Name: how cement curing changes porosity
Uploaded: 2024-11-07T14:48:30.000Z
Duration: 1 min 18 s
Channel: JoVE

A medida que la pasta de cemento fresca se endurece, pasa de un estado fluido a una masa sólida, atrapando el agua en varias formas, como agua en gel, agua capilar y agua combinada.
El agua de gel, que queda atrapada dentro de los poros del gel de cemento, suele constituir aproximadamente el 28% del volumen total del gel de cemento.
Alrededor del 23% de la masa de cemento seco está constituida por el agua combinada que se asocia a los distintos productos resultantes del proceso de hidratación.
Cuando la pasta de cemento tiene más agua de la necesaria para la hidratación, el exceso de agua forma poros capilares, que constituyen aproximadamente el 18,5% del volumen de cemento original y, a menudo, están llenos de agua.
La relación entre el volumen combinado de gel y poros capilares y el volumen total de la pasta de cemento determina la porosidad total de la pasta de cemento.
La relación agua-cemento es un factor crucial, ya que el exceso de agua crea más poros capilares, lo que conduce a una mayor porosidad y a una pasta de cemento endurecida potencialmente más débil.
Un curado adecuado puede reducir la porosidad al permitir una hidratación continua, que llena los poros capilares con productos de hidratación.

porosidad en el hormigón

Porosity in Cement Paste

La porosidad del hormigón es una medida de los espacios vacíos dentro de su estructura. Estos espacios afectan significativamente su resistencia y durabilidad. Cuando el agua y el cemento interactúan, una reacción química llamada hidratación crea una pasta semisólida. Esta pasta incluye agua combinada, que constituye aproximadamente el 23 % de la masa seca del cemento, y agua en gel, que llena los minúsculos huecos conocidos como poros de gel, y representa aproximadamente el 28 % del volumen de gel del cemento.

El equilibrio entre agua y cemento en la mezcla es fundamental: influye en el grado de hidratación y, por lo tanto, en la porosidad y la resistencia del hormigón curado. En un proceso de hidratación ideal, el espacio adicional no ocupado por productos de hidratación sólidos forma poros capilares, que representan alrededor del 18,5 % del volumen original del hormigón. A medida que el hormigón se cura, la hidratación continua puede llenar los poros capilares con productos de hidratación, lo que aumenta la densidad del material.

Para lograr una hidratación completa y una resistencia óptima, el proceso de curado debe manejarse con cuidado. Permite una hidratación adicional, reduciendo la porosidad al llenar los espacios capilares con productos de hidratación más estables y, como resultado, densificando la pasta. Este proceso meticuloso es crucial para lograr un hormigón duradero y de alta calidad que sea menos susceptible a la degradación ambiental y mecánica.

Porosidad en el hormigón

A medida que la pasta de cemento fresca se fraga, pasa de un estado fluido a una masa sólida, atrapando el agua en varias formas, como agua en gel, agua capilar y ...

Education

Educación

JoVE Core

Civil Engineering

Ingeniería Civil

Unit 1

Unidad 1

Strength of Concrete

Resistencia del hormigón

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

how cement curing changes porosity

Cement curing changes porosity in the hardened paste. Porosity means the void spaces inside concrete. These spaces affect both strength and durability. When water and cement react, hydration forms a semi-solid paste that traps water in different ways.

Some of that water becomes combined water. It makes up about 23% of the cement's dry mass. Other water stays as gel water, which fills very small voids called gel pores. Gel pores account for about 28% of the cement gel volume.

The water-to-cement ratio is important in the mix. It controls how much hydration can happen. That, in turn, affects the porosity and strength of the cured concrete. In an ideal hydration process, the space not filled by solid hydration products becomes capillary pores, which are about 18.5% of the original cement volume.

As concrete cures, hydration can continue. More hydration products can fill the capillary pores and make the material denser. Careful curing helps complete this process and reduces porosity. The result is durable, high-quality concrete that is less likely to break down under environmental and mechanical stress.

How Cement Curing Changes Porosity

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Cement curing changes porosity in the hardened paste. Porosity means the void spaces inside concrete. These spaces affect both strength and durability. When water and cement react, hydration forms a semi-solid paste that traps water in different ways. Some of that water becomes combined water. It makes up about 23% of the cement's dry mass. Other water stays as gel water, which fills very small voids called gel pores. Gel pores account for about 28% of the cement gel volume. The...

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Concrete Transition Zone and Its Porosity

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key terms and concepts

Learn how hydration, gel water, and capillary pores affect cement paste porosity, strength, and durability as concrete cures.

How Cement Curing Changes Porosity | JoVE K12

JoVE Core Civil Engineering provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

civil engineering

How Cement Curing Changes Porosity

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