## 4 Impact of CTE on Concrete Pavements  
Concrete pavement's capacity to withstand large loads and strains, workability, and durability have made it the preferred technology for bridge decks, roads, airports, etc. [25]. In comparison to flexible pavements, concrete pavements are more likely to develop thermal stress as concrete has low ability to expand and contract in response to temperature changes [26]. Significant thermal expansion or contraction before concrete gains strength may lead to development of transverse cracks [27]. In case of concrete pavement, thermal expansion in concrete creates tension and compression stresses, causing cracks, chipping, and warping, particularly in concrete slabs exposed to high temperatures. Significant temperature fluctuations between day and night increase stress, leading to the formation of cracks, potholes, and other defects [12]. This, in turn, affects the effectiveness of load transfer across joints by influencing their contraction and expansion. Efficient load transfer is vital for managing load-induced stress and, more importantly, for preventing faulting over the lifespan of the pavement [28]. CTE is a parameter which is required to understand joint movement, curling stress, and crack spacing and width for continuously reinforced concrete pavement [11]. CTE is a crucial characteristic in the design of concrete pavements because it can influence the axial and curling stresses, which, in turn, affects the pavement's serviceability and performance. Early-age cracking, fatigue cracking, faulting, and joint spalling can all be influenced by CTE [17,29]. Proper consideration should be provided while placing the concrete pavement in summer, to avoid coincidence in peak ambient temperature and peak heat of hydration which may increase expansion of concrete [30]. Slab curling (as shown in Figure 1) occurs when differences in moisture content andtemperature along the slab depth due to temperature gradient cause it to distort, usually curling upward at the edges. When slabs curl upward, they lose support from the sub-base, becoming more susceptible to fatigue cracking from traffic-induced deflections. Proper moisture control and slab design are important to reduce curling and its impact on slab performance [31]. Temperature curling reduces slab-base contact, causing failure under heavy truck loads [32]. CTE can cause spalling distress due to aggregate separation from surrounding paste, which was observed in some continuously reinforced concrete pavement in Texas. It was mainly observed due to the bond stress at the interface between coarse aggregate and paste which increases with the aggregate's CTE [33]. In the case of Jointed Plain Concrete Pavement, the CTE regulates joint opening, which impacts load transfer via joints and cracks. Additionally, it influences the performance of joint sealants, the onset of spalling, and blow-up failure. The degree of longitudinal, transverse, and corner cracking caused by thermal curling in jointed concrete pavements is thought to be influenced by the concrete's CTE [34]. A study was carried out involving a combination of field evaluations, laboratory testing, and data analysis to investigate the relationship between spalling and the CTE of concrete in continuously reinforced concrete pavement in Texas, and test results indicated that concrete in sections with spalling had CTE values greater than 9.9 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C [35]. The difference in CTEs between concrete and steel reinforcement (CTE \(\sim\)11-13 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C) and concrete (CTE \(\sim\)9-10 \(\times\) 10\({}^{-6}\)/\({}^{\circ}\)C) causes thermal stresses in both the concrete and reinforcement [36]. Since longitudinal steel restricts the movement of the concrete, vertical tensile stresses in continuously reinforced concrete pavement rise with rise in CTE [37; 38]. Using data from crack surveys and laboratory testing of samples from roughly 100 segments of in-service highway pavements across the state of California, [PERSON] et al.