https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:7426 Wed 11 Apr 2018 16:59:52 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:54071 Tue 30 Jan 2024 14:09:51 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:29620 Tue 28 Jan 2020 16:28:41 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:51600 This paper presents observations of carbonation and alkali loss for well-compacted reinforced concrete columns from the exterior and interior of a 60-y-old in-land building. Calcium carbonate formation was detected only in the outermost 10 mm to 15 mm. However, alkali loss and concrete pH reduction extended much further inward but reinforcement corrosion was not observed. Theoretical thermodynamic conditions dictate that corrosion initiation of reinforcement can result only from the long-term dissolution and loss by leaching of calcium hydroxide from the concrete matrix. These appear rate-limited by the barrier effect of carbonated concrete. These interpretations provide a new model for “carbonation” initiation of reinforcement corrosion. The results also show the potential for concretes to absorb atmospheric carbon dioxide (greenhouse gases) for an extended time without significant risk of reinforcement corrosion.]]> Tue 12 Sep 2023 12:31:56 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:42576 95% of calcite (CaCO₃) recovery from synthetic lime wastewater followed by 85-90% from LSP & RSP under optimized conditions. Subsequent reduction of total dissolved solids and suspended solids in the range of 78-82% and 76-77% in LSP & RSP was also observed. Mineralogical analysis using X-ray diffraction technique along with standards (lime, calcite, lime & calcite mix) confirms the production of calcite. Statistical analysis showed a P value < 0.05 indicating a higher degree of correlation (R₂ > 0.95) among the process conditions and variables using response surface methodology and was further validated using artificial neural networking. This study demonstrates a sustainable and cleaner way of resource recovery from waste through CO₂ fixation from lime solid waste (sludge).]]> Thu 25 Aug 2022 15:17:59 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:11661 Sat 24 Mar 2018 10:31:58 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:15380 Sat 24 Mar 2018 08:18:55 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:15386 Sat 24 Mar 2018 08:18:54 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:11340 Sat 24 Mar 2018 08:08:16 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20201 2 concentration and temperature, change relative humidity(RH),and consequently change RC infrastructures’ surrounding environment. Especially in the long run, the decline of the safety, serviceability and durability of RC structures may be accelerated. Carbonation induced corrosion damage of RC infrastructure in Xiamen and Shaoguan under a changing climate is investigated for time period 2010 ~ 2100. The projection of atmospheric CO₂ concentration, temperature and RH in both cities are based on the representative concentration pathways (RCPs). The time-dependent reliability analysis was conducted by Monte Carlo simulation and includes the uncertainty of dimensions,material properties, climate projections, and predictive models. The corrosion damage risks of RC structures are represented by the probability of severe cracking of concrete cover. Results show that climate change may increase mean carbonation depth by 8mm by 2100. Moreover, carbonation-induced damage risk for RC buildings in temperate areas can be increased by 12% ~ 19%. This research provides a reference for impacts of future climate change on RC structures and development of climate adaptation strategies.]]> Sat 24 Mar 2018 08:06:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:21837 Sat 24 Mar 2018 08:00:50 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:17692 Sat 24 Mar 2018 07:57:42 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19360 Sat 24 Mar 2018 07:52:01 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25378 Sat 24 Mar 2018 07:39:09 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:30699 2 partial pressure (0.05 to 0.1 %), pertinent to a novel greenhouse calcium looping process. The kinetic parameters were obtained and compared with those reported in the literature. Various gas–solid reaction mechanisms were considered to determine the best reaction mechanism for the carbonation reaction. The diffusion function, or G(x)=x², had the best least-squares linear fit, which resulted in a first-order reaction for the carbonation reaction in the greenhouse calcium looping process. Moreover, the activation energy and pre-exponential factor of the carbonation reaction were established to be 19.7 kJ mol⁻¹ and 295.8 min⁻¹ kPa⁻¹, respectively. The derived kinetic parameters were used in Aspen Plus to optimize the carbonator reactor size. The required size of the reactor decreased with increasing operating temperature of the reactor. Exergy analysis revealed that the overall exergetic efficiency of greenhouse calcium looping could be more than 80 %.]]> Sat 24 Mar 2018 07:35:09 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25538 Sat 24 Mar 2018 07:26:03 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:25995 Sat 24 Mar 2018 07:24:29 AEDT ]]>