PSI - Issue 28

Chbani Hamza et al. / Procedia Structural Integrity 28 (2020) 430–439 Author name / Structural Integrity Procedia 00 (2019) 000–000

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3. Formulation of concrete B25 After the characterization of the aggregates, a granulometric analysis will be carried out, this analysis consists in determining the dimensional distribution of the grains constituting the aggregate whose dimensions are between 0,063 and 16 mm. The objective of the particle size analysis is to be able to determine the dosage of the concrete components in terms of weight per cubic meter. 3.1. Granulomertic analysis : Dreux-Gorisse method The Dreux-Gorisse method Dreux and Festa (1998) is one technique among others that allow determining the proportions of the various constituents (sand, cement, gravel, water) of the concrete, starting with a granulometric analysis. This analysis consists of dividing the aggregates into several categories according to size using a series of sieves. The aggregate sample used must be washed before starting the sieve analysis procedure. We carried out this analysis through the following steps:  Drying the aggregates in an oven at a temperature of 105°C for 72 hours;  Nesting the sieves one after the other in descending order;  Pour the aggregates at the top of the sieve column ;  Ensure that a cover is fitted to prevent loss of material;  Start vibrating the sieve assembly using an electric sieve shaker . Sieve size analysis consists in determining the size distribution of the grains constituting an aggregate with dimensions between 0,063 and 125 mm. We call:  Refusal on a sieve: the amount of material that is retained on the sieve.  Sieveage : the amount of material that passes through the sieve. From the sieve size analysis, we determined the proportion by weight and percentage of the different aggregates in the sample according to their sizes between 0,063 and 16 mm. Tables 3, 4 and 5 represent the founded results. This analysis allowed us to draw the sieve size curve (Fig.3), on this curve we plot the variation of the percentage of cumulative sieve in linear scale versus the size of the aggregate in logarithmic scale.

Table 3. Sieve size analysis of sand (0/4)

Sieve diameter (mm)

Cumulative sieveage (%.)

Refusal (g)

Cumulative refusal (g)

Cumulative refusal (%)

5 4

0

0

0 1

100

15

15

99 85 74 59 23

2,5

210 165 225 540 210 120

225 390 615

15 26 41 77 91 99

1,25 0,63

0,315

1155 1365 1485

0,16 0,08

9 1