PSI - Issue 55

Afif Rahma et al. / Procedia Structural Integrity 55 (2024) 206 – 213 Afif Rahma/ Structural Integrity Procedia 00 (2019) 000 – 000

207

2

acceptable ductility, but it was not immune to the phenomenon of water and air erosion, self-degradation and the continuous deformation of the soil (Maini 2005, Bredenoord 2023). Currently, to deal with these shortcomings, researchers are directing their work along two axes. The first group worked on soil characteristics to improve the properties of earth-concrete (Obonyo 2010, Guettala 2006, Arooz 2018, Ronsoux 2013); while the second attempted to get better material by investigating the properties of fibre plants such as vegetable straw (Demir 2006) banana fibres (Mostafa 2016), rice husk and ash (Damanhuri 2020). In underdeveloped countries, especially in rural and deserted areas where mud does not exist, cost and ease of implementation become the two main construction criteria. To meet these two conditions, this work aims to provide an alternative to fibre earth concrete that is easy to manufacture and fulfils the respective properties for construction safety. Meanwhile apart from the use of steel fibres, a third trend has appeared where the engineer chooses to use fibres produced industrially, such as glass fibre (Annamaneni 2023 ) , polyester fibre (Mohsin 2020), carbon fibre (Ghanem 2019), macro synthetic fibres (Bolat 2014), and polypropylene fibres (Ravishankar 2021). In addition, all research works on polypropylene fibre show how the fibres act within the concrete and the rate of improving its mechanical properties. Blazy and Blazy (2021) showed the possibility of using polypropylene fibres enhanced on concrete for architectural elements of public spaces. Matar and Zéhil (2019) studied the ability to use polypropylene fibre to improve the physical and mechanical properties of recycled aggregate concrete. Nasser et al. (2018) proved that the addition of propylene fibres for 1.5% of the cement volume improves significantly the strength of concrete in compression. Ahmad et al. (2021) worked on many volume ratios of polypropylene fibre to detect its performance on fresh concrete and hard concrete properties under compressive strength, split tensile strength and flexure strength. Magnur et al. (2017) approved the same results. Memon et al. (2018) showed the inverse role of fibre length where they observed that with an increase in the size of fibre the compressive strength decreased significantly. On the other hand, research is carried out on the use of dune sand as the main aggregate for concrete. Ahmad et al. (2022) presented a review of the effect of Dune sand on concrete properties. They indicated that dune sand can be used in concrete up to 40% without any negative effect on strength and durability; therefore, they indicated that the negative impact of this fine aggregate on strength and durability was due to poor grading and fineness, which restricts the complete (100%) substation of dune sand, but they noted its negative effect where a significant decrease in flowability was observed. The use of dune sand as a natural material remains conditioned by its availability in nature on the one hand and its mineralogical composition and its physical and mechanical properties on the other. Tsoar (1997) has extensively studied the physical properties of this material, and its mobility and ecological implementation. Al-Shammery and Jasim (2018) have studied the mineralogy of sand dunes found in the region of the southeast of Iraq and tried to determine its origin or source; likewise, Nasir et. Al. (1999) have worked along the same line on the genesis of heavy minerals in coastal dune sands implemented in south-eastern Qatar. Based on this panoramic review, this study seeks to propose a conception and suitable solution for the use of dune sand as the main aggregate, reinforced with macro polypropylene fibre, for housing construction in rural or desert areas in underdeveloped countries, where mud is not available. 2. Materials and methods 2.1. Concrete composition In this investigation, the concrete was designed from natural white dune sand for a maximum size of 1.18 mm (figure 1), cement type CEM I/ 32.5 N/mm 2 and polypropylene fibre. The laboratory test gives the following values for the physical and mechanical properties of sand: Specific gravity 2.61 g/cm 3 , dry density 19 kN/m 3 , specific surface area 114 cm 2 /g, finesse modulus 1.4%, sand equivalent 83%, humidity 0.3%, and absorption 2.67%; while, the mineralogy composition was as follows: SiO 2 (72.2%), F 2 O 3 (2.2%), Al 2 O 3 (11%), CaO (5.7%), K 2 O (2.6%), Na 2 O (2.3%), MgO (1.7%), LOI (2%).