# Life Cycle Cost Analysis and Deterioration Patterns of Limestone Paving
## 5 Results and Discussion  
### Properties of Unweathered and In situ Aged Paving Limestones  
The contents of impure chemical elements in the stones are presented in Figure 3. Compared to the reference stone, RPHL, the limestone from Jordan, NUPL, has many more chemical impurities, Al, Fe, Cl, and SO\({}_{4}\) contents. These impurities are generally associated with clay mineral impurities in limestone. The clay impurities in limestone are prone to the impacts of high humidity and UV radiation and might cause the deterioration of the stone [1; 61]. According to [PERSON] [1], the decay process in stones containing high amounts of impurities may take only a few years. Figure 4 shows the general engineering properties of the studied paving stones. It can be seen that the bulk densities of the NUPL and RPHL are typical for limestone; see Table 1. However, the bulk density of NUPL is approximately 7% lower than the minimal limit recommended by [50; 51] for building stone. The lower bulk density of NUPL is indirect evidence of higher porosity and water absorption than those of the reference limestone (see Figure 4). The Amsler abrasion wear of the NUPL is higher by 33% than that of the reference limestone, RPHL. The estimated wear resistances of the RPHL and NUPL, calculated using Equation (1), are 22 and 24 mm, respectively [42]. \[\text{Wide Wheel}=17+1.7\cdot\text{(Amsler)} \tag{1}\]  
where  
Wide Wheel--Capon (\"Wide Wheel Abrasion Test\"). Amsler--Amsler abrasion wear. Thus, NUPL is more appropriate for paving a promenade in an intensive pedestrian environment compared to RPHL (see Table 1). Figure 3: Elemental analysis of minor chemical elements in paving stones. RPHL—reference paving hard limestone; NUPL—new (unweathered) paving limestone from Jordan. It was found that the water absorption and evaporation characteristic values of the NUPL are six to fifteen times higher than those of the reference RPHL, as can be seen in Figure 5. The relatively small changes in capillary water absorption compared to the large increase in total water absorption suggest that most of the additional water uptake occurred in larger pores or microcracks formed during weathering, rather than through capillary action in fine pores. This indicates that environmental exposure primarily caused mechanical damage and structural fragmentation, increasing the total porosity, without significantly altering the fine-pored capillary network, which governs capillary absorption. Furthermore, the evaporation capacity of the NUPL evaluated in terms of moisture residue in the stone after 168 h long in-lab exposure was about 15 times less than that in the case of the reference RPHL. Thus, it could be considered that the intensive water absorption and sluggish water evaporation of the NUPL from Jordan, taken together with the high content of impurities in this stone (see Figure 3) might cause the advanced deterioration of the NUPL during one-year-long in-use exposure in the hot and wet climate near Copernaum, the Sea of Galilee (Lake Kinnert), Israel. Unfortunately, no tests of the chemical and physical/engineering properties of the NUPL were carried out by the contractor prior to paving the promenade. As was previously mentioned, the defects appeared in the paving after only one year. Therefore, the defective performance of the NUPL in the pedestrian promenade could serve as evidence of how disregarding the basic chemical/physical/engineering properties of paving stones and keeping up only with their aesthetical appearance and sufficient strength characteristics might lead to construction faults costing many millions of dollars. Hence, the chemical, physical, and engineering properties of specific building stones compared with those of a reference local stone of known lifespan should be considered as a necessary criterion for minimizing the probability of defects appearing in the external stone paving.