Hydro-thermal hydration of regenerated binding materials and Influences on properties of its hardened pastes

Title: Hydro-thermal hydration of regenerated binding materials and Influences on properties of its hardened pastes
Author(s): Y. He, L. Lu, S. Hu
Paper category : conference
Book title: International Conference on Microstructure Related Durability of Cementitious Composites
Editor(s): W. Sun, K. van Breugel, C. Miao, G. Ye and H. Chen
Print-ISBN: 978-2-35158-065-3
e-ISBN: 978-2-35158-084-4
Publisher: RILEM Publications
Publication year: 2008
Pages: 1027 - 1034
Total Pages: 8
Nb references: 6
Language: English

Abstract: To efficiently recycle the rapidly increased amount of waste concrete, the production of high strength calcium-silicate material with the waste concrete is proposed. The mortar separated from waste concrete is treated with grinding and calcining processes, and then used as the raw material for producing calcium-silicate products. With mechanical tests, and XRD, SEM tests, the properties of the samples prepared with the treated mortar are investigated and compared with those of untreated mortar and ground quartz sand. The results show that the thermal activating treatment by calcining the mortar at suitable low temperature (in this experiment, 650 °C)contributes a lot to the compressive strength of the sample, and the reason is that the hydration of high reactive regenerated binding materials formed in the calcining process of the mortar. The type of the mineral phases formed in the samples is tightly related to the content of Ca(OH)2 or fCaO in raw materials. But even without additionally added Ca(OH)2, the thermal activating treated mortar itself can provide enough Ca and Si for producing high strength calcium-silicate materials.

Online publication: 2009-06-09
Publication type : full_text
Public price (Euros): 0.00