Vol.:(0123456789) 1 3 International Journal of Pavement Research and Technology https://doi.org/10.1007/s42947-022-00270-y ORIGINAL RESEARCH PAPER An Assessment of Strength, Durability and Economic Benefits of Stabilized Silty Soil for Construction of Low Volume Roads Sanjeev Sinha 1  · Shiva Kumar Mahto 1  · Hillol Chakravarty 1  · Samir Saurav 1 Received: 20 March 2022 / Revised: 4 November 2022 / Accepted: 22 December 2022 © The Author(s), under exclusive licence to Chinese Society of Pavement Engineering 2023 Abstract Growing concern over the combustion cost and environment has made road engineers and scientists to explore the possi- ble use of locally available materials for the construction of roads. The present study evaluated the strength and durability characteristics of five sites having locally available silty soils using lime and cement–sand stabilization technique. The test results showed that the cement–sand stabilization technique using 6% cement and 5% local sand resulted in higher strength and durability as compared to lime stabilization. There is also a significant increase in the value of the soaked California bearing ratio (CBR). As unconfined compressive strength (UCS) attained the threshold strength as prescribed by IRC SP 72 2015 for the granular sub-base (GSB) layer, by the use of sand cement stabilization, this technique of stabilization for local silty soils could be used for GSB for low volume road (LVR) construction. As observed from microstructural results which were performed by analysing SEM images, sand cement stabilisation leads to CSH gel and agglomerate formation thereby increasing strength and durability properties. The cost analysis for the replaced stabilized GSB layer showed that using sand– cement stabilization, the estimated cost can be reduced by 56% of the total cost as compared to the conventional method. Keywords Silty soil · Stabilization · Unconfined compressive strength · Durability · Economic analysis 1 Introduction Pavement design is guided by the engineering properties of soil and the projected traffic expected to ply on the road. The inclusion of local materials not only reduces the cost of con- struction but also provides high performance if the material is of satisfactory quality. Poor natural soil necessitates either replacement or requires soil stabilization [1–5]. For replace- ment, a long-distance haul of satisfactory road construction materials not only increases the transportation cost but also puts strain on the environment. The growing economic and environmental costs for the utilization of such materials for road construction have become a challenge for engineers. Thus, soil stabilisation is always preferred for such construc- tion activities [6]. The term soil stabilization means the improvement of the stability or bearing capacity by the use of controlled com- paction; proportioning or the addition of suitable admix- ture or stabilizers [7]. Physical and chemical stabilisation methods are used to prepare the stabilized soil as pavement component material [8–11]. The physical method of the soil stabilization process may include the blending of soils to achieve the desired gradation, whereas, the chemical method includes the mixing of additives that may alter the gradation, texture, or plasticity or act as a binder for the cementation of the soil [12]. 1.1 Background The present study focuses on silty alluvial soil. Previous studies have investigated stabilization techniques to enhance the properties of silty soil with different materials. In a study, the effect of lime and lime–cement stabilization with reduced clay and silt content was evaluated. The combina- tion of lime and cement at 5% gave better strength with 15% * Shiva Kumar Mahto shivam.phd19.ce@nitp.ac.in Sanjeev Sinha sanjeev@nitp.ac.in Hillol Chakravarty hillol140870@nitp.ac.in Samir Saurav samsauvik@gmail.com 1 Department of Civil Engineering, National Institute of Technology, Patna, Bihar 800005, India