Specification for shotcrete specifies control over slump, time lag between batching and placing, compressive strength, shotcrete thickness, density and permeability. The wet-mix shotcrete is required to have quality control over the workability for easy pneumatic placement, minimum rebound and good compaction. This paper reports the quality assurance experience gained from a project involving 2700 cubic metre of shotcrete, during the construction of 35 km long Southern Sydney Freight Line project, lasted over 3 years. The field experience showed that quality assurance specification for shotcrete mix must be followed to ensure the quality of placed shotcrete.
Neupane, K, Sriravindrarajah, R, Baweja, D & Chalmers, D 2015, 'Effect of curing on the compressive strength development in structural grades of geocement concrete', CONSTRUCTION AND BUILDING MATERIALS, vol. 94, pp. 241-248.View/Download from: Publisher's site
Sri Ravindrarajah, R & Baraca, G 2015, 'High strength ultrafine fly Ash Concretes with Silica Fume or Hydrated Lime Addition', International Journal of Constructive Research in Civil Engineering, vol. 1, no. 1, pp. 14-18.
Production of sustainable concrete mixes for infrastructure construction is targeted by the concrete industry. This is resulted in the use of supplementary cementitious materials, admixtures and recycled materials. The effects of either silica fume or hydrated lime addition (about 10% by weight of the cementitious materials) on the mechanical properties of high strength fly ash concrete are investigated. The investigated properties are compressive strength, tensile strength, modulus of elasticity and drying shrinkage. The results indicated that the silica fume addition caused the compressive strength to improve by 24% and 15%, at the ages of 28 and 56 days, respectively. On the other hand, the hydrated lime addition had reduced the strength by 12% and 20% at the ages of 28 and 56 days, respectively. The modulus of elasticity of concrete was found to increase by the addition both silica fume and hydrated lime. 56-day drying shrinkage was increased by 3% or 14%, by the silica fume or hydrated lime addition, respectively. It is concluded that the addition of 10% hydrated lime to fly ash concrete had the undesirable effects of reducing compressive strength and increasing the drying shrinkage. On the other hand the addition of silica fume resulted in improved hardened concrete properties.
Sri Ravindrarajah, R & White, SR 2014, 'Non-Delayed Heat Application Effects on The Strength of Concrete For Railway Sleepers', Concrete Research Letters, vol. 5, no. 1, pp. 716-721.View/Download from: UTS OPUS
Precast concrete sleepers production requires the application of low-pressure steam curing to accelerate the early age strength development. In this curing process, heat is gradually applied to the sleepers after 2 hours from casting. A typical production specification for concrete sleepers limits the rate of temperature rise to 24
C per hour and the maximum temperature to 70
C. However, it is not usual to consider heat application immediately after casting to achieve improved productivity to meet the supply demand. This paper reports the results of an experimental investigation into the effect of non-delayed heat application on the early age and later age compressive strength for the typical concrete mixes used for the production of concrete sleepers in Australia. The mixes had either ordinary Portland cement or high early-age strength Portland cement with the low calcium fly ash as binder materials. The results showed that the compressive strength after 8 hours and 28 days were significantly reduced when non-delayed heat application was carried out. Delayed ettringite formation (DEF) could be one of the reasons for the strength reductions and a delayed period up to 4 hours is beneficial in controlling the strength loss.
Aoki, Y, Sri Ravindrarajah, R & Khabbaz, H 2012, 'Properties Of Pervious Concrete Containing Fly Ash', Road Materials and Pavement Design, vol. 13, no. 1, pp. 1-11.View/Download from: UTS OPUS or Publisher's site
Pervious concrete is one of the most effective pavement materials to address a number of important environmental issues, such as recharging groundwater and reducing stormwater runoff. In this paper, the findings of an experimental investigation on proper
Spanos, A, Sri Ravindrarajah, R & Swamy, RN 2012, 'Material and structural implications of using ferrocement as permanent formwork', Indian Journal of Concrete, vol. 86, no. 8, pp. 9-23.
This paper critically examines the potential of ferrocement panels for use as permanent load-bearing formwork for one-way and two-way slabs. The ferrocement panels used were 333mm wide and 25 or 37.5 mm thick, reinforced with a wide range of combination of mesh and skeletal steel. Initial flexural tests on the panel itself showed excellent crack control, high ductility and energy absorption capacity and lower shrinkage and creep. The feasibility of using ferrocement as permanent formwork is then illustrated by tests on one-way composite slabs. These tests showed that deflection and design loads are the two major criteria for design, and that deflection can be satisfactorily estimated by elastic analysis of uncracked sections. The composite panels showed enhanced stiffness, superior crack control and higher ultimate flexural strength compared to conventional slabs. Natural bond between in-situ concrete and ferrocement panels ensured full composite action and structural integrity. This type of construction is shown to have superior serviceability performance compared to conventional slabs.
Sri Ravindrarajah, R, Neo, HW & Lai, JE 2012, 'Mix Design for Pervious Recycled Aggregate Concrete', International Journal of Concrete Structures and Materials, vol. 6, no. 4, pp. 239-246.View/Download from: UTS OPUS
Pervious concrete is a tailored-property concrete with high water permeability which allow the passage of water to flow through easily through the existing interconnected large pore structure. This paper reports the results of an experimental investigation into the development of pervious concrete with reduced cement content and recycled concrete aggregate for sustainable permeable pavement construction. High fineness ground granulated blast furnace slag was used to replace up to 70 % cement by weight. The properties of the pervious concrete were evaluated by determining the compressive strength at 7 and 28 days, void content and water permeability under falling head. The compressive strength of pervious concrete increased with a reduction in the maximum aggregate size from 20 to 13 mm. The relationship between 28-day compressive strength and porosity for pervious concrete was adversely affected by the use of recycled concrete aggregate instead of natural aggregate. However, the binder materials type, age, aggregate size and test specimen shape had marginal effect on the strength-porosity relationship. The results also showed that the water permeability of pervious concrete is primarily influenced by the porosity and not affected by the use of recycled concrete aggregate in place of natural aggregate. The empirical inter-relationships developed among porosity, compressive strength and water permeability could be used in the mix design of pervious concrete with either natural or recycled concrete aggregates to meet the specification requirements of compressive strength and water permeability.
Cabral, E, Schalch, V, Molin, D, Ribeiro, J & Sri Ravindrarajah, R 2010, 'Shrinkage modelling for recycled aggregate concretes', IBRACON Structures and Materials Journal, vol. 3, no. 1, pp. 1-23.View/Download from: UTS OPUS or Publisher's site
Concerns with conservation of nonrenewable resources are propelling academic research regarding the use of recycled aggregates in concrete production. Concreteâs shrinkage is a phenomenon intimately linked to concrete loss of water, which is almost inevitable, since the majority of concrete structures is exposed to an environment where atmospheric humidity is below saturation condition. This paper presents an experimental study where concretes were produced varying water/cement ratio (from 0.4 to 0.8) and type and proportion of construction & demolition waste (concrete, cement, and red ceramic) used as coarse and fine recycled aggregates. Mathematical models correlating such variables with concreteâs shrinkage at 56 and 224 days of age were built. The results indicate that, for the age of 56 days, the data presented excessive variability, revealing only 4 of the 7 tested variables as significant. For the age of 224 days, the proposed model still presented considerable variability, however all tested variables were detected as significant. Results point out that substitution of natural aggregates by recycled aggregates increases shrinkage, being this effect stronger when substitution comprises fine aggregates. The most pronounced effect was associated to the use of recycled concrete fine aggregate. The slightest effect was observed using recycled concrete coarse aggregate.
Vessalas, K, Ray, AS, Thomas, P, Sri Ravindrarajah, R, Joyce, PA & Haggman, J 2009, 'Pitchstone Fines - A New Naturally Occuring Pozzolan from North Queensland', Concrete Forum, vol. 2, no. 1, pp. 11-15.View/Download from: UTS OPUS
Global warming presents an ever-challenging battle to humankind, as emissions arising from industrially produced gteenhouse gases are predicted to alter the long-term climatic patterns of earth. Harmful environmental emissions arising during the manufactute of Portland cements (C) can be effectively reduced by incorporating siliceous-aluminous based supplementary cementitious materials (SCMs), as partial cement replacements. In Australia, mined pitchstone fines (PF), derived as waste material from expandable perlire production, area viable SCM for reducing cement consumption using an eco-friendly approach. This paper reports on the results of an experimental investigation into the pozzolanic activity of PP. Up to 40% cement was replaced with PF in mortar mixes. In addition, PP was used to partially replace sand. Strength activity index (SM) values for PP were evaluated using accelerated 28-day compressive strengths for all PP substitution levels, with flows and wet densities of mortar mixes reported.
Vessalas, K, Ray, AS, Thomas, P, Sri Ravindrarajah, R, Joyce, PA & Haggman, J 2009, 'Pitchstone fines pozzolanic activity assessment as partial Portland cement (PC) replacements', Journal of Australasian Ceramic Society, vol. 44, no. 1, pp. 7-12.View/Download from: UTS OPUS
Mined pitchstone fines (PF), derived as a waste by-product from expandable perlite production in Australia, are a viable, environmentally friendly aluminosilicate supplementary cementitious material (SCM) suitable for partial Portland cement (PC) replacement, thus reducing greenhouse gas emissions resulting from PC manufacture. This paper reports on the findings of pozzolanic activity exhibited at 10%, 20% and 40% replacement levels of PC, through compressive strength determinations of mortar after 1, 7 and 28 days ageing, using strength activity index (SAI) criteria. Additionally, flows and wet densities have been examined using a polycarboxylic based high-range water-reducing admixture (HRWRA) superplasticiser and fixed water content relative to cementitious material present for all PF substitution levels.
Ray, AS, Sri Ravindrarajah, R, Guerbois, JL, Thomas, P, Border, SN, Ray, H, Haggman, J & Joyce, P 2007, 'Evaluation of waste perlite fines in the production of construction materials', Journal Of Thermal Analysis And Calorimetry, vol. 88, no. 1, pp. 279-283.View/Download from: UTS OPUS or Publisher's site
The use of supplementary cementitious materials (SCM) is a well established practice worldwide in the manufacture of Portland cement (PC)-based construction materials. While utilisation of industrial by-products has been successful, the potential of mining wastes is yet yo receive adequate attention in the context of construction materials. In an expanded form perlite, which is a naturally occurring, hydrated volcanic siliceous glass, is an adeal material as a lightweight aggregate for usein a wide range of construction materials including concrete. The mining and processing of the grades of perlite required for the production of lightweight aggregate results inthe cereation of a fine grained waste wjhich currently hasno economic value. This paper reports preliminary data on the utilisation of waste perlite fines as a SCM in calcium silicate-based construction material and discusses the potential of this mining waste to reduce the environmental impact of the production of conventional cement-based consturction materials.
Sivapathasundaram, R & Sri Ravindrarajah, R 1998, 'Properties of polystyrene aggregate concrete having densities of 1300 and 1900 kg/m3', Journal of the Australian Ceramic Society.
Sri Ravindrarajah, R & Collins, J 1998, 'Temperature development in mass concrete containing polystyrene aggregate concrete'.
Sri Ravindrarajah, R & Tuck, AJ 1994, 'Properties of hardened concrete containing treated expanded polystyrene beads', Cement and Concrete Composites, vol. 16, no. 4, pp. 273-277.View/Download from: Publisher's site
Sri Ravindrarajah, R, Thomas, PR, Ray, A & Sugo, H 1993, 'Processing of piggery waste and its usage in cement mortar', Journal of Resource Management and Technology, vol. 21, pp. 69-75.
Sri Ravindarajah, R 1992, 'Strength evaluation of high-strength concrete by ultrasonic pulse velocity method', Journal Non-Destructive Testing (Australia), vol. 29, pp. 6-9.
Paramasivam, P. & Sri Ravindrarajah, R. 1988, 'Effect Of Arrangements Of Reinforcements On Mechanical-properties Of Ferrocement', ACI Structural Journal, vol. 85, no. 1, pp. 3-11.
Sri Ravindrarajah, R 1987, 'Utilization Of Waste Concrete For New Construction', Conservation & Recycling, vol. 10, no. 2-3, pp. 69-74.
Sri Ravindrarajah, R & Tam, CT 1987, 'Recycling concrete as fine aggregate in concrete', International Journal of Cement Composites and Lightweight Concrete, vol. 9, no. 4, pp. 235-241.View/Download from: Publisher's site
Increasing shortage of natural aggregates for concrete in urban areas leads to a search for aggregates from new sources. This paper examines the use of crushed concrete fines (CCF) produced from 'waste' concrete as fine aggregate in concrete. Tests were carried out to study the properties of crushed concrete fines and the properties of concrete incorporating them. The results show that the modulus of elasticity, pulse velocity, and the long-term properties such as drying shrinkage and creep are significantly affected. It has been found that the detrimental effects of using crushed concrete fines in concrete can be mitigated by a partial replacement of crushed concrete fines with pulverised fuel ash (pfa). © 1987.
Sri Ravindrarajah, R, Loo, Y & Tam, CM 1987, 'Recycled Concrete As Fine And Coarse Aggregates In Concrete', Magazine Of Concrete Research, vol. 39, no. 141, pp. 214-220.
Tam, CM, Lim, T, Sri Ravindrarajah, R & Lee, SL 1987, 'Relationship Between Strength And Volumetric Composition Of Moist-cured Cellular Concrete', Magazine Of Concrete Research, vol. 39, no. 138, pp. 12-18.View/Download from: Publisher's site
Sri Ravindrarajah, R 1985, 'Casting delay om workability and strength of concrete', International Journal of Cement Composites and Lightweight Concrete, vol. 7, no. 2, pp. 109-113.View/Download from: Publisher's site
Placing of concrete may be delayed from the time of mixing due to many reasons. This investigation showed that although the delay causes considerable loss in workability, there was no detrimental effect on compressive strength for concretes with or without set-retarding admixture or superplasticizer. Incremental addition of superplasticizer was capable of maintaining the concrete slump within a small variation throughout the delay period. The effectiveness of superplasticizer to improve the workability was found to be a function of initial slump and the age of fresh concrete. © 1985.
Sri Ravindrarajah, R & Tam, CM 1985, 'Properties Of Concrete Made With Crushed Concrete As Coarse Aggregate', Magazine Of Concrete Research, vol. 37, no. 130, pp. 29-38.
Sri Ravindrarajah, R 1984, 'Quality concrete production for housing projects', International Journal of Housing Science and its Applications, vol. 8, no. 2, pp. 181-184.
Sri Ravindrarajah, R & Tam, CT 1984, 'Flexural strength of steel fibre reinforced concrete beams', International Journal of Cement Composites and Lightweight Concrete, vol. 6, no. 4, pp. 273-278.View/Download from: Publisher's site
This paper describes the influence of steel fibre distribution on the ultimate strength of concrete beams. The effect of delayed casting between the plain concrete and fibre concrete layers on the ultimate strength of concrete beams is also investigated. For the same amount of fibres used, strength of (partially) reinforced beams with fibres in the bottom layer only is about 25% more than that for fully reinforced beams. The presence of fibres in the compression zone does not significantly improve the beam strength. A delay in casting between the plain concrete and fibre concrete layers does not significantly change the ultimate strength of partially fibre reinforced concrete beams. © 1984.
Green, D.W., Ali, I., Ramakrishna, G., Sri Ravindrarajah, R. & Hamdani, I. 1983, 'New Method For Proportioning Concrete Mix - Discussion', Proceedings Of The Institution Of Civil Engineers Part 1-design And Construction, vol. 74, no. AUG, pp. 519-523.
Sri Ravindrarajah, R. 1983, 'Aggregate Grading For Nuclear Concrete - Discussion', Journal Of Construction Engineering And Management-asce, vol. 109, no. 4, pp. 478-479.View/Download from: Publisher's site
Sri Ravindrarajah, R. & Tam, C.M. 1983, 'Dimensional Stability Of Ferrocement', Journal Of Ferrocement-bangkok, vol. 13, no. 1, pp. 1-12.
Mccarter, W., Forde, M., Whittington, H. & Sri Ravindrarajah, R. 1982, 'Resistivity Characteristics Of Concrete', Proceedings Of The Institution Of Civil Engineers Part 2-research And Theory, vol. 73, no. MAR, pp. 223-224.
Sri Ravindrarajah, R 1982, 'Additional phenomenon on the effect of pre-sustained loading', The International Journal of Cement Composites and Lightweight Concrete, vol. 4, pp. 251-252.
Cement kiln dust, a waste material in the cement industry, contains partially processed raw materials. This paper reports an investigation into its usage in concrete as a partial replacement for cement. The percentages of cement replacement by weight were 0, 25, 50, 75 and 100 in cement paste and 0, 15, 25, 35 and 45 in both 1:1.5:3 and 1:2:4 concretes. The results showed that the kiln dust is a cementitious material and it causes the following effects when used as cement replacement: 1. 1. retards the setting of cement; 2. 2. increases the water demand for a constant consistency; and 3. 3. decreases the concrete strength. For the same workability concrete, cement can be replaced by up to 15 per cent with cement kiln dust without causing significant strength loss. © 1982.
Sri Ravindrarajah, R. 1982, 'Fiber Reinforced-concrete Short Columns Under Uniaxially Eccentric Loads', Proceedings Of The Institution Of Civil Engineers Part 2-research And Theory, vol. 73, no. SEP, pp. 695-696.
Swamy, RN & Sri Ravindrarajah, R 1982, 'Development of a conductivity probe to monitor setting time and moisture movement in concrete', Cement, Concrete and Aggregates, vol. 4, pp. 73-80.
Sri Ravindrarajah, R & Alvaro, M 2015, 'Flexural behaviour of ferrocement with PVA fibre reinforced high strength mortar', FERRO-11 – 11th International Symposium on Ferrocement and 3rd ICTRC - International Conference on Textile Reinforced Concrete, 11th International Symposium on Ferrocement (FERRO' 11), RWTH Aachen University, AAchen, Germay, pp. 111-118.View/Download from: UTS OPUS
Ferrocement is a composite material, consisting of mortar reinforced with continuous steel-wire mesh layers. The strength, stiffness, deflection and cracking characteristics of the fer-rocement composite in flexure are affected by a number of factors, namely member thick-ness, span length, quantity and distribution of the wire-mesh reinforcement and mortar quality. This paper reports the results of an experimental investigation into the flexural be-haviour of 100mm by 500mm by 19mm ferrocement slabs with four layers of welded wire mesh reinforcement embedded in a high-strength (28-day compressive strength of 80MPa) mortar. Uncoated PVA fibres, having either 6mm or 12mm in length, with a fixed volume fraction of 0.25% were incorporated in the mortar matrix. The results showed that ferroce-ment with high-strength mortar is a highly ductility composite material and the addition of PVA fibres in mortar had improved the failure load of ferrocement but significantly modi-fied the flexural behaviour of the ferrocement by reducing the post-failure load ductility. Although the increased in the PVA fibre length from 6mm to 12mm had improved the fail-ure load of the ferrocement, it had reduced the post-failure load ductility
Khamchin Moghaddam, F, Sri Ravindrarajah, R & Sirivivatnanon, V 2015, 'PROPERTIES OF METAKAOLIN CONCRETE – A REVIEW', International Conference on Sustainable Structural Concrete, La Plata, Argentina.View/Download from: UTS OPUS
The use of cement supplementary materials in structural concrete is widely accepted by the construction industry for technical, economical and environmental reasons. Metakaolin (MK), produced by calcining kaolinite at high temperature is suitable for concrete production due to its pozzolanic property. This paper reviews the some of the research published on effects of using MK on engineering properties of structural concrete as a cement replacement material. The review shows that the use of relatively finer MK to partially replace cement reduces the consistency of concrete and enhanced the strengths, deformational and durability properties of concrete. MK is most effective in enhancing compressive strength (particularly at early ages) compared to other strengths and modulus of elasticity was least improved. Drying shrinkage and creep of MK concretes are lower than those for the control concrete. The high pozzolanic reactivity of MK with calcium hydroxide contributes to both porosity reduction and pore-structure refinement in the pastes and concrete. As the consequence, the durability of concrete is improved through increased resistance to chloride penetration and controlled expansion, due to alkali-silica reaction and sodium sulphate attack.
Sri Ravindrarajah, R & Kassis, SJ 2014, 'Effect of supplementary cementitious materials on the properties of pervious concrete with fixed porosity', Proceedings of the 23rd Australasian Conference on the Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, Southern Cross University, Byron Bay, Australia, pp. 53-58.View/Download from: UTS OPUS
Pervious concrete is significantly different to that of conventional concrete as it has the ability to allow water to percolate through it large sized pores. This unique ability presents many environmental benefits such as minimising storm water run-off, recharging groundwater and reducing the heat absorption in the pavement. This paper reports the results of an experimental investigation into the use of supplementary cementitious materials on the properties of pervious concrete (compressive strength, stiffness and water permeability) having the porosity of about 20%. The investigation considered four mixes with the following combinations of cement and supplementary cementitious materials, by weight proportion: (a) 100% cement; (b) 75% cement and 25% fly ash; (c) 92.6% cement and 7.4% silica fume; and (d) 84.2% cement, 8.2% fly ash and 7.6% silica fume. The results showed that the cement replacements with supplementary cementitious materials had improved the compressive strength, reduced modulus of elasticity and decreased the water permeability of pervious concrete with fixed porosity.
Mohammad, KJ, Singh, A & Sri Ravindrarajah, R 2013, 'Permeability and drying of pervious concrete pavers', New Developments in Structural Engineering and Construction, Hawaii, USA.
Sri Ravindrarajah, R 2012, 'Acids attack on silica fume high-strength concrete', From Materials to Structures: Advancement through Innovation - PROCEEDINGS OF THE 22ND AUSTRALASIAN CONFERENCE ON THE MECHANICS OF STRUCTURES AND MATERIALS, Australasian Conference on the Mechanics of Structures and Materials, CRC PRESS / BALKEMA, SYDNEY, AUSTRALIA, pp. 1193-1197.View/Download from: UTS OPUS or Publisher's site
This paper reports the results of a study on the corrosion of high strength concrete with silica fume subjected to 15% concentration of sulphuric acid, hydrochloric acid and lactic acid. Silica fume were used to replace 8% and 15% of the cement, by weight. The results showed that partial replacement of cement with silica fume had no effect on lactic acid resistance, improved the hydrochloric acid resistance and worsened the sulphuric acid attack. Sulphuric acid attack resulted in concrete disintegration at an almost constant rate, the hydrochloric attack rate was reduced with time, whereas the lactic acid attack resulted leaching of corrosion products, at a slower rate under stagnant condition.
Sri Ravindrarajah, R 2012, 'High-strength self-compacting concrete for sustainable construction', From Materials to Structures: Advancement through Innovation - PROCEEDINGS OF THE 22ND AUSTRALASIAN CONFERENCE ON THE MECHANICS OF STRUCTURES AND MATERIALS, Australasian Conference on the Mechanics of Structures and Materials, CRC PRESS / BALKEMA, Sydney, Australia, pp. 1021-1025.View/Download from: UTS OPUS
Concrete for sustainable infrastructure construction of civil engineering structures is required to use environmentally friendly concrete-making materials and to minimize both energy and manpower needs in concrete placing.With the intension of improving both environmental and economical sustainability, this study on self-compacting concrete with ground granulated blast furnace slag and recycled concrete aggregate was conducted. This paper reports the results of an experimental investigation into the production and properties of high-strength self-compacting concrete mixes with a combination of Portland cement and ultra-fine slag (up to 50% of cement replacement) and with either natural or recycled concrete coarse aggregate. The strengths development and chloride migration coefficient was evaluated. The use of ultra-fine slag was found to improve the stability of self-compacting concrete independent of the type of coarse aggregate.The use of recycled concrete decreased the strengths and modulus of elasticity and increased the chloride permeability for the high strength self-compacting concrete.
Whitson, P & Sri Ravindrarajah, R 2013, 'Evaluation of self-curing admixture in a flowing fly ash concrete', International Conference in Tends and Challenges in concrete structures, Indian Concrete Institute, Ghaziabad, India, pp. 391-399.
Water curing is the most effective curing method to promote continuous hydration of Portland cement and cement supplementary materials in concrete. In practice, this ideal curing condition is provided for a limited period in concrete construction. Membrane curing is used to prevent the drying of freshly placed concrete surface and to minimize the risk of plastic shrinkage cracking, particularly in concrete slabs. Self-curing admixture is relatively new chemical admixture to improve the water retention in concrete. This paper discusses the results of an experimental investigation into the evaluation of a self-curing admixture in a flowing fly ash concrete. The self-curing admixture was found to improve the compressive strength of concrete under air-stored condition. However, no significant improvements in tensile strength and modulus of elasticity were recorded. The lowest drying shrinkage for self-curing concrete indicates the effectiveness of water retention property of the self-curing admixture. It is concluded that a self-curing admixture is a useful ingredient in concrete mixes when water curing procedure is difficult to apply and should not be considered as alternative to water curing.
Sri Ravindrarajah, R. 2012, 'FIBRE-REINFORCED AND FERROCEMENT CAR-PARK PAVERS', 10th INTERNATIONAL SYMPOSIUM ON FERROCEMENT AND THIN REINFORCED CEMENT COMPOSITES, 10th INTERNATIONAL SYMPOSIUM ON FERROCEMENT AND THIN REINFORCED CEMENT COMPOSITES, UNAICC, CUBA, pp. 481-488.
Aerated reinforced concrete pavers having different sizes and shapes are widely used in many countries for out-door car-park pavement construction. The aeration allows the percolation of surface water into subsoil and considered as superior to the impervious concrete or bituminous pavements. A survey conducted at a car-park site in Singapore showed that, due to poor crack resistance, a noticeable number of the pavers was cracked and disintegrated, causing inconvenience to the car parks users. Tilting, settling and rocking of pavers are primary causes of failure of these slabs as the result of unstable base due to soil movement. In order to develop an alternative to the steel reinforced concrete pavers with improved crack resistance, steel fibre reinforced mortar and ferrocement aerated pavers were produced and tested in flexure. The results showed that both the steel fibre reinforced mortar and ferrocement pavers showed superior performance compared to the steel reinforced concrete slabs. Ferrocement pavers showed improved crack resistance under flexural loading, thus having the potential of durability and reduced maintenance cost. It is concluded that both steel fibre reinforced and ferrocement are suitable for the manufacture of precast aerated pavers for open car parks pavement construction.
Sri Ravindrarajah, R. 2012, 'FLEXURAL BEHAVIOUR OF LIGHTWEIGHT FERROCEMENT PANELS', 10th INTERNATIONAL SYMPOSIUM ON FERROCEMENT AND THIN REINFORCED CEMENT COMPOSITES, UNAICC, CUBA, pp. 243-249.
Thin ferrocement elements are found worldwide acceptance for many residential applications, including water storage tanks, bus shelters and sunshades. Traditionally, wood is used as fence material and in recent times colour bond aluminium sheeting are used to minimise the maintenance cost and to increase the durability, at added cost. Since aluminium sheets are manufactured with high energy cost, its usage is questioned from the sustainability point of view. In addition, aluminium fences are heated up easily under sun radiation and have poor sound absorption. This paper reports the results of an investigation into the development of lightweight ferrocement 32mm thin panels using expanded polystyrene beads. The investigated parameters in this study were: (a) density of lightweight mortar (1200, 1300, 1400 and 1500 kg/m3) and (b) number of layers of steelmesh-reinforcement (l, 2 and 3). The paper presents the engineering properties of lightweight mortars, drying shrinkage of standard and ferrocement elements, flexural behaviour of 150 mm by 600 mm by 32mm panels under increasing load including cracking characteristics. The results showed that both mortar density and reinforcement details had noticeable influence on the behaviour of ferrocement panels. The advantages of ferrocement panels over conventional panels are also highlighted.
Sri Ravindrarajah, R & Suarez, C 2011, 'Effectiveness of FRP confinement on bearing strength of steel fibre reinforced concrete', Proceedings of the 1st Middle East Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2011), Middle East Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures, EMPA, Dubai, UAE, pp. 1-8.View/Download from: UTS OPUS
Carbon Fibre Reinforced Polymers (CFRP) is successfully used to strengthen concrete members in compression, shear and flexure. This paper reports the results of an experimental study into the confinement efficiency of CFRP for bearing strength of steel fibre-reinforced concrete. The total area to bearing area ratio is maintained at 4.6. The results indicate that the confinement efficiency of CFRP, under both compression and bearing, had increased by the presence of steel fibres in the concrete matrix. The relationship between confinement efficiency and steel fibre content has to be established through future results. The ductility improvement for confined concrete over the unconfined concrete is observed from the results. The addition of high modulus steel fibres have further increased the ductility of confined concrete due to the crack arresting capacity of the fibres.
Sri Ravindrarajah, R, Ming, CH & Quan, PQ 2011, 'Self-compacting high strength recycled aggregate concrete for sustainable construction', International Symposium. on Innovation & Sustainability of Structures in Civil Engineering, Xiamen, China.View/Download from: UTS OPUS
Sri Ravindrarajah, R, Neo, HW & Lai, JE 2011, 'Performance of pervious recycled aggregate concrete with reduced cement content', Proceedings of the International Conference on Structural Engineering, Construction and Management (ICSECM-2011), The International Conference on Structural Engineering, Construction and Management, Nethwin Printers Ltd, Kandy, Sri Lanka, pp. 1-13.View/Download from: UTS OPUS
Pervious concrete is a tailored concrete to have very high water permeability. The presence of interconnected pores of different sizes and shapes allow the passage of water to now through casily. Permeable concrete pavement was shown to have signi licant advantages in stormwater management over impervious pavements and minimizing the risk of flooding in urban environment. This paper reports the results of an experimental investigation into the development of pervious concrete with reduced Portland cement content and recycled concrete aggregate. The performance of pervious concrete was evalliated through strength development, density, void content and permeability. The use of recycled concrete aggregate was found to affect the compressive strength of pervious concrete without influencing the permeability. The relationships between strength and void content, and permeability and porosity are reported. Through the empirical relationship presented, pervious concrete mixes with either natural aggregate or recycled concrete aggregate to meet the strength and permeability requirements could be designed.
Sri Ravindrarajah, R, Saltmer, JD, Quan, PQ & Ming, CX 2011, 'Self-compacting concrete with recycled concrete aggregate and high fineness slag', 7rd European Cong. on Concrete Engineering: New materials and Technologies for Concrete Structures, Hungary.
Sri Ravindrarajah, R. & Scheffers, C.A. 2011, 'Finite element analysis of Carbon Fibre Reinforced Polymer confined concrete under bearing load', 9th International Sympsium on High Performance Concrete, New Zealand.
Sri Ravindrarajah, R, Do, T, Nguyen, L & Aoki, Y 2010, 'Effect of clogging on the water permeability of pervious concrete', Incorporating Sustainable Practice in Mechanics of Structures and Materials - Proceedings of the 21st Australasian Conference on the Mechanics of Structures and Materials (ACMSM21), Australasian Conference on the Mechanics of Structures and Materials, CRC Press/Balkema, Melbourne, Australia, pp. 873-876.View/Download from: UTS OPUS or Publisher's site
Use of pervious concrete for pavement construction provides benefits such as reducing the stormwater run-off and recharging the ground water. This paper discusses the results of an experimental investigation into the effect of pore structure clogging and compaction on the water permeability of pervious concrete. The water permeability of pervious concrete was studied under falling head. The results showed that the clayey materials presence in the percolating water had seriously reduced the water permeability of pervious concrete. High-pressure water cleaning was found to partially recover the water permeability of pervious concrete. Since compaction causes pore structure modification, it should not be used with pervious concrete to ensure high water permeability of pervious concrete.
Sri Ravindrarajah, R 2010, 'Concrete for sustainable construction', Third Asian Conference on Ecstasy in Concrete, Chennai, India, pp. 135-153.
Sri Ravindrarajah, R & Fraser, IB 2010, 'Quality assurance for pavement concrete for airport apron construction', Third Asian Conference on Ecstasy in Concrete, Chennai, India, pp. 589-598.
Sri Ravindrarajah, R & Sabaa, BA 2010, 'Experience of using 100 years service life design specification for motorway project in Australia', 2nd Int. Symp. on 'Service Life Design for Infrastructure, Delft, pp. 493-499.
Sri Ravindrarajah, R, Scheffers, CA & Reinaldy 2010, 'Bearing strength of CFRP confined concrete', 5th Int. Conf. on FRP Composites in Civil Engineering, Beijing, China.
Sri Ravindrarajah, R. & Sabaa, B. 2010, 'Specifying 100-year design life infrastructure projects - the pitfalls', Proceedings Of The 6Th International Conference On Concrete Under Severe Conditions - Environment And Loading (Consec'10), Concrete under Severe Conditions: Environment and loading, CRC Pressl Balkema, Mexico, pp. 1675-1681.View/Download from: UTS OPUS
This paper presents a review of Scope of Works and Technical Criteria (SWTC) documents for infrastructure projects in Australia and approaches adopted to provide the durability structures that meet 100 years design life. The paper provides an assessment of the exposure environment, and shows how appropriate designs are achieved by use of field data in the prediction of progress of carbonation and chloride diffusion modelling. Economical designs that provide the required design life without the need for expensive repairs are achieved provided the parameters used in the prediction models are comparable to field data in the project environment.
Aoki, Y, Sri Ravindrarajah, R & Khabbaz, H 2009, 'Effect Of Fly Ash Performance Of Pervious Concrete', Ninth ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete and Tenth ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues - SUPPLEMENTARY PAPERS, ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete and Tenth ACI International Conference onRecent Advances in Concrete Technology and Sustainability Issues, ACI International Conference, Seville, Spain, pp. 511-520.View/Download from: UTS OPUS
Production of good quality pervious concrete is necessary to meet specification requirements for the construction of durable concrete pervious pavements. This paper reports and discusses the results of an experimental investigation into the physical and engineering properties ofpervious concrete having varying amounts of fly ash as the cement replacement material. The following properties were studied: porosity density, compressive strength weight loss on drying, free drying shrinkage and water permeability. The results thowed that porosity has significant effect on compressive strength and permeability of pervioos concrete. Replacement of cement with fly ash up to 50%, by mass ofbinder, had no significant effect on the water permeability and shrinkage ofshe pervious concrete, although marginal effect on strength was noticed.
Aoki, Y, Sri Ravindrarajah, R & Khabbaz, H 2008, 'Environmentally friendly sustainable pervious concrete', Future in Mechanics of Structures and Materials, Proceedings of the 20th Australasian Conference on the Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, Taylor & Francis Group, Toowoomba, Queensland, Australia, pp. 567-575.View/Download from: UTS OPUS
Portland cement is considered as one of the environmentally unfriendly materials due to its contribution to the increased liberation of carbon dioxide to the enviromnent during production. In addition to its impervious nature when it is used for pavement application, it contributes to increased stormwater runoff to drainage systems over-burdening the infrastructure and causing excessive flooding in built up areas. This paper presents the results of an experimental investigation associated with quantifying the properties of previous concrete containing fly ash, up to 50% as partial replacement for cement. The main goal of this research is to promote the utilisation of fly ash for developing durable and sustainable pervious concrete which creates less negative enviromnental impacts.
Sri Ravindrarajah, R & Scheffers, CA 2009, 'Bearing strength of concrete with and without FRP confinement', 24th Biennial Conf. of the Concrete Institute of Australia, Sydney, Australia.
Sri Ravindrarajah, R. & Lyte, M.C. 2008, 'Properties of adjusted density high-performance concrete', Future in Mechanics of Structures and Materials, Proceedings of the 20th Australasian Conference on the Mechanics of Structures and Materials, Australasian Conference on the Mechanics of Structures and Materials, CRC Press, Taylor & Francis Group, Toowoomba, Australia, pp. 351-355.View/Download from: UTS OPUS
Lightweight expanded polystyrene a well known material to absorb impact energy is being used to produce adjusted density concrete having enhanced impact energy absorption capacity concrete. Two structural concrete grade 30 and 45 MPa normal weight concrete and lightweight polystyrene concrete were tested for their impact response under 75 kg weight test through 462mm drop. The impact response of concrete was monitored through load-time plot. Peak load and contact time are considered as important measurable quantities in identifying the energy absorbing capacity of concrete. The results showed that for a given structural grade the concrete containing expanded polystyrene aggregate out-performed the nonnal weight concrete in its impact resistance. Under the tested impact loading condition, polystyrene concrete having the compressive strength of 30 MPa showed 28% increase in the contact time and 18% reduction in the peak load compared to the similar grade normal weight concrete
Sri Ravindrarajah, R. & Mansour, M. 2009, 'Current Practices on Cement Rendering In Australia', Proceedings of the 1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE), 1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE), Sebelas Maret University, Solo, Indonesia, pp. 39-48.
Cement rendering is widely used in Australia in the construction of new buildings and to rehabilitate the existing old buildings. Rendering buildings are normally carried out by tradesmen with varying degree of experience. The quality of the rendering is significantly varied and failure of render is not uncommon. This paper reports the existing practice of cement rendering in Australia and highlights the factors influencing the causes of poor performance of cement rendering. Interviews were conducted with renders, builders, clients and architects in relation to their experience on rendering practices and the results of these interviews are reported. A case study on the performance of rendered sea wall is reported.`
Wang, Y, Li, J, Samali, B & Sri Ravindrarajah, R 2008, 'A New Damage Detection Method for Reinforced Concrete Beams Based on Modal Strain Energy', Proceedings of the 9th International Conference on Motion and Vibration Control, International Conference on Motion and Vibration Control, Technische Universitaet Muenchen, Munich, pp. 1-10.View/Download from: UTS OPUS
Wang, Y, Samali, B & Sri Ravindrarajah, R 2008, 'Non-destructive damage detection in reinforced concrete beams based on modal strain energy', Proceedings of Australasian structural Engineering Conference, Australasian structural Engineering Conference, The Meeting Planners, Melbourne, pp. 1-8.View/Download from: UTS OPUS
Kaul, R., Sri Ravindrarajah, R. & Smith, S.T. 2006, 'Deformational Behaviour Of FRP Confined Concrete Under Sustained Compression', CICE 2006 - Composites in Civil Engineering, International Conference on FRP Composites in Civil Engineering, International Institute for FRP in Construction, Florida International University, Miami, Florida, USA, pp. 207-210.View/Download from: UTS OPUS
Confining concrete is an effective method to enhance the strength and ductility of reinforced concrete columns. Fibre reinforced polymer (FRP) composites are emerging as a suitable confining material to replace conventional materials such as steel and fibre-reinforced cement composites. Past research on the behaviour of FRP confined concrete in compression is considerable however limited research has been reported on the behaviour of confined concrete under sustained compressive loading. This paper reports the preliminary results of an experimental investigation on the deforinational behaviour of carbon FRP (CFRP) confined concrete columns under sustained compressive stress levels corresponding to 40% and 60% of the unconfined concrete compressive strength for up to 50 days. The results show that the creep of confined concrete columns is marginally influenced under moderate sustained stress/strength ratios.
Smith, S.T., Kaul, R., Sri Ravindrarajah, R. & Otoom, O. 2005, 'Durability Considerations for FRP-Strengthened RC Structures in the Australian Environment', Australian Structural Engineering Conference 2005: Structural Engineering - Preserving and Building into the Future, Australian Structural Engineering Conference, Tour Hosts Pty Limited, Newcastle, Australia, pp. 1-10.View/Download from: UTS OPUS
Sri Ravindrarajah, R. & Subhan, T. 2005, 'Adjusted density high-strength concrete using expanded polystyrene beads', International Conference on Concrete for Concrete Structures, International Conference on Concrete for Concrete Structures, Faculty of Science and Technology of the University of Coimbra, Coimbra, Portugal, pp. 1-8.
Sri Ravindrarajah, R., Difalco, V. & Surian, S. 2005, 'Effects of binder materials on the properties of polystyrene aggregate concrete', Quality of concrete structures and recent advances in concrete materials and testing, International ACI/CANMET Conference on the Quality of Concrete Structures and Recent Advances In Concrete Materials and Testing, American Concrete Institute, Olinda, Brazil, pp. 33-48.View/Download from: UTS OPUS
Sri Ravindrarajah, R., Farrokhzadi, F. & to be deleted, A. 2003, 'Properties of flowing concrete and self-compacting concrete with high-performance superplacticiser', Proceedings of the 3rd International RILEM Symposium, 3rd International Symposium on self-compacting concrete, RILEM Publications, Reykjavik, Iceland.
Sri Ravindrarajah, R., Siladyi, D. & Adamopoulous, B. 2003, 'The development of high strength self-compacting concrete with reduced segregation potential', Proceedings of the 3rd International RILEM Symposium, 3rd International Conference on Self-Compacting Concrete, RILEM Publications, Reykjavik, Iceland, pp. 1048-1050.
Sri Ravindrarajah, R. 2003, 'The bleeding of fresh concrete containing cement supplementary materials', The 9th east asia-pacific conference on structural engineering and construction proceedings, East Asia-Pacific Conference on Structural Engineering and Construction, Institut Teknologi Bandung, Bali, Indonesia, pp. 117-122.
Sri Ravindrarajah, R. & Jones, W. 2003, 'Properties of Adjusted Density High-Performance Concrete', Advances in Structures, International Conference on Advances in Structures, A.A. Balkema, Swets & Zeitlinger B.V. Lissie, The Netherlands, Sydney, Australia, pp. 1011-1016.View/Download from: UTS OPUS
Sri Ravindrarajah, R., Stewart, M. & Greco, D. 2001, 'Variability of recycled concrete aggregate and its effects on the properties of concrete', Proceedings of 2001 Second International Conference on Engineering Materials, 2001 Second International Conference on Engineering Materials, Canadian Society of Civil Engineers / Japan Society of Civl Engineers, San Jose, USA, pp. 113-124.View/Download from: UTS OPUS
Sri Ravindrarajah, R 2000, 'Controlling freeze and thaw durability of structural grade concrete with recycled expanded aggregate', Second Int. Symp. on Structural Lightweight Aggregate Concrete, Norway.
Sri Ravindrarajah, R & Sabaa, BA 2000, 'Impact resistance of polystyrene aggregate concrete with and without polypropylene fibres', Second Int. Symp. on Structural Lightweight Aggregate Concrete, Norway.
Sri Ravindrarajah, R & Sabaa, BA 2000, 'Investigation of pull-out strength between polystyrene aggregate concrete and reinforcing steel', Second Int. Symp. on Structural Lightweight Aggregate Concrete, Norway.
Sri Ravindrarajah, R 1999, 'Bearing strength of concrete containing polystyrene aggregate', 8th RILEM Conf. on the Durability of Building Materials & Components, Vancouver, Canada.
Sri Ravindrarajah, R 1999, 'Deterioration and Restoration of Concrete Jetties', 11th Asian-Pacific Corrosion Control Conference, Hanoi, Vietnam.
Sri Ravindrarajah, R 1999, 'Effects of binder materials on drying shrinkage of high-strength concrete', Concrete Communication Conf. 1999, Cardiff, Wales, UK.
Sri Ravindrarajah, R 1999, 'Workability assessment for polystyrene aggregate concrete', CONPAT 99: V IBEROAMERICAN Congress of Building Pathologies, Montevideo, Uruguay.
Sri Ravindrarajah, R 1998, 'Residual compressive and tensile strengths for high-strength concrete exposed to high-temperature up to 800oC', Inter. Conf. on High Performance High Strength Concrete: Material Properties, Structural Behaviour and Field Applications, Perth, Australia.
Sri Ravindrarajah, R 1998, 'Slag blend cement concrete for a cable-stayed bridge foundation', Int. Symp. on Innovative World of Concrete, Calcutta, India.
Sri Ravindrarajah, R. 1994, 'Properties of concrete used in 27m by 21m by 5m pile cap construction', International Conference on Blended Cements, Kuala Lumpur, Malaysia.
Sri Ravindrarajah, R & Mercer, CM 1993, 'Sulphuric acid attack on high-strength concrete', 6th Int. Conf. on Durability of Building Materials and Components, Omiya, Japan.
Sri Ravindrarajah, R & Naji, BT 1993, 'Internal sulphate attack on polystyrene concrete', 6th Int. Conf. on Durability of Building Materials and Components, Omiya, Japan.
Sri Ravindrarajah, R & Oven, GR 1993, 'Degradation of cement mortar lining in water pipes', Concrete 2000, Economic and Durable Construction through Excellence, Dundee.
Sri Ravindrarajah, R & Tuck, AJ 1993, 'Properties of polystyrene aggregate concrete', 13th Australasian Conf. on the Mechanics of Structures & Materials, Wollongong.