Engineering behavior of cement-treated marine dredged clay during early and later stages of curing

• Strength development of cement-treated clay changes before and after 3 days of curing
• The initial strength is determined by specific volume normalized by the liquid limit.
• The strength increment parameter is determined by the cement content.
• A strength estimation formula is proposed by normalized specific volume and the cement content.

Dredged clay has been re-used as a construction material, backfilling of quay walls, artificial barrier layers of waste disposal sites, and submerged embankments by proper treatment with cement. However, strength development of cement-treated clay has not been fully understood during very early and later stages of curing. In this study, vane shear and unconfined compression tests were conducted to examine the strength development of cement-treated clay under different stages of curing time, ranging from 0.5 h to 90 days. On the basis of the results, the strength development was found to be changed before and after 3 days of curing and it can be clearly divided into two stages depending on curing time; early stage (t < 3 days) and later stage (t > 3 days). The strength at 1 h curing was determined based on two indices, initial water content and specific volume of cement-treated clay normalized by water content and specific volume at liquid limit. In addition, the strength increment coefficients in early and later stages were obtained by cement content. Based on strength at 1 h curing and strength increment coefficients, two equations were developed to estimate the strength during early and later stages of curing. With the development of the formula, it is possible to determine the strength of cement-treated clays at any stage of curing.