Drying Shrinkage of Alkali Activated Cements
	Name: Drying Shrinkage of Alkali Activated Cements File: Hojati 05-17-16.pdf Size(MB): 2.58MB Extension: PDF Event: 2016 ICSC - WASHINGTON DC Speaker Name: Hojati, M. Managed by: sdickens Date Uploaded: June 21, 2016; 11:43 am Download Count: 406 Downloads This Month: 406 Your Geographic Information: Country: United States State/Region: Michigan City: Ann Arbor Zip Code: 48104 Area Code: 734 Your IP: 35.172.217.40 Description: This paper studied the drying shrinkage of four different AAC binders, all having a 28-day compressive strength greater than 30 MPa. These include an alkali activated class F fly ash (AAFA), an alkali activated slag (AAS), and two alkali activated F fly ash/slag blended binders with different proportions of slag and fly ash. All four binders, as well as a control OPC binder had the same (liquid/solid)vol and as such, same initial porosity. Drying shrinkage and mass loss of mini-prisms were monitored as a function of time at different relative humidities (RH). In addition, the effect of moist curing temperature (23oC vs. 60oC) on the subsequent drying shrinkage magnitude was evaluated. The results showed that all AAC binders cured at 23oC have high shrinkage in comparison with the OPC binder, and shrinkage increased with higher content of fly ash in the AAC. However, steam curing (60oC) had a significant impact on drying shrinkage and the steam cured AAFA binder showed the smallest shrinkage. The results also showed that shrinkage of AACs varied depending on the ambient RH. Interestingly, for AACs containing slag, the largest drying shrinkage was observed at 50% RH, with lower humidities resulting in lower shrinkage.