Pub Date : 2021-10-31DOI: 10.1080/14488353.2021.1995132
M. Nawaz, A. Heitor, M. Sivakumar
ABSTRACT Increase in industrial and construction activities has led to an enormous rise in waste generation and its hazardous impacts on the environment. Quarrying of rocks and manufacturing of artificial sands for civil engineering projects leads to the dumping of rock waste dust, which is a source of landfill problems. Further, excessive energy requirements for cement manufacturing, higher greenhouse gas emissions and rapid depletion of natural resources have focused the research towards the development of environment friendly and sustainable materials such as geopolymers. In this paper, a novel geopolymer has been developed from industrial wastes such as basalt rock fines considering partial replacement with ground granulated blast furnace slag up to 30%. After a detailed mix-design investigation, the optimum molarity (M) of the sodium hydroxide solution was found to be 8 M whereas the optimum ratio (R) of sodium silicate to sodium hydroxide solution as 0.75. Unconfined compressive strength evaluation showed 7-day strengths up to 34 MPa, comparable to geopolymers based on conventional precursor materials. The scanning electron microscopy imaging of the specimens revealed a dense geopolymer gel formation resulting in a homogeneous microstructure. As a result, this innovative material produced can be used as an alternative, sustainable and cost-effective construction material.
{"title":"Development and evaluation of a novel geopolymer based on basalt rock waste and ground granulated blast furnace slag","authors":"M. Nawaz, A. Heitor, M. Sivakumar","doi":"10.1080/14488353.2021.1995132","DOIUrl":"https://doi.org/10.1080/14488353.2021.1995132","url":null,"abstract":"ABSTRACT Increase in industrial and construction activities has led to an enormous rise in waste generation and its hazardous impacts on the environment. Quarrying of rocks and manufacturing of artificial sands for civil engineering projects leads to the dumping of rock waste dust, which is a source of landfill problems. Further, excessive energy requirements for cement manufacturing, higher greenhouse gas emissions and rapid depletion of natural resources have focused the research towards the development of environment friendly and sustainable materials such as geopolymers. In this paper, a novel geopolymer has been developed from industrial wastes such as basalt rock fines considering partial replacement with ground granulated blast furnace slag up to 30%. After a detailed mix-design investigation, the optimum molarity (M) of the sodium hydroxide solution was found to be 8 M whereas the optimum ratio (R) of sodium silicate to sodium hydroxide solution as 0.75. Unconfined compressive strength evaluation showed 7-day strengths up to 34 MPa, comparable to geopolymers based on conventional precursor materials. The scanning electron microscopy imaging of the specimens revealed a dense geopolymer gel formation resulting in a homogeneous microstructure. As a result, this innovative material produced can be used as an alternative, sustainable and cost-effective construction material.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42423708","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 : 2021-10-28DOI: 10.1080/14488353.2021.1971596
Branavan Arulmoly, Chaminda Konthesingha
ABSTRACT Construction industries around the world are facing many difficulties in obtaining good-quality fine aggregates for concrete and mortar due to a shortage of river sand. This problem leads the researchers to find possible alternatives to replace river sand in construction. A brief review has been carried out to identify the alternatives suggested by researchers, merits and demerits of substitutions, availability of standards, and previous studies on the effects of replacing river sand with alternatives in concrete and mortar. Manufactured sand (M Sand), offshore sand, sea sand, quarry dust, and demolition waste have been identified as the most common substitutions for river sand. M Sand and quarry dust have more angularity, rougher surface, higher total specific surface, and lower presence of deleterious substances than river sand, offshore sand, and sea sand. These characteristics played a vital role in the fresh, hardened, and durability performance of cement-based mixes where studies revealed both positive and negative outcomes when comparing with river sand concrete and mortar. Intensely, the strengths of cement-based mixes were improved with angular and rough particles while the workability was declined. The void content and specific surface of alternatives manifested pivotal effects on water absorption of concrete and mortar.
{"title":"Pertinence of alternative fine aggregates for concrete and mortar: a brief review on river sand substitutions","authors":"Branavan Arulmoly, Chaminda Konthesingha","doi":"10.1080/14488353.2021.1971596","DOIUrl":"https://doi.org/10.1080/14488353.2021.1971596","url":null,"abstract":"ABSTRACT Construction industries around the world are facing many difficulties in obtaining good-quality fine aggregates for concrete and mortar due to a shortage of river sand. This problem leads the researchers to find possible alternatives to replace river sand in construction. A brief review has been carried out to identify the alternatives suggested by researchers, merits and demerits of substitutions, availability of standards, and previous studies on the effects of replacing river sand with alternatives in concrete and mortar. Manufactured sand (M Sand), offshore sand, sea sand, quarry dust, and demolition waste have been identified as the most common substitutions for river sand. M Sand and quarry dust have more angularity, rougher surface, higher total specific surface, and lower presence of deleterious substances than river sand, offshore sand, and sea sand. These characteristics played a vital role in the fresh, hardened, and durability performance of cement-based mixes where studies revealed both positive and negative outcomes when comparing with river sand concrete and mortar. Intensely, the strengths of cement-based mixes were improved with angular and rough particles while the workability was declined. The void content and specific surface of alternatives manifested pivotal effects on water absorption of concrete and mortar.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42801304","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 : 2021-10-28DOI: 10.1080/14488353.2021.1984371
Sumanth Kumar B, Rama Seshu D
ABSTRACT Geopolymer concrete is gradually assuming significance from the point of sustainability in the concrete industry. The reinforced concrete corbels are used for supporting the precast beams. This paper presents an experimental investigation on the interface shear strength of reinforced geopolymer concrete corbels. A total of forty-five symmetric double cantilever reinforced GPC corbels were cast and tested. The parameters of the study include the compressive strength of GPC and the percentage of secondary reinforcement i.e. closed loop ties crossing the interface. The experimental shear strength at the interface of reinforced geopolymer concrete corbels obtained is compared with available analytical models and design codes applicable to the conventional concrete. The results of the study indicated that the interface shear capacity of geopolymer concrete was evaluated based on conventional concrete analytical models that underestimates the shear capacity of GPC corbels. Further the experimental shear strengths of corbel are about 9% higher than the predicted interface shear strength of GPC corbels using the analytical expression proposed in this paper.
{"title":"An experimental study on the interface shear strength of reinforced geopolymer concrete corbels","authors":"Sumanth Kumar B, Rama Seshu D","doi":"10.1080/14488353.2021.1984371","DOIUrl":"https://doi.org/10.1080/14488353.2021.1984371","url":null,"abstract":"ABSTRACT Geopolymer concrete is gradually assuming significance from the point of sustainability in the concrete industry. The reinforced concrete corbels are used for supporting the precast beams. This paper presents an experimental investigation on the interface shear strength of reinforced geopolymer concrete corbels. A total of forty-five symmetric double cantilever reinforced GPC corbels were cast and tested. The parameters of the study include the compressive strength of GPC and the percentage of secondary reinforcement i.e. closed loop ties crossing the interface. The experimental shear strength at the interface of reinforced geopolymer concrete corbels obtained is compared with available analytical models and design codes applicable to the conventional concrete. The results of the study indicated that the interface shear capacity of geopolymer concrete was evaluated based on conventional concrete analytical models that underestimates the shear capacity of GPC corbels. Further the experimental shear strengths of corbel are about 9% higher than the predicted interface shear strength of GPC corbels using the analytical expression proposed in this paper.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46777410","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 : 2021-10-27DOI: 10.1080/14488353.2021.1995131
S. Hazari, Sima Ghosh, Richi Prasad Sharma
ABSTRACT A methodology for the analysis of soil slope made up of c-ϕ soil using a modified pseudo-dynamic approach is tried to develop here. In this study, the slope is divided into a number of vertical slices and the failure surface of the slope is assumed to be logarithmic spiral. The suggested modified pseudo-dynamic approach satisfies the zero-stress boundary condition at the free ground surface and considers the damping properties of the materials. Results of the present analysis are presented in tabular form. The effects of the variation of different parameters like horizontal and vertical seismic acceleration, slope angle, soil friction angle, damping ratio, frequency ratio, cohesion and surcharge on the FOS are shown graphically. Consequently, required reinforcement strength is evaluated to ensure the safety of the slope under seismic loading conditions. The results obtained from the present method are compared with the results of the available literature and also a numerical validation of the model is given using PLAXIS 2D.
{"title":"Modified pseudo-dynamic analysis of slope considering logarithmic spiral failure surface with numerical solution","authors":"S. Hazari, Sima Ghosh, Richi Prasad Sharma","doi":"10.1080/14488353.2021.1995131","DOIUrl":"https://doi.org/10.1080/14488353.2021.1995131","url":null,"abstract":"ABSTRACT A methodology for the analysis of soil slope made up of c-ϕ soil using a modified pseudo-dynamic approach is tried to develop here. In this study, the slope is divided into a number of vertical slices and the failure surface of the slope is assumed to be logarithmic spiral. The suggested modified pseudo-dynamic approach satisfies the zero-stress boundary condition at the free ground surface and considers the damping properties of the materials. Results of the present analysis are presented in tabular form. The effects of the variation of different parameters like horizontal and vertical seismic acceleration, slope angle, soil friction angle, damping ratio, frequency ratio, cohesion and surcharge on the FOS are shown graphically. Consequently, required reinforcement strength is evaluated to ensure the safety of the slope under seismic loading conditions. The results obtained from the present method are compared with the results of the available literature and also a numerical validation of the model is given using PLAXIS 2D.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45251719","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 : 2021-10-26DOI: 10.1080/14488353.2021.1991549
Anu James, Babu Kurian
ABSTRACT Diaphragm walls are the ideal solutions for constructive utilisation of underground space to surmount the space constraints causing hindrance to infrastructural developments in urban areas. Accurate analysis methods to determine the wall forces and deformations are vital for the safe and cost-effective implementation of diaphragm wall projects. This paper describes a simplified method formulated for the analysis of diaphragm walls to process design values. The developed methodology is a combination of the net pressure method, the apparent pressure method and the limit equilibrium concept, with modifications to mitigate the demerits of each method towards the applicability for diaphragm walls. The design values for each excavation stage of a diaphragm wall supported excavation acted upon by any loading condition and ground water level can be computed with the methodology. Formulations for determining vertical axial forces are developed from the basic concepts of pile foundations by modifying the expressions to integrate the specific requirements of diaphragm walls. The developed formulations are validated against numerical analysis with Plaxis by comparing wall internal forces and axial strut forces. Around 90% of the results were found to have a percentage variation of less than 10% compared to Plaxis results, indicating the suitability of the method for application to diaphragm walls.
{"title":"Diaphragm wall retaining system – a simplified model for design loads","authors":"Anu James, Babu Kurian","doi":"10.1080/14488353.2021.1991549","DOIUrl":"https://doi.org/10.1080/14488353.2021.1991549","url":null,"abstract":"ABSTRACT Diaphragm walls are the ideal solutions for constructive utilisation of underground space to surmount the space constraints causing hindrance to infrastructural developments in urban areas. Accurate analysis methods to determine the wall forces and deformations are vital for the safe and cost-effective implementation of diaphragm wall projects. This paper describes a simplified method formulated for the analysis of diaphragm walls to process design values. The developed methodology is a combination of the net pressure method, the apparent pressure method and the limit equilibrium concept, with modifications to mitigate the demerits of each method towards the applicability for diaphragm walls. The design values for each excavation stage of a diaphragm wall supported excavation acted upon by any loading condition and ground water level can be computed with the methodology. Formulations for determining vertical axial forces are developed from the basic concepts of pile foundations by modifying the expressions to integrate the specific requirements of diaphragm walls. The developed formulations are validated against numerical analysis with Plaxis by comparing wall internal forces and axial strut forces. Around 90% of the results were found to have a percentage variation of less than 10% compared to Plaxis results, indicating the suitability of the method for application to diaphragm walls.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44968433","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 : 2021-08-31DOI: 10.1080/14488353.2021.1974658
T. Weir, G. White, R. Espinosa
ABSTRACT Foamed bitumen stabilisation is a unique pavement treatment option for improving new granular materials or rehabilitating existing granular layers that have exceeded their serviceable life. As a type of expedient construction technology, the application of foamed bitumen stabilisation technology to Australian pavements is exceptionally promising, with the product of the stabilisation process being a flexible material for use as base and subbase course, but with an increased modulus and reduced susceptibility to the effects of moisture ingress. Increasing demands on pavements, compounded with quality unbound pavement materials proving more difficult to acquire is necessitating the hauling of materials over long distances and this significantly increases typical pavement construction and maintenance costs. However, stabilisation of existing, marginal and non-standard granular materials can offer a logistically convenient and cost-effective solution. This paper reviews the design, construction and characterisation of foamed bitumen stabilised granular material for pavements. First, the technology of foamed bitumen stabilisation is summarised and then the design and production practices are reviewed, before concluding with future developments for stabilisation practices.
{"title":"Review of the design, characterisation and production of foamed bitumen stabilised base courses for pavement construction","authors":"T. Weir, G. White, R. Espinosa","doi":"10.1080/14488353.2021.1974658","DOIUrl":"https://doi.org/10.1080/14488353.2021.1974658","url":null,"abstract":"ABSTRACT Foamed bitumen stabilisation is a unique pavement treatment option for improving new granular materials or rehabilitating existing granular layers that have exceeded their serviceable life. As a type of expedient construction technology, the application of foamed bitumen stabilisation technology to Australian pavements is exceptionally promising, with the product of the stabilisation process being a flexible material for use as base and subbase course, but with an increased modulus and reduced susceptibility to the effects of moisture ingress. Increasing demands on pavements, compounded with quality unbound pavement materials proving more difficult to acquire is necessitating the hauling of materials over long distances and this significantly increases typical pavement construction and maintenance costs. However, stabilisation of existing, marginal and non-standard granular materials can offer a logistically convenient and cost-effective solution. This paper reviews the design, construction and characterisation of foamed bitumen stabilised granular material for pavements. First, the technology of foamed bitumen stabilisation is summarised and then the design and production practices are reviewed, before concluding with future developments for stabilisation practices.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43450656","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 : 2021-08-19DOI: 10.1080/14488353.2021.1961969
T. Zahra, C. Rafferty
ABSTRACT Changes in Australian Masonry Standards and National Code of Construction for reinforced masonry (RM) under compression impress the need of a grout annulus and vertical bar confinement using 6 mm tie bars. Maintaining the verticality and centricity of reinforcement and restraining them with the tie bars is challenging and time consuming. BlockAid have designed masonry bar chairs to align and restrain the reinforcing bars central in the block cores. This paper presents an investigation to ascertain the performance of BlockAid bar chairs in supporting the reinforcing bars in the RM walls subject to vertical compression and out-of-plane loads. The mean compressive strength in the fully grouted RM walls with BlockAid bar chairs was determined equivalent to the control specimen which sustained maximum load of 3100kN, compared to 3030kN for the BlockAid sample. Strain in the vertical steel bars, with BlockAid bar chairs, remained compressive throughout the loading with no evidence of buckling. The out-of-plane test results of BlockAid walls were similar in terms of failure modes, load-displacement behaviour and steel strain variations. These observations conclude that BlockAid bar chairs are effective in restraining the vertical bars against buckling and do not compromise the compression and bending capacity of RM walls.
{"title":"Influence of blockaid chairs on compression and out-of-plane behaviour of reinforced masonry walls","authors":"T. Zahra, C. Rafferty","doi":"10.1080/14488353.2021.1961969","DOIUrl":"https://doi.org/10.1080/14488353.2021.1961969","url":null,"abstract":"ABSTRACT Changes in Australian Masonry Standards and National Code of Construction for reinforced masonry (RM) under compression impress the need of a grout annulus and vertical bar confinement using 6 mm tie bars. Maintaining the verticality and centricity of reinforcement and restraining them with the tie bars is challenging and time consuming. BlockAid have designed masonry bar chairs to align and restrain the reinforcing bars central in the block cores. This paper presents an investigation to ascertain the performance of BlockAid bar chairs in supporting the reinforcing bars in the RM walls subject to vertical compression and out-of-plane loads. The mean compressive strength in the fully grouted RM walls with BlockAid bar chairs was determined equivalent to the control specimen which sustained maximum load of 3100kN, compared to 3030kN for the BlockAid sample. Strain in the vertical steel bars, with BlockAid bar chairs, remained compressive throughout the loading with no evidence of buckling. The out-of-plane test results of BlockAid walls were similar in terms of failure modes, load-displacement behaviour and steel strain variations. These observations conclude that BlockAid bar chairs are effective in restraining the vertical bars against buckling and do not compromise the compression and bending capacity of RM walls.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49212350","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 : 2021-08-06DOI: 10.1080/14488353.2021.1941596
V. G. Maheswari, M. Ajisha, Jaslin J. Christopher
ABSTRACT This work focus on the effect of Microwave power, Ozonation and Fenton reagent in microwave coupling Ozonation and Fenton oxidation process for the disintegration of COD of leachate. The experimental parameters like pH, COD, temperature, Oxidant dosage, microwave power and reaction time were varied. The results showed that 70% of COD removal efficiency was achieved at 450 W within 10 minutes interval in microwave process, 57.4% of COD removal efficiency was achieved at 60 minutes, ozone dosage 159 mg/L, pH 11. In Fenton Process, 52.91% COD removal efficiency at 60 minutes with H2O2 66.47 mµ/L and Fe2+ 80 mµ/L. Individual process showed an adverse reaction time consumption. On comparison of three processes, microwave achieved higher COD removal with shorter reaction time. In O3+ Fe process 83% COD removal was achieved at 75 minutes of reaction time. The experiment revealed the combined process of M+ O3+ Fe induces to the disintegration of COD in Leachate with a shorter reaction period.
{"title":"Municipal solid waste leachate treatment using ultrasonication microwave & Ozonation combined Fenton process","authors":"V. G. Maheswari, M. Ajisha, Jaslin J. Christopher","doi":"10.1080/14488353.2021.1941596","DOIUrl":"https://doi.org/10.1080/14488353.2021.1941596","url":null,"abstract":"ABSTRACT This work focus on the effect of Microwave power, Ozonation and Fenton reagent in microwave coupling Ozonation and Fenton oxidation process for the disintegration of COD of leachate. The experimental parameters like pH, COD, temperature, Oxidant dosage, microwave power and reaction time were varied. The results showed that 70% of COD removal efficiency was achieved at 450 W within 10 minutes interval in microwave process, 57.4% of COD removal efficiency was achieved at 60 minutes, ozone dosage 159 mg/L, pH 11. In Fenton Process, 52.91% COD removal efficiency at 60 minutes with H2O2 66.47 mµ/L and Fe2+ 80 mµ/L. Individual process showed an adverse reaction time consumption. On comparison of three processes, microwave achieved higher COD removal with shorter reaction time. In O3+ Fe process 83% COD removal was achieved at 75 minutes of reaction time. The experiment revealed the combined process of M+ O3+ Fe induces to the disintegration of COD in Leachate with a shorter reaction period.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1941596","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41313250","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 : 2021-07-21DOI: 10.1080/14488353.2021.1953236
Tengjiang Yu, Haitao Zhang, Guangyuan Wu, D. Chen
ABSTRACT The seasonal distribution coefficients of traffic volume have not been yet taken into account in asphalt pavement design in China. Through comprehensive analysis on the assessed data and the factors affecting monthly distribution coefficients of traffic volume in different areas, the monthly and seasonal distribution coefficients of traffic volume in Harbin city, China has been predicted and determined using a back propagation (BP) neural network algorithm. The research contents involve data investigation and analysis of monthly distribution coefficients of traffic volume, analysing the factors affecting the mentioned coefficients, prediction and determination of monthly and seasonal distribution coefficients of traffic volume, and application of those coefficients, etc. Through the application of monthly and seasonal distribution coefficients, the seasonal traffic volumes in a year were calculated, and the application results demonstrated that the seasonal distribution of traffic volume has a scientific rationality. In addition, this study indicated that the seasonal traffic volume could accurately evaluate the actual conditions about axle loads on the pavement, resulting in the asphalt pavement design to be more rational. Eventually, the findings could appropriately meet the requirements of actual vehicle loads passing on the road surface.
{"title":"Determination and application of seasonal distribution coefficients of traffic volume in pavement design","authors":"Tengjiang Yu, Haitao Zhang, Guangyuan Wu, D. Chen","doi":"10.1080/14488353.2021.1953236","DOIUrl":"https://doi.org/10.1080/14488353.2021.1953236","url":null,"abstract":"ABSTRACT The seasonal distribution coefficients of traffic volume have not been yet taken into account in asphalt pavement design in China. Through comprehensive analysis on the assessed data and the factors affecting monthly distribution coefficients of traffic volume in different areas, the monthly and seasonal distribution coefficients of traffic volume in Harbin city, China has been predicted and determined using a back propagation (BP) neural network algorithm. The research contents involve data investigation and analysis of monthly distribution coefficients of traffic volume, analysing the factors affecting the mentioned coefficients, prediction and determination of monthly and seasonal distribution coefficients of traffic volume, and application of those coefficients, etc. Through the application of monthly and seasonal distribution coefficients, the seasonal traffic volumes in a year were calculated, and the application results demonstrated that the seasonal distribution of traffic volume has a scientific rationality. In addition, this study indicated that the seasonal traffic volume could accurately evaluate the actual conditions about axle loads on the pavement, resulting in the asphalt pavement design to be more rational. Eventually, the findings could appropriately meet the requirements of actual vehicle loads passing on the road surface.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1953236","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43849698","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 : 2021-07-21DOI: 10.1080/14488353.2021.1953235
Leisheng Zhou, Han Wang, Shichao Zhu, Jinyi Liu, Ying Zhu
ABSTRACT The multi T-beam finite element model with an initial crack was generated based on the element and direct methods. The element method was used to evaluate the bonding performance of the fibre reinforced plastic (FRP)-to a concrete interface. On the other hand, the direct method introduced the basic theory of elastic fracture mechanics and calculated the crack tip energy release rate of the initial crack. In addition, the crack propagation risk before and after hybrid bonding FRP (HB-FRP) reinforcement was discussed. The simulation results showed that under traffic load, the bonding stress of FRP-concrete interface is very small in the absence of an initial crack, but the intermediate crack (IC) debonding is easier occurred at the flexural crack of the beam mid-span. With the function of the mechanical fastener, the interface debonding was suppressed with regard to overloading less than 4 times the design traffic load. Furthermore, it was shown that the higher the crack was, the greater the G I value was at the crack tip, which means a more unstable the crack was, and the easier it was to propagate. Also, the higher the initial crack was, the weaker the effect of HB-FRP reinforcement was in suppressing crack propagation.
{"title":"Performance evaluation of a 20m-T Section bridge beam strengthened by HB-FRP","authors":"Leisheng Zhou, Han Wang, Shichao Zhu, Jinyi Liu, Ying Zhu","doi":"10.1080/14488353.2021.1953235","DOIUrl":"https://doi.org/10.1080/14488353.2021.1953235","url":null,"abstract":"ABSTRACT The multi T-beam finite element model with an initial crack was generated based on the element and direct methods. The element method was used to evaluate the bonding performance of the fibre reinforced plastic (FRP)-to a concrete interface. On the other hand, the direct method introduced the basic theory of elastic fracture mechanics and calculated the crack tip energy release rate of the initial crack. In addition, the crack propagation risk before and after hybrid bonding FRP (HB-FRP) reinforcement was discussed. The simulation results showed that under traffic load, the bonding stress of FRP-concrete interface is very small in the absence of an initial crack, but the intermediate crack (IC) debonding is easier occurred at the flexural crack of the beam mid-span. With the function of the mechanical fastener, the interface debonding was suppressed with regard to overloading less than 4 times the design traffic load. Furthermore, it was shown that the higher the crack was, the greater the G I value was at the crack tip, which means a more unstable the crack was, and the easier it was to propagate. Also, the higher the initial crack was, the weaker the effect of HB-FRP reinforcement was in suppressing crack propagation.","PeriodicalId":44354,"journal":{"name":"Australian Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2021-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/14488353.2021.1953235","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49311948","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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