Costs and carbon emissions for geopolymer pastes in comparison to ordinary portland cement

Geopolymer concrete is seen as a potential alternative to standard concrete, and an opportunity to convert a variety of waste streams into useful by-products. One key driver in geopolymer development is the desire to reduce greenhouse gas emissions from the production of concrete products. This paper presents an examination of the lifecycle cost and carbon impacts of Ordinary Portland Cement (OPC) and geopolymers in an Australian context, with an identification of some key challenges for geopolymer development. The results of the examination show that there is wide variation in the calculated financial and environmental “cost” of geopolymers, which can be beneficial or detrimental depending on the source location, the energy source and the mode of transport. Some case study geopolymer concrete mixes based on typical Australian feedstocks indicate potential for a 44–64% reduction in greenhouse gas emissions while the financial costs are 7% lower to 39% higher compared with OPC.     

MODELING MULTIPLE-USE IN NATURAL AREAS: PART II - THE SANTEE SWAMP STUDY1

ABSTRACT: The previous paper in this two-part series presented the basic information of a newly developed mathematical model of multiple-use in natural areas. The model is a unified system for the assessment of cases where development is proposed for relatively natural areas. This paper presents the results of an application of the model to a study of the proposed timber harvest in the Great Santec Swamp in South Carolina. This was done in an effort to demonstrate the utility of the model as a planning and assessment tool. Four potential uses of the Swamp were investigated: logging of hardwood saw timber, hunting, fishing, and nature observation. The model system proved to be extremely useful in the evaluation of potential management schemes and in the selection of the most promising or optimal management plan.