Experimental Investigation on the Cyclic Behaviour of Nano Basalt Enhanced Epoxy Filler Modified Bamboo Reinforced Concrete Slabs

Buildings are designed to stand firm against the weight of their own materials and the people inside them, but they must also survive the repeated stresses of daily life. Wind pushes against a skyscraper, traffic vibrates a bridge, and earthquakes shake the ground beneath a home. To handle these forces, engineers rely on materials that can bend without breaking and absorb energy rather than shattering. For over a century, steel has been the standard choice for reinforcing concrete because it is strong and flexible. However, steel requires immense amounts of energy to produce and leaves a heavy carbon footprint. In response, researchers have turned their attention to bamboo, a fast-growing plant that is naturally strong and renewable. The challenge has always been that bamboo behaves differently than steel; it can rot when wet and does not bond perfectly with concrete, often leading to sudden failures when the structure is pushed to its limits.

A team of researchers in India set out to solve this problem by treating bamboo with a special coating to make it behave more like steel under repeated stress. They wanted to see if they could create a sustainable building material that could withstand the kind of shaking and bending that happens during earthquakes or heavy usage. Their work focused on a specific type of concrete slab, a flat panel used in floors or roofs, reinforced with strips of bamboo. Instead of using raw bamboo, they dipped the strips in an epoxy resin, a strong glue-like substance, and mixed in tiny particles of basalt rock and glass. This mixture was designed to fill the gaps between the bamboo and the concrete, creating a tighter grip and allowing the two materials to work together more effectively. The goal was to test whether this treated bamboo could survive multiple cycles of heavy loading and unloading without losing its strength or stiffness.

The researchers cast small concrete panels, each measuring 600 by 450 by 50 millimeters, using a standard mix of cement and sand. They created several versions of these panels to compare performance. Some panels contained no reinforcement at all, serving as a baseline to show how plain concrete fails. Others were reinforced with steel, the traditional benchmark. The remaining panels used bamboo strips that had received different treatments: some were left raw, some were coated only in epoxy, and others were coated in epoxy mixed with sand, glass, or a combination of glass and nano-sized basalt powder. Once the panels were cured for a month, they were placed in a testing machine that pushed down on them with two points of force, then released, and repeated this process over and over. This simulated the kind of repeated stress a building might face during a storm or seismic event. The machine recorded how much force the panels could take, how much they bent, and how much energy they absorbed before they finally broke.

The results showed a clear difference between the untreated and treated materials. The plain concrete panels cracked and failed quickly, unable to handle more than a few cycles of pressure. The panels with raw bamboo performed slightly better but still lost their stiffness rapidly and failed after a few cycles. The steel-reinforced panels held up the best, absorbing the most energy and maintaining their shape for the longest time, which confirmed the reliability of the traditional method. However, the panels reinforced with bamboo treated with the epoxy and nano-basalt mixture came remarkably close to the steel performance. This specific treated bamboo panel withstood a maximum load of 60.6 kilonewtons and absorbed 76.8 kilonewton-millimeters of energy, figures that were very close to the 62.6 kilonewtons and 83.3 kilonewton-millimeters achieved by the steel panels. In contrast, the untreated bamboo and other less advanced treatments fell significantly short of these numbers.

Beyond just the numbers, the way the panels failed told an important story about safety. When the untreated bamboo panels failed, they did so suddenly and catastrophically, splitting apart without warning. The treated panels, however, showed a much more gradual decline. As the load increased, they developed cracks that spread evenly across the surface rather than concentrating in one weak spot. This behavior meant that the structure would give visible signs of distress long before it collapsed, allowing people time to react. The treated bamboo also retained its stiffness much better than the raw bamboo, losing only about 25 percent of its rigidity after multiple cycles, whereas the raw bamboo lost more than half. This ability to stay stiff and absorb energy repeatedly suggests that the coating successfully prevented the bamboo from slipping inside the concrete, a common cause of failure in untreated versions.

To ensure these findings were accurate, the researchers also built a computer model of the panels to simulate the physical tests. The digital simulation matched the real-world results closely, confirming that the mathematical models used to predict how concrete and bamboo interact were working correctly. This alignment between the physical experiments and the computer simulations gives confidence that the results are reliable and not just a fluke of the specific samples tested. The study concludes that by using a simple coating of epoxy mixed with nano-basalt and glass, bamboo can be transformed into a viable alternative to steel for reinforcing concrete in structures that face repeated or moderate shaking. While it did not completely replace steel in every metric, it proved that a sustainable, plant-based material can be engineered to perform with a level of durability and safety that makes it a serious contender for future construction, particularly in regions where steel is expensive or difficult to source.