| Title |
An Experimental Study on Thermal Properties according to Rock Types of the Crushed Aggregates for Concrete |
| Authors |
Cho, Kyung-Suk ; Kim, Sang-Heon ; Seo, Chee-Ho |
| DOI |
http://dx.doi.org/10.5659/JAIK_SC.2016.32.4.31 |
| Keywords |
Crushed Aggregates ; Rock Types ; Thermal Expansion ; Specific Heat ; Thermal Conductivity ; Cooling methods |
| Abstract |
The analysis of the petrologic characteristics and thermal properties of crushed aggregates for concrete such as granite, gneiss, dolomite, shale and andesite found that rock-forming minerals decided the thermal properties of the aggregates. The thermal expansion coefficients of aggregates containing lots of quartz increased rapidly at 573 ℃ due to quartz transition. The mass of aggregate containing carbonate minerals decreased rapidly at 750 ℃ due to decarboxylation, while its specific heat capacity increased relatively. The mass of aggregates containing hydrated silicate minerals decreased more significantly and their specific heat capacities were greater when compared with aggregates containing feldspar or quartz. It is deduced that the hydroxyle group (OH) in hydrated silicate dissolved as its bond became loose at high temperatures. Aggregates containing mafic minerals turned red at high temperatures due to oxidation response. And, the comparison of cooling methods showed that rapid cooling using water resulted in more reduction in aggregate mass than slow cooling at room temperatures. |