**1.1 Output and source of the innocuous recycling resources in Taiwan**

The attention of shortage of the primitive aggregate has been received in Taiwan. Although the natural resource in Taiwan is rather lack, the innocuous recycling resources are quite plentiful (e.g., construction residual soil, granite sludge, lime sludge, reservoir sediments, and so on). Using above-mentioned resources to manufacture the recycling green building materials is a good means in light of several aspects, including the reduction of waste, recycling of resource, and low carbon society. The Taiwan government has been devoted to developing the sustainability of society and has promulgated some acts to achieve this goal (Hsieh et al., 2012). Certainly, use of above-mentioned resources is one of the crucial issues because the resources and space for storing waste in Taiwan is so limited. Moreover, the global warming (or so-called climate change) is one of hot issues, in which how to reduce CO2 has received much attention.

For the promotion and facility of reuse and recycling of construction residual soil, which are generally sorted as 9 categories (i.e. B1 to B7) in Taiwan as shown in Table 1 (Industrial Technology Research Institute [ITRI], 1996). Herein the construction residual soils of B1, B2-1, B2-2, and B5 categories were immediately reused through uncomplicated process (like crushing and sieving, etc.), but the reuse rate of B2-3, B3, B4, B6, and B7 categories is extremely low due to their poor properties. According to the evaluation by the Construction and Planning Agency Ministry of the Interior, R.O.C. the construction residual soil of about 40 millions m3 is generated every year as shown in Table 2, and the B2-3, B3, B4, B6, and B7 categories with extremely low reuse rate accounted for more than 50 %.

Cold-Bonding Technique – A New Approach to Recycle

reconstruction of CPDC An-Shun site in the future.

Innocuous Construction Residual Soil, Sludge, and Sediment as Coarse Aggregates 97

uncontaminated and innocuous lime sludge in vegetation area. The CPDC expected to recycle the above-mentioned uncontaminated and innocuous lime sludge as recycling coarse aggregates through using cold-bonding technique for the remediation and

Fig. 1. The surrounding location of CPDC An-Shun site (Chao et al., 2008).

technique is the reduction of energy consumption and CO2 emission.

Based on the purposes of green building materials (i.e. reduction of waste and CO2 footprint, energy conservation, lightening of material, and so on), it is a critical issue for building and construction department to treat the wastes properly and encourage the recycling of resources. In spite of many investigators (Chen et al., 2010; Hung & Hwang, 2007) indicate that the sintering technique has been successfully applied to recycle abovementioned resources as lightweight aggregates. But the energy consumption and CO2 emission of sintering process are too much to be extensively adopted. A new approach, the cold-bonding technique (Cai et al., 2010, 2012 & Tsai et al., 2011, 2012) incorporates the principles of the cement chemistry (Mehta, 1986; Mindess & Young, 1981) and composite material (Gibson, 1994), was developed to recycle these resources as recycling coarse aggregates. Consequently, the main difference between cold-bonding and sintering

The cold-bonding recycling coaese aggregate was regarded as a fiber reinforced concrete or a cement-based composite that is the original concept for developing cold-bonding recycling coarse aggregates. In which cement, blast-furnace slag (BF slag), and fly ash are regarded as cementitious materials or binders, the construction residual soil, granite or lime sludge is as a filler (i.e. aggregate), and the glass fiber is as a reinforcement. In view of the fundamental principle of concrete materials (Dowling, 1993; Skalny & Mindess,

**1.2 Mechanism of cold-bonding technique** 


Table 1. Categories of construction residual soil in Taiwan.


Table 2. Output of the construction residual soil every year in Taiwan (ITRI, 1996).

The granite sludge of about 300,000 to 500,000 ton was generated from cutting and grinding granite in Taiwan. The common treatment and final disposal technology of granite sludge were solidification and landfill in the past, therefore its recycling amount is only approximately 50,000 ton every year. The granite sludge should not be classified as an industrial waste, but rather a recycling resource. On the basis of environmental protection aspects and increase economic benefits, the cold-bonding technique was adopted to recycle granite sludge as coarse aggregates.

The China Petrochemical Development Corporation (CPDC) An-Shun site that was a decommissioned chloroalkaline and pentachlorophenol manufacturing plant in Tainan, Taiwan includes 115,000 m3 of chloroalkaline plant, 40,000 m3 of pentachlorophenol plant, 47,000 m3 of vegetation area, 27,000 m3 of grass area, and 155,000 m3 of seawater storage pond as shown in Fig. 1 (Chao et al., 2008). The highest mercury concentration was found in the chloroalkaline plant with a level as high as 3,370 mg/kg in soil, way above the soil control standard of 20 mg/kg. The worst dioxin contamination was found in the pentachlorophenol plant with levels as high as 64,100,000 ng-I-TEQ/kg in soil, whereas the soil control standard is 1,000 ng-I-TEQ/kg. But there is a large amount of about 90,000 m3 of

B1 (m3) B2-1 (m3) B2-2 (m3) B2-3 (m3) B3 (m3) B4 (m3) B5 (m3) B6 (m3) B7 (m3) Total (m3) 2002 9,745,339 3,157,653 2,660,776 3,859,634 6,253,732 4,641,081 286,941 175,606 131,461 30,912,223 2003 6,491,354 6,256,473 4,009,632 6,125,236 6,927,483 4,852,074 995,285 803,362 424,588 36,885,487 2004 4,109,131 8,417,495 6,705,485 6,530,775 8,408,148 5,177,942 809,651 612,185 107,955 40,878,767 2005 2,178,436 8,148,354 6,974,924 9,182,229 8,409,695 5,884,677 1,095,015 485,395 78,657 42,437,382 2006 1,749,982 7,975,805 6,272,035 9,352,248 7,340,871 5,571,844 1,370,277 917,939 46,155 40,597,156 2007 3,099,089 6,538,887 4,829,821 9,762,949 6,524,040 4,483,718 1,636,861 1,294,205 31,871 38,201,441 2008 3,079,980 7,420,172 4,499,688 8,924,265 6,560,130 3,821,069 1,895,799 538,005 55,848 36,794,956 2009 2,419,110 5,494,537 3,982,374 8,289,454 3,818,809 1,917,679 1,393,881 529,180 237,392 28,082,416 2010 1,862,649 5,984,624 3,840,541 11,238,137 3,732,365 2,533,991 1,653,261 948,366 680,717 32,474,651 Total 34,735,070 59,394,000 43,775,276 73,264,927 57,975,273 38,884,075 11,136,971 6,304,243 1,794,644 327,264,479 (%) 10.61 18.15 13.38 22.39 17.72 11.88 3.40 1.93 0.55 100.00

Table 2. Output of the construction residual soil every year in Taiwan (ITRI, 1996).

The granite sludge of about 300,000 to 500,000 ton was generated from cutting and grinding granite in Taiwan. The common treatment and final disposal technology of granite sludge were solidification and landfill in the past, therefore its recycling amount is only approximately 50,000 ton every year. The granite sludge should not be classified as an industrial waste, but rather a recycling resource. On the basis of environmental protection aspects and increase economic benefits, the cold-bonding technique was adopted to recycle

The China Petrochemical Development Corporation (CPDC) An-Shun site that was a decommissioned chloroalkaline and pentachlorophenol manufacturing plant in Tainan, Taiwan includes 115,000 m3 of chloroalkaline plant, 40,000 m3 of pentachlorophenol plant, 47,000 m3 of vegetation area, 27,000 m3 of grass area, and 155,000 m3 of seawater storage pond as shown in Fig. 1 (Chao et al., 2008). The highest mercury concentration was found in the chloroalkaline plant with a level as high as 3,370 mg/kg in soil, way above the soil control standard of 20 mg/kg. The worst dioxin contamination was found in the pentachlorophenol plant with levels as high as 64,100,000 ng-I-TEQ/kg in soil, whereas the soil control standard is 1,000 ng-I-TEQ/kg. But there is a large amount of about 90,000 m3 of

Code Properties of construction residual soil B1 Rocks, gravels, crushed rocks, or sand

B5 Brick and concrete blocks

granite sludge as coarse aggregates.

B3 Silt B4 Clay

B2-1 Blended soil, gravels, and sand (soil <30 % by vol.) B2-2 Blended soil, gravels, and sand (30 %<soil<50 % by vol.) B2-3 Blended soil, gravels, and sand (soil>50 % by vol.)

B6 Sediment or soil contains >30 % moisture by wt. B7 Bentonite from continuous walls construction

Table 1. Categories of construction residual soil in Taiwan.

uncontaminated and innocuous lime sludge in vegetation area. The CPDC expected to recycle the above-mentioned uncontaminated and innocuous lime sludge as recycling coarse aggregates through using cold-bonding technique for the remediation and reconstruction of CPDC An-Shun site in the future.

Fig. 1. The surrounding location of CPDC An-Shun site (Chao et al., 2008).
