## 6 Pavement Construction, Maintenance, and Rehabilitation Based on Life Cycle Assessment
[PERSON] [125] reported that ICBP is an attractive alternative for heavy-duty applications in terms of maintenance costs rather than for applications with light traffic. Figure 15 shows that the major cost of an ICBP occurs during the construction phase, while the maintenance cost is much lower than for AP. The reason for this is that CPBs are reusable, significantly reducing the time and cost of maintenance and rehabilitation [125]. Therefore, the economic analysis of the ICBP life cycle shows an attractive pavement alternative. The research by [PERSON] et al. [123] used a Present Worth Cost model of a transportation infrastructure project [126] for the following three pavement systems construction: the AP, ICBP, and do-nothing scenario courses. The combined LCC and the pavement age plot for the three systems at a 6.2% interest rate are shown in Figure 16.  
The AP and ICBP structures met the required level of services. At the same time, the Do-nothing scenario was unsuitable based on poor driving characteristics and potholing, which could worsen after the rainy season without a wearing surface course. Therefore, the Do-nothing scenario was an unacceptable option. Furthermore, the ICBP construction proved to be less expensive than AP, again showing the CPB maintenance process over the years as a more viable option than AC. In addition, the regression modeling analysis had a Durbin-Watson statistic coefficient of 0.95, indicating that the LCC model is highly robust in replicating the project data. Figure 16: LCC versus pavement age for the three systems (adapted from [123]). Figure 15: Costs based on Life Cycle Cost (LCC) (adapted from [3]). Table 9 lists the studies conducted by field or laboratory experiments to identify the ICBP components' impact on LCA. The research by [PERSON] et al. [127] analyzed different sidewalk systems, e.g., B: ICBP; C: continuous concrete pavement (CCP); and S1, S2, and S3: the concrete slab pavement (CSP) being not structurally equivalent, as shown in Figure 17 (without scale). In addition, the life cycle impacts for 1 m\({}^{2}\) of the pavements are presented in absolute values in Table 10.  
ICBP (system B) showed the lowest environmental impacts by far, with the effects being reduced by approximately 70% in all impact categories compared to the highest impact type (CSP: system S3). Then, CPB was the best choice in urban environments, but these blocks may have functional and maintenance problems, depending on the use conditions. In light of this finding, redesigning sidewalks using environmental criteria brought significant benefits. The research by [PERSON] et al. [29] tested concrete mixtures put into built-in models of manufacturing machinery to produce CPB being compacted to a height of 60 mm, using a vibrational pressure with a frequency of 90 Hz. Furthermore, Figure 18 compares the energy consumption (EC), global warming potential (GWP), saved land occupation, and saved the land transformation for the CPB with 20-80% RCA content. LCA demonstrated that the EC of the CPBs with 80% RCA rose by 9.80% compared to 20% RCA, while changing the RCA content from 20% to 80% increased the GWP by 8.10%. Furthermore, the area of the saved land occupation and transformation decreased by 17.15% and increased by 11.56%, respectively, when the RCA content changed from 20% to 80%. Then, the crushing process was needed to obtain RCAs, which meant a higher EC in the extraction phase for CPBs with more recycled materials. However, considering the land saving, a CPB with 80% RCA could be recommended in practice, saving 0.55 m\({}^{2}\) of land resources and being 5.36% higher than 20% RCA. Analyzing the research by [PERSON] et al. [132], firstly, Figure 19 shows cross-sections of the scenarios: ICBP, bioretention cells (BC), and infiltration trenches (ITs). Then, Figure 20 demonstrates the benefits of all scenarios compared to an equivalent conventional pipe drainage network with AP in terms of runoff reduction, environmental enhancement, and cost savings.