Andrews, P, Town, RM, Hedley, MJ & Loganathan, P 1996, 'Measurement of plant-available cadmium in New Zealand soils', AUSTRALIAN JOURNAL OF SOIL RESEARCH, vol. 34, no. 3, pp. 441-452.
View/Download from: Publisher's site
View description>>
Several methods of measuring plant-available cadmium (Cd) were compared using soils that had accumulated Cd under normal New Zealand agricultural practices (low total Cd concentrations, and phosphatic fertiliser as the dominant Cd source). The study encompassed 9 New Zealand soils with different Cd input histories. Cadmium was extracted from these soils by demineralised water, 0.05 M Na2EDTA, l M NH4OAC (pH 7), 0.01 M CaCl2, and 0.05 M CaCl2 and quantified by differential pulse anodic stripping voltammetry (DP-ASV) and graphite furnace atomic absorption spectrophotometry (AAS). The DP-ASV measures the free Cd ion and that associated with labile complexes, but not large organic Cd complexes. Extractable Cd levels were compared with those which are plant-available, as determined by pot studies (lettuce). The 0.01 M CaCl2-extractable Cd measured by AAS and 0.05 M CaCl2-extractable Cd measured by DP-ASV gave the best estimate of plant availability of Cd.
Gurung, SR, Stewart, RB, Loganathan, P & Gregg, PEH 1996, 'Aluminium-organic matter-fluoride interactions during soil development in oxidised mine waste', SOIL TECHNOLOGY, vol. 9, no. 4, pp. 273-279.
View/Download from: Publisher's site
View description>>
A three year field trial assessing the suitability of mine waste rock as a surrogate subsoil with different depths of topsoil showed that pasture yield was significantly lower in the unmodified waste rock (UWR) treatments compared to waste rock modified with lime and potassic superphosphate (MWR) during the first two years but there was no difference in yield in the third year between the waste rock treatments. The reduced yield in UWR during the first two years was considered to be due to phytotoxic levels of aluminium (Al) in the UWR soil solution. Soil samples from the waste rock interface (A) and waste rock at depth ≤ 300 mm (B) collected at the end of the three year trial were analysed for different forms of soil Al, total soluble fluoride (F), dissolved organic carbon (DOC) and soil pH to determine whether organic matter and F leachate from the topsoil reduced Al toxicity at the waste rock interface (A) during soil development over 3 years. Results showed that after 3 years, 0.02 M CaCl2 extractable Al (Al(Ca)) and 1 M KCl extractable exchangeable + soluble Al (Al(K)) were effectively reduced in the MWR interface (A) by lime and fertiliser applications but they remained at very high phytotoxic levels (Al(Ca) = 17-21 μg g-1, Al(K)=261-339 μg g-1) in the UWR interface (A) irrespective of topsoil depth treatment. The corresponding organic bound Al (Al(OM)) ranged from 200 to 214 μg g-1 and DOC was in the range 169-203 μg g-1 in both UWR and MWR interfaces (A). These values were a significant two-fold higher than the values at depth ≤300 mm (B) which were considered to be the original levels of Al(OM) and DOC in UWR. The increase in Al(OM) and DOC by the third year is probably due to progressive leaching of organic ligands produced from the decomposition of organic matter in the topsoil subject to an annual rainfall of 2500 mm. This evidence for the reduction in Al toxicity by organic matter is further supported by significant dry root density (DRD) in the UWR ...
Indraratna, B 1996, 'Utilization of lime, slag and fly ash for improvement of a colluvial soil in New South Wales, Australia', Geotechnical & Geological Engineering, vol. 14, no. 3, pp. 169-191.
View/Download from: Publisher's site
View description>>
In Australia, colluvial soils form large terrains which are often subjected to considerable erosion and mass movement. This study presents a laboratory evaluation of the improvement effected by hydrated lime, milled blast furnace slag and fly ash on a fine grained (erosive) colluvial soil in New South Wales, Australia. Geotechnical tests were conducted to determine the compaction and consolidation characteristics and the compressive and shear strength properties of the blended and natural soil specimens. The effect of these additives on the Atterberg limits and pH levels is also investigated. As large amounts of fly ash and steel slag are produced in New South Wales, it is economically attractive to utilize these industrial by-products for ground improvement rather than employing conventional methods such as lime treatment. This study demonstrates that for the colluvial soil tested, milled slag is the most effective in terms of improving the internal friction angle of the treated soil, while lime is the most suitable for achieving the optimum compressive strength. Non-pozzolanic fly ash is found to be inappropriate as a soil improving agent. The cost of ground treatment using the various additives is also estimated and compared. © 1996 Chapman & Hall.
Indraratna, B & Lasek, G 1996, 'Laboratory evaluation of the load-deflection behaviour of clay beams reinforced with galvanised wire netting', Geotextiles and Geomembranes, vol. 14, no. 10, pp. 555-573.
View/Download from: Publisher's site
View description>>
In Australia the utilisation of clay in the construction of landfill liners has recently come under criticism either due to the difficulty in reproducing the laboratory results on site, or because of the potential for cracking of the compacted liner after construction. Realising that clay is weak in tension and given the possibility of certain areas of the liner being subjected to flexure, a testing program was undertaken to determine the effects of placement (compaction), moisture content and internal reinforcement on the potential failure of clay liners. In particular, this paper discusses the load carrying capacity and deformation sustained by compacted clay beams in flexure, and the improvement gained through the introduction of an economical reinforcement in the form of galvanised steel wire netting. Results obtained by flexural bending tests are discussed in detail, and the extent of improvement provided by galvanised wire netting is evaluated. © 1997 Elsevier Science Ltd. All rights reserved.
INDRARATNA, B, DILEMA, ELG & VAFAI, F 1996, 'AN EXPERIMENTAL STUDY OF THE FILTRATION OF A LATERITIC CLAY SLURRY BY SAND FILTERS.', Proceedings of the Institution of Civil Engineers - Geotechnical Engineering, vol. 119, no. 2, pp. 75-83.
View/Download from: Publisher's site
View description>>
In many parts of the world, residual soils are used for the construction of impervious dam cores. This paper discusses the experimental details and design aspects of sand filters in the retention of a range of particle sizes in a clay slurry. Lateritic residual soil has a propensity to crack at relatively small tensile strains, if compacted either at low moisture content or at energy levels greater than the standard Proctor method. From laboratory results, a distinct demarcation between effective and noneffective filters was identified in considering the filter permeability and a specific particle size of the base soil (clay floes) retained by the filter. The equivalent of specific grain size <5g5, determined by hydrometer analysis was considered as the reference base particle, and the cation concentration of the base soil slurry was taken to represent the typical reservoir water chemistry of several dams in Thailand. The permeability of the filter was examined as a function of the sand grain sizes and the resulting empirical relationships are given in the paper. The performance of granular filters, including clogging behaviour, has'been studied according to~the particle sizes and uniformity coefficients of the filter media. The applicability of the proposed empirical relationships in practice is discussed in contrast to the conventional filter criteria.
Loganathan, P, Hedley, MJ, Gregg, PEH & Currie, LD 1996, 'Effect of phosphate fertiliser type on the accumulation and plant availability of cadmium in grassland soils', NUTRIENT CYCLING IN AGROECOSYSTEMS, vol. 46, no. 3, pp. 169-178.
View/Download from: Publisher's site
View description>>
Cadmium (Cd), a potentially toxic heavy metal for humans and animals, accumulates in the liver and kidneys of older animals grazing New Zealand and Australian pastoral soils. Phosphorus (P) fertiliser is the major input of Cd into these farming systems. A study was conducted to evaluate the effects, over 10 years, of annual application (30 kg P ha-1 yr-1) of four forms of P fertilisers having different solubilities and Cd contents [41, 32, 10 and 5 μg Cd g-1 for North Carolina phosphate rock (NCPR), single superphosphate (SSP), diammonium phosphate (DAP) made from low Cd phosphate rocks and Jordan phosphate rock (JPR) respectively] on soil and herbage Cd concentrations. Ten years of fertiliser application caused a marked increase in surface soil Cd concentrations. Total soil Cd was significantly higher in SSP and NCPR treatments compared to control (no P fertiliser), JPR and DAP treatments in the 0-30 and 30-75 mm soil depths. Plant-available Cd (0.01 M CaCl2 extractable Cd) was higher in SSP treatments than in control and other fertiliser treatments. Chemical analysis of herbage samples showed that there was no significant difference in Cd concentration in pasture grasses between treatments in the second year of the trial but in the eighth and tenth year, plots fertilised with SSP and NCPR had significantly higher Cd in pasture grasses in most of the seasonal cuts compared to control, JPR and DAP. Cadmium recovery by both grasses and clover was less than 5% of Cd applied in fertiliser. Clover Cd concentration and yield were much lower than those for grass and therefore its contribution to pasture Cd uptake was very low (< 7%). A strong seasonal effect on grass Cd concentration, which is inversely related to pasture growth rate, was observed in all three sampling years - Cd concentration was highest during autumn and lowest in spring. Total Cd contents of the fertilisers and their rate of dissolution rather than soil pH [pH (H2O) at 30-75 mm depth of 5.39, 5.20, ...
Manoharan, V, Loganathan, P, Parfitt, RL & Tillman, RW 1996, 'Changes in soil solution composition and aluminium speciation under legume-based pastures in response to long-term phosphate fertiliser applications', AUSTRALIAN JOURNAL OF SOIL RESEARCH, vol. 34, no. 6, pp. 985-998.
View/Download from: Publisher's site
View description>>
This study describes some of the effects of 8 years of annual application of 6 types of phosphatic fertilisers on the chemical composition and aluminium (Al) speciation in soil solution extracted from a soil under pasture. Soil samples at 2 depths, 0-30 and 30-75 mm, were collected at the end of 8 years. Soil solutions were extracted by centrifuging at 12 000 RCF and analysed for Al, Na, K, Ca, Mg, F, NO3, Cl, and SO4, as well as pH and ionic strength. Soil and soil solution pH were significantly increased at both depths by application of North Carolina phosphate rock (NCPR) compared with the control. In contrast, diammonium phosphate (DAP) significantly decreased the soil and solution pH. Single superphosphate (SSP) did not have any significant effect on soil or solution pH compared with the untreated control. The surface soil (0-30 mm) solution pH was on average 0.6 of a unit higher than the subsurface soil (30-75 mm) solution pH. Total monomeric Al concentration [Al], measured by the pyrocatecol violet (PCV; 4 min) method, ranged from 1.5 to 4.8 μM in the surface soil and 2.5 to 12.2 μM in the subsurface soil. The DAP and higher rates of SSP application resulted in a large increase in total and inorganic monomeric [Al] in the soil solution extracted from the subsurface soil. Total soluble [F] ranged from 2.7 to 23.5 μM and 3.2 to 25.6 μM in the surface and subsurface soils, respectively, and was significantly increased by the application of NCPR and by higher rates of SSP. The predominant forms of inorganic monomeric Al present in the soil solution were estimated to be the non-phytotoxic Al-F complexes, AIF2+, and AIF2/+. There was a marked decrease in toxic Al species (Al3+, Al(OH)2+, Al(OH)2/+) in soil solution following NCPR and SSP application. This was due primarily to complexation of Al with F derived from these fertilisers forming non-toxic Al-F complexes. The results suggest that the long-term application of reactive phosphate rock such as NCPR may con...
Manoharan, V, Loganathan, P, Tillman, RW & Parfitt, RL 1996, 'Assessing aluminum phytotoxicity in long-term phosphate fertilized pasture soils', COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS, vol. 27, no. 5-8, pp. 1731-1748.
View/Download from: Publisher's site
Ngo, HH & Vigneswaran, S 1996, 'Application of downflow floating medium flocculator/prefilter (DFF) - coarse sand filter (CSF) in nutrient removal', Water Science and Technology, vol. 33, no. 8, pp. 63-70.
View/Download from: Publisher's site
View description>>
In this study, the applicability and the advantages of the downflow floating medium filter (DFF) in wastewater treatment were examined. The experimental results indicated that the DFF with in-line flocculation addition is a good pretreatment unit to reduce phosphorus load (up to 80-89% removal). The DFF also resulted in uniform filterable-flocs of 32-42 µm throughout the filter run. Thus it can also successfully be used as a flocculator. The backwashing of floating medium was achieved with a small quantity of water and at low backwash velocity. The introduction of floating medium filter bed on top of a coarse sand filter unit (CSF) increased the filter run time and removal efficiency (more than 87 and 94% of NH3-N and T-P removal respectively), particularly at a low filtration rate (5 m3/m2.h).
Stewart, MG 1996, 'Optimization of serviceability load combinations for structural steel beam design', Structural Safety, vol. 18, no. 2-3, pp. 225-238.
View/Download from: Publisher's site
View description>>
In Australia, typical design load combinations for serviceability are ψsQ and G + ψsQ (D and D + L in the US) where G and Q are design dead and live loads, respectively, and ψs is a short-term live load factor. Code calibration is conducted herein for Australian and US serviceability load combinations, for structural steel beams in flexure. The effects that office, retail, domestic and car parking loads and tributary areas have on serviceability reliability is described. It was found that serviceability reliabilities for different floor uses vary considerably for Australian and US serviceability load combinations; whereas the differences between serviceability reliabilities for one year and duration of a single tenancy reference periods were not great. Short-term live load factors for most floor uses were adjusted (sometimes significantly) to ensure that serviceability reliabilities exceed the minimum target level of 1.65. Consequently, the present paper provides suggested values for short-term live load factors that may be used in Australian and possibly in US codes. Copyright © 1996 Elsevier Science Ltd.
Stewart, MG 1996, 'Serviceability Reliability Analysis of Reinforced Concrete Structures', Journal of Structural Engineering, vol. 122, no. 7, pp. 794-803.
View/Download from: Publisher's site
View description>>
A probabilistic model is developed to estimate immediate, creep, and shrinkage deflections. Monte Carlo simulation is used to estimate deflections and probabilities of serviceability failure (lifetime and for each 8 yr tenancy) for reinforced concrete beams sized according to the span-to-depth ratio serviceability requirements of Australian, British, and American Concrete Structures Codes. Serviceability failure is denned to occur when a deflection exceeds an allowable deflection limit as a result of flexure. It was found that the span-to-depth ratio serviceability requirements of these codes produce significantly different serviceability reliabilities. This is probably a consequence of the fact that the serviceability specifications of these codes have not been subjected to code calibration. A code-calibration exercise considering load factors, loading combinations, and/or allowable deflection limits may minimize these variations in serviceability reliabilities.
Thomas, PS 1996, 'Dependence of the friction process on the molecular structure and architecture of thin polymer films', Tribology International, vol. 29, no. 8, pp. 631-637.
View/Download from: Publisher's site
Zhou, JL, Fileman, TW, Evans, S, Donkin, P, Mantoura, RFC & Rowland, SJ 1996, 'Seasonal distribution of dissolved pesticides and polynuclear aromatic hydrocarbons in the Humber Estuary and Humber coastal zone', Marine Pollution Bulletin, vol. 32, no. 8-9, pp. 599-608.
View/Download from: Publisher's site
Ball, JE & Luk, KC 1970, 'Determination of the rainfall distribution over a catchment using hydroinformatic tools', HYDROINFORMATICS '96, VOLS 1 AND 2, 2nd International Conference on Hydroinformatics (Hydroinformatics 96), A A BALKEMA, ZURICH, SWITZERLAND, pp. 369-376.
Baweja, D, Roper, H & Sirivivatnanon, V 1970, 'Corrosion of steel in marine concrete: Long-term half-cell potential and resistivity data', American Concrete Institute, ACI Special Publication, pp. 89-110.
View description>>
This paper presents some results from a major research project carried out on corrosion of steel reinforcement in concrete. The performance of a range of Portland and blended cement concretes containing fly ash and blast furnace slag exposed to simulated marine conditions was evaluated over a period of six years. A large amount of data relating to corrosion of embedded steel in concrete was obtained in this project. Long-term half cell potential data on reinforcement within concrete slabs and resistivity data on the same concrete specimens has been considered in detail in this paper. Rates of corrosion of steel in concrete were also measured using potentiodynarnic anodic polarization procedures. Trends observed in the data were different for the portland and blended cement concretes investigated. It was found that concrete resistivity may influence the measured half cell potential of steel in concrete. This factor needs to be taken into account for half cell potential data interpretations.
Keshavarzy, A & Ball, JE 1970, 'Characteristics of turbulent shear stress applied to bed particles in an open channel flow', STOCHASTIC HYDRAULICS '96, 7th IAHR International Symposium on Stochastic Hydraulics, A A BALKEMA, MACKAY, AUSTRALIA, pp. 451-458.
Sirivivatnanon, V, Marsh, P & Nelson, P 1970, 'Field performance of portland cement and fly ash concrete subjected to flowing seawater', American Concrete Institute, ACI Special Publication, pp. 463-479.
View description>>
The concrete lining the outfall canal of Munmorah Power Station, built by the Electricity Commission of New South Wales (now operating as Pacific Power) in the mid-1960s, has been subjected to flowing sea water for 30 years. Two type of concretes, a portland-cement concrete and a fly-ash concrete, were used for the construction of the canal. This presented an ideal opportunity for a comparison to be made of the performance of the two binders in concretes which were subjected to the same aggressive environment. Limited information was available on the concretes from trial mixture records. A recent field investigation revealed similar chloride ingress into the two concretes in the tidal zone. This was so despite the fact that the fly-ash concrete had a lower binder content than the portland-cement concrete. As such, a lower strength grade and hence a fly-ash concrete with higher water permeability can perform as well as a portland-cement concrete. In the dry area above the high tide mark, the carbonation depth of the fly-ash concrete was greater than the portland-cement concrete. No corrosion was found in any reinforcing steel as there were sufficient cover in both concretes to prevent the chloride ions or carbonation front reaching the steel. The effectiveness of a number of investigative techniques was evaluated during the investigation. It was found that the apparent chloride diffusion coefficients, determined from short-term immersion, the water permeability coefficients, and copper to copper sulfate half-cell potential measurements were poor indicators of the real long-term performance.
