Properties of roller-compacted concrete pavement containing waste aggregates and nano SiO2

Abstract

This study deals with the use of waste materials as replacement of fine aggregate in roller-compacted concrete pavement (RCCP). To achieve this, waste ceramic, waste concrete, and waste glass were initially crushed and mixed and then replaced natural fine aggregate at varying amounts in RCCP. Furthermore, to mitigate the probable negative effects of waste aggregates and also to improve the mechanical properties of cement paste, nano SiO2 was employed in the mixes design. After preparing the mixes, Vebe time, compressive strength, splitting tensile strength, water absorption, abrasion resistance, and skid resistance were measured. The results show that more than 40% of sand replacement with waste materials could have a negative effect on the properties of RCCPs. However, this impact is negligible up to 10% of waste material proportions. The compressive strength of the mixes containing waste materials was lower than that of the control mix, except for the sample containing 10% ceramic waste.In terms of water absorption, mixes with waste materials had higher water absorption than the control mix. Besides, abrasion somewhat increased as a result of adding waste materials, except for the samples containing 10% glass and 10% ceramic wastes that showed a slight decrease. Moreover, mixes with waste materials had higher skid resistance than the control mix. Overall, waste ceramic mixes showed better mechanical properties and waste glass mixes had better performance in terms of water absorption. In addition, using nano SiO2 leads to improve the mechanical properties of the RCCP; the optimum content of nano SiO2 has determined to be 0.7% of cement weight.