Liu, B, Ray, AS & Thomas, P 2013, 'Investigation of autoclaved cement systems with reactive MgO and Al2O3-SiO2 rich fired clay brick', Advances In Cement Research, vol. 25, no. 5, pp. 281-287.View/Download from: UTS OPUS or Publisher's site
Portland cement (PC) is one of the world's most important building materials, as it is a fundamental component of concrete. However, the manufacture of PC is highly energy intensive and leads to the emission of carbon dioxide (CO2). One promising control
Liu, B, Ray, AS & Thomas, P 2008, 'Physical and mechanical properties of autoclaved alumina-silica rich industrial waste cement systems incorporating reactive magnesia', Concrete Forum, vol. 1, no. 1, pp. 18-22.View/Download from: UTS OPUS
The utilisation of industrial waste products as supplementary cementitious materials to produce blended Portland cement has increased worldwide in recent years. This study aims to investigate physical and mechanisal properties of the addition of clay-brick waste and reactive magnesia (MgO) as a low-emmission alternative to ordinary Portland cement (OPC) binders in autoclaved calcium silicate based building products
Liu, B, Ray, AS, Thomas, P, Klimesch, DS & Guerbois, JL 2007, 'Mechanical properties of hydrothermally treated alumina-silica rich industrial waste cement system - effect of magnesia addition', Journal of Solid Waste Technology and Management, vol. 33, no. 2, pp. 61-66.View/Download from: UTS OPUS
The utilisation of industrial waste products such as fly ash, blast furnace slag and fired clay-brick, as supplementary cementing materials to produce blended Portland cement (PC) has increased worldwide in recent years. The incentive was directed towards the utilisation of wastes and industrial by-products in order to minimise PC consumption, thus reduce CO2 emissions. This study aims to investigate the potential of magnesia (MgO) as a supplementary material in combination with alumina-silica rich fired clay brick waste fines. Compressive strength results showed adverse effects on the additions of brick waste fines and MgO. However, for blended PC with the addition of both brick waste and magnesia, an apparent synergy, indicating a minimising of strength reduction, was observed. X-ray diffraction (XRD) data revealed the presence of brucite, a hydration product of MgO, in the MgO blended PC suggesting a lack of pozzolanic activity of MgO.
Liu, B, Thomas, P, Ray, AS, Williams, RP & Donne, S 2007, 'DSC Characterisation Of Chemically Reduced Electrolytic Manganese Dioxide', Journal Of Thermal Analysis And Calorimetry, vol. 88, no. 1, pp. 177-180.View/Download from: UTS OPUS or Publisher's site
The thermal decomposition of electrolytic manganese dioxide (EMD), in an inert atmosphere, and the effect of chemical reduction on EMD, using 2-propanol under reflux (82 degrees C), was investigated by differential scanning calorimetry (DSC). This study
Liu, B, Ray, AS & Thomas, P 2007, 'Strength development in autoclaved aluminosilicate rich industrial waste-cement systems containing reactive magnesia', Journal of the Australian Ceramics Society, vol. 43, no. 1, pp. 82-87.View/Download from: UTS OPUS
Liu, B, Thomas, P, Ray, AS & Guerbois, JL 2007, 'A TG analysis of the effect of calcination conditions on the properties of reactive magnesia', Journal Of Thermal Analysis And Calorimetry, vol. 88, no. 1, pp. 145-149.View/Download from: UTS OPUS or Publisher's site
The reactivity of MgO obtained from calcination of magnesium carbonate at different temperatures has been investigated by means of hydration in a constant relative humidity environment at 40 degrees C for periods up to 24 days. Natural magnesite and AR g grade basic MgCO3 calcinated in the range of 500-1000 degrees C was characterised in terms of surface area, crystallite size, morphology, and hydration rate. It was foudn that the hydration rate is dependent on the surface area and crystallite size wwhere temperature was the main variable affecting them. The most reactive MgO was produced at the lowest calcination temperature with the highest surface area and the smallest crystallite size. The basic MgO specimens showed higher degree of hydration compared to the natural mgO specimens due to the smaller surface area and larger cyrstallite size. The low MgO content of the starting natural magnesite is also attributable to the lower reactivity. This preliminary study serves as a mean to investigate poetntial utilisation of reactive MgO asa supplementary cementitious material in eco-freindly cements.
Liu, B, Thomas, P, Williams, RP & Donne, S 2005, 'Thermal characterization of chemically reduced electrolytic manganese dioxide', Journal Of Thermal Analysis And Calorimetry, vol. 80, no. 3, pp. 625-629.View/Download from: UTS OPUS or Publisher's site
Samples of electrolytic manganese dioxide (EMD) were chemically reduced using 2-propanol under reflux (82 degrees C) for 1, 2, 3, 6 and 24 h intervals. XRD analysis showed that the gamma-MnO2 structure was preserved although the lattice dimensions were o
Liu, B, Thomas, P, Ray, AS & Williams, RP 2004, 'The effect of sampling conditions on the thermal decomposition of electrolytic manganese dioxide', Journal Of Thermal Analysis And Calorimetry, vol. 76, no. 1, pp. 115-122.View/Download from: UTS OPUS or Publisher's site
The effect of sampling conditions on the decomposition of electrolytic manganese dioxide using thermal methods is reported. Significant differences were observed in the mechanism of the decomposition by simply changing the reaction environment from a closed pan to an open pan configuration. The purge gas atmosphere was also observed to influence the decomposition mechanism. As a product of the decomposition is oxygen, the change in the mechanism observed between the experimental conditions may be explained in terms of the ease of removal of oxygen from the reaction site.
Liu, B, Ray, AS & Thomas, P 2010, 'Drying shrinkage of hydrothermally cured cements with reactive magnesia and clay brick waste', Proceedings of the 12th International Inorganic-Bonded Fiber Composites Conference, International Inorganic-Bonded Fiber Composites Conference, Aalborg University, Aalborg, Denmark, pp. 90-95.View/Download from: UTS OPUS
In recent years, worldwide research and development in the cement industry has gathered momentum with an aim to explore innovative and sustainable methods to deliver environmentally responsible Portland Cement (PC) based construction products. This study investigated physical and mechanical properties of autoclaved cement-quartz sand blends with the addition of clay-brick waste (CB waste) and reactive magnesia (MgO) with the aim to lower CO2 emissions through the reduction of PC consumption. Mechanical properties and drying shrinkage showed improvements with the incorporation of CB waste due to increased amounts and crystallinity of Al-tobermorite. The addition of reactive MgO to PC in hydrothermal conditions was observed to have a negative effect on the compressive strength. XRD data indicated that MgO did not take part in the reaction during the hydration of the cement and may even retard tobermorite formation. However, the expansive nature from the hydration of MgO to brucite may have compensated for drying shrinkage.
Ray, AS, Connan, H, Liu, B & Thomas, P 2009, 'Alumina-Silica Rich Clay Brick Waste In Hydrothermally Treated Cement-Based Construction Products', Proceedings of the 34th Conference on Our World In Concrete & Structures, Conference On Our World In Concrete & Structures, CI-Premier Conference Organisation, Singapore, Singapore, pp. 289-296.View/Download from: UTS OPUS
An urgent need for creative, sustainable approaches, which minimise the environmental impact of conventional Portland Cement (PC) -based construction materials, is recognised throughout the world. In recent years intensive research has been directed to the use of alumino-silicate materials to produce blended PC. The reduction of CO2 emissions, through the minimisation of PC consumption in the manufacture of PC-based construction products, and utilisation of industrial byproducts, to limit environmental impact, are the principal drivers of this worldwide activity. A number of supplementary cementitious materials (SCMs) containing alumina and silica such as fly ash, granulated blast furnace slag and silica fume are well known additives for the production of blended PCs due to their pozzolanic properties. The potential of other by-products such as those from the construction and demolition industry are less known however, even though they represent an excellent source of reactive alumina and silica-rich material. This paper deals with fired clay bricks (CB), generated as a waste product from construction and demolition activities, and their value as an additive in the manufacture of PC-based construction products. The research findings reported in this paper are from laboratory scale experiments conducted under hydrothermal conditions in an autoclave where fmely ground Cl3 waste was incorporated in the mixes. From a combination of analytical techniques including X-ray Diffraction, Differential Thermal Analysis, Scanning Electron Microscopy and solid-state Nuclear Magnetic Resonance, it was established that the aluminosilicate phase in the fired clay bricks promoted the development of the tobermorite, the principal binder in most calcium silicate products under hydrothermal conditions. The use of CB waste as a cement replacement for the manufacture of these products was also demonstrated as a viable option.