Sriravindrarajah Rasiah | University of Technology Sydney (original) (raw)

Papers by Sriravindrarajah Rasiah

Construction and Building Materials

Structural grades geocement concretes require reduced binder and water contents. Fly ash and slag... more Structural grades geocement concretes require reduced binder and water contents. Fly ash and slag proportions in geocement influences the mix design. Strength improvement for geocement concretes is 15-20% from 28 to 90 days. Geocement concretes develop up to 45% of 28-day ambient strength in 4 h at 70°C. Heat-cured strength is linearly related to ambient strength for geocement concretes.

Road Materials and Pavement Design, 2012

Pervious concrete is one of the most effective pavement materials to address a number of importan... more 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 properties of pervious concrete are reported and discussed. The amount of general purpose Portland cement has been reduced by introducing fly ash as a cementitious agent in pervious concrete samples. The properties of various pervious concrete samples including density, porosity, compressive strength, water permeability and drying shrinkage have been carefully measured. In addition, the relationships among these properties are explored. According to the results, high porosity samples indicated higher permeability, whereas their compressive strength was reduced. There was no significant difference between properties of pervious concrete samples containing fly ash and those samples comprising only cement as a cementitious agent. Hence, environmentally friendly pervious concrete with fly ash can be produced in lieu of conventional pervious concrete.

Magazine of Concrete Research, 1987

... Ahead of print articles are fully citable using the DOI number and accessible using the link ... more ... Ahead of print articles are fully citable using the DOI number and accessible using the link below. More like this? In this publication; By this author: R. Sri Ravindrarajah , YH Loo , CT Tam. Synopsis. The effects of using crushed ...

Magazine of Concrete Research, 1985

... than the original crushed granite aggregate. The resistance to mechanical actions such as imp... more ... than the original crushed granite aggregate. The resistance to mechanical actions such as impact, crushing and abrasion for the recycled concrete aggregates is also lower. The effects of using recycled concrete aggregates ...

Magazine of Concrete Research, 1987

... Authors: CT Tam; TY Lim; R. Sri Ravindrarajah; SL Lee; Source: Magazine of Concrete Research,... more ... Authors: CT Tam; TY Lim; R. Sri Ravindrarajah; SL Lee; Source: Magazine of Concrete Research, Volume 39, Issue 138, pages 12 –18 , ISSN : 0024 ... The journal also publishes articles ahead of print to ensure you receive access to the latest research as soon as it is published. ...

23rd Australasian Conference on the Mechanics of Structures and Materials (ACMSM23), Dec 9, 2014

Pervious concrete is significantly different to that of conventional concrete as it has the abili... more 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.

Precast concrete sleepers production requires the application of low-pressure steam curing to acc... more 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 24oC per hour and the maximum temperature to 70oC. 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.

International conference on Trends and Challenges in Concrete Structures, Dec 19, 2013

Water curing is the most effective curing method to promote continuous hydration of Portland ceme... more 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.

22nd AUSTRALASIAN CONFERENCE ON THE MECHANICS OF STRUCTURES AND MATERIALS, Dec 2012

Concrete for sustainable infrastructure construction of civil engineering structures is required ... more 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 proper-ties 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.

Proceedings of the CONPAT 99: V IBEROAMERICAN Congress of Building Pathologies,, 1999

Incorporating expanded polystyrene granules in a concrete matrix can produce lightweight polystyr... more Incorporating expanded polystyrene granules in a concrete matrix can produce lightweight polystyrene aggregate concrete of various densities. This paper examines the suitability of the DIN 1048: Compaction Index test to the polystyrene aggregate concrete having the unit weight of 1600, 1800 and 2000 kg/m3, with the cement contents of 350, 420, 490, and 560 kg/m3 . A comparison is made between the compaction index and slump. It was found that workability of polystyrene aggregate concrete could be classified in terms of the compaction index. The compaction index ranges are 1.03 to 1.13, 1.14 to 1.29, 1.30 to 1.40, and 1.41 to 1.52 for high, medium, low and very low degrees of workability, respectively. For a given workability, the slump of concrete is significantly affected by its unit weight.

Cement, Concrete, and Aggregates, 1982

The development of a three-dimensional conductivity probe, based on the measurement of electrical... more The development of a three-dimensional conductivity probe, based on the measurement of electrical conductance between electrodes, to evaluate the setting time of fresh concrete and the variation of moisture content with time in hardened concrete is reported. The construction and calibration of the conductivity probe are described, and a calibration curve translating electrical conductance measurements into available moisture content is presented. Tests are then reported to evaluate the setting time of fresh concrete, and these are related to internal temperature variations. These tests are then extended to study moisture variations in hardened concrete under load and no-load
conditions in both sealed and unsealed environments. These measurements taken for up to two years are related to internal humidity measurements. The results show that the conductivity probe is a simple and inexpensive device that gives quantitative information in any direction and possesses qualities of accuracy, reliability, long-term stability, and local resolution.

This paper reports the results of an experimental study into the effects of incorporating expande... more This paper reports the results of an experimental study into the effects of incorporating expanded polystyrene beads in concrete on the temperature development in an insulated thick concrete section. A varying amount of non-heat conducting expanded polystyrene beads by partially replacing the normal weight aggregates to obtain the unit weights of 2215, 2100, and 1835 kg/m3. Cement content and water to cement ratio for the mixtures were kept constant at 500 kg/m3 and 0.30, respectively. The concrete mixture with the largest amount of polystyrene beads produced a peak temperature of 85.6 C compared to 70.6 C for the control concrete mixture.

New Developments in Structural Engineering and Construction, Jun 18, 2013

Pervious concrete, a tailored concrete with connected large-sized voids, allows the water to flow... more Pervious concrete, a tailored concrete with connected large-sized voids, allows the water to flow through easily. In-situ pervious concrete pavements is produced with no or minimum compaction with fairly dry but workable concrete mix. This construction method contributes to variable permeability and strength performance within the pervious concrete pavements. In order to improve the reliability of pervious concrete pavements the use of precast pervious pavers produced with strict quality control is a possible solution. This paper reports the results of an investigation into the performance of 300mm by 300mm by 75mm matured laboratory-made pervious concrete pavers, in relation to overall water permeability, variability of water permeability within each paver and rate of drying of saturated pavers at 20oC, 30oC and 40oC . The void content of the twelve precast pavers used in this study is varied between 12% and 22%. The results showed: (a) the existence of non-uniformity of water permeability within a pervious concrete paver independent of its porosity; (b) an increase in the thickness of the pervious concrete paver decreased the water infiltration rate; (c) with the decrease in the void content the overall permeability of the pervious concrete pavers is decreased; (d) the drying rate of pervious slabs is increased with the increase in temperature; (e) the influence of void content on dry rate is reduced with the increase in the drying temperature.

International Journal of Concrete Structures and Materials, Dec 2012

Pervious concrete is a tailored-property concrete with high water permeability which allow the pa... more 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.

The Indian Concrete Journal, Aug 2012

This paper critically examines the potential of ferrocement panels for use as permanent load-bear... more 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.

7th International Symposium on Cement and Concrete, Jinan, China, May 9, 2010

Aerated steel reinforced concrete slabs are used in Singapore and other countries. The aeration a... more Aerated steel reinforced concrete slabs are used in Singapore and other countries. The aeration allows the percolation of surface water into subsoil and considered as superior to the conventional concrete or bituminous pavements. This paper reports the results of a survey conducted at a car-park site. The failure of the slabs is mainly resulted from unstable base. Tilting, settling and rocking of slabs are primary cause of these slabs. In order to develop an alternative to the conventionally steel reinforced concrete slabs, steel fibre reinforced mortar and ferrocement slabs are produced and tested in flexure. The results showed that the steel fibre reinforced mortar slabs and ferrocement slabs showed superior performance compared to the conventional steel reinforced concrete slabs. Ferrocement slabs showed improved crack resistance under flexural loading. It is concluded that both steel fibre reinforced and ferrocement are suitable for the manufacture of precast aerated car park slabs.

Construction and Building Materials

Structural grades geocement concretes require reduced binder and water contents. Fly ash and slag... more Structural grades geocement concretes require reduced binder and water contents. Fly ash and slag proportions in geocement influences the mix design. Strength improvement for geocement concretes is 15-20% from 28 to 90 days. Geocement concretes develop up to 45% of 28-day ambient strength in 4 h at 70°C. Heat-cured strength is linearly related to ambient strength for geocement concretes.

Road Materials and Pavement Design, 2012

Pervious concrete is one of the most effective pavement materials to address a number of importan... more 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 properties of pervious concrete are reported and discussed. The amount of general purpose Portland cement has been reduced by introducing fly ash as a cementitious agent in pervious concrete samples. The properties of various pervious concrete samples including density, porosity, compressive strength, water permeability and drying shrinkage have been carefully measured. In addition, the relationships among these properties are explored. According to the results, high porosity samples indicated higher permeability, whereas their compressive strength was reduced. There was no significant difference between properties of pervious concrete samples containing fly ash and those samples comprising only cement as a cementitious agent. Hence, environmentally friendly pervious concrete with fly ash can be produced in lieu of conventional pervious concrete.

Magazine of Concrete Research, 1987

... Ahead of print articles are fully citable using the DOI number and accessible using the link ... more ... Ahead of print articles are fully citable using the DOI number and accessible using the link below. More like this? In this publication; By this author: R. Sri Ravindrarajah , YH Loo , CT Tam. Synopsis. The effects of using crushed ...

Magazine of Concrete Research, 1985

... than the original crushed granite aggregate. The resistance to mechanical actions such as imp... more ... than the original crushed granite aggregate. The resistance to mechanical actions such as impact, crushing and abrasion for the recycled concrete aggregates is also lower. The effects of using recycled concrete aggregates ...

Magazine of Concrete Research, 1987

... Authors: CT Tam; TY Lim; R. Sri Ravindrarajah; SL Lee; Source: Magazine of Concrete Research,... more ... Authors: CT Tam; TY Lim; R. Sri Ravindrarajah; SL Lee; Source: Magazine of Concrete Research, Volume 39, Issue 138, pages 12 –18 , ISSN : 0024 ... The journal also publishes articles ahead of print to ensure you receive access to the latest research as soon as it is published. ...

23rd Australasian Conference on the Mechanics of Structures and Materials (ACMSM23), Dec 9, 2014

Pervious concrete is significantly different to that of conventional concrete as it has the abili... more 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.

Precast concrete sleepers production requires the application of low-pressure steam curing to acc... more 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 24oC per hour and the maximum temperature to 70oC. 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.

International conference on Trends and Challenges in Concrete Structures, Dec 19, 2013

Water curing is the most effective curing method to promote continuous hydration of Portland ceme... more 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.

22nd AUSTRALASIAN CONFERENCE ON THE MECHANICS OF STRUCTURES AND MATERIALS, Dec 2012

Concrete for sustainable infrastructure construction of civil engineering structures is required ... more 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 proper-ties 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.

Proceedings of the CONPAT 99: V IBEROAMERICAN Congress of Building Pathologies,, 1999

Incorporating expanded polystyrene granules in a concrete matrix can produce lightweight polystyr... more Incorporating expanded polystyrene granules in a concrete matrix can produce lightweight polystyrene aggregate concrete of various densities. This paper examines the suitability of the DIN 1048: Compaction Index test to the polystyrene aggregate concrete having the unit weight of 1600, 1800 and 2000 kg/m3, with the cement contents of 350, 420, 490, and 560 kg/m3 . A comparison is made between the compaction index and slump. It was found that workability of polystyrene aggregate concrete could be classified in terms of the compaction index. The compaction index ranges are 1.03 to 1.13, 1.14 to 1.29, 1.30 to 1.40, and 1.41 to 1.52 for high, medium, low and very low degrees of workability, respectively. For a given workability, the slump of concrete is significantly affected by its unit weight.

Cement, Concrete, and Aggregates, 1982

The development of a three-dimensional conductivity probe, based on the measurement of electrical... more The development of a three-dimensional conductivity probe, based on the measurement of electrical conductance between electrodes, to evaluate the setting time of fresh concrete and the variation of moisture content with time in hardened concrete is reported. The construction and calibration of the conductivity probe are described, and a calibration curve translating electrical conductance measurements into available moisture content is presented. Tests are then reported to evaluate the setting time of fresh concrete, and these are related to internal temperature variations. These tests are then extended to study moisture variations in hardened concrete under load and no-load
conditions in both sealed and unsealed environments. These measurements taken for up to two years are related to internal humidity measurements. The results show that the conductivity probe is a simple and inexpensive device that gives quantitative information in any direction and possesses qualities of accuracy, reliability, long-term stability, and local resolution.

This paper reports the results of an experimental study into the effects of incorporating expande... more This paper reports the results of an experimental study into the effects of incorporating expanded polystyrene beads in concrete on the temperature development in an insulated thick concrete section. A varying amount of non-heat conducting expanded polystyrene beads by partially replacing the normal weight aggregates to obtain the unit weights of 2215, 2100, and 1835 kg/m3. Cement content and water to cement ratio for the mixtures were kept constant at 500 kg/m3 and 0.30, respectively. The concrete mixture with the largest amount of polystyrene beads produced a peak temperature of 85.6 C compared to 70.6 C for the control concrete mixture.

New Developments in Structural Engineering and Construction, Jun 18, 2013

Pervious concrete, a tailored concrete with connected large-sized voids, allows the water to flow... more Pervious concrete, a tailored concrete with connected large-sized voids, allows the water to flow through easily. In-situ pervious concrete pavements is produced with no or minimum compaction with fairly dry but workable concrete mix. This construction method contributes to variable permeability and strength performance within the pervious concrete pavements. In order to improve the reliability of pervious concrete pavements the use of precast pervious pavers produced with strict quality control is a possible solution. This paper reports the results of an investigation into the performance of 300mm by 300mm by 75mm matured laboratory-made pervious concrete pavers, in relation to overall water permeability, variability of water permeability within each paver and rate of drying of saturated pavers at 20oC, 30oC and 40oC . The void content of the twelve precast pavers used in this study is varied between 12% and 22%. The results showed: (a) the existence of non-uniformity of water permeability within a pervious concrete paver independent of its porosity; (b) an increase in the thickness of the pervious concrete paver decreased the water infiltration rate; (c) with the decrease in the void content the overall permeability of the pervious concrete pavers is decreased; (d) the drying rate of pervious slabs is increased with the increase in temperature; (e) the influence of void content on dry rate is reduced with the increase in the drying temperature.

International Journal of Concrete Structures and Materials, Dec 2012

Pervious concrete is a tailored-property concrete with high water permeability which allow the pa... more 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.

The Indian Concrete Journal, Aug 2012

This paper critically examines the potential of ferrocement panels for use as permanent load-bear... more 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.

7th International Symposium on Cement and Concrete, Jinan, China, May 9, 2010

Aerated steel reinforced concrete slabs are used in Singapore and other countries. The aeration a... more Aerated steel reinforced concrete slabs are used in Singapore and other countries. The aeration allows the percolation of surface water into subsoil and considered as superior to the conventional concrete or bituminous pavements. This paper reports the results of a survey conducted at a car-park site. The failure of the slabs is mainly resulted from unstable base. Tilting, settling and rocking of slabs are primary cause of these slabs. In order to develop an alternative to the conventionally steel reinforced concrete slabs, steel fibre reinforced mortar and ferrocement slabs are produced and tested in flexure. The results showed that the steel fibre reinforced mortar slabs and ferrocement slabs showed superior performance compared to the conventional steel reinforced concrete slabs. Ferrocement slabs showed improved crack resistance under flexural loading. It is concluded that both steel fibre reinforced and ferrocement are suitable for the manufacture of precast aerated car park slabs.