Laboratory Analysis of Recycled Cement Stabilized Concrete Aggregates as Subbase Materials

Abstract

Rigid Pavement rehabilitation and reconstruction of concrete structures generate large quantities of Recycled Concrete Aggregate (RCA). These recycled aggregates could be used as material for subbase courses in pavement construction. The strength characteristics of RCA materials usually limit their application in road subbases. The high volume usage of RCA in subbase applications is better ensured by meeting the minimum standards set by the specification for material performance. When used as a substitute for natural aggregates in subbase applications, most RCA materials do not often meet the minimum requirements set by the specification. In such cases, stabilization with different stabilizers allows the use of these RCA's materials with the minimum required strength characteristics. In the present study, an attempt is made to evaluate the suitability of RCA as a subbase material using Ordinary Portland Cement (OPC) as a binding material. Concrete waste was pulverized and sieved to obtain the required gradation for the granular subbase (Gradation-II) as per MORT&H-V revision. RCA is treated with different dosages of cement and samples were prepared. The prepared samples were cured for 3, 7 & 28 days, and were tested. Compaction, California Bearing Ratio (CBR), Unconfined Compressive Strength (UCS), and permeability tests were conducted. From the laboratory studies conducted, it is observed that the Portland cement stabilized RCA mix exhibits an increase in strength, with an increase in the dosage of stabilizer and curing period.