The Phase Transformation of Recycling Concrete in Recalcination

Abstract:

In this paper, the artificial aggregates were prepared by limestone and industrial wastes in accordance with the ratio of cement raw meal, to obtain the recycling concrete replacing natural aggregates. Cement clinker could be regenerated by these recycling concrete and the aim of recycling could be realized. After these concrete was cured for 90 days, then was crushed and grinded, the phase transformation of recycling concrete in recalcination would been studied by XRD and so on. The experimental results showed that the composition of the recycling concrete met the demand of clinker modulus and C₂S, C₃S, C₄AF, C₃A were well crystallized at 1400 °C. So these recycling concrete could be directly calcined. The calcium hydroxide dehydrated around the temperature of 500°C. The calcium silicate hydrate was dehydrated gradually between the temperature of 400°C and 1000°C. At the same time, C₂S crystallized during the temperature range. C₄AF and C₃A stared to crystallize around the temperature of 1000°C. Due to the composition of these concrete was complex, the lowest eutectic temperature dropped. C₃S started to crystallize around the temperature of 1250°C and the best crystallization was achieved at the temperature of 1400°C.

• Periodical: Materials Science Forum (Volumes 743-744)
• Pages: 175-179
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.743-744.175
• Online since: January 2013
• Authors: Zhi Gang Zhang, Zong Hui Zhou, De Cheng Zhang, Xin Cheng
• Keywords: Industrial Waste, Phase Transformation, Recalcination, Recycled Concrete (RC)

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DOI: 10.1023/b:jmsc.0000025827.65956.18