Although the construction of block pavements has grown fast in the last decades,there is still a need for simple tools that could be applied to design them.This paper analyzed and verified concrete block pavements for...Although the construction of block pavements has grown fast in the last decades,there is still a need for simple tools that could be applied to design them.This paper analyzed and verified concrete block pavements for urban and local roads composed of rectangular concrete pavers with plane side surfaces(no interlocking effect).The examined blocks were laid on a bedding sand layer,a cement treated base layer and a granular unbound foundation layer.The commercial finite element(FE)software ANSYS?was used to calculate the response of the pavement when subjected to different loading,construction configurations.Three wheel positions,five blocks patterns,three bedding sand thicknesses and joints gaps have been considered to evaluate stress-strain condition on pavement materials.Fatigue and rutting verification was performed respectively for bound and unbound pavement materials using analytical curves available in the literature.At the end of this study,a proposal for a catalogue is presented.It has nine pavement sets,because it takes into account three values of subgrade capacity(30,90,and 150 MPa of resilient modulus)and three levels of traffic(400,000,1,500,000,and 4,000,000 passages of commercial vehicles during the service life).The obtained results provide an inexpensive procedure for the preliminary design of concrete block pavements.展开更多
The indiscriminate disposal of plastic waste poses significant environmental and economic threats,necessitating innovative recycling strategies that align with circular economy principles.The primary objective was to ...The indiscriminate disposal of plastic waste poses significant environmental and economic threats,necessitating innovative recycling strategies that align with circular economy principles.The primary objective was to assess the im-pact of varying plastic-to-sand ratios on the compressive strength of these com posite pavement blocks,optimising resource utilisation.These objectives were achieved through research investigating the feasibility of utilising four com-mon post-consumer thermoplastics-HDPE,PP,PET,and PS,as binding agents in pavement block production.This directly addresses the circular economy imperative by transforming waste into a valuable construction resource,mini-mising landfill burden,and creating a closed-loop system.Compared with con-ventional concrete pavers,these plastic-sand blocks offer the potential for a reduced carbon footprint by valorising waste materials and potentially decreas-ing reliance on energy-intensive cement production.The methodology in-volved melting each plastic type individually and combining it with sand at five different ratios:3:7,4:6,5:5,6:4,and 7:3(plastic:sand).The resulting mixtures were moulded into pavement blocks and subjected to compressive strength test-ing.One-way ANOVA revealed varying optimal plastic-to-sand ratios for HDPE,PP,PET,and PS pavement blocks,as determined by compressive strength anal-ysis.For HDPE,while ratios of 30:70,50:50,60:40,and 70:30 showed compara-ble performance,and the 40:60 combination exhibited the highest compressive strength.In contrast,PP mixtures demonstrated optimal strength at a 60:40 ratio,with the 40:60,50:50,and 70:30 ratios showing similar behaviour that could be substituted.PET mixtures achieved peak strength at a 30:70 ratio,and only the 40:60 and 70:30 ratio combinations could be substituted without impacting the compressive strength.Similarly,PS mixtures exhibited optimal performance at a 50:50 ratio,with some substitution potential observed at 30:70,40:60,60:40,and 70:30 ratios.These findings demonstrate that specific plastic types have unique optimal mixing ratios with sand to achieve maximal compressive strength,thereby transforming plastic waste into durable pavement blocks that support a circular economy.展开更多
文摘Although the construction of block pavements has grown fast in the last decades,there is still a need for simple tools that could be applied to design them.This paper analyzed and verified concrete block pavements for urban and local roads composed of rectangular concrete pavers with plane side surfaces(no interlocking effect).The examined blocks were laid on a bedding sand layer,a cement treated base layer and a granular unbound foundation layer.The commercial finite element(FE)software ANSYS?was used to calculate the response of the pavement when subjected to different loading,construction configurations.Three wheel positions,five blocks patterns,three bedding sand thicknesses and joints gaps have been considered to evaluate stress-strain condition on pavement materials.Fatigue and rutting verification was performed respectively for bound and unbound pavement materials using analytical curves available in the literature.At the end of this study,a proposal for a catalogue is presented.It has nine pavement sets,because it takes into account three values of subgrade capacity(30,90,and 150 MPa of resilient modulus)and three levels of traffic(400,000,1,500,000,and 4,000,000 passages of commercial vehicles during the service life).The obtained results provide an inexpensive procedure for the preliminary design of concrete block pavements.
文摘The indiscriminate disposal of plastic waste poses significant environmental and economic threats,necessitating innovative recycling strategies that align with circular economy principles.The primary objective was to assess the im-pact of varying plastic-to-sand ratios on the compressive strength of these com posite pavement blocks,optimising resource utilisation.These objectives were achieved through research investigating the feasibility of utilising four com-mon post-consumer thermoplastics-HDPE,PP,PET,and PS,as binding agents in pavement block production.This directly addresses the circular economy imperative by transforming waste into a valuable construction resource,mini-mising landfill burden,and creating a closed-loop system.Compared with con-ventional concrete pavers,these plastic-sand blocks offer the potential for a reduced carbon footprint by valorising waste materials and potentially decreas-ing reliance on energy-intensive cement production.The methodology in-volved melting each plastic type individually and combining it with sand at five different ratios:3:7,4:6,5:5,6:4,and 7:3(plastic:sand).The resulting mixtures were moulded into pavement blocks and subjected to compressive strength test-ing.One-way ANOVA revealed varying optimal plastic-to-sand ratios for HDPE,PP,PET,and PS pavement blocks,as determined by compressive strength anal-ysis.For HDPE,while ratios of 30:70,50:50,60:40,and 70:30 showed compara-ble performance,and the 40:60 combination exhibited the highest compressive strength.In contrast,PP mixtures demonstrated optimal strength at a 60:40 ratio,with the 40:60,50:50,and 70:30 ratios showing similar behaviour that could be substituted.PET mixtures achieved peak strength at a 30:70 ratio,and only the 40:60 and 70:30 ratio combinations could be substituted without impacting the compressive strength.Similarly,PS mixtures exhibited optimal performance at a 50:50 ratio,with some substitution potential observed at 30:70,40:60,60:40,and 70:30 ratios.These findings demonstrate that specific plastic types have unique optimal mixing ratios with sand to achieve maximal compressive strength,thereby transforming plastic waste into durable pavement blocks that support a circular economy.
