Portland cement-based concrete (PCC) is the most widely used construction material. In the manufacturing of PCC, admixtures are added into concrete to enhance the properties of fresh or hardened concrete. However, undesired interactions between admixtures and the hydration of cement may exist which limit the effects of the admixtures, or prevent applications of some admixtures in concrete. If the undesired interaction between the admixture and cement hydration can be minimized/eliminated, optimal effects of using admixtures in concrete can be achieved.
Researchers at The University of Alabama have developed a versatile, low-cost tool called hard encapsulation to store or control the release of admixture in concrete to minimize or avoid undesired interactions between the admixtures and hydration of cement. This tool uses perforated cenospheres to load and then release or seal the admixtures within concrete as needed.
Compared with existing polymer-based micro-encapsulation: •Admixture microcapsules with cenosphere shell have much higher stiffness & strength. •Compatible & chemically reactive with concrete. •Cenospheres are low-cost industrial waste, easily manufactured & implemented. •Highly stable & durable chemically and temperature-wise.