Experimental investigations for curling stress in self compacting concrete pavements

Abstract

A highway pavement is a structure consisting of superimposed layers of processed materials newlineabove the natural soil sub-grade. In India, flexible pavements are preferred for road constructiondue to lower construction costs and speedy construction as compared to rigid pavements. newlineHowever, the maintenance costs of the rigid pavements are relatively lower as compared to the newlinemaintenance costs of flexible pavements. The rigid pavements are constructed by casting cement newlineconcrete slabs over dry lean concrete or granular sub-bases. The cement concrete pavements are newlinedesigned to withstand traffic loads and environmental loads during its service life. The newlineenvironmental factors that are considered in the concrete pavement analysis are temperature, newlinehumidity, precipitation and frost/heave. The stresses induced in the concrete pavements on newlineaccount of daily temperature variation are termed as curling stress. The curling stresses are as newlineimportant as axle loads in the concrete pavement analysis as they alone can trigger the failure of newlinethe cement concrete pavements. newlineThe rigid pavements are constructed with normally vibrated concrete. Self-compacting concrete newline(SCC) is preferred over normal concrete mainly due to improved mechanical properties and newlinespeed of construction. Due to environmental regulations and concerns, the use of natural river newlinesand in concrete manufacture is becoming impractical and obsolete. Nowadays crushed sand is newlinewidely used in concrete manufacturing process. Hence, the properties of SCC mix prepared with newlinenatural sand and crushed sand were tested in the present research. SCC is a concrete with high newlinebinder content, which poses a challenge from the point of view of sustainability. Thus, use of newlinepozzolanic materials like fly ash and its effect on the properties of SCC were also investigated. newlineIn the present study, 20% Class C fly ash dosage as a cement replacement material was obtainedthrough experimental trials. newlineThe thermal properties of concrete are influenced by the thermal properties of the matrix and newlineaggregate phase.