Waterproofing Constructions

Transcription

1 Waterproofing Constructions Technological Solutions and Selection Criteria Extended Abstract Raul da Costa Cabanas Perdigão Dissertation for attainment of the Degree of Master in Civil Engineering Jury President: Professor Carlos dos Santos Pereira Orient: Professor Alberto Martins Pereira da Silva Vowel: Professor Pedro Manuel Gameiro Henriques September of 007

2 Extended Abstract This investigation as two main objectives: the first one is to make a search in the Portuguese market and collect the most common and most used solutions to make one structure waterproof; the second one is to present one way of analysing and comparing those solutions according with the structure that is to be treated. In order to get information about the waterproofing solutions many manufacturers were consulted as well as their representatives. At this time the main preoccupation was to get products that had a good quota in the market or that give reliable and trusted information. Following this first phase all the solutions were crossed in order to get information for the same type of product from the different manufacturers. Therefore, and adopting a totally independent position, all the products and his derivatives are presented by alphabetic order, however when translating to English this order may be lost:. Additive Mortar;. Bituminous Emulsion;. Bitumen Membrane;.. Base of Elastomer;.. Base of Plastomer;.. Oxidated Bitumen;. Liquid Membrane;.. Base Butyl Rubber;.. Base of Styrene-Plastic Dispersion;.. Base of Resin;.. Base of Polyurethane;. Polyurea Membrane; 6. PVC Membrane; 7. Copolymer Ink. To each and every types of solution were studied the same characteristics in order to be able to compare them. The comparison method used consists in giving points to each characteristic of all the solutions. It s normal that some characteristics have more importance than others in the final choice. According to its importance it was given classifications from one to five to those that are more important and one to three to the less important. It s important to call the attention for the fact that besides some have less weight on the final decision they are still important and have to be considered.

3 The first characteristic studied was the condition of the support base. After analysing all the solutions it was quite quickly to notice that all solutions need to have the support base completely cleaned, without detritus, to increase the contact area between the surface and the waterproofing solution. At this time some differences started to be evident. Besides this common requirement others are made but they change of solution for solution The second characteristic to be considered was the climacteric conditionals to a correct application. There are solutions that don t impose any kind of condition, and there are other s that limit the application to the air temperature, the relative moistness of air and the exposure to the wind and sun. The easiness of application is also important when selecting the waterproofing system. According to each type of product there are many ways of application with different tools such as paintbrush, roller, blowpipe and many others. To proceed to its application it can be necessary to appeal to specialized man power depending on the specificity of the work and the complexity of the used machines. In every piece-work there is a timeline to accomplish. Therefore it s very important to get one solution that has a fast cure time. To go of meeting to this factor the healing time had to be considered and there are some differences in this chapter. There are few solutions that only need some hours, sometimes even less than one hour, but there are also some that need four days. After this it was studied the final costs of the solution. In this valour it s included the price of the product and the costs associated to the application. The price of the solution was given by the manufacturer and the costs of the application were calculated according to the income tables of the LNEC or once again they were given by the manufacturers. To make this calculation it had to be defined one work team. The work team was made according with the method of application of the solution. There are teams made of painters and maids while others are of waterproof technicians and maids among others. The choice on what solution will be applied also depends of its response when it s mechanically requested. The mechanical resistance is very important in order to know if the solution will resist. The capacity of elongation till the rupture is the factor to be considered and analysed. The solutions studied present values that go from 0% till 00%. When the waterproofing is applied people have to think in the long run or there will be extra costs associated to its maintenance that can be very high. The last topic to be considered was the durability of the waterproofing system. It s called the attention to the inexistent information

4 about this subject in the technique file. This information was get directly from the manufacturers and in the most cases it s quite difficult to get a precise number. This happens because the durability depends of the exposure of the system to the climacteric condition and also because some of them are relatively recent and it s still hard to know for sure how long can they last. The waterproofing solutions can be used in very types of structures. In this investigation were considered five different parts of the building. They are presented from the top to the bottom of the building followed by other types of structures: ) Roofing; ) Façade; ) Embedded structures; ) Reservoir; ) Asphalt floor. For each structure was made a research of the main characteristics (presented above) of every available solution. The second part of this research consists on the analysis and comparison of all the solutions. In order to do this comparison it was necessary to create a classification method. This classification can be made on two ways. The first is relative to all the characteristics that have a quantitative way of representation, for example the mechanical resistance, and to create some value interval and attribute to each interval a point. The second way of classification it refers to the characteristics that can only be classified qualitatively, for example, conditions of the base and climacteric conditions. In this case the classification is given according with the amount of demands made by the manufacturer. For instance a solution that only need to have a support base clean and don t need special weather conditions will have the top classification. On the other side is a solution that needs a support base with many preparation works and also need special weather conditions. The resume tables are presented in the final pages while its analysis and some of the conclusions that can be made are now presented. The first table refers to the coverings. Making a first analysis it is evident in the first place that to differentiate the possible uses of the solutions in accessible coverings, not accessible coverings or gardened coverings its used colors. The existing solutions for the accessible or gardened coverings can equally be used in not accessible coverings. Analyzing the totals obtained for each solution it is evident that the one that got the biggest quotation was the PVC membrane and this can be used in any covering showing therefore to be the best choice, theoretically. It s theoretically because there are other solutions with a final

5 quotation very next to the membrane of PVC for what they should be considered in more concrete situations. The solutions with a very similar classification are the liquid membranes in a base of copolymers and the liquid membrane in a base of polyurethane. On the other side is the Additive Mortar that as got a low total and therefore is not a solution to be considered when waterproofing coverings. In the accessible coverings the solutions with higher quotation are the membrane of PVC, the liquid copolymer membrane and the liquid polyurethane membrane, being that the choice will fall again on one of these alternatives. The difference between the final punctuations is the minimum and in accordance with the specific request of each construction there can be others conditionals. In respect to the non accessible coverings the choice will be made among the same solutions, mentioned before, because they are once again the ones who have the highest punctuation. Finally there are the gardened coverings. For these cases the solutions with higher final quotation are the membrane of PVC and the liquid polyurethane membrane. From a closer look it can be evidenced, for these two solutions that the PVC membrane presents a more constant classification in each one of the criteria making that in the end it is the one that gets the better classification. On the other hand the liquid membrane of polyurethane, for the several characteristics, presents either very good or very bad quotations, for example, it has maximum quotation for costs but in relation to the easiness of application and reparation it presents a very low quotation. There is an alternative way of consulting this table. When the conditionals of the construction are different from the normal it may happen that only one of the characteristics will be considered. For example when the constructor wants a solution that independent from all the other has the best mechanical resistance for a not accessible covering. Looking to the table its possible to see that the best solution are the liquid copolymer membrane and the liquid membrane of polyurethane. They have the maximum classification. To untie this it can be used a second criterion. For instance it can be used the durability and in this case the liquid membrane of polyurethane has the best classification being therefore this one the final choice. The existing solutions of waterproofing to apply in façades are only three. When comparing with the coverings it represents a significant reduction. Two solutions have a final quotation very good while the other one has a quite low classification when comparing with the first two. It s called the attention for the fact that the solution with the lesser classification is once again the aditivada mortar. The solution with the best classification is the copolymer ink being therefore the system of waterproofing recommended for the façade. However there is another solution that presents a

6 total classification very next to the best and that it corresponds to the Liquid Membrane in a Base of Copolymer. According with this it s recommended a detailed analysis in accordance with each particular case. In the cases where for particular conditions, inherent to the construction itself, there is a main characteristic to be considered the consulting method is in all equal to the one described previously. For example, there can be a case where the durability is the only thing that matters to the constructor. In this case the final choice will be the additive mortar. In the process of choice of the solution to adopt for the waterproofing of embedded structures it has to be considered the conditional associates to the construction process. Depending on this process it is the possibility of applying the system of waterproofing from the inside or from the outside. Once again this differentiation is made in the table using colors that identify the method of application of each solution. From the systems of waterproofing studied the only one that can be applied from the inside is the additive mortar while the remaining six are applied from the outside. A first analysis of the totals obtained for each solution evidences that the quotations do not reach so high values as in the previous cases, being the membrane of PVC and the bituminous emulsion, with a total of 7 points, in a maximum of, the ones that have the best quotation. However 7 in a total of point are clearly low. This can indicate by one side that the studied solutions may not be the most proper or, on the other side, that the definition of the classifications to attribute has not been the better. In the cases where the constructive process only allows the waterproofing system to be applied from the inside, this must be made with the additive mortar. In fact the waterproofing systems that are applied from the outside are the ones that get better quotation being therefore advised its choice. The membrane of PVC and the bituminous emulsion are the solutions with the higher total, 7 points, followed by the liquid membrane in a butyl rubber base with 6 points. For this reason the choice of the solution to apply will pass, in normal conditions, necessarily for one of these three solutions. In the cases where there is a doubt in the choice between PVC membrane and the bituminous emulsion, it can be used to untie, for example, and depending on each case, the cost of the solution that is much cheaper for the bituminous solution. In the case of the reservoirs there are varied waterproofing solutions, being the choice conditioned for its final use. The reservoirs considered are the ones that are used for potable water it s also considered the reservoirs for the non potable water and finally those that are conceived to have chemically aggressive products. The differentiation of the solutions for each one of these cases is made, once again, using colors in order to be easily identifiable. 6

7 Watching carefully the table above it results that the only solution studied for potable water is the additive mortar as well as for the reservoirs of chemically aggressive products the only solution is the polyurea membrane. It is called attention for the fact that these two solutions can also be used in the cases of the not potable water reservoirs, but as its total classification is low in comparison with the remains is very improbable that the choice will fall again on these solutions. Making the analysis for the case of the reservoirs for non potable water it is quite easy to understand that the solution that has the best final classification is the PVC membrane with a total of 0 out of points. The solutions that if follow are the bituminous emulsion and the bitumen membrane in a base of plastomer, with a total of 6 values. Through this difference it is easy to conclude that the PVC membrane must be the preferential choice for these cases. If it opts to have only one criterion in account, for example, the cost the PVC membrane leaves of being the ideal solution because it presents superior costs, causing to have a lower classification, in relation to other solutions such as the bituminous emulsion among others. The last studied case was the asphalt floor. As it can be observed from the studied solutions only three can be used in this case. Reading the gotten total classifications for each solution of waterproofing one evidence is that the bitumen membrane in a base of plastomer is the one that get the highest punctuation (8 points), followed, with by the minimum difference, by the liquid membrane in a base of polyurethane. With a quite inferior classification is the liquid membrane in a base of resin. This leads to the bitumen membrane in a base of plastomer as the final as the solution to adopt without ignoring the liquid membrane in a base of polyurethane. The solution to adopt will be the bitumen membrane in a base of plastomer without leaving however, to have in account the liquid membrane in a base of polyurethane. Once again can be opted one alternative way of consulting the table having in account only one or part of the criteria. For example, if the cost is the only criteria to consider, the solutions with higher classification are the bitumen membrane in a base of plastomer and the liquid membrane in a base of resin. It has to be considered a second criterion to untie that is also important, for example, the easiness of application, that in this case it attributes the highest classification to the liquid membrane in a base of resin. With this example it is also intended to demonstrate that although in the generality the liquid membrane in a base of resin is to be the worst case, is important that it s considered to prevent cases like this example. 7

8 This investigation allows taking some conclusions. In first place we can relate that all the solutions need a the support base clean and firm, what makes all sense because there can t be anything between the support and the waterproofing system causing damage. On the other hand, the firmness is necessary so that the base can support the waterproofing system. Many solutions demand other supplemental works of preparation of the support and for that they are in disadvantage. In relation to the atmospheric conditions the point of agreement between all the studied solutions is the necessity of the base to be relatively dries before and during the application process, so that the properties of the final system are not modified. The method of application of the solutions varies from case to case not existing a universal method. The cure time is also very varied having solutions where the cure time is inferior to one hour while in other cases reaches four days. The mechanical resistance associated to each solution is also very changeable having systems of waterproofing with a null elongation capacity till the rupture and others with values of about 00%. The durability of the waterproofing systems is a parameter that many times isn t properly evaluated but that should have very influence in the final choice of a solution, being that for this parameter there are solutions that reach the 0 years. The cost for the inevitable importance was left, deliberately, for last, but also to enhance that many times the choice fall on the solutions with lower cost of acquisition. This is probably the most important conclusion that can be taken from this study, that is, the cheapest solution in a short time finishes being more expensive as well as inadequate for the case. With this work is intended to call the attention for this question being presented the criteria which have to be considered in the choice of the waterproofing system. Finally, analyzing the final tables for each case, the best solution, and common most cases, is the PVC membranes. From a more careful analysis results that the PVC membrane never is the solution with the lower cost of acquisition and application, but once all the criteria are considered, this turns to be the best choice. However and according with a more specific case the PVC membrane may not be the best choice and hat is way its recommended to follow every steps when ever choosing a solution. 8

9 Tables

10 Criteria Solution Additive Mortar Bitumen Membrane Elastomer Plastomer Oxidated Butyl Rubber Liquid Membrane Styrene-Plastic Dispersion Copolymer Polyurethane PVC Cost Condition of the Support Base and the Weather Easiness of Application and Reparation Healing Time Accessible covering or not Not accessible covering Gardened covering as well as all the other types considered Table - Classifications for roof waterproofing Mechanical Resistance Durability TOTAL

11 Solutions Criterion of Selection Additive Mortar Liquid Membrane in a Base of Copolymer Copolymer Ink Cost Condition of the Support Base and Atmospheric Easiness of Application and Reparation Healing Time Table - Classifications for Façade Mechanical Resistance Durability TOTAL 9 0

12 Criteria Solution Additive Mortar Bituminous Emulsion Bitumen Membrane Elastomer Plastomer Liquid Membrane Butyl Rubber Resin PVC Cost Condition of the Support Base and Atmospheric Easiness of Application and Reparation Healing Time Applied by the outside Applied by the inside Table - Classifications for Embedded Structures Mechanical Resistance Durability TOTAL 7 6 7

13 Criteria Solution Additive Mortar Bituminous Emulsion Bitumen Membrane Elastomer Plastomer Liquid Membrane in a Base of Butyl Rubber Polyurea Membrane PVC Cost Condition of the Support Base and Atmospheric Easiness of Application and Reparation Healing Time Potable water Not potable water Chemically aggressive products Table - Classifications for reservoir Mechanical Resistance Durability TOTAL 6 6 0

14 Solutions Criterion of Selection Bitumen Membrane in a Base of Plastomer Liquid Membrane Resins Polyurethane Cost Condition of the Support Base and Atmospheric Easiness of Application and Reparation Healing Time Table - Classifications for Asphalt floor Mechanical Resistance Durability TOTAL 8 7