Effect of pozzolans on the hydration process of Portland cement cured at low temperatures

Soriano, Lourdes; Monzó, J.; Bonilla, M.; Tashima, Mauro M.; Payá, J.; Borrachero, M.V.

doi:10.1016/j.cemconcomp.2013.05.007

Cited by 74 publications

(38 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The term pozzolan has been extended to cover all siliceous/aluminous materials, which in finely divided form and in the presence of water, will chemically react with calcium hydroxide (CH) to form compounds with cementitious properties. Blended Portland cement production from the combustion of silicon-rich plant residues such as sugar cane bagasse ash, rice husk ash are reported elsewhere (25,(84)(85)(86)(87)(88)(89)(90)(91). The use of regional agro-industrial residues is a constructive way to save energy in transport and for a more simplified logistics to attend the global civil construction market.…”

Section: Natural Pozzolans As Mineral Additionmentioning

confidence: 99%

Non-conventional cement-based composites reinforced with vegetable fibers: A review of strategies to improve durability

et al. 2015

View full text Add to dashboard Cite

The present review shows the state-of-art on the approachs about improving the processing, physical-mechanical performance and durability of non-conventional fiber-cement composites. The objective of this review is to show some of these strategies to mitigate the degradation of the vegetable fibers used as reinforcement in cost-effective and non-conventional fiber-cement and, consequently, to improve their mechanical and durability properties for applications in the housing construction. Beyond the introduction about vegetable fibers, the content of this review is divided in the following sections: (i) surface modification of the fibers; (ii) improving fiber-to-cement interface; (iii) natural pozzolans; (iv) accelerated carbonation; (v) applications of nanoscience; and (vi) principles of functionally graded materials and extrusion process were briefly discussed with focus on future research needs. RESUMEN: Compuestos cementantes no convencionales reforzados con fibras vegetales: Una revisión de estrategias para mejorar la durabilidad.La presente revisión explora la actualidad en el campo de los compuestos de fibrocemento no convencionales en relación a mejoras en el proceso productivo, el rendimiento físico-mecánico y la durabilidad. El objetivo de esta revisión es exponer algunas estrategias para mitigar la degradación de las fibras vegetales utilizadas como refuerzo en fibrocementos no convencionales y rentables, obteniendo en consecuencia una mejoría en el rendimiento de sus propiedades mecánicas y durabilidad para su aplicación en el área de la construcción de viviendas. Además de la introducción en relación a las fibras vegetales, el contenido de esta revisión se divide en las siguientes secciones: (i) modificación de la superficie de las fibras; (ii) mejoramiento de la interfaz fibra-cemento; (iii) puzolanas naturales; (iv) carbonatación acelerada; (v) aplicaciones de la nanociencia; y (vi) principios de los materiales funcionalmente graduados y el proceso de extrusión fueron discutidos brevemente con un enfoque a investigaciones futuras.

show abstract

Section: Natural Pozzolans As Mineral Additionmentioning

confidence: 99%

Non-conventional cement-based composites reinforced with vegetable fibers: A review of strategies to improve durability

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Chemical Reaction in Ordinary Portland Cement (OPC) Hydration Process: SFCC waste was proven to behave as an excellent pozzolan for early curing age by improving both durability and mechanical behaviour in the cementitious system [18]. According to literature in previous study, SFCC which consists primarily of active silica (SiO2) and alumina (Al2O3) [19] shows pozzolanic activity and contributes to the acceleration of the hydration and setting processes [20].…”

Section: Pozzolanic Reactions and Pore Filling Effect Of Sfcc And Ns mentioning

confidence: 99%

Microstructural characterization of catalysis product of nanocement based materials: A review

et al. 2018

View full text Add to dashboard Cite

Abstract. Cement as an essential element for cement-based products contributed to negative environmental issues due to its high energy consumption and carbon dioxide emission during its production. These issues create the need to find alternative materials as partial cement replacement where studies on the potential of utilizing silica based materials as partial cement replacement come into picture. This review highlights the effectiveness of microstructural characterization techniques that have been used in the studies that focus on characterization of calcium hydroxide (CH) and calcium silicate hydrate (C-S-H) formation during hydration process of cement-based product incorporating nano reactive silica based materials as partial cement replacement. Understanding the effect of these materials as cement replacement in cement based product focusing on the microstructural development will lead to a higher confidence in the use of industrial waste as a new non-conventional material in construction industry that can catalyse rapid and innovative advances in green technology.

show abstract

“…Several techniques to characterize pozzolanic reactivity of SCM have been performed such as pozzolanic activity index (5), thermogravimetric analysis (TGA) of Portland cement pastes or calcium hydroxide pastes (6) and electrical conduc tivity measurements of lime/pozzolan suspensions (7) and blended Portland cement mortars (8). Among these methods, techniques based on electrical conductivity measurements are considered easy and rapid tests to evaluate the pozzolanic reaction, when compared with the existent techniques.…”

Section: Introductionmentioning

confidence: 99%

“…In that method, the soluble silica in HF solution was indirectly determined by means of the measurement of electrical conductivity due to the formation of SiF 6 2− and H + ions. The pozzolanic activity index was calculated indirectly by comparison to amorphous silica.…”

Section: Introductionmentioning

confidence: 99%

New method to assess the pozzolanic reactivity of mineral admixtures by means of pH and electrical conductivity measurements in lime:pozzolan suspensions

Tashima¹,

Soriano²,

Monzó³

et al. 2014

Mater. construcc.

Self Cite

View full text Add to dashboard Cite

A very simple method based on electrical conductivity and pH measurements was proposed for assessing reactivity of pozzolans. Calcium hydroxide:pozzolan water suspensions were monitored by means of measurements of electrical conductivity and pH values. In these suspensions, Ca(OH) 2 in solid state was initially present, being them, thus, saturated in this reagent. Three testing temperatures were selected (40, 50 and 60 °C). In the experiments carried out, calcium hydroxide was suspended in deionized water for yielding a lime saturated suspension. The addition of siliceous pozzolan (two types of rice husk ash RHA and two types of densified silica fume DSF were tested) to the saturated lime suspension can produce the unsaturation of the system, depending on the testing time, testing temperature and reactivity of pozzolan. When unsaturation was reached, the loss of electrical conductivity was higher than 30% and the variation of pH was higher than 0.15 units. These threshold values were selected for characterizing the reactivity of pozzolans by means of a proposed template, classifying the pozzolan in three different reactivity levels. RESUMEN:Nuevo método para evaluar la reactividad puzolánica de adiciones minerales por medio de medidas de pH y conductividad eléctrica en suspensiones cal:puzolana. En este trabajo se propone un método simple basado en medidas de conductividad eléctrica y pH. Se determinaron los valores de conductividad eléctrica y pH de suspensiones acuosas de hidróxido cálcico:puzolana. En las suspensiones, había inicialmente Ca(OH) 2 en estado sólido, de manera que dichas suspensiones estaban, por tanto, saturadas respecto a ese reactivo. Se seleccionaron tres temperaturas de trabajo (40, 50 and 60 °C). En las experiencias, el hidróxido cálcico fue mezclado con agua desionizada, generando una suspensión saturada en cal. La adición de puzolana silícea (se ensayaron dos tipos de ceniza de cáscara de arroz y dos tipos de humo de sílice densificado) a la suspensión saturada de cal puede producir la insaturación del sistema, dependiendo del tiempo, temperatura y reactividad de la puzolana. Cuando se alcanza la insaturación, la pérdida de conductividad eléctrica fue mayor a 30% y la variación de pH fue mayor que 0.15 unidades. Estos valores umbral fueron seleccionados para caracterizar la reactividad de las puzolanas por medio de una plantilla propuesta al efecto, clasificando la puzolana en tres niveles de reactividad diferentes.

show abstract

Effect of pozzolans on the hydration process of Portland cement cured at low temperatures

Cited by 74 publications

References 35 publications

Non-conventional cement-based composites reinforced with vegetable fibers: A review of strategies to improve durability

Non-conventional cement-based composites reinforced with vegetable fibers: A review of strategies to improve durability

Microstructural characterization of catalysis product of nanocement based materials: A review

New method to assess the pozzolanic reactivity of mineral admixtures by means of pH and electrical conductivity measurements in lime:pozzolan suspensions

Contact Info

Product

Resources

About