Mixing Rocks: How Limestone Changes Concrete's Strength and Radiation Shielding

Concrete is everywhere. It's in buildings, bridges, and even some radiation shielding. But did you know that adding limestone can change how strong it is and how well it blocks radiation? A recent study looked at how limestone from different places affects concrete. First, they mixed limestone from three different spots with regular cement. They used different amounts, from 5% to 20%. Then, they checked how the concrete hardened over time. They looked at things like how much water it needed, how fast it set, and how strong it got. The results were interesting. Limestone from Alexandria worked best for early strength. It helped the concrete harden faster and get stronger quicker. But limestone from El-Menia was better for long-term strength. It made the concrete stronger over a longer time. Meanwhile, limestone from Helwan didn't work as well, especially when they used more of it. It made the concrete weaker because it was coarser and less reactive.But the study didn't stop at strength. They also checked how well the concrete could block radiation. Concrete with Alexandria limestone was the best at blocking gamma rays and neutrons. It had the highest radiation protection efficiency, especially at certain energy levels. This study shows that not all limestone is the same. Where it comes from matters. It also shows that concrete can be used for more than just building things. It can also help protect against radiation. This is important for making buildings safer and more sustainable.