A hillside in Mexico City, where regular concrete has contributed to depleted aquifers. Photo: Marina Micheli/Flickr

Concrete is the most commonly used building material worldwide. In recent years, manufacturers have been working to create products that enhance the performance of concrete in a number of ways. Often these products take the form of additives. Typically found in powdered or liquid form, concrete additives are included during the mixing process to achieve various effects. Additives are not new. They have been around for generations, however, new formulas are focused on making concrete more sensitive to environmental and ecological concerns. Here are a few examples.