Novel and Sustainable Binder Systems
High volume limestone in cementitious systems: physico-chemical effects and properties
The environmental impact, particularly the significant emission of greenhouse gases associated with the manufacture of ordinary portland cement (OPC) has catalyzed studies on the use of several environmentally benign alternate materials as partial OPC replacements. Fine limestone powder is one such material that has shown to be a viable partial OPC replacement material. A clear understanding of the effects of limestone replacement in combination with fly ash or metakaolin on the fresh and hardened properties has facilitated new strategies to proportion binder formulations which show comparable or superior properties to traditional OPC formulations. Read more.
Iron based binders – Waste Utilization and carbon dioxide sequestration
Methods to reduce the amount of greenhouse gases (GHG) such as CO2 in the atmosphere is an active research area. Mineral route of carbonation, where mined mineral rocks are used as the feedstock through which CO2 is passed is one of the promising routes to reduce the concentration of CO2 in the atmosphere. We have forwarded, for the first time, the possibility of carbonating waste metallic iron powder to develop sustainable binder systems for concrete. The fundamental premise of this work is that metallic iron will react with aqueous CO2 under controlled conditions to form complex iron carbonates which have binding capabilities. Read more
Alkali Activation of alumino-silicates
Several strategies are being recommended and adopted towards reducing the production of ordinary Portland cement (OPC) which is proven to be a large contributor of greenhouse gas emission. Among these methods, one of the most studied one is the development of binder systems using alkaline activation of aluminosilicate materials such as fly ash (coal combustion by-product), or ground granulated blast furnace slag. This methodology is extremely beneficial in concrete because the process of forming a value-added material by utilizing large volumes of an industrial waste/byproduct alleviates concerns related to its disposal and results in a lower ecological foot-print for the concrete thus produced. Read more.
Rheological response of cementitious binders
Rheological studies of concentrated suspensions of solid particles in a continuous liquid medium are commonly used to assess the characteristics of materials in industries ranging from food to pharmaceuticals to construction materials. The flow behavior of these concentrated suspensions is influenced by surface contacts between solid particles and interparticle forces such as van Der Waals and steric forces. We have developed methods to extract yield stress of cementitious suspensions without approximating models and elucidated the rheological response of several sustainable binders. Read more.