkali-Aggregate Reaction and formation of chloroaluminates; (3) testing in water gives very low expansion as a result of alkali dilution and consequent pH reduction in the pore solution; (4) when testing in 1 M NaOH, the rate of expansion is affected by the initial concrete alkali content; (5) testing concrete prisms in 1 M NaOH at 80°C is the most rapid testing procedure but is unreliable for determining the potential alkali-reactivity of Aggregates; and (6) testing in 1 M NaOH at 38°C appears the most promising procedure among those investigated, for a number of reasons. For instance, compared with the concrete prism method CSA A23-2-14A (e.g. testing in air at ≈ 100% RH), the test duration could be reduced from 1 year to 6 months, and the concrete specimens under test are not subjected to alkali leaching and humidity variations. Some results also suggest that low-alkali concretes exposed to salt solutions could be protected for some long period of time against AAR.
Xiangyin Mo - One of the best experts on this subject based on the ideXlab platform.
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long term effectiveness and mechanism of lioh in inhibiting alkali silica Reaction
Cement and Concrete Research, 2003Co-Authors: Xiangyin Mo, Chenjie Yu, Zhongzi XuAbstract:Excess expansion and cracking of concrete occurs when some of the alkali reactive rocks are used as coarse Aggregate in concrete made with high-alkali cement. Although lithium compounds are one of the techniques used to reduce the effects of alkali-silica Reaction ASR), the long-term effectiveness has not been tested thoroughly and the evidence to prove such effects is also lacking. This article used a practical alkali reactive Aggregate-Beijing Aggregate to test the long-term effectiveness of LiOH in inhibiting alkali-Aggregate Reaction (AAR) expansion. The mortar bars used had been cured at 80 deg C. for 3 years after being autoclaved for 24 h at 150 deg C. Under these conditions, LiOH was able to inhibit long-term alkali-silica Reaction (ASR) expansion effectively. The authors include electron micrographs that illustrate the processes under discussion.