What's The Deal With Translucent Concrete?

By John Oncea, Editor

Translucent concrete retains the structural properties of traditional concrete while allowing light to pass through it. The material offers a unique aesthetic, allowing for interesting light and shadow play while reducing reliance on artificial lighting.

Optical materials, according to ScienceDirect, are “materials whose function is to alter or control electromagnetic radiation in the ultraviolet (UV), visible, or infrared (IR) spectral regions. Such materials are fabricated into optical elements such as lenses, mirrors, windows, prisms, polarizers, detectors, and modulators, etc., and they can be used to refract, reflect, transmit, disperse, polarize, detect, and transform light.”

At the microscopic level, the interaction between atoms and their electronic configurations in a material with electromagnetic radiation (photons) determines the material’s macroscopic optical properties, such as transmission and refraction. These optical properties depend on various factors, including the wavelength of the incident light, the temperature of the material, the applied pressure, and, in certain cases, the external electric and magnetic fields applied to the material.

A wide range of substances can be used as optical materials, and when selecting one, consideration needs to be made to transparency and refractive index, along with their spectral dependencies. Additionally, factors such as material uniformity, strength and hardness, temperature limits, hygroscopic nature, and chemical resistance may also need to be considered.

Most optical elements are made from glass, crystalline materials, polymers, plastics … and concrete.

What Is Translucent Concrete?

Translucent concrete, often called light-transmitting concrete, is redefining the boundaries of architectural design and energy efficiency. According to the National Center for Biotechnology Information, this material merges the structural robustness of traditional concrete with the ability to transmit natural or artificial light, opening up new avenues for sustainable and visually compelling construction.

Translucent concrete is produced by embedding optical fibers, typically made of glass or plastic, within a standard concrete matrix, according to IMARC Group. These fibers function as conduits, channeling light from one side of the concrete panel to the other. The result is a material that maintains the load-bearing capabilities of concrete while allowing light to pass through, creating striking visual effects and functional daylighting solutions.

The International Advanced Research Journal in Science, Engineering and Technology writes that this concept, though first patented in the 1930s, gained significant traction in the early 2000s with Áron Losonczi’s patented LiTraCon, which brought the material to commercial and architectural prominence. Today, translucent concrete is recognized as a premium building material, often costing more than conventional concrete due to the expense of optical fibers and the complexity of its fabrication.

How Is Translucent Concrete Made?

The manufacturing process involves precisely arranging optical fibers, in some cases, bundled or spaced at regular intervals, within the concrete matrix. The ratio of fiber area to concrete volume is a critical factor: increasing the fiber content directly increases the amount of light transmitted through the material. For example, research has shown that using 1 mm diameter fibers can yield up to 85% higher transmittance compared to 0.5 mm fibers at the same spacing.

The orientation and spacing of the fibers also influence performance. While direct sunlight provides the best transmittance, the acceptance cone of the fibers (up to 61°) allows for effective light transmission even when the sun is not at an optimal angle. The compressive strength of translucent concrete is comparable to that of traditional concrete, especially when using high-performance cementitious matrices and optimizing fiber integration.

Material Properties And Performance

Translucent concrete exhibits mechanical strength that meets the requirements for structural applications, with compressive strength only slightly lower than conventional mixes, writes the International Journal Of Progressive Research In Engineering Management And Science. Adjustments in fiber type and matrix composition can further enhance strength.

The percentage of light transmitted depends on fiber content, and studies report light transmission rates ranging from 4% to over 12% with increasing fiber volume. By allowing daylight to penetrate deep into building interiors, translucent concrete reduces the need for artificial lighting and can help modulate solar heat gain.

Its climate-responsive transmittance is especially beneficial in regions with significant seasonal variation, optimizing energy use throughout the year. Advances in material science have improved the tensile strength, weather resistance, and longevity of translucent concrete, making it suitable for both interior and exterior applications.

Applications And Architectural Impact

Translucent concrete is being adopted in a variety of settings. It is used on building exteriors as façades and cladding to create visually dynamic surfaces that change with natural light conditions. For interior partitions and walls, it provides privacy while introducing soft, diffuse daylight into spaces, reducing reliance on electric lighting.

The material is also employed in flooring, staircases, tiles, and even furniture, where interplay with light enhances both aesthetics and utility. In infrastructure, translucent concrete is explored for use in tunnels, sidewalks, and public spaces to improve safety and visibility without additional lighting infrastructure. Its unique properties also enable novel artistic expressions by manipulating light and shadow in ways that are not possible with traditional materials.

Market Growth And Technological Advancements

The market for translucent concrete is expanding rapidly, driven by demand for innovative, sustainable, and visually distinctive building materials. The global market size was estimated at $12.5 million in 2024, with projections reaching $228.6 million by 2033, according to Research and Markets.

This growth is fueled by technological innovations that have made the integration of optical fibers more efficient and cost-effective, enhancing both light transmission and mechanical properties. As energy codes become stricter and green building certifications more desirable, materials that contribute to daylighting and energy savings are increasingly favored. Additionally, the ability to customize color, pattern, and fiber arrangement allows architects to create unique, signature elements for high-end and public projects.

Challenges And Ongoing Research

Despite its advantages, translucent concrete faces several challenges. The inclusion of optical fibers and the precision required in manufacturing make it more expensive than standard concrete, limiting its use primarily to premium or showcase projects.

Research continues into optimizing fiber ratios, improving durability, and developing cost-effective production methods to broaden its applicability. While current uses are often decorative or non-load-bearing, ongoing studies aim to extend translucent concrete’s role in structural elements without compromising safety or performance.

Emerging research is exploring the integration of smart sensing capabilities, phase change materials for enhanced thermal regulation, and recycled fibers to reduce environmental impact. As manufacturing becomes more efficient and costs decrease, translucent concrete is poised to play a larger role in mainstream construction, combining the best of photonics and civil engineering for the next generation of sustainable, light-filled buildings.