A cleaner production of one-part alkali activated cement (AAC) was implemented by mixing chemically
treated concrete waste (CTC) with slag. The treatment process was conducted by the addition of NaOH to
concrete waste (CoW) at NaOH to CoW weight ratios of 0.2, 0.1, and 0.05 (namely, CTC-1. CTC-2, and CTC3, respectively), followed by mixing with water and drying. The solidified material was ground then drymixed with slag to create one-part alkali AAC powder with fixed particle size. The amount of CTC was
varied to achieve constant Na2O content (2 wt %) in all mixtures. The results indicated that the prepared
one-part AACs can react with water to yield hardened materials with acceptable compressive strength.
Comparing with CTC-1 and CTC-3, the CTC-2 was found to have a dominant impact on the activation of
slag hydration, which associated with the higher mechanical properties, lower pore volume, and drying
shrinkage. The addition of lead bearing sludge (LBS) to one-part AAC containing CTC-2 resulted in a
positive impact on the performance of the prepared cement. According to toxicity characteristic leaching
procedures the prepared cement showed a potential effect on solidification/stabilization of Pb-containing-sludge. |
