Concrete is one of the most widely used construction materials. Production of portland cement, however, is carbon intensive, and the cement industry accounts for nearly 8% of global carbon dioxide (CO2) emissions. The concrete industry also consumes significant amounts of natural aggregate. Currently, global annual production of concrete is 4.4 billion tons. Typically, 70% of concrete is aggregate, translating to 3.1 billion tons of stone and sand being harvested every year. Excessive extraction of rock and sand depletes natural resources and causes environmentally detrimental secondary effects (e.g., erosion, deforestation, and damage to river ecosystems). Steel is another important element in concrete construction. The production of steel rebar is widely considered the largest single source of greenhouse gases produced in concrete construction. For example, steel production accounts for about 51% of the total energy consumption and about 49% of the total CO2 emission for residential buildings. In this talk, the speaker will present three recently completed projects on using different recycled materials to replace virgin counterparts in concrete. All three studies suggested that recycled materials are a viable option to promote sustainability and achieve cost benefits for the concrete industry.
Xijun Shi PhD, PE
Texas State University