Unveiled: the little-known material changing the face of construction – sticky rice mortar

Sticky rice mortar is a traditional building material made from glutinous rice, lime, and other natural materials. It has been used for centuries in Southeast Asia to construct temples, palaces, and other structures. Sticky rice mortar is renowned for its exceptional strength, durability, and water resistance.

Composition and Preparation

The primary ingredient in sticky rice mortar is glutinous rice, also known as sweet rice. This type of rice is high in starch, which acts as a natural adhesive. The rice is cooked and then pounded into a paste. Lime, another key ingredient, is added to provide strength and durability. Other materials, such as sand, ash, and plant fibers, may also be incorporated to enhance the mortar’s properties.

Properties and Advantages

Sticky rice mortar possesses several unique properties that make it an ideal building material:

• Exceptional Strength: The glutinous rice starch forms a strong bond, creating a durable and long-lasting mortar.
• Water Resistance: The lime in the mortar reacts with carbon dioxide in the air to form calcium carbonate, which makes the mortar resistant to water penetration.
• Flexibility: Sticky rice mortar is flexible, allowing it to withstand earthquakes and other seismic events without cracking.
• Biodegradability: As a natural material, sticky rice mortar is biodegradable and environmentally friendly.

Historical Significance

Sticky rice mortar has played a significant role in Southeast Asian architecture for centuries. It was used to construct some of the region’s most iconic structures, including:

• Angkor Wat, Cambodia: The world-renowned temple complex was built using sticky rice mortar, which has contributed to its remarkable longevity.
• Borobudur, Indonesia: The largest Buddhist temple in the world, Borobudur was constructed using sticky rice mortar, which has protected it from the elements for centuries.
• Bagan, Myanmar: The ancient city of Bagan is home to thousands of temples and pagodas, many of which were built with sticky rice mortar.

Modern Applications

While sticky rice mortar is primarily associated with historical structures, it is also finding modern applications:

• Restoration and Preservation: Sticky rice mortar is used to restore and preserve ancient buildings and monuments, as it is compatible with the original materials.
• Sustainable Building: Due to its natural and biodegradable properties, sticky rice mortar is becoming increasingly popular in sustainable building practices.
• Artistic Expression: Architects and artists are experimenting with sticky rice mortar as a creative medium, using its unique properties to create innovative sculptures and installations.

Cultural Significance

Beyond its practical uses, sticky rice mortar holds cultural significance in Southeast Asia:

• Symbol of Heritage: Sticky rice mortar is a symbol of the region’s rich architectural history and cultural heritage.
• Community Involvement: In some communities, the preparation and application of sticky rice mortar is a communal activity, fostering a sense of unity and tradition.
• Religious Beliefs: In some cultures, sticky rice mortar is believed to possess spiritual properties and is used in religious ceremonies.

How to Make Sticky Rice Mortar

Although the traditional methods of making sticky rice mortar vary slightly from region to region, the general process involves the following steps:

1. Cook the Rice: Glutinous rice is cooked until it becomes soft and sticky.
2. Pound the Rice: The cooked rice is pounded into a fine paste using a mortar and pestle.
3. Add Lime: Lime is added to the rice paste and mixed thoroughly.
4. Incorporate Other Materials: Sand, ash, or other materials may be added to enhance the mortar’s properties.
5. Mix with Water: Water is gradually added to the mixture until it reaches a workable consistency.

Final Thoughts: The Enduring Legacy of Sticky Rice Mortar

Sticky rice mortar is a testament to the ingenuity and craftsmanship of Southeast Asian builders. Its exceptional strength, durability, and water resistance have allowed it to withstand the test of time and continue to be used in both traditional and modern applications. As a symbol of cultural heritage and architectural excellence, sticky rice mortar remains a vital part of the region’s built environment.

Questions We Hear a Lot

1. What is the difference between sticky rice mortar and regular mortar?

Sticky rice mortar uses glutinous rice as the primary adhesive, while regular mortar uses cement or lime. Sticky rice mortar is more flexible and water-resistant than regular mortar.

2. How long does sticky rice mortar last?

Sticky rice mortar can last for centuries, as evidenced by the ancient structures it has been used to build.

3. Is sticky rice mortar expensive?

Sticky rice mortar is generally more expensive than regular mortar due to the cost of glutinous rice and the labor-intensive process of preparation.