Experimental study on CO2 curing for enhancement of recycled aggregate properties

Abstract In this paper, the results of an experimental program on studying the use of a carbonation process to enhance the properties of recycled aggregates are presented. Hardened concretes prepared by using different water-to-cement ratios in the laboratory, were crushed to produce recycled aggregates with different particle sizes. Before and after the laboratory carbonation process, the physical properties of the recycled aggregate, including water absorption and density were determined. The extent of CO 2 curing of the recycled aggregate was quantified by assessing the carbonation percentage of the aggregates. Carbonation resulted in reduction in water absorption values and increase in density and these showed that the properties of recycled aggregate were improved. The factors influencing the CO 2 curing process, including curing time, particle size and moisture contents of the recycled aggregate, were investigated.

[1]  L. Lange,et al.  Preliminary Investigation into the Effects of Carbonation on Cement-Solidified Hazardous Wastes , 1996 .

[2]  C. Dobson,et al.  The carbonation of OPC and OPC/silica fume hardened cement pastes in air under conditions of fixed humidity , 1993 .

[3]  P. Chindaprasirt,et al.  Influence of rice husk–bark ash on mechanical properties of concrete containing high amount of recycled aggregates , 2008 .

[4]  Amnon Katz,et al.  Treatments for the Improvement of Recycled Aggregate , 2004 .

[5]  Jianzhuang Xiao,et al.  Experimental study on the failure mechanism of recycled concrete , 2011 .

[6]  B. Johannesson,et al.  Microstructural changes caused by carbonation of cement mortar , 2001 .

[7]  C. J. Lynsdale,et al.  Carbonation of CH and C-S-H in Composite Cement Pastes Containing High Amounts of BFS , 2010 .

[8]  C. Tam,et al.  Microstructural analysis of recycled aggregate concrete produced from two-stage mixing approach , 2005 .

[9]  Manabu Kanematsu,et al.  Application of Conventionally Recycled Coarse Aggregate to Concrete Structure by Surface Modification Treatment , 2007 .

[10]  Mark G. Richardson,et al.  Fundamentals of Durable Reinforced Concrete , 2002 .

[11]  D. Cocke,et al.  An FTIR and XPS investigations of the effects of carbonation on the solidification/stabilization of cement based systems-Portland type V with zinc , 1993 .

[12]  Hanning Xiao,et al.  Influence of coating recycled aggregate surface with pozzolanic powder on properties of recycled aggregate concrete , 2009 .

[13]  T. Hansen.  Recycling of Demolished Concrete and Masonry , 1992 .

[14]  Kazunobu Hirai,et al.  Influence of Environmental Moisture and Temperature on Carbonation of Mortar , 1990 .

[15]  Chi Sun Poon,et al.  The use of recycled aggregate in concrete in Hong Kong , 2007 .

[16]  J. Khatib,et al.  Properties of concrete incorporating fine recycled aggregate , 2005 .

[17]  Chi Sun Poon,et al.  Feasibility study of using recycled fresh concrete waste as coarse aggregates in concrete , 2012 .

[18]  P. Rouxhet,et al.  Carbonation of the hydration products of tricalcium silicate , 1976 .

[19]  A. Cairns-smith,et al.  Morphology and CO2 uptake in tobermorite gel , 1975 .

[20]  Anthony J. Tarquin,et al.  Role of Carbonation in Transient Leaching of Cementitious Wasteforms , 1997 .

[21]  Vivian W. Y Tam,et al.  Diversifying two-stage mixing approach (TSMA) for recycled aggregate concrete: TSMAs and TSMAsc , 2008 .

[22]  Valeria Corinaldesi,et al.  Influence of mineral additions on the performance of 100% recycled aggregate concrete , 2009 .

[23]  C. Tam,et al.  Removal of cement mortar remains from recycled aggregate using pre-soaking approaches , 2007 .

[24]  L. Lange,et al.  The effect of accelerated carbonation on the properties of cement-solidified waste forms , 1996 .

[25]  C. Poon,et al.  Comparisons of natural and recycled aggregate concretes prepared with the addition of different mineral admixtures , 2011 .

[26]  E. Reardon,et al.  High pressure carbonation of cementitious grout , 1989 .