ASTM_D_8298_-_D_8298M_-_20.pdf

Designation:D8298/D8298M20Standard Test Method forDetermination of Erosion Control Products(ECP)Performance in Protecting Slopes from Continuous Rainfall-Induced Erosion Using a Tilted Bed Slope1This standard is issued under the fixed designation D8298/D8298M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,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 test method is used to evaluate the ability oferosion control products(ECP)to protect slopes from rainfall-induced erosion using an adjustable tilting bed slope.Thestandard slopes range from 2.5:1 to 4:1(H:V)having targetrainfall intensities between 4.0 and 5.0 in./h 100 and 125mm/h.1.2 There are three main elements the ECPs must have theability to perform:1.Absorb the impact force of raindrops,thereby reducing soil particle loosening and detachmentthrough“splash”mechanisms;2.Slow runoff and encourageinfiltration,thereby reducing soil particle displacement andtransport through“overland flow”mechanisms;and 3.Trapsoil particles beneath the ECP.When comparing data fromdifferent ECPs under consideration,it is important to keep thetest conditions the same for the ECPs being evaluated,forexample,the rainfall intensity rate and the slope.1.3 The results of this test method can be used to evaluateperformance and acceptability,and can be used to compare theeffectiveness of different ECPs.This method provides a com-parative evaluation of an ECP to baseline bare soil conditionsunder controlled and documented conditions.This test methodcan provide information about a product that is under consid-eration for a specific application where no performance infor-mation currently exists.1.4 This test method covers the use of three different soiltypes,ECP installation:sprayed,rolled,or dry applied,and arunoff collection procedure.This test is typically performedindoors,but may be performed outside as long as certainrequirements are met.Partially enclosed facilities are accept-able providing the environmental conditions are met.1.5 UnitsThe values stated in either inch-pound units orSI units are to be regarded separately as standard.The valuesstated in each system may not be exact equivalents;therefore,each system shall be used independently of the other.Combin-ing values from the two systems may result in nonconformancewith the standard.Reporting of test results in units other thaninch-pound shall not be regarded as nonconformance with thisstandard.1.5.1 The gravitational system of inch-pound units is usedwhen dealing with inch-pound units.In the system,the pound(lbf)represents a unit of force(weight),while the units formass is slugs.The slug unit is not given,unless dynamic(F=ma)calculations are involved.1.5.2 It is common practice in the engineering/constructionprofession to concurrently use pounds to represent both a unitof mass(lbm)and of force(lbf).This practice implicitlycombines two separate systems of units;the absolute and thegravitational systems.It is scientifically undesirable to com-bine the use of two separate sets of inch-pound units within asingle standard.As stated,this standard includes the gravita-tional system of inch-pound units and does not use/present theslug unit of mass.However,the use of balances and scalesrecording pounds of mass(lbm)or recording density in lbm/ft3shall not be regarded as nonconformance with this standard.1.5.3 Calculations are done using only one set of units;either gravitational inch-pound or SI.Other units are permis-sible provided appropriate conversion factors are used tomaintain consistency of units throughout the calculations,andsimilar significant digits or resolution,or both are maintained.1.6 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026,unless superseded by this test method.1.6.1 The procedures used to specify how data are collected/recorded and calculated in the standard are regarded as theindustry standard.In addition,they are representative of thesignificant digits that generally should be retained.The proce-dures used do not consider material variation,purpose forobtaining the data,special purpose studies,or any consider-ations for the users objectives;and it is common practice toincrease or reduce significant digits of reported data to becommensurate with these considerations.It is beyond the scopeof these test methods to consider significant digits used inanalysis methods for engineering data.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.25 on Erosion andSediment Control Technology.Current edition approved Aug.1,2020.Published August 2020.DOI:10.1520/D8298_D8298M-20.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Consho