|Title:||Sustainable Concretes for Transportation Infrastructure|
|Authors:||Carolyne Namagga and Rebecca Atadero|
|Publication Date:||Jul 2010|
|MPC Project #:||301|
|Keywords:||fly ash, pavements, sustainable development|
|Type:||Research Report – MPC Publications|
This research focuses on the beneficial utilization of Spray Dryer Ash (SDA) and investigates its performance in concrete for structural and transportation applications. Based on the challenges associated with disposal of all coal ashes, and SDA in particular, and the economic and environmental costs linked to cement production, this research seeks to provide an environmentally friendly and more cost effective concrete product by utilizing SDA in partial replacement of cement in concrete. The SDA used in this study is similar to Class C fly ash, which is known to provide increased strength and durability when used in concrete. The sulfur content of the SDA slightly exceeds ASTM specified limits for fly ash used in concrete, which has prevented its beneficial application in the past. This interim report describes the first stage of a study to demonstrate the potential feasibility using this SDA in concrete. Numerous concrete specimens were manufactured from mixes with varying percentages of SDA. Results of compression testing indicate that even when fifty percent of the cement is replaced with SDA, the mix can achieve adequate strength. In preparation for freeze-thaw durability testing the required amount of air entraining admixture was determined. The presence of SDA results in a higher demand for air entrainer in order to produce mixes with the same air content.