Name: protecting mortar during weather changes
Uploaded: 2024-09-12T16:16:29.000Z
Duration: 1 min 21 s
Channel: JoVE

Par temps froid, le ciment à durcissement rapide est utilisé dans la préparation du mortier. De l’eau chaude y est ajoutée, en maintenant la température du mortier entre 40 degrés et 120 degrés Fahrenheit, jusqu’à ce qu’il soit placé.
Pour des températures inférieures à 32 degrés Fahrenheit, les éléments de maçonnerie et les sacs de ciment sont stockés sur une plate-forme surélevée, recouverts de feuilles résistantes à l’eau et chauffés à l’aide de radiateurs d’appoint.
Le gel du sable est évité en le chauffant à l’aide d’une couverture électrique ou de caloducs.
De plus, des brise-vent sont prévus sur le chantier si la vitesse du vent est supérieure à 15 milles à l’heure.
À la fin des travaux, le mur de maçonnerie est recouvert de couvertures isolantes pendant 24 heures pour éviter le gel.
Par temps chaud, les éléments de maçonnerie, le sable, les sacs de ciment et les équipements de mortier sont protégés de la lumière directe du soleil.
Pour la maçonnerie par temps chaud, on pratique le rinçage à l’eau avec de l’eau, l’ajout d’eau froide au mélange de mortier et le prémouillage des éléments de maçonnerie avant de les poser.
À la fin des travaux, un spray de brouillard est appliqué sur la maçonnerie et recouvert de membranes résistantes aux intempéries pour la protéger du soleil.

maçonnerie par temps froid et chaud

Par temps froid, la construction en maçonnerie nécessite des précautions particulières pour éviter que le mortier ne gèle avant de durcir, car cela peut affaiblir considérablement sa résistance et son étanchéité. La température du mortier doit être maintenue entre 15,6 °C et 26,67 °C pour favoriser une hydratation et un durcissement appropriés. En dessous de 4,44 °C, l'eau du mortier doit être chauffée, mais ne doit pas dépasser 48,89 °C, car les températures élevées peuvent réduire la résistance à la compression et à l'adhérence du mortier.

D'autres pratiques clés incluent le maintien des éléments de maçonnerie et du sable au sec et à l'abri du gel, l'utilisation de sable chauffé pour maintenir le mortier à une température optimale et l'utilisation de ciment de type III pour un durcissement plus rapide. Le mortier doit être mélangé en petites quantités pour éviter le refroidissement, et les postes de travail des maçons doivent être protégés du vent et chauffés si nécessaire. La maçonnerie nouvellement posée doit être protégée du gel pendant au moins une journée, et les surfaces doivent être couvertes pour se protéger de la pluie et de la neige.

Par temps chaud, le défi consiste à empêcher le mortier de sécher trop rapidement. Les éléments de maçonnerie peuvent nécessiter d'être humidifiés avant utilisation pour éviter une absorption excessive d'eau du mortier. Garder les éléments de maçonnerie, les ingrédients du mortier et les postes de travail à l'ombre permet de gérer ce problème. Souvent, la maçonnerie est traitée avec un spray anti-brouillard puis recouverte de membranes résistantes aux intempéries pour la protéger du soleil en fin de journée.

Maçonnerie par temps froid et chaud

Par temps froid, le ciment à durcissement rapide est utilisé dans la préparation du mortier. De l’eau chaude y est ajoutée, en maintenant la température du mortier entre 40 degrés et ...

masonry-in-cold-and-hot-weather-conditions

Education

Enseignement

JoVE Core

Civil Engineering

Génie civil

Unit 1

Unité 1

Masonry

Maçonnerie

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

Masonry in Cold and Hot Weather Conditions

protecting mortar during weather changes

Masonry work changes in cold and hot weather because mortar must stay at the right temperature and moisture level. If mortar freezes before it cures, its strength and watertightness can drop. For proper hydration and curing, mortar should stay between 60°F and 80°F.

When the weather is below 40°F, the water used for mortar must be heated. The water should not exceed 120°F, because very hot water can reduce compressive strength and bond strength. Masonry units and sand should also stay dry and protected from freezing. Heated sand can help keep the mortar near the best temperature.

Cold-weather work also calls for Type III cement, which cures faster. Masons should mix mortar in small batches so it does not cool too much before use. Workstations should be shielded from wind and heated when needed. Newly laid masonry must be protected from freezing for at least one day. Surfaces should also be covered to block rain and snow.

Hot weather creates the opposite problem, because mortar can dry too fast. Masonry units may need to be dampened before use so they do not pull too much water from the mortar. Keeping the units, mortar ingredients, and work area in the shade also helps. At the end of the day, masonry is often given a fog spray and then covered with weather-resistant membranes to protect it from sunlight.

Protecting Mortar During Weather Changes

composite masonry walls

Bonding and Materials in Composite Masonry

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Masonry Curtain Walls and Support Systems

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How Masonry Walls Gain Extra Strength

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cavity drainage and flashings in masonry walls

cavity-drainage-and-flashings-in-masonry-walls

Moisture Control in Masonry Cavity Walls

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thermal insulation in masonry walls

Masonry Wall Insulation Options

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expansion and contraction in masonry walls

expansion-and-contraction-in-masonry-walls

Masonry Wall Joints for Temperature and Moisture

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How Buildings Handle Structural Movement

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Building Joints for Movement and Stability

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Repairing Damaged Mortar Joints in Masonry

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masonry in cold and hot weather conditions

Masonry work changes in cold and hot weather because mortar must stay at the right temperature and moisture level. If mortar freezes before it cures, its strength and watertightness can drop. For proper hydration and curing, mortar should stay between 60°F and 80°F. When the weather is below 40°F, the water used for mortar must be heated. The water should not exceed 120°F, because very hot water can reduce compressive strength and bond strength. Masonry units and sand should also stay dry and...

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key terms and concepts

Learn how cold and hot weather affect masonry mortar, from heating materials and using Type III cement to shading, dampening, and fog spraying.

Protecting Mortar During Weather Changes | 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

Protecting Mortar During Weather Changes

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