SOLID-STATE SI-29 AND AL-27 NMR AND FTIR STUDY OF CEMENT PASTES CONTAINING INDUSTRIAL-WASTES AND ORGANICS

Si-29 and Al-27 NMR and FTIR have been used to study the products of OPC hydration in the presence of a heavy metal containing stabilized waste which is commercially solidified, selected organics and pulverised fuel ash. Si-29 NMR unambiguously quantifies the extent of silicate polymerisation, which is severely retarded in mixes containing the stabilized waste. Al-27 NMR spectroscopy indicates the presence of both ettringite and monosulfate in a cement containing 2% of the stabilized waste, while only ettringite is detected in the spectra of samples with 19 and 30% additions. Phenol and ethylamine also reduce silicate condensation, although a sample containing both the metal waste and mixed organics showed silicate condensation levels similar to those found in a normal OPC paste. It is difficult to draw firm conclusions from the FTIR results due to band overlap in the region of interest.