## 1 Introduction  
Reconstituted clays can provide a frame of reference for an assessment of the influence of soil structure on the mechanical behaviour of intact clays. Hence, geotechnical engineers, and researchers have often relied on the mechanical properties (such as compressibility, expansion, and strength, etc.) of reconstituted or remoulded clays to interpret, extrapolate and establish the corresponding characteristics of clay subgrade materials. Based on this, several efforts have been made over the past 80 decades to formulate various constitutive models and theories to study the behaviour of reconstituted soils. One of the most popularly known reconstituted soil framework is the \"critical state\" soil mechanics which was developed between early and mid-20 th century. Critical state soil mechanics has become so widely embraced as one of the logical concepts that can be applied to solve many engineering problems given its capacity to incorporate theories of plasticity, yielding, flow, etc for the modelling of soil behaviour [1; 2; 3; 4; 5; 6]. A reconstituted clay could be defined as a clay that has been rigorously mixed at a moisture content that is equal to or greater than its liquid limit (LL). [PERSON] [7] introduced the \"intrinsic properties\" concept of reconstituted clays to serve as a basis for the interpretation of the natural soil. The name \"intrinsic\" describes the properties of a clay that has been remoulded at a moisture content of between its liquid limit (LL) and 1.25 to 1.5 times its LL (without the need for air or oven drying) and then consolidated one-dimensionally. Figure 1 depicts the intrinsic or inherent compression curve for a given remoulded clay. The values \(e_{100}^{*}\) and \(e_{1000}^{*}\) are the intrinsic void ratios that correspond to effective state pressures (\(\sigma_{\rm v}\)) 100 kPa and 1000 kPa respectively. It is important to note that the asterisk is used to signify an intrinsic property. Figure 1 also indicates the normalisation of the values of intrinsic compressibility by the assignment of fixed values to \(e_{100}^{*}\) and \(e_{1000}^{*}\) through a parameter referred to as the void index, \(I_{v}\) (measure of the compactness of a given soil). Voidindex is mathematically expressed as in Equation (1), and could be seen in Figure 1, that a unique slope called the intrinsic compression line (ICL) has been achieved, and this slope represents the remoulded clay subgrade material itself rather than one that has undergone some post-depositional modifications through weathering, desiccation, unloading, etc. In order to obtain an accurate measurement and assessment of intrinsic compressibility index of clays, very expensive and time-consuming experiments are often performed using a conventional oedometer or in some cases a modified form of the consolidometer. Moreover, when undertaken on clays with very high initial moisture contents, the procedure may even become inevitably cumbersome. The associated difficulties of measuring intrinsic compressibility index prompted a growing body of research in the use of statistically based estimates or correlation equations. [PERSON] [7] demonstrated that soil's intrinsic constants can be empirically correlated with its Atterberg limits. Following this, several modifications to Burland's relationships has been made in the most recent past by various researchers [8; 9; 10; 11; 12; 13]. Some of these studies have also attempted to extend these empirical correlations to cover the influence of factors such as initial moisture content, mineralogy, etc on the intrinsic compressibility of clays [14; 15; 16; 17]. For instance, [PERSON] and [PERSON] [14] investigated the influence of different initial water contents on the compression behavior of three clays. They concluded that intrinsic compression indices tend to increase nonlinearly with increasing initial water contents. On the other hand, research carried out by [PERSON] et al.