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

Rozważmy próbkę drobnych kruszyw przesiewanych przez standardowy zestaw sit. Zwróć uwagę na masę kruszyw zatrzymanych na każdym sicie.
Obliczyć łączną masę kruszyw zatrzymanych na każdym sicie i wyrazić ją jako udział procentowy w całkowitej masie próbki.
Jeśli, na przykład, wszystkie cząstki są zatrzymywane na lub powyżej określonego sita i nic przez nie nie nie przechodzi, skumulowany procent zatrzymany dla tego sita i tych ułożonych pod nim jest wprowadzany jako 100.
Moduł rozdrobnienia oblicza się, sumując skumulowaną wartość procentową zatrzymaną na każdym sicie i dzieląc sumę przez 100.
Moduł rozdrobnienia jest indeksem liczbowym, który reprezentuje klasyfikację kruszyw.
W przypadku stosowania kruszyw pochodzących z tego samego źródła, niewielkie różnice w gradacji kruszywa drobnego są mniej widoczne wizualnie niż w przypadku kruszyw gruboziarnistych.
Różnice te znajdą odzwierciedlenie w wartości modułu rozdrobnienia, która będzie bardziej wnikliwa w przypadku kruszyw drobnych niż grubych.
Zazwyczaj wartość modułu rozdrobnienia dla kruszyw drobnych waha się od 2,3 do 3,1; im wyższa wartość, tym grubsze kruszywa.

moduł grubości

Moduł drobnoziarnistości (FM) kruszywa to wskaźnik liczbowy mierzący grubość lub drobność cząstek. Oblicza się go, dodając skumulowane procenty kruszywa zatrzymanego na każdym z określonych szeregów sit i dzieląc sumę przez 100.

Rozważ przeprowadzenie analizy sitowej piasku przez zestaw sit ASTM. Ciężar kruszywa zatrzymanego w każdym sicie i misce umieszczonej na dnie jest rejestrowany, jak podano w kolumnie B tabeli 1.

Aby określić moduł drobnoziarnistości piasku, należy obliczyć skumulowaną masę kruszywa zatrzymanego na każdym sicie (kolumna C tabeli 1) i wyrazić ją jako procent całkowitej masy (kolumna D tabeli 1). Na koniec określa się sumę skumulowanych procentów kruszywa zatrzymanego na każdym sicie i mnoży przez 100, aby uzyskać moduł drobnoziarnistości piasku.

Tabela 1: Analiza sitowa piasku

<table style="text-align: center;" border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Kolumna A</td>
			<td>Kolumna B</td>
			<td>Kolumna C</td>
			<td>Kolumna D</td>
		</tr>
		<tr>
			<td>Sito ASTM</td>
			<td>Masa zatrzymana 
 na każdym sicie (g)</td>
			<td>Łączna masa 
 zatrzymana na każdym sicie (g)</td>
			<td>Skumulowany procent zatrzymany na każdym sicie (%)</td>
		</tr>
		<tr>
			<td>
			⅜ cm
			</td>
			<td>0</td>
			<td>0</td>
			<td>0</td>
		</tr>
		<tr>
			<td>Nr 4</td>
			<td>5</td>
			<td>0+5 = 5</td>
			<td>5/500 = 1</td>
		</tr>
		<tr>
			<td>Nr 8</td>
			<td>55</td>
			<td>5+55 = 60</td>
			<td>60/500 = 12</td>
		</tr>
		<tr>
			<td>Nr 16</td>
			<td>65</td>
			<td>60+65 = 125</td>
			<td>125/500 = 25</td>
		</tr>
		<tr>
			<td>Nr 30</td>
			<td>90</td>
			<td>125+90 = 215</td>
			<td>215/500 = 43</td>
		</tr>
		<tr>
			<td>Nr 50</td>
			<td>160</td>
			<td>215+160 = 375</td>
			<td>375/500 = 75</td>
		</tr>
		<tr>
			<td>Nr 100</td>
			<td>90</td>
			<td>375+90 = 465</td>
			<td>465/500 = 93</td>
		</tr>
		<tr>
			<td>Bottom pan</td>
			<td>35</td>
			<td>Całkowita waga = 465+35 = 500</td>
			<td></td>
		</tr>
	</tbody>
</table>
<img alt="Eq1" src="/files/ftp_upload/16872/16872%20_Equation_PT_001v2.svg" style="height: 14px;">
<img alt="Eq2" src="/files/ftp_upload/16872/16872%20_Equation_PT_002v2.svg" style="height: 36px;">
Ogólnie rzecz biorąc, moduł drobnoziarnistości piasku wynosi od 2,3 do 3,1. Niższe wartości oznaczają, że piasek jest drobniejszy, natomiast wyższe wartości oznaczają, że piasek jest grubszy.

Moduł grubości

Rozważmy próbkę drobnych kruszyw przesiewanych przez standardowy zestaw sit. Zwróć uwagę na masę kruszyw zatrzymanych na każdym sicie.
Oblicz ...

Education

JoVE Core

Civil Engineering

Inżynieria lądowa

Unit 1

Jednostka 1

Aggregates and Water

Kruszywa i woda

KEY TERMS AND CONCEPTS

KLUCZOWE TERMINY I POJĘCIA

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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specific gravity of aggregate

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moisture content and bulking of aggregate

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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.

civil engineering

Fineness Modulus from Sieve Analysis

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