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Mitigación de la contracción en las calzas hidráulicas naturales libres de superplastificantes para la conservación

Yang Wu¹, Shibing Dai¹

¹College of Architecture and Urban Planning, Tongji University, No. 1239 Siping Road, Shanghai 200092, China.

Materials (Basel, Switzerland)

|August 28, 2025

Resumen

El encogimiento de la lechada hidráulica natural (NHL) es un desafío en la reparación de mampostería histórica. Este estudio optimizó la composición de la lechada NHL y encontró que los agentes expansivos basados en óxido de calcio (CaO) reducen efectivamente la contracción, con un uso controlado recomendado para sustratos de alta absorción.

Área de la Ciencia:

Ciencias de los materiales de construcción
Ingeniería de conservación del patrimonio
Ingeniería geotécnica

Sus antecedentes:

El agrietamiento es un mecanismo de deterioro primario en las estructuras de mampostería históricas.
El encofrado con cal natural hidráulica (NHL) es una intervención clave, favorecida por su compatibilidad con los materiales del patrimonio.
El encogimiento de la lechada durante el curado a menudo compromete la efectividad de la lechada NHL en la conservación de la mampostería.

Objetivo del estudio:

Para investigar las características de encogimiento de la lechada sin superplastificador.
Identificar las composiciones óptimas de la lechada y evaluar el impacto de los agentes expansivos y las propiedades del sustrato en la contracción.
Proporcionar estrategias de diseño de materiales para el encofrado efectivo de mampostería histórica.

Principales métodos:

Investigación experimental de la composición de la lechada, los agentes expansivos y las propiedades del sustrato.
Aplicación del método de Taguchi para optimizar las relaciones de agua, aglutinante y agregado.
Las mediciones del encogimiento después de 28 días de experimentos de simulación de curado y cocido.

Principales resultados:

Se identificó una composición de lechada optimizada utilizando el método de Taguchi.
Los agentes expansivos basados en óxido de calcio (CaO) demostraron ser los más eficaces para mitigar el encogimiento de la lechada NHL.
La absorción de agua del sustrato influye significativamente en la contracción de la lechada; el uso controlado de agentes expansivos es crucial para los sustratos con una alta absorción de agua capilar (> 25 kg/m2 h1/2).

Conclusiones:

Las formulaciones optimizadas de lechada NHL pueden compensar efectivamente el encogimiento.
La selección y dosificación de los agentes expansivos deben tener en cuenta las propiedades del sustrato, en particular la absorción de agua.
Los hallazgos ofrecen estrategias prácticas para mejorar la durabilidad y el rendimiento de las estructuras de mampostería histórica.

Palabras clave:

agente expansivo contracción de la lechada conservación de la mampostería histórica estrategias de mitigación Cal hidráulica natural Sin superplastificantes

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