DIN 18132-2012 Soil testing procedures and testing equipment - Determination of water absorption《土壤、检验程序和检验仪器 吸水能力测定》.pdf

1、April 2012DEUTSCHE NORM Normenausschuss Bauwesen (NABau) im DINDIN-SprachendienstEnglish price group 9No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for

2、 German Standards (DIN-Normen).ICS 93.020!$7“1902058www.din.deDDIN 18132Soil, testing procedures and testing equipment Determination of water absorption,English translation of DIN 18132:2012-04Baugrund, Versuche und Versuchsgerte Bestimmung des Wasseraufnahmevermgens,Englische bersetzung von DIN 181

3、32:2012-04Sol, mthodes et appareiles dessais Dtermination de labsorption deau,Traduction anglaise de DIN 18132:2012-04SupersedesDIN 18132:1995-12www.beuth.deDocument comprises pages1404.13DIN 18132:2012-04 2 A comma is used as the decimal marker. Contents Page Foreword . 3 1 Scope . 4 2 Normative re

4、ferences . 4 3 Terms and definitions 4 4 Designation . 5 5 Apparatus 5 6 Sample mass . 8 7 Preparation of equipment 8 8 Sample preparation 8 9 Procedure 8 9.1 Short-term test (1 h) 8 9.2 Long-term test (1 h) 9 10 Evaluation 10 10.1 Plotting the measured values 10 10.2 Determining the water absorptio

5、n capacity . 10 10.3 Expression of results . 10 Annex A (informative) Examples of calculation 11 A.1 Example no. 1 11 A.2 Example no. 2 13 DIN 18132:2012-04 3 Foreword This document has been prepared by Working Committee NA 005-05-03 AA Baugrund, Laborversuche of the Normenausschuss Bauwesen (Buildi

6、ng and Civil Engineering Standards Committee). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. DIN shall not be held responsible for identifying any or all such patent rights. Amendments This standard differs from DIN 18132:1995-1

7、2 as follows: a) The long-term test (where t 1 h) has been revised. Previous editions DIN 18132: 1995-12 DIN 18132:2012-04 4 1 Scope This standard is intended for use in earthwork and foundation engineering. It specifies a method of determining the water absorption capacity of fine soil. The water a

8、bsorption capacity is a function of the specific surface area of the fines and the activity of clay minerals. The method provides a parameter that can be correlated with soil mechanics parameters such as the liquid limit and the plastic limit, and the swelling and shrinkage characteristics, of the s

9、oil and is thus suitable for use in civil engineering applications for assessing mineral building materials (such as bentonites) which are used for sealing purposes. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references

10、, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN 12242-1, Laboratory glassware Conical ground joints Dimensions and tolerances DIN 12256, Laboratory glassware Tightness testing of conical joints, spherical

11、 joints and stopcocks DIN 18196, Earthwork Soil classification for civil engineering purposes DIN EN ISO 14688-1, Geotechnical investigation and testing Identification and classification of soil Part 1: Identification and description ISO 4793:1980, Laboratory sintered (fritted) filters Porosity grad

12、ing, classification and designation 3 Terms and definitions For the purposes of this document, the following definitions apply. 3.1 water absorption capacity wAratio of mass of water absorbed by the dried sample material in the test apparatus mwgto the dry sample mass md. dwgAmmw = (1) where mwgis t

13、he limit value, of the mass of water absorbed over time, in g; mdis the dry mass of the sample, in g. NOTE The water absorption capacity may also be expressed as a percentage by mass. For soil highly susceptible to swelling, the mwgvalue used in the calculation of wAshall be that obtained after a te

14、st duration t of 24 h. DIN 18132:2012-04 5 3.2 water absorption capacity classes specific range of water absorption. In civil engineering applications, fine soil is classified in terms of water absorption capacity into five classes as given in Table 1. Table 1 Water absorption capacity classes Class

15、 (moisture level) wA% Very low Up to 40 Low Over 40 up to 60 Medium Over 60 up to 85 High Over 85 up to 130 Very high Over 130 NOTE See Table 2 for correlation of water absorption capacity with soil group. Table 2 Correlation of water absorption capacity with soil group wASoil group Typical building

16、 materials % (see DIN 18196) Up to 40 SE, SU, US , ST, TS Quarry fines Over 40 up to 60 UL, TL Silt-bentonite mixture Over 60 up to 85 UM, TM Fine-graded clay Over 85 up to 130 TA Clay for mineral seals Over 130 TA Bentonites 4 Designation Designation of a laboratory method of determining the water

17、absorption capacity (A) of soil: Method DIN 18132 A 5 Apparatus For determining the water absorption capacity, the following apparatus is required: Drying oven. Apparatus for determining the water absorption capacity (see Figure 1), consisting of an extension tube with glass filter disc to receive t

18、he sample, glass tubing, and a burette of 2 ml nominal capacity and with 0,005 ml scale intervals, calibrated at a reference temperature of 20 C. The burette shall be arranged horizontally so that its axis is at a distance of 50 mm 1 mm lower than the top disc surface. The filter shall not be soiled

19、. The extension tube including the filter disc shall either be cleaned (e.g. in an ultrasonic bath) after 50 tests have been carried out, or replaced. Mortar and pestle, or ball mill. DIN 18132:2012-04 6 Balance, capable of being read to an accuracy of 0,003 g. Desiccator. Funnel, short stem (see Fi

20、gure 1); when inserted into the extension tube, the clear distance between stem and filter disc shall be 20 mm. Smooth paper, for filling in the sample material into the extension tube. DIN 18132:2012-04 7 Dimensions in millimetres Key Funnel outside diameter: d1= 35 mm 5 mm Funnel inside diameter:

21、d2= 5 mm 1 mm Length of stem: l = 20,8 mm 1 mm 1 Stand 2 Glass tubing, with DIN 12242 HNS 14/23 socket and DIN 12242 KNS 10/19 cone, with cone and socket axes at right angles to each other 3 Burette, with DIN 12242 HNS 10/19 socket 4 Glass extension tube, with DIN 12242 HNS 29/32 socket and DIN 1224

22、2 KNS 14/23 cone, with sintered filter disc (3 mm thick, of porosity grade P 100) as in ISO 4793:1980, fused to the tube so as to be square to its axis and with distance of 50 mm to the burette axis 5 Clamp, for adjusting the burette (3) 6 Funnel, short stem, of 35 mm outside diameter and smooth inn

23、er surface. The stem shall be cut to size so that the clear distance between the stem (once the funnel is inserted) and the disc is 20 mm. The stem shall be ground and fire polished. 7 Sheet of paper, about 80 mm 90 mm in size, smooth, folded lengthwise 8 Ground glass stopper with DIN 12242 KNS 29/3

24、2 cone and capillary hole 9 Sample NOTE See DIN 12256 for tightness of DIN 12242 V 10/19 and DIN 12242 V 14/23 conical joints. Figure 1 Apparatus for determining the water absorption capacity (short-term test) DIN 18132:2012-04 8 6 Sample mass The sample shall have a dry mass of about 20 g and shall

25、 not contain any particles larger than 0,4 mm in diameter. 7 Preparation of equipment The inner surfaces of the glassware shall be clean. In order to preclude false results due to inadequate adhesion of water to the surface, the burette shall be cleaned and rinsed several times with demineralized wa

26、ter prior to testing. The burette (3), glass tubing (2), and extension tube (4) (see Figure 1) including the part above the glass filter disc shall be filled with de-aerated, demineralized water without any bubbles forming and shall be connected taking care that all conical grounds are tight. The bu

27、rette is to be adjusted so as to be horizontal. The water level in the tube is now just at the top face of the disc. Any drop of water adhering to the tip of the burette shall be blotted. The meniscus level now represents the zero reading/zero mark. Any water adhering to the inner surface of the tub

28、e shall be blotted. 8 Sample preparation In order to remove any particles larger than 0,4 mm in diameter, the sample material shall be passed through a 0,4 mm sieve. The undersize shall be dried at 105 C, triturated and then redried at 105 C until constant mass is reached. For cooling to ambient tem

29、perature the sample shall be placed in a desiccator. NOTE 1 Drying at 105 C may cause changes to the water absorption capacity when certain minerals, e.g. three-layer clay minerals (smectites), are involved. This can be significant for a water absorption capacity wAgreater than 80 %. More informatio

30、n in this respect will be obtained if the test is repeated using a sample dried at 60 C. NOTE 2 Ball mills shall not be used for trituration, since this would cause an increase in the specific surface area of particles (depending on the duration of trituration) and thus a higher moisture being measu

31、red. In this respect, the procedure set out in DIN 18124 shall be followed, which specifies that the sample be dried and carefully comminuted (e.g. by using a mortar and pestle). The particles shall not be crushed. 9 Procedure 9.1 Short-term test (1 h) The sample of mass as specified in Table 3 (mas

32、s md) shall be reweighed and placed on the filter disc using the funnel. The stem of the funnel shall be concentric with the tube to obtain a reproducible conical sample. For filling the sample material in the funnel, a sheet of smooth paper (lengthwise folded) shall be used (7). If the duration of

33、the test is expected to be more than 15 min, a glass stopper (8) shall be fitted on the tube (see Figure 1). Table 3 Mass of samples Dry sample mass Anticipated water absorption capacity mdwAg % 1 1 h) In tests lasting more than 1 h, evaporation effects will falsify results. In order to preclude suc

34、h effects, a modified test assembly as illustrated in Figure 2 shall be used. The burette shall be detached from the glass extension tube with its filter disc and shall be reconnected using a flexible hose. The extension tube including the glass tubing shall be placed on a balance (see Clause 5) wit

35、h its auto re-zero function switched off. The balance can be connected to a PC via a data interface. Care shall be taken that the burette is not sucked empty. It shall lie horizontal. For soil highly susceptible to swelling where the absorption process takes more than 24 h, the water absorption capa

36、city shall be that determined after a test duration of 24 h. Key 1 Stand 2 Glass tubing, with DIN 12242 HNS 14/23 socket and DIN 12242 KNS 10/19 cone, with cone and socket axes at right angles to each other 3 Burette, with DIN 12242 socket 4 Glass extension tube, with DIN 12242 HNS 29/32 socket and

37、DIN 12242 KNS 14/23 cone, with sintered filter disc (3 mm thick, of porosity grade P 100) as in ISO 4793:1980, fused to the tube so as to be square to its axis and with distance of 50 mm to the burette axis 5 Clamp, to hold the funnel 6 Funnel 7 Sample 8 Balance, with 0,001 g resolution 9 Hose 10 St

38、and, height adjustable Figure 2 Apparatus for determining the water absorption capacity (long-term test: 1 h) DIN 18132:2012-04 10 10 Evaluation 10.1 Plotting the measured values The mass of water mwabsorbed after time t shall be calculated as follows: mw= (Vw Vk) w(2) where Vwis the volume of water

39、 absorbed after time t, in cm3; Vkis the volume of water evaporated after time t, in cm3; wis the density of the water; w= 1,0 g/cm3. The moisture content shall then be calculated from: 100dw=mmw % (3) where mdis the dry mass of the sample placed on the filter disc, in g. The water absorption capaci

40、ty shall be represented on a graph as a function of time (see Figures A.1 and A.2). In the graph, the x axis represents time t on a logarithmic scale, and the y axis represents the moisture content w on a linear scale. 10.2 Determining the water absorption capacity The water absorption capacity wAsh

41、all be taken either as the maximum value read from Figure A.1 or the value for 24 h as read from Figure A.2. The wAvalues shall be classified as shown in Table 2. 10.3 Expression of results The following shall be reported: a) standard designation; b) soil group of sample material, as in DIN EN ISO 1

42、4688-1; c) percentage by mass of particles smaller than 0,4 mm; d) information on any minerals or organic matter that might have affected the water absorption capacity (e.g. montmorillonites), e) ambient temperature, f) water absorption capacity, wA. DIN 18132:2012-04 11 Annex A (informative) Exampl

43、es of calculation A.1 Example 1 Determination of water absorption capacity of loess loam, using a sample of dry mass md= 1,000 g and a test duration t 1 h. Method DIN 18132 A Soil type: silt, clayey and fine sandy, calcareous, slightly plastic Percentage by mass of particles 1 h. Method DIN 18132 A

44、Soil type: clay, distinctly plastic Percentage by mass of particles 0,4 mm: 100 % Notice: The sample material contains clay minerals highly susceptible to swelling. Ambient temperature: 21 C Result: wA= 81,8 % (see Figure A.2) Table A.2 Determining the moisture content for example no. 2 Time at whic

45、h reading is taken Mass of water Moisture content t wm 100=dwmmw min g % 0,25 0,429 49,8 0,5 0,632 73,4 1 0,641 74,4 2 0,646 75,0 4 0,650 75,5 8 0,639 74,2 15 0,644 74,8 30 0,652 75,7 60 0,662 76,9 120 0,673 78,2 240 0,680 79,0 360 0,682 79,2 1 440 0,704 81,8 DIN 18132:2012-04 14 Figure A.2 Diagram for example 2