Issue 58

H. Suiffi et alii, Frattura ed Integrità Strutturale, 58 (2021) 296-307; DOI: 10.3221/IGF-ESIS.58.22

M ATERIALS AND METHOD

Sand composition he sand used is normal sand. It comes from the quarries of the city of Kenitra (Morocco). The maximum size of GI lightweight aggregates is 16mm and the maximum size of normal GII aggregates is 20mm.

T

Cement composition The type of cement used is the product Lamaalem35®, a Portland cement composed of class CPJ 35 as defined by standard NM 10.1.004. This cement is obtained by grinding clinker, gypsum and other constituents. It has an onset of setting at 20 °C measured on a pure paste, which only appears after 1 hour 30 minutes with a hot expansion of less than 10 mm and shrinkage after 28 days measured on a normal mortar of less than 800 μ m/m. Concrete formulation with polypropylene fibers The composition of the concrete used is a cement matrix made up of gravel GI and GII from the Kenitra quarries, sand, cement, water and an appropriate NANOMENT HP 2038 admixture, for an overall density of 2417 kg/m 3 , see Tab. 1.

PP by volume of concrete

Coarse aggregates GI

Coarse aggregates GII

PP by weight of concrete

Water

Cement

Sand

admixture

Liters

kg/m 3

kg/m 3

kg/m 3

kg/m 3

kg/m 3

%

kg/m 3

Sample concrete

185

350

865

492

522

1.4

0

0

Concrete with 0.05% PP Concrete with 0.10% PP Concrete with 0.30% PP Concrete with 0.50% PP

185

350

865

492

522

1.4

0.05

0.45

185

350

865

492

522

1.4

0.10

0.90

185

350

865

492

522

1.4

0.30

2.70

185

350

865

492

522

1.4

0.50

4.50

Table 1: Composition of concrete with polypropylene fibers In this experimental part, four concrete formulations with volume percentages of addition of polypropylene ranging from 0.05%, 0.10%, 0.30% and 0.50% were prepared for each fiber. A formulation of a control concrete without fiber is included for comparison. Fiber used The fiber used is a polypropylene fiber (Fig..1). It is manufactured by the SIKA company and fibrillated in pre-dosed pulp bags.

Figure 1: Polypropylene fiber (PP).

298