Name: fineness modulus from sieve analysis
Uploaded: 2024-11-07T14:48:25.000Z
Duration: 1 min 19 s
Channel: JoVE

Stellen Sie sich eine Probe von feinen Zuschlagstoffen vor, die durch einen Standardsatz von Sieben gesiebt werden. Notieren Sie das Gewicht der Zuschlagstoffe, die auf jedem Sieb zurückgehalten werden.
Berechnen Sie das kumulative Gewicht der auf jedem Sieb zurückgehaltenen Zuschlagstoffe und drücken Sie es als Prozentsatz des Gesamtgewichts der Probe aus.
Wenn z. B. alle Partikel auf oder über einem bestimmten Sieb zurückgehalten werden und nichts durch dieses Sieb hindurchgeht, wird der kumulative Prozentsatz, der für dieses Sieb und die darunter gestapelten Partikel zurückgehalten wird, als 100 eingetragen.
Der Feinheitsmodul wird berechnet, indem der kumulative Prozentsatz des Rückstands auf jedem Sieb addiert und die Summe durch 100 dividiert wird.
Der Feinheitsmodul ist ein numerischer Index, der die Einstufung von Gesteinskörnungen darstellt.
Bei der Verwendung von Gesteinskörnungen aus der gleichen Quelle sind geringfügige Abweichungen in der Abstufung der Feingesteinskörnung optisch weniger deutlich als bei groben Gesteinskörnungen.
Diese Unterschiede spiegeln sich im Feinheitsmodulwert wider, der für feine Zuschlagstoffe aufschlussreicher ist als für grobe Zuschlagstoffe.
Typischerweise liegt der Wert des Feinheitsmoduls für feine Gesteinskörnungen zwischen 2,3 und 3,1; je höher der Wert, desto gröber die Gesteinskörnungen.

feinheitsmodul

Der Feinheitsmodul (FM) von Gesteinskörnungen ist ein numerischer Index, der die Grobheit oder Feinheit der Partikel misst. Er wird berechnet, indem die kumulierten Prozentsätze der Körnung, die auf jedem Sieb einer bestimmten Siebreihe zurückbleiben, addiert und die Summe durch 100 geteilt wird.
Erwägen Sie die Durchführung einer Siebanalyse von Sand mit einem Satz ASTM-Siebe. Das Gewicht des in jedem Sieb und jeder am Boden platzierten Pfanne zurückgehaltenen Zuschlagstoffs wird aufgezeichnet, wie in Spalte B der Tabelle 1 angegeben.
Um den Feinheitsmodul von Sand zu bestimmen, berechnen Sie das kumulative Gewicht des auf jedem Sieb zurückgehaltenen Zuschlagstoffs (Spalte C von Tabelle 1) und drücken Sie es als Prozentsatz des Gesamtgewichts aus (Spalte D von Tabelle 1). Schließlich wird die Summe der kumulativen Prozentsätze des auf jedem Sieb zurückgehaltenen Zuschlagstoffs bestimmt und mit 100 multipliziert, um den Feinheitsmodul des Sandes zu erhalten.
Tabelle 1: Siebanalyse auf Sand

<table border="1">
 <tr>
 <td style="text-align: center;">Spalte A</td>
 <td style="text-align: center;">Spalte B</td>
 <td style="text-align: center;">Spalte C</td>
 <td style="text-align: center;">Spalte D</td>
 </tr>
 <tr>
 <td style="text-align: center;">ASTM-Sieb (Siebgröße)</td>
 <td style="text-align: center;">Auf jedem Sieb zurückgehaltenes Gewicht (g)</td>
 <td style="text-align: center;">Kumulatives Gewicht auf jedem Sieb zurückgehalten (g)</td>
 <td style="text-align: center;">Kumulativer Prozentsatz, der auf jedem Sieb zurückgehalten wird (%)</td>
 </tr>
 <tr>
 <td style="text-align: center;">⅜ cm</td>
 <td style="text-align: center;">0</td>
 <td style="text-align: center;">0</td>
 <td style="text-align: center;">0</td>
 </tr>
 <tr>
 <td style="text-align: center;">Nr. 4</td>
 <td style="text-align: center;">5</td>
 <td style="text-align: center;">0+5 = 5</td>
 <td style="text-align: center;">5/500 = 1</td>
 </tr>
 <tr>
 <td style="text-align: center;">Nr. 8</td>
 <td style="text-align: center;">55</td>
 <td style="text-align: center;">5+55 = 60</td>
 <td style="text-align: center;">60/500 = 12</td>
 </tr>
 <tr>
 <td style="text-align: center;">Nr. 16</td>
 <td style="text-align: center;">65</td>
 <td style="text-align: center;">60+65 = 125</td>
 <td style="text-align: center;">125/500 = 25</td>
 </tr>
 <tr>
 <td style="text-align: center;">Nr. 30</td>
 <td style="text-align: center;">90</td>
 <td style="text-align: center;">125+90 = 215</td>
 <td style="text-align: center;">215/500 = 43</td>
 </tr>
 <tr>
 <td style="text-align: center;">Nr. 50</td>
 <td style="text-align: center;">160</td>
 <td style="text-align: center;">215+160 = 375</td>
 <td style="text-align: center;">375/500 = 75</td>
 </tr>
 <tr>
 <td style="text-align: center;">Nr. 100</td>
 <td style="text-align: center;">90</td>
 <td style="text-align: center;">375+90 = 465</td>
 <td style="text-align: center;">465/500 = 93</td>
 </tr>
 <tr>
 <td style="text-align: center;">Untere Pfanne</td>
 <td style="text-align: center;">35</td>
 <td style="text-align: center;">Gesamtgewicht = 465+35 = 500</td>
 <td style="text-align: center;"></td>
 </tr>
</table>

<img alt="Equation1" src="/files/ftp_upload/16872/16872%20_Equation_PT_001v2.svg" style="height: 14px;">
<img alt="Equation2" src="/files/ftp_upload/16872/16872%20_Equation_PT_002v2.svg" style="height: 36px;">
Im Allgemeinen hat Sand einen Feinheitsmodul von etwa 2,3 bis 3,1. Niedrigere Werte bedeuten, dass der Sand feiner ist, während höhere Werte bedeuten, dass der Sand gröber ist.

Feinheitsmodul

Stellen Sie sich eine Probe von feinen Zuschlagstoffen vor, die durch einen Standardsatz von Sieben gesiebt werden. Notieren Sie das Gewicht der Zuschlagstoffe, die auf jedem Sieb zurückgehalten werden.
Berechnen Sie die ...

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JoVE Core

Civil Engineering

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Unit 1

Einheit 1

Aggregates and Water

Gesteinskörnungen und Wasser

KEY TERMS AND CONCEPTS

KERNBEGRIFFE UND KONZEPTE

Fineness Modulus

fineness modulus from sieve analysis

Fineness modulus is a numerical index used to describe how coarse or fine aggregate particles are. For sand, it is found from sieve analysis using a standard set of ASTM sieves. The result helps show whether the sample is finer or more coarse.

To calculate fineness modulus, first record the weight of aggregate retained on each sieve and in the pan at the bottom. Then find the cumulative weight retained on each sieve. Next, express each cumulative weight as a percentage of the total sample weight. The fineness modulus is obtained by adding those cumulative percentages and dividing the sum by 100.

A sand sample can be tested with sieves such as ⅜ inch, No. 4, No. 8, No. 16, No. 30, No. 50, and No. 100. In the example, the retained weights are 0 g, 5 g, 55 g, 65 g, 90 g, 160 g, 90 g, and 35 g in the bottom pan. The cumulative percentages retained are 0, 1, 12, 25, 43, 75, and 93, based on a total weight of 500 g.

In general, sand has a fineness modulus of about 2.3 to 3.1. Lower values mean the sand is finer. Higher values mean the sand is more coarse.

Fineness Modulus from Sieve Analysis

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fineness modulus

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key terms and concepts

Learn how fineness modulus is calculated from sieve analysis of sand, using cumulative retained percentages on ASTM sieves to judge particle size.

Fineness Modulus from Sieve Analysis | JoVE K12

JoVE Core Civil Engineering provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

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Fineness Modulus from Sieve Analysis

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