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Hotter, weaker, riskier: Effects of prolonged heat on concrete wall integrity

ByopinionJuly 9, 20233 Mins read828

Prolonged extreme heat may affect the integrity of concrete walls in long term. Photo by Michael Skok - Unsplash

By: Ir. Ts. Dr. Daud Mohamad

The design of concrete buildings in Malaysia does not have specific rules or guidelines that set a maximum age for structures. Instead, the design process follows certain codes and standards that focus on making the buildings strong, safe, and sustainable.

The lifespan of a concrete building in Malaysia depends on factors like how well it was built, how it’s maintained, the environment it’s in, and how it’s used. With proper design, construction, and maintenance, concrete buildings can last for many decades or even longer.

However, regular inspections, maintenance, and repairs are necessary to ensure the building remains structurally sound and safe over time. In Malaysia or any other country, it’s important to involve qualified structural engineers and follow recommended maintenance practices to ensure the longevity and safety of concrete buildings.

When it comes to concrete’s response to temperature, there are certain considerations. Concrete in Malaysia doesn’t have specific requirements for minimum thermal temperatures. However, it’s crucial to follow general guidelines to ensure the durability and performance of concrete in different climates.

During the curing process, concrete is sensitive to extreme temperatures. To achieve the necessary strength and durability, it’s recommended to maintain a minimum temperature of 10°C (50°F) during the initial curing phase to prevent freezing and promote proper hydration. In Malaysia’s hot tropical climate, additional precautions should be taken during concrete placement and curing to prevent excessive heat. Guidelines provided by the American Concrete Institute (ACI) offer measures like shading the concrete, cooling the aggregates and mixing water, and using temperature control methods to maintain acceptable temperature levels.

Thermal concrete, also known as insulated concrete, is designed to have better thermal insulation properties compared to regular concrete. It helps reduce the transfer of heat through the building’s structure. By using thermal concrete in walls, floors, or roofs, buildings can benefit in several ways:

1.Improved energy efficiency: Thermal concrete reduces the need for heating or cooling systems by reducing heat transfer. This leads to lower energy consumption and cost savings.

2.Enhanced comfort: Buildings made with thermal concrete have better temperature regulation, providing a more comfortable indoor environment by reducing heat loss in cold weather and heat gain in hot weather.

3.Reduced HVAC system size: The improved insulation of thermal concrete allows for smaller or optimized heating, ventilation, and air conditioning (HVAC) systems, resulting in cost and energy savings.

4.Environmental benefits: Thermal concrete’s lower energy consumption reduces greenhouse gas emissions associated with energy production, contributing to environmental sustainability.

It’s important to note that the effectiveness of thermal concrete in saving energy depends on various factors like insulation properties, thickness, and overall building design. To maximize energy savings and thermal performance, it’s crucial to consider a holistic approach to building design and insulation strategies, including other energy-efficient features like insulation materials and windows. Consulting with experts in building design and energy efficiency can help determine the most suitable solutions for specific projects.

With the current high temperatures in Malaysia, it’s important to be aware of the integrity of buildings. Concrete walls can be affected by exposure to high temperatures, leading to certain changes. The effects depend on the intensity and duration of the exposure and can include:

1.Expansion and cracking: Concrete expands when heated and contracts when cooled. Rapid heating or uneven temperature distribution can cause cracking and spalling.

2.Loss of strength: High temperatures can dehydrate the cement paste in concrete, resulting in a loss of strength.

3.Chemical changes: Elevated temperatures can alter the chemical composition of concrete, affecting its integrity and performance.

4.Structural integrity: Prolonged exposure to high temperatures can weaken the overall structure of concrete walls, potentially leading to collapse or failure.

It’s important to understand that the severity of these effects depends on factors such as the specific type of concrete mix, the presence of reinforcing elements like steel bars, the thickness of the wall, and the duration and intensity of the heat exposure.

Although reinforced concrete buildings typically can maintain their integrity and avoid collapse when exposed to the current high temperatures in Malaysia; as an informed citizen, we should be wary of its susceptibility to prolonged heat exposure too.

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^{The author is a Senior Lecturer and a member of the Institute of Energy Infrastructure (IEI), Universiti Tenaga Nasional (UNITEN). He may be reached at daud@uniten.edu.my}