Pub Date : 2021-07-21DOI: 10.1080/14488353.2021.1953682
T. Kiran, M. E. Mathews, A. N, U. J. Alengaram, A. Andrushia
ABSTRACT Structural engineers must be cautious about fire accidents in buildings, as a result critical deterioration occurs in the strength and serviceability of concrete structures. Self-Compacting Concrete (SCC) is an efficient material developed using Supplementary Cementitious Materials (SCM). This research intends to evaluate the effect of mineral admixtures such as Metakaolin (MK), Silica Fume (SF) and Fly Ash (FA) on the mechanical and durability characteristics of SCC exposed to elevated temperature. Two SCC mixes satisfying the European Federation of National Associations Representing for Concrete (EFNARC, 2005) workability stipulations developed to achieve 20MPa and 50MPa. The specimens were exposed to elevated temperatures following the ISO 834 standard fire curve. Compressive strength, water absorption, acid resistance and Rapid Chloride Penetration Test (RCPT) tests were carried out on heat-affected SCC specimens exposed to elevated temperature. A reduction in strength of 48% and 64% were obtained for the M20 and M50 grade SCC specimens, respectively.
{"title":"Influence of mineral admixtures on the residual mechanical properties and durability characteristics of self-compacting concrete subjected to high temperature","authors":"T. Kiran, M. E. Mathews, A. N, U. J. Alengaram, A. Andrushia","doi":"10.1080/14488353.2021.1953682","DOIUrl":"https://doi.org/10.1080/14488353.2021.1953682","url":null,"abstract":"ABSTRACT Structural engineers must be cautious about fire accidents in buildings, as a result critical deterioration occurs in the strength and serviceability of concrete structures. Self-Compacting Concrete (SCC) is an efficient material developed using Supplementary Cementitious Materials (SCM). This research intends to evaluate the effect of mineral admixtures such as Metakaolin (MK), Silica Fume (SF) and Fly Ash (FA) on the mechanical and durability characteristics of SCC exposed to elevated temperature. Two SCC mixes satisfying the European Federation of National Associations Representing for Concrete (EFNARC, 2005) workability stipulations developed to achieve 20MPa and 50MPa. The specimens were exposed to elevated temperatures following the ISO 834 standard fire curve. Compressive strength, water absorption, acid resistance and Rapid Chloride Penetration Test (RCPT) tests were carried out on heat-affected SCC specimens exposed to elevated temperature. A reduction in strength of 48% and 64% were obtained for the M20 and M50 grade SCC specimens, respectively.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"244 - 260"},"PeriodicalIF":1.3,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1953682","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47212981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-20DOI: 10.1080/14488353.2021.1945258
Mohsen Aboutalebi Esfahani, Seyed Mohammad Navid Khoddami
ABSTRACT More penetration of the prime coat increases the stabilisation thickness of the sub-asphalt layer and makes it more difficult for water to penetrate. Therefore, the purpose of this study is to identify the effective parameters on the penetration of Cationic Emulsion Bitumen (CEB) and investigate their effects. Short and long-term penetration tests are used. For better evaluation, two types of silica and limestone aggregates are selected in dry and wet conditions. To better compare the results of penetration, the penetration of MC250 cutback bitumen was also measured. The results show that among the identified parameters, the maximum penetration increase is influenced by the time of penetration, the material of aggregates, aggregate humidity, type of prime coat, kerosene percentage, and colloid mill speed which is equal to emulsifier percentage and the percentage of pure bitumen. Also, the least effect is observed for increasing soap temperature. Another result is that the CEB penetration in limestone aggregates is inappropriate in all cases. However, the penetration of CEB in silica aggregates in almost all cases provides minimum requirement so that the moisture being most effective to increase it. The value of MC250 penetration in limestone aggregates is only appropriate for wet and long-term conditions.
{"title":"Evaluation and identification of parameters affecting the penetration of emulsion bitumen on aggregates","authors":"Mohsen Aboutalebi Esfahani, Seyed Mohammad Navid Khoddami","doi":"10.1080/14488353.2021.1945258","DOIUrl":"https://doi.org/10.1080/14488353.2021.1945258","url":null,"abstract":"ABSTRACT More penetration of the prime coat increases the stabilisation thickness of the sub-asphalt layer and makes it more difficult for water to penetrate. Therefore, the purpose of this study is to identify the effective parameters on the penetration of Cationic Emulsion Bitumen (CEB) and investigate their effects. Short and long-term penetration tests are used. For better evaluation, two types of silica and limestone aggregates are selected in dry and wet conditions. To better compare the results of penetration, the penetration of MC250 cutback bitumen was also measured. The results show that among the identified parameters, the maximum penetration increase is influenced by the time of penetration, the material of aggregates, aggregate humidity, type of prime coat, kerosene percentage, and colloid mill speed which is equal to emulsifier percentage and the percentage of pure bitumen. Also, the least effect is observed for increasing soap temperature. Another result is that the CEB penetration in limestone aggregates is inappropriate in all cases. However, the penetration of CEB in silica aggregates in almost all cases provides minimum requirement so that the moisture being most effective to increase it. The value of MC250 penetration in limestone aggregates is only appropriate for wet and long-term conditions.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"195 - 207"},"PeriodicalIF":1.3,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1945258","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45965494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-19DOI: 10.1080/14488353.2021.1953234
S. Oyebisi, A. Ede, F. Olutoge, H. Owamah, T. Igba
ABSTRACT The thermal performance (TP) of concrete structures is vital to the evaluation of the fire response. Thus, this study examined the thermal properties slag-based geopolymer concrete (GPC) incorporating corncob ash (CCA). Corncob was valorised and partially used as a substitution for slag under the ambient curing conditions. Sodium hydroxide (SH) solution and sodium silicate (SS) gel were used as alkaline activators at 12, 14, and 16 M concentrations. The TP of GPC was compared with that of Portland cement concrete (PCC). Thermal predictions were developed based on the thermal properties. Based on the findings, GPC exhibited lower thermal conductivity (TC) and thermal diffusivity (TD) with increasing specific heat capacity (SHC), indicating good thermal insulation properties (TIP) compared with PCC. The TIP increased with increasing CCA content in the mixture at all levels of alkaline activators. Thus, CCA improves the insulating capacity of the GPC. In addition, a good correlation exists between the GPC produced and thermal properties. These findings can be beneficial in the hot climate regions and utilised for structural insulating construction concrete. Finally, the proposed models can be used in the assessment of GPC structures incorporating supplementary cementitious materials (SCMs) to enhance the TIP of construction materials.
{"title":"Slag-based geopolymer concrete incorporating ash: effects on thermal performance","authors":"S. Oyebisi, A. Ede, F. Olutoge, H. Owamah, T. Igba","doi":"10.1080/14488353.2021.1953234","DOIUrl":"https://doi.org/10.1080/14488353.2021.1953234","url":null,"abstract":"ABSTRACT The thermal performance (TP) of concrete structures is vital to the evaluation of the fire response. Thus, this study examined the thermal properties slag-based geopolymer concrete (GPC) incorporating corncob ash (CCA). Corncob was valorised and partially used as a substitution for slag under the ambient curing conditions. Sodium hydroxide (SH) solution and sodium silicate (SS) gel were used as alkaline activators at 12, 14, and 16 M concentrations. The TP of GPC was compared with that of Portland cement concrete (PCC). Thermal predictions were developed based on the thermal properties. Based on the findings, GPC exhibited lower thermal conductivity (TC) and thermal diffusivity (TD) with increasing specific heat capacity (SHC), indicating good thermal insulation properties (TIP) compared with PCC. The TIP increased with increasing CCA content in the mixture at all levels of alkaline activators. Thus, CCA improves the insulating capacity of the GPC. In addition, a good correlation exists between the GPC produced and thermal properties. These findings can be beneficial in the hot climate regions and utilised for structural insulating construction concrete. Finally, the proposed models can be used in the assessment of GPC structures incorporating supplementary cementitious materials (SCMs) to enhance the TIP of construction materials.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"208 - 221"},"PeriodicalIF":1.3,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1953234","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42504643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-03DOI: 10.1080/14488353.2021.1896124
Biruk Tadele, Emer Tucay Quezon
ABSTRACT The ageing property of the asphalt binder is time-dependent. A time-dependent short term ageing property of 80/100 penetration grade bitumen and the possibility of waste engine oil rejuvenation for the highly aged asphalt binder performance were investigated. Four specimens of equal weight from the penetration grade-80/100 bitumen are collected. The first specimen was checked for quality requirements. The other three specimens were aged using rolling thin film oven for 85, 115, and 145 minutes to simulate the delay during hot mix asphalt production, hauling, and compaction. The highly aged bitumen was rejuvenated with 2%, 5%, and 10% Waste Engine Oil by weight. Results indicated that as the ageing time increased, penetration and ductility decreased, softening point, flash point, fire point, and mass loss increased. A conventional test showed that highly aged bitumen from the trial period was 145 minutes and 10% waste engine oil obtained the optimum dosage. Further, multiple stress creep recovery analyses indicated the rejuvenated binder is prone to pavement rutting above 70°C, and rejuvenation is effective for pavement temperature below 70°C. Hence, exposing the asphalt binder for temperature for a more extended period affects pavement performance.
{"title":"Evaluation of waste engine oil rejuvenation for highly short term aged asphalt binder","authors":"Biruk Tadele, Emer Tucay Quezon","doi":"10.1080/14488353.2021.1896124","DOIUrl":"https://doi.org/10.1080/14488353.2021.1896124","url":null,"abstract":"ABSTRACT The ageing property of the asphalt binder is time-dependent. A time-dependent short term ageing property of 80/100 penetration grade bitumen and the possibility of waste engine oil rejuvenation for the highly aged asphalt binder performance were investigated. Four specimens of equal weight from the penetration grade-80/100 bitumen are collected. The first specimen was checked for quality requirements. The other three specimens were aged using rolling thin film oven for 85, 115, and 145 minutes to simulate the delay during hot mix asphalt production, hauling, and compaction. The highly aged bitumen was rejuvenated with 2%, 5%, and 10% Waste Engine Oil by weight. Results indicated that as the ageing time increased, penetration and ductility decreased, softening point, flash point, fire point, and mass loss increased. A conventional test showed that highly aged bitumen from the trial period was 145 minutes and 10% waste engine oil obtained the optimum dosage. Further, multiple stress creep recovery analyses indicated the rejuvenated binder is prone to pavement rutting above 70°C, and rejuvenation is effective for pavement temperature below 70°C. Hence, exposing the asphalt binder for temperature for a more extended period affects pavement performance.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"19 1","pages":"225 - 234"},"PeriodicalIF":1.3,"publicationDate":"2021-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1896124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43733532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-24DOI: 10.1080/14488353.2021.1941597
Keith W. K. Kong
ABSTRACT In sewer environments, there are complex chemical and microbiological processes with a reaction between the hydrogen sulphide, a gas produced by the used water, and aerobic feeding microorganism. This resulted in production of sulphuric acid which would cause long-term corrosion on cement based concrete structures. This corrosion process is known as “Microbiologically Influenced Corrosion“. Generally, the ordinary Portland cement-based concrete is not considered as a suitable material for direct exposure to acidic sewer environments. As such, it is necessary to prevent the aggressive environments from developing, as well as to prevent the corrosive environments from coming in contact with the concrete elements. A robust corrosion protection system must be specified and provided for the tunnels and underground structures to ensure the durability of these structures under the aggressive sewer environments and able to withstand a design life span of 100 years. Case example with discussion on seven proven corrosion protection lining systems based on current technology. Past experience of the tunnels is provided with further exploratory study in terms of cost effectiveness and quantity analysis for these seven lining systems to be investigated. A technical specification for Portland cement–based Microbiologically Influenced Corrosion resistant concrete is provided.
{"title":"Double corrosion protection of sewage tunnel linings","authors":"Keith W. K. Kong","doi":"10.1080/14488353.2021.1941597","DOIUrl":"https://doi.org/10.1080/14488353.2021.1941597","url":null,"abstract":"ABSTRACT In sewer environments, there are complex chemical and microbiological processes with a reaction between the hydrogen sulphide, a gas produced by the used water, and aerobic feeding microorganism. This resulted in production of sulphuric acid which would cause long-term corrosion on cement based concrete structures. This corrosion process is known as “Microbiologically Influenced Corrosion“. Generally, the ordinary Portland cement-based concrete is not considered as a suitable material for direct exposure to acidic sewer environments. As such, it is necessary to prevent the aggressive environments from developing, as well as to prevent the corrosive environments from coming in contact with the concrete elements. A robust corrosion protection system must be specified and provided for the tunnels and underground structures to ensure the durability of these structures under the aggressive sewer environments and able to withstand a design life span of 100 years. Case example with discussion on seven proven corrosion protection lining systems based on current technology. Past experience of the tunnels is provided with further exploratory study in terms of cost effectiveness and quantity analysis for these seven lining systems to be investigated. A technical specification for Portland cement–based Microbiologically Influenced Corrosion resistant concrete is provided.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"156 - 173"},"PeriodicalIF":1.3,"publicationDate":"2021-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1941597","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42412953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-23DOI: 10.1080/14488353.2021.1942405
Ahmed A. Elansary, Yasser Y. Elnazlawy, H. Abdalla
ABSTRACT Wide beams are commonly used in reinforced concrete (RC) structures for architectural considerations such as facilitating the placement of services and providing adequate clear height. However, behaviour of these beams is not as efficient as normal width beams due to the small structural depth. Motivated by the lack of guidelines for wide RC beams with spiral reinforcement, this paper investigates their shear behaviour using innovative lateral reinforcement configurations. A comprehensive experimental program was conducted by testing nine beams under four-point loading. The effect of different parameters on the behaviour of such beams was investigated. These parameters included number, dimensions, and configurations of spirals. The experimental program also included testing of 18 standard cylinders spirally reinforced under compression to study the performance of confined concrete in the compression zone of wide beams. The results showed that the spiral lateral reinforcement is an efficient alternative for traditional closed stirrups for shear resistance in wide beams. Compared to regular closed stirrups, using spiral reinforcement or inclined links with regular closed stirrups can greatly improve the shear capacity and deformation. Also, reduction in the amount of lateral reinforcement can be achieved if the proposed lateral reinforcement is adopted instead of traditional stirrups. Based on the test results and the ACI 318–19 code, an equation is proposed and validated to estimate the shear strength of wide beams with regular/spiral lateral reinforcement.
{"title":"Shear behaviour of concrete wide beams with spiral lateral reinforcement","authors":"Ahmed A. Elansary, Yasser Y. Elnazlawy, H. Abdalla","doi":"10.1080/14488353.2021.1942405","DOIUrl":"https://doi.org/10.1080/14488353.2021.1942405","url":null,"abstract":"ABSTRACT Wide beams are commonly used in reinforced concrete (RC) structures for architectural considerations such as facilitating the placement of services and providing adequate clear height. However, behaviour of these beams is not as efficient as normal width beams due to the small structural depth. Motivated by the lack of guidelines for wide RC beams with spiral reinforcement, this paper investigates their shear behaviour using innovative lateral reinforcement configurations. A comprehensive experimental program was conducted by testing nine beams under four-point loading. The effect of different parameters on the behaviour of such beams was investigated. These parameters included number, dimensions, and configurations of spirals. The experimental program also included testing of 18 standard cylinders spirally reinforced under compression to study the performance of confined concrete in the compression zone of wide beams. The results showed that the spiral lateral reinforcement is an efficient alternative for traditional closed stirrups for shear resistance in wide beams. Compared to regular closed stirrups, using spiral reinforcement or inclined links with regular closed stirrups can greatly improve the shear capacity and deformation. Also, reduction in the amount of lateral reinforcement can be achieved if the proposed lateral reinforcement is adopted instead of traditional stirrups. Based on the test results and the ACI 318–19 code, an equation is proposed and validated to estimate the shear strength of wide beams with regular/spiral lateral reinforcement.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"174 - 194"},"PeriodicalIF":1.3,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1942405","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45893689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.1080/14488353.2021.1930639
Zhiqiang Wang, Z. Lei
ABSTRACT In order to study the waterproof performance of non-curable rubber modified asphalt material at deformation joints, the grouting situation of non-curable rubber modified asphalt material in the deformation joint was simulated through the test, the maximum opening amount of deformation joint under the action of constant water pressure was studied, and the corresponding waterproof performance was evaluated. The results show that under water pressures of 0.25 MPa, 0.3 MPa and 0.4 MPa, the widths of deformation joints that the non-curable rubber modified asphalt material can bear are about 11.5 mm ~ 12 mm, 11 mm ~ 11.5 mm and 10 mm ~ 11 mm, respectively. Meantime, the failure types of deformation joints under different water pressures are further clarified. When the water pressure is high, if there is water leakage in the deformation joint, cracks may appear along the direction of deformation joint, which will lead to the failure of deformation joint and gradually expand the failure range along the direction of deformation joint. When the water pressure is low, the occurrence probability of cracks is small and the failure range is relatively limited. The research has considerable guiding significance to the waterproofing of tunnel engineering.
{"title":"Waterproof performance of non-curable rubber modified asphalt material at deformation joints","authors":"Zhiqiang Wang, Z. Lei","doi":"10.1080/14488353.2021.1930639","DOIUrl":"https://doi.org/10.1080/14488353.2021.1930639","url":null,"abstract":"ABSTRACT In order to study the waterproof performance of non-curable rubber modified asphalt material at deformation joints, the grouting situation of non-curable rubber modified asphalt material in the deformation joint was simulated through the test, the maximum opening amount of deformation joint under the action of constant water pressure was studied, and the corresponding waterproof performance was evaluated. The results show that under water pressures of 0.25 MPa, 0.3 MPa and 0.4 MPa, the widths of deformation joints that the non-curable rubber modified asphalt material can bear are about 11.5 mm ~ 12 mm, 11 mm ~ 11.5 mm and 10 mm ~ 11 mm, respectively. Meantime, the failure types of deformation joints under different water pressures are further clarified. When the water pressure is high, if there is water leakage in the deformation joint, cracks may appear along the direction of deformation joint, which will lead to the failure of deformation joint and gradually expand the failure range along the direction of deformation joint. When the water pressure is low, the occurrence probability of cracks is small and the failure range is relatively limited. The research has considerable guiding significance to the waterproofing of tunnel engineering.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"27 4","pages":"130 - 146"},"PeriodicalIF":1.3,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1930639","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41293889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-24DOI: 10.1080/14488353.2021.1926072
X. Hao, P. Visintin, D. Oehlers
ABSTRACT There are innumerable tests on small stocky circular cylinders with either internal passive encasement of the concrete with circular stirrups or spirals, or external passive encasement through fibre-reinforced polymer (FRP) wrapping or through the use of FRP tubes or steel tubes. These tests have shown that passive confinement can increase the strength but, in particular, can substantially increase the ductility of concrete cylinders. Because of these important benefits, the effect of passive confinement on the concrete stress/strain in a particular cylinder section is invariably derived from tests such that substantial member testing is required. In this paper, it is shown how the passive stress/strain of the concrete for a particular circular member can theoretically be determined directly from their partial-interaction shear-friction and partial-interaction bond-slip material properties for any reinforcement arrangement and geometry of the circular cylinder. This procedure provides tools for designing for the benefits of passive confinement directly without the need for member testing.
{"title":"Simulating the passive confinement of circular concrete cylinders allowing for size effect","authors":"X. Hao, P. Visintin, D. Oehlers","doi":"10.1080/14488353.2021.1926072","DOIUrl":"https://doi.org/10.1080/14488353.2021.1926072","url":null,"abstract":"ABSTRACT There are innumerable tests on small stocky circular cylinders with either internal passive encasement of the concrete with circular stirrups or spirals, or external passive encasement through fibre-reinforced polymer (FRP) wrapping or through the use of FRP tubes or steel tubes. These tests have shown that passive confinement can increase the strength but, in particular, can substantially increase the ductility of concrete cylinders. Because of these important benefits, the effect of passive confinement on the concrete stress/strain in a particular cylinder section is invariably derived from tests such that substantial member testing is required. In this paper, it is shown how the passive stress/strain of the concrete for a particular circular member can theoretically be determined directly from their partial-interaction shear-friction and partial-interaction bond-slip material properties for any reinforcement arrangement and geometry of the circular cylinder. This procedure provides tools for designing for the benefits of passive confinement directly without the need for member testing.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"80 - 114"},"PeriodicalIF":1.3,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1926072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49037603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-24DOI: 10.1080/14488353.2021.1930635
Bharvi Sharma, Raju Sharma, P. Bansal
ABSTRACT In the present study, an attempt has been made to produce lightweight concrete (LWC) by replacing fine aggregates with expanded perlite and pumice. The first set of LWC is prepared by replacing the fine aggregates with expanded perlite at varying proportions, i.e. 0%, 25%, 50%, and 100%. The second set of the mix is prepared to study the effect of replacement of natural sand with equal proportionality of dual particles (expanded perlite and pumice). The replacement of fine aggregate with lightweight aggregates (expanded perlite and pumice) efficiently developed the LWC based on the density specified by Eurocode 2 Part 1–1 (density < 2200 kg/m3). The incorporation of expanded perlite efficiently brought down the density of developed LWC lower than 2200 kg/m3. However, the density of the mix prepared using expanded perlite and pumice exhibited slightly greater than the density of only expanded perlite contained LWC. The incorporation of pumice in the LWC imparts the pozzolanic reactivity and shows better strength and durability properties than the only expanded perlite contained LWC. Furthermore, the microstructure properties revealed that the presence of porous lightweight material unable to improve the interfacial transition zone (ITZ) compared to conventional concrete.
{"title":"Effect of fine aggregate replacement with expanded perlite and pumice on the development of lightweight concrete","authors":"Bharvi Sharma, Raju Sharma, P. Bansal","doi":"10.1080/14488353.2021.1930635","DOIUrl":"https://doi.org/10.1080/14488353.2021.1930635","url":null,"abstract":"ABSTRACT In the present study, an attempt has been made to produce lightweight concrete (LWC) by replacing fine aggregates with expanded perlite and pumice. The first set of LWC is prepared by replacing the fine aggregates with expanded perlite at varying proportions, i.e. 0%, 25%, 50%, and 100%. The second set of the mix is prepared to study the effect of replacement of natural sand with equal proportionality of dual particles (expanded perlite and pumice). The replacement of fine aggregate with lightweight aggregates (expanded perlite and pumice) efficiently developed the LWC based on the density specified by Eurocode 2 Part 1–1 (density < 2200 kg/m3). The incorporation of expanded perlite efficiently brought down the density of developed LWC lower than 2200 kg/m3. However, the density of the mix prepared using expanded perlite and pumice exhibited slightly greater than the density of only expanded perlite contained LWC. The incorporation of pumice in the LWC imparts the pozzolanic reactivity and shows better strength and durability properties than the only expanded perlite contained LWC. Furthermore, the microstructure properties revealed that the presence of porous lightweight material unable to improve the interfacial transition zone (ITZ) compared to conventional concrete.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"115 - 129"},"PeriodicalIF":1.3,"publicationDate":"2021-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1930635","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41447898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-09DOI: 10.1080/14488353.2021.1921342
O. Ofuyatan, Kayode-Thomas Enoch, Oluwafuminiyi Ogundeji, David O. Omole
ABSTRACT Abundant waste is being generated in the demolition or renovation in the construction industry. Improper disposal of this waste creates environmental concern as they form huge landfills without proper use. This study examined the fresh, hardened, durability, and microstructural analysis of self-compacting concrete made with recycled aggregates (RA) and marble waste as a 10–30% granite substitute. Slump flow test, T50cm test, V-funnel test, and L-box test were conducted on the fresh concrete. Compressive strength, split tensile strength, flexural strength, microstructural properties, and carbonation of the hardened concrete were determined. The physical tests revealed that though the recycled aggregates and marble waste do not have properties as good as the natural coarse aggregates, recycled aggregates were observed to exhibit a better strength than marble waste. SCC with marble waste had better fresh state properties than those with recycled aggregates. SCC with recycled aggregates had better-hardened state properties than those with marble waste. It can be inferred from the microstructural analysis that the utilisation of partial granite replacement improved the interaction between the concrete constituents. However, the sample with recycled aggregate was still better than that with marble waste in this regard.
{"title":"Marble waste and recycled concrete aggregates in self compacting concrete (SSC): an evaluation of fresh and hardened properties","authors":"O. Ofuyatan, Kayode-Thomas Enoch, Oluwafuminiyi Ogundeji, David O. Omole","doi":"10.1080/14488353.2021.1921342","DOIUrl":"https://doi.org/10.1080/14488353.2021.1921342","url":null,"abstract":"ABSTRACT Abundant waste is being generated in the demolition or renovation in the construction industry. Improper disposal of this waste creates environmental concern as they form huge landfills without proper use. This study examined the fresh, hardened, durability, and microstructural analysis of self-compacting concrete made with recycled aggregates (RA) and marble waste as a 10–30% granite substitute. Slump flow test, T50cm test, V-funnel test, and L-box test were conducted on the fresh concrete. Compressive strength, split tensile strength, flexural strength, microstructural properties, and carbonation of the hardened concrete were determined. The physical tests revealed that though the recycled aggregates and marble waste do not have properties as good as the natural coarse aggregates, recycled aggregates were observed to exhibit a better strength than marble waste. SCC with marble waste had better fresh state properties than those with recycled aggregates. SCC with recycled aggregates had better-hardened state properties than those with marble waste. It can be inferred from the microstructural analysis that the utilisation of partial granite replacement improved the interaction between the concrete constituents. However, the sample with recycled aggregate was still better than that with marble waste in this regard.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":"20 1","pages":"67 - 79"},"PeriodicalIF":1.3,"publicationDate":"2021-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1921342","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49622751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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