The research of [2] identified the difficulties and benefits in the production system of facade coating using the wet-process sprayed mortar and conventional processes. Data of losses and productivity were obtained in two projects. Table 2 presents relevant characteristics of these projects.

[20] contemplated the analysis of the coating productivity using wet-process sprayed mortar. Table 3 presents the main characteristics found in that study.

The third study deals with the research carried out by [21], in a development with 21 floors. In order to measure the losses of processed mortar, the author took into account the balance between the theoretical quantity and the actual quantity of processed mortar bags consumed, including the average thickness of the coated surface.

[22]'s research on the productivity of the workforce for the execution of mortar coating involved 14 cases from various regions of Brazil. From the total, 10 were related to the wet-process sprayed mortar system. Cases 1, 2, 3, and 4 were characterized by high thicknesses (varying from 3 to 8 centimeters) in the coating layer, while in cases 5, 6, and 7 the projection was applied on structural masonry, with thicknesses lower than 2 cm and presenting an extensive area per construction worker. Cases 12, 13, and 14 refer to the projection in internal areas, whose thickness did not exceed 2 cm.

The set of favorable situations evidenced by [22] for the execution of the external coating included: adoption of a projection plane before the beginning of the task, management focused on the production per floor, thicknesses less than 3 cm, use of precast windows, few corners. On the other hand, the unfavorable situations were: execution of framings after the plaster application and independent production, that is, one rocker per floor.

According to research by [21], it was possible to indicate reference values for losses of industrialized mortar applied in internal areas using the wet-process sprayed mortar. Fig. (1) shows the minimum, average, and maximum values obtained by [21].

Fig. (1). Losses of industrialized mortar in internal cladding.

According to projects evaluated by [2], the losses of industrialized mortar in external cladding ranged from 5.17% to 32.82%, as shown in the Fig. (2).

Fig. (2). Losses of industrialized mortar in external cladding.

Based on the researches by [20] and [22], reference values for labor productivity were gathered in the execution of the wet-process sprayed mortar in internal cladding, as shown in Fig. (3).

Fig. (3). Productivity (M’hr/m2) for internal cladding.

According to Fig. (3), the productivity values evidenced by [22] were better than those obtained by [20] in case E2. While [22] observed variations from 0.23 to 0.26 M’hr/m², with an average of 33 m²/day/man [20], observed variations around 0.62M’hr/m² or 12.9 m²/day/man.

Fig. (4) represents the reference values for the productivity of cladding execution in external areas, according to the research studies [2], [20] and [22], indicating the minimum, average, and maximum values obtained in their case studies, including the range established by TCPO 14 [23].

Fig. (4). Productivity (M’hr/m2) for external cladding.

According to the values shown in Fig. (4), the productivity shown by [2] in Case E, with a variation from 0.88 to 1.42 M’hr/m² [20], in Case E1, with a variation from 0.43 to 1.44 M’hr/m², and [22], with a variation from 0.65 to 0.91 M’hr/m² are consistent with the range of values established by TCPO 14 [23].

In all of the analyzed projects, except for D, the projection mortar was bagged and palletized or stacked on wooden platforms, with the indication for mechanical application.

In works A, B, C, E and F, the mortar was dry and transported to the vicinity of the mixing plant, from the tank where it was wrapped up . This route involved the use of equipment such as pallet carriage, for horizontal transport, and a winch, for vertical transportation. In G and H works, the bagged mortar was transferred from the bagging tank to the mixer, by only horizontal transport, using the skytrack, or telescopic handler.

For the mortar mixing, all projects used mixer equipment, in which the operator performed the water/dry material ratio, according to the production requirement. After that, the fresh mortar is thrown directly into the chamber of the projection equipment.

Only in the construction work D, the projection counted on the use of the coupled container method and in the other works analyzed, the wet-process sprayed mortar system was performed through the use of a projection pump.

Projects G e H used scaffolding, with the time required for assembly and disassembly influences the production team productivity. However, such apparatus type can contribute for the simultaneous execution of several stretches along the facade.

As Table 6 shows, project A was the only one in this research with wet-process sprayed mortar cladding in internal areas. Fig. (6) represents the box plot of loss values.

Fig. (6). Industrialized mortar losses in internal area (%).

Considering a coefficient of variation equivalent to 45%, the loss data collected in project A constitute a distribution classified as high dispersion, being higher than 30%, with values varying from 27.93% to 150.02%. From the Box Plot presented, 50% of the loss index for project A was between 53.26% and 122.29% (quartile 1 and quartile 3, respectively).

Fig. (7). Comparison of industrialized mortar losses (%) from project A and reference studies.

As it can be observed in Fig. (7), the loss values for A were higher than those found by [21], which varied from 3.11% to 16.26%, taking into account that they are projects with the same production system and that the mortar application occurred in internal areas. As most loss values for project A were higher than 53%, with an average of 81.23%, it can be considered that the industrialized mortar losses in this project were high.

Fig. (8) shows box plot graphs of projects E, F, G, and H, characterized by the wet-process sprayed mortar in internal area claddings.

Fig. (8). Industrialized mortar losses (%) in external area.

The distribution of the losses data collected in project E presented a variation coefficient of 63%, classified as high dispersion, with values varying from 7.04% (quartile 1) to 23.93% (quartile 3), as the box plot shows. These values were obtained in a period in which the wet-process sprayed mortar was already consolidated in the company.

In project F, the collected data distribution resulted in a variation coefficient of 36%, indicating a high dispersion, with values varying from 28.85% to 58.74%, equivalent to quartile 1 and quartile 3, respectively, according to the box plot.

The data collected in G presented a variation coefficient equivalent to 119%, indicating a high dispersion, with losses varying from 6.38% to 148.4%. According to the box plot analysis, half of the data is between 6.38% and 106.02%. Among the factors that may have influenced these indexes, it was noticed the low consistency presented by the mortar used in the projection and by several stretches with reference levels, indicating a thickness above 4cm, considered as high.

In project H, the loss values ranged from 13.13% to 26.53%, presenting a variation coefficient of 30%, setting up average data dispersion. From the box plot, 50% of the values are comprised between 14.14% and 21.82%. The results were satisfactory to the construction site management that applied wet-process sprayed mortar for the first time.

Regarding the reference values identified in the literature, the loss results in E and F can be compared to case E from the research of [2], since they present similar mechanization system characteristics, in the same way as G and H can be compared with case V from [2].

According to Fig. (9), the average loss value in work E is close to the value found by [2] in case E. The losses found in F were higher than the results of [2].

Fig. (10) shows variations in projects G and H as well as in case V of [2]. Based on the data presented in this graph, it can be seen that project G presents both the lowest and the highest loss index, and that project H presents the best loss result, considering the average value of all averages presented.

Fig. (9). Comparison of industrialized mortar losses (%) from projects E and F and reference studies.

Fig. (10). Comparison of industrialized mortar losses (%) from projects G and H and reference studies.

Fig. (11) shows a box plot of masons’ productivity values in M’hr/m² from project A.

Fig. (11). Masons’ productivity (M’hr/m2) in internal claddings.

According to the analysis in the graph above, the weekly productivity index for project A ranged from 0.21M’hr/m² to 2.06M’hr/m² with a variation coefficient of 48%, indicating a high data dispersion, with half of these values concentrated in a range from 0.7M’hr/m² to 1.36M’hr/m². Among the factors that favored the team’s productivity, it is possible to highlight: workmanship with experience in wet-process sprayed mortar, average thickness of the cladding layer ranging from 0.7cm to 1.0cm, and application in internal areas.

Since project A was characterized by performing an inner cladding using a portable system, the RUP results can be compared with case E2 values found by [20] and the values obtained by [22], for internal cladding.

Comparing, according to Fig. (12), A’s productivity values and the values obtained in [20] and [22] surveys, for internal cladding, it is noted that the RUP mean and maximum values in project A are higher than the results found by those authors.

Fig. (12). Comparison of productivity (M’hr/m2) in A and reference studies.

Fig. (13) indicates box plots for the analyzed projects with mortar cladding in external areas.

Fig. (13). Masons’ productivity (M’hr/m2) in external cladding.

As projects B and C belong to the same construction company, the implementation of the projection system occurred in the same period with the goal of executing the cladding in only two panels of a facade in each work.

In B, the productivity variation was between 0.18 M’hr/m² and 0.34 M’hr/m², with half of these values concentrated in the range of 0.21 M’hr/m² to 0.3 M’hr/m². In project C, the productivity variation was from 0.23 M’hr /m² to 0.75 M’hr /m². In those cases, the predominant workforce knew how to execute the wet-process sprayed mortar and the thickness of the cladding layer averaged 4cm to 6cm. Those two facts were an advantage for the productivity.

Project D presented a productivity variation of 0.43 M’hr/m² to 1.17 M’hr/m² with a variation coefficient of 46%, indicating a high data dispersion, with half of these values concentrated in the range of 0.48 M’hr/m² to 0.93 M’hr/m².

The productivity variation in project E was from 0.59 Hm/m² to 1.60 Hm/m², with a variation coefficient of around 54%, setting a high dispersion in the obtained data. During the collection phase, the following abnormalities were recorded: projection equipment breakage, hose clogging, delays in the transport of bagged material to the projection pavement, and demotivation by the masons in continuing to work with the system due to the problems mentioned.

The productivity data collected in the project F ranged from 0.7 M’hr/m² to 1.81M’hr/m² with a variation coefficient of 44%, indicating high data dispersion. Factors such as labor turnover, equipment breakdown, and team demotivation influenced the low productivity indexes in F.

In G, the registered productivity varied from 1.04M’hr/m² to 5.91M’hr/m² with a variation coefficient of 91%, indicating a high dispersion in the obtained data. The RUP values ​​recorded in G indicate a low productivity for a team composed by 5 masons and 3 helpers. The factors identified as influential in production were: a great deal of adjustments and corners, the mortar consistency, equipment breaks, hose clogging, and the team's lack of motivation because of the low productivity.

In project H, the productivity of the production team varied from 0.46 M’hr/m² to 0.82 M’hr/m² with a variation coefficient of 20%, that is, presenting data with average dispersion and half of the values in the range of 0.54M’hr/m² to 0.78M’hr/m². The team that performed the service was subcontracted and knew the projection technique, which favored to reach a good productivity. The RUP values were satisfactory for the construction site management. Briefly, the factors influencing productivity were: geometric characteristics of the area with few corners and adjustments, workmanship with experience in the wet-process sprayed mortar, and the use of a scaffolding, which favored masons movement along the stretch in execution.

The following works were compared: the productivity data obtained in projects B, C, D, E, F with the values found by [2] for case E [20], for Case E1 [22], and TCPO 14 [23]. Fig. (14) indicates the minimum, average and maximum results of the analyzed works together with the values found in the literature.

Fig. (14). Comparison of productivity (M’hr/m2) in B, C, D, E and F and reference studies.

According to Fig. (14), the result variations in B and C constitute the best productivity results among the analyzed ones. The results of D are consistent with the variations obtained in case E1 of [20] and [22]. The projects E and F presented minimum values consistent with the reference studies, but the maximum RUP values are higher than those predicted by [20] and [22]. Considering the average productivity value obtained, these are within the reality of the reference studies and TCPO 14 [23].

Project G and H were characterized by the execution of an external area cladding, using the system with a fixed mixer station located on the ground floor and a scaffolding. Because of that, they can be compared with the results of case V in [2]. Fig. (15) shows the productivity variations in G, H and case V of [2], including the range of values established by TCPO 14 [11].

Fig. (15). Comparison of productivity (M’hr/m2) in G and H and reference studies.

According to Fig. (15), project H obtained productivity values higher than case V in [2], since the maximum RUP value in H is lower than the minimum value of RUP in [2]. The minimum RUP value in G is consistent with the results of [2], but presents the average and maximum values outside the reality found in project H and case V in [2]. Regarding the values established by TCPO 14 [23], H presents coherent variations while G presents discrepant variations.