1、Designation: D7492/D7492M 11D7492/D7492M 16Standard Guide forUse of Drainage System Media with Waterproofing Systems1This standard is issued under the fixed designation D7492/D7492M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision,
2、the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide makes recommendations for the selection and application of prefabricated drainage media used in
3、 conjunctionwith waterproofing systems on horizontal and vertical surfaces. Drainage media considered include rigid and semi-rigid insulationboards and rigid materials including plastics. The scope of this guide does not cover other drainage media including gravel andfilter fabric systems that can b
4、e constructed. The scope of this guide does not cover drainage materials or drainage system designsused for vegetative roof systems. Vegetative roof systems require specialized designs.1.2 The committee with jurisdiction over this standard is not aware of any other comparable standards published by
5、otherorganizations.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in eachsystem may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from thetwo systems may result in
6、 non-conformance with the standard.1.4 This standard may involve hazardous materials, operations and equipment. This standard does not purport to address allof the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriatesafety a
7、nd health practices and determine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C165 Test Method for Measuring Compressive Properties of Thermal InsulationsC898 Guide for Use of High Solids Content, Cold Liquid-Applied Elastomeric Waterproofing M
8、embrane with Separate WearingCourseC981 Guide for Design of Built-Up Bituminous Membrane Waterproofing Systems for Building DecksC1471 Guide for the Use of High Solids Content Cold Liquid-Applied Elastomeric Waterproofing Membrane on VerticalSurfacesD896 Practice for Resistance of Adhesive Bonds to
9、Chemical ReagentsD1079 Terminology Relating to Roofing and WaterproofingD2434 Test Method for Permeability of Granular Soils (Constant Head) (Withdrawn 2015)3D3273 Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental ChamberD3385 Test Method for Infilt
10、ration Rate of Soils in Field Using Double-Ring InfiltrometerD4511 Test Method for Hydraulic Conductivity of Essentially Saturated PeatD4630 Test Method for Determining Transmissivity and Storage Coefficient of Low-Permeability Rocks by In SituMeasurements Using the Constant Head Injection TestD4716
11、 Test Method for Determining the (In-plane) Flow Rate per Unit Width and Hydraulic Transmissivity of a GeosyntheticUsing a Constant HeadD5898 Guide for Details for Adhered Sheet WaterproofingD6622 Guide for Application of Fully Adhered Hot-Applied Reinforced Waterproofing SystemsE154 Test Methods fo
12、r Water Vapor Retarders Used in Contact with Earth Under Concrete Slabs, on Walls, or as Ground Cover1 This guide is under the jurisdiction of ASTM Committee D08 on Roofing and Waterproofing and is the direct responsibility of Subcommittee D08.22 on Waterproofingand Dampproofing Systems.Current edit
13、ion approved Nov. 15, 2011Feb. 1, 2016. Published March 2012March 2016. Originally approved in 2011. Last previous edition approved in 2011 asD7492/D7492M 11. DOI: 10.1520/D7492_D7492M-11.10.1520/D7492_D7492M-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Cust
14、omer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard and is intended only to p
15、rovide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof t
16、he standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Refer to Terminology D1079 for definitions of terms used in this guide.4. Summary of Practice
17、4.1 This guide describes a method to estimate the amount of water a drainage system may need to carry. The guide also offersdescriptions of the various drainage systems in existence today along with suggestions on how different building situations willrequire different performance characteristics fr
18、om the drainage medium chosen. Items to be aware of during the installation ofdrainage systems is also covered along with illustrations of typical drainage systems.5. Significance and Use5.1 This guide provides information and guidelines for the selection and installation of drainage systems media t
19、hat are inconjunction with waterproofing systems. This guide is intended to be used in conjunction with Guides C898, C981, C1471, D5898,and D6622 and to provide guidelines for the total waterproofing and drainage system.6. General6.1 In selecting a drainage medium for use with waterproofing, conside
20、ration should be given to the design of the waterproofingsystem. In particular orientation of the system, attachment recommendations, connections to interior and exterior drainage systemsand external loads applied to the system. Additional considerations include the materials and construction over t
21、he drainagemedium, installation recommendations, durability, and penetrations and joints. (See Figs. 1-3.) In all designs, the potential slipplanes should be considered.6.2 CompatibilityIt is essential that all components and contiguous elements of the waterproofing system are compatible andthat the
22、 design of the systems waterproofing and drainage is coordinated to form an integrated waterproofing system.6.3 Basic ComponentsThe various types of drainage media available are outlined in Section 12 of this guide and all consistof one or more of the following basic components. The basic components
23、 of typical drainage medium are a mounting surface thatis placed against the waterproofing membrane to prevent embedment of the media, a porous core that provides a drainage path,and a filter fabric bonded over the porous core to prevent clogging of the drainage paths. Fibrous and foam drainage medi
24、a arehomogeneous materials that are sufficiently dense that they can be placed directly against the waterproofing membrane. Other foamboards merely provide periodic grooves creating paths to drain water away from the waterproofed surface. However fibrous andfoam media may not function properly in ho
25、rizontal or nearly horizontal (6.61L/s (Eq X1.3 and Eq X1.4 above), another drain would be necessary to prevent water from filling up the drainage media.X1.2.2 The assumption that flow is proportional to hydraulic gradient is conservative. Flow rate has been found to more closelycorrelate with (i)0.
26、5 or one can use the Manning equation (below) to determine flow in drainage composites in low slope situations.Using the assumption that flow is proportional to (i)0.5, Eq X1.4 becomes:D7492/D7492M 169Q/length actual! 5Q/L i 5 1.0 3 i actual!#0.5! (X1.8)Q/length53.31 L/s 2m 30.0208!0.550.477 L/s 2m
27、2.31 gpm/ft#X1.2.3 The Manning Equation provides another way to estimate flow for a low slope orientation of a drainage composite:Q 5K/n! A Rh!2/3S0.5 (X1.9)where:K = unit conversion constant, 1.49 IP/SI units; 1.0 SI/SI units,n = Gauckler-Manning coefficient, material/surface dependent,A = area for
28、 flow, perpendicular to flow, ft2, m2,Rk = hydraulic radius = area for flow/wetted perimeter, ft, m,S = slope of surface often equal to i, the hydraulic gradient, ft/ft; m/m, andQ = volume/time, ft3/s; m3/sec.X1.2.3.1 To use the Manning equation, certain features of the drainage media must be known.
29、 In the example above example withaan egg carton type drainage composite, the additional data needed is as follows. Each cone of the drainage media will be assumedto be 12.7 mm high 12 in., 9.5 mm 38 in. wide, and the gap between each cone: 9.5 mm 12 in. wide. Thus in 0.3 m 1 ft ofdrainage composite
30、, there will be 0.3048 m/(9.5 + 9.5) mm or 16 openings. As before, the slope (S) will be 0.0208. The area forflow for a single opening will be:Cone height cone spacing = 0.0127 m 0.0095 m = 1.21 10-4m2 0.0013 ft2Rh =Area for Flow/Perimeter of opening = 1.21 10-4/( 12.7 mm +9.5 mm + 12.7 mm + 9.5 mm)
31、 = 0.00272 m 0.00891 ftX1.2.3.2 Gauckler-Manning coefficients can be found in various Civil Engineering text books and, in this case, a good estimatefor a composite core made of polystyrene would be 0.012. (This assumes a single opening of a drainage composite is completelysurrounded by the polystyr
32、ene core, howevercore; however, in a typical drainage composite one of the wetted sides of an openingwould be fabric, so a larger K may be appropriate. But for this example 0.012 will be used.)X1.2.3.3 Substituting the values into the Manning equation:Q 5K/n! A Rh!2/3S0.551/0.012!31.21x1024 m230.002
33、72 m!2/330.0208!0.552.8331025 m3/s 0.449 gpm! (X1.10)X1.2.3.4 This is the flow through one space between two cones and since the circumference around the drain is 0.3048 m 1 ft,see above there will be 16 of these openings thus the flow into the drain predicted by the Manning equations is:163Q 51632.
34、8331025 m3/s 54.5331024 m3/s 7.18 gpm# (X1.11)X1.2.3.5 As can be seen, the linear analysis gives the most conservative value while the Manning equation gives the highest valueof flow at the drain/drainage composite interface.All three of these analysis methods are used in water flow analysis in cons
35、tructiondesign.Also as mentioned above the limiting factor in plaza deck drainage in many cases will be the number and size of the drains.Thus since many areas have drain requirements for flat roofs, this drain requirement could then be used for a starting point todetermine the number of drains for
36、a plaza deck with the above analysis used to determine if for a particular plaza deck systemthat the number of drains could be reduced.X1.2.3.6 The above analysis strongly indicates that the drainage composite/drain interface will be the key design feature in manyplaza deck drainage systems and show
37、s the water flow through this interface is affected by the diameter and number of drains, slopeof the plaza deck, and characteristics of the drainage composite (cone height and spacing). Thus the designer can manipulate thesevariables to achieve the best design.D7492/D7492M 1610X2. USEFUL EQUATIONS
38、FOR ESTIMATING DRAINAGE REQUIREMENTS FOR VERTICAL WALLSX2.1 To determine the drainage capacity needed for a vertical orientation, decide either to size the media to handle possible waterflow before the backfill has consolidated or to base the water flow rate on the permeability ratings of the surrou
39、nding soil. If thedrainage rate needed is to be based on unconsolidated soil, the conservative approach would be similar to the approach used aboveon plaza decks. The drainage capacity would be the agreed upon rainfall rate multiplied by the area that has the potential to catchthis rain and direct i
40、t toward the vertical wall. This would be very conservative as obviously some of this rain would either bypassthe drainage media and go directly into the foundation footing drainage system or be retained by the soil.X2.1.1 The approach used on consolidated soil would use Darcys equation (Eq X1.3) wh
41、ere Qd is the flow rate in L/s, k is thesoils permeability coefficient in mm/s.,mm/s, (i) is the hydraulic gradient in metermetre head loss/ metermetre of liquid travel andAis the area in m2 perpendicular to the flow Q. In virtually all cases, this is the surface area of drainage media on the vertic
42、al wall.Anumber ofASTM tests are available to determine soil or rock permeability coefficients, such as see Test Methods D2434, D4511,D4630, and D3385. Once the appropriate test has determined the permeability coefficient of the soil, then a good assumption forthe hydraulic gradient is 1.0 and these
43、 numbers along with the surface area of drainage media can be substituted into Darcysequation above to determine the drainage capacity (Q) needed. Except for soils consisting of gravel or coarse sand where drainagemedia would likely be superfluous, the calculated Q will generally be quite small.Samp
44、le calculation:Qd 5kIAv (X2.1)where:Qd = see Eq X1.1 (L/s),k = soil permeability constant (mm/s), see see Test Methods D2434, D4511, and D4630,k = soil permeability constant (mm/s), see Test Methods D2434, D4511, and D4630,I = amount of head lost/length of fluid travel (in vertical flow this equals
45、1.0),Av = m2 of below grade wall per m of wall length, andA = area of soil/drainage media interface per metre of vertical wall length, m2/m; I = 1; k determined by testing, approximately0.00167 mm/s for clay soils, approximately 1.67 mm/s for sand.X2.1.2 Assuming ana 2.44 m 8 ft high piece drainage
46、system in a clay soil: Drainage Capacity Required = kIA = 0.00167 mm/s 1 2.44 m2/m length 1.0 L/m2-mm = 0.00407 L/s per metre wall length; 14.9 in3/min per foot wall lengthX2.1.3 This approach will also work in areas where potential water tables may exist. In these cases, the permeability of the soi
47、llayer or layers which are below the water table or which may transport water during wet weather periods should be determinedand used in Darcys equation to size the drainage media. Of course if there are soil layers that have a higher permeability than thelayers that are in the water table, then usi
48、ng the higher permeability coefficient would be appropriate and conservative.X2.1.4 There are other sources that can be used to determine water flows and amounts in various areas. The (NRCS) NationalResources Conservation Service (formerly the USDASoil Conservation Service) provides models such as t
49、he TR-55 which modelssmall watersheds. There are also software providers which have programs to model watersheds such as Hydrocad (trademarked)at H. Information can also be found in Section 4 of the National Engineers Handbook available from the NRCS. Theseresources can be used to refine the above analysis on vertical wall drainage systemsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are exp
