The Influence of Nano‐SiO₂ and Recycled Polypropylene Plastic Content on Physical, Mechanical, and Shrinkage Properties of Mortar

Abstract

This work is aimed to study the possibility of recycling plastic waste (polypropylene (PP)) as aggregate instead of sand in the manufacturing of mortar or concrete. For this, an experimental study was carried out to evaluate the influence of nano-SiO2 and recycled PP plastic particles' content on physical, mechanical, and shrinkage properties and microstructure of the mortars with recycled PP plastic particles. The sand is substituted with the recycled PP plastic particles at dosages (0%, 20%, 40%, and 60% by volume of the sand). The nano-SiO2 content is 5% by weight of cement. The physical (porosity, water absorption, and density), mechanical (compressive and flexural strength) and shrinkage properties of the mortars were evaluated, and a complementary study on microstructure of the interface between cementitious matrix and PP plastic particles was made. The measurements of physical and mechanical properties showed that PP-filled mortar had lower density and better toughness (higher ratio of flexural strength to compressive strength). However, the compressive strength and flexural strength of PP-filled mortar is reduced, and the porosity, water absorption, autogenous shrinkage, and dry shrinkage increased as compared to normal cement mortar. The addition of nano-SiO2 reduced the porosity, water absorption, and drying shrinkage of PP-filled mortar and effectively improved the mechanical properties, but increased its autogenous shrinkage. A microscopic study of the interfacial zone (plastic-binder) has shown that there is poor adhesion between PP plastic particles and cement paste. From this work, it is found that recycled PP plastic waste has a great potential to be a construction material. It can be used as partial replacement of natural aggregates instead.

Effect of Polypropylene Fiber on Properties of Alkali‐Activated Slag Mortar

“…Compared with the control group, the water absorption of P1, P2, P3, and P4 groups decreased by 1.48%, 2.94%, 4.49%, and 5.34%, respectively, at 28 d. e low water absorption values can be attributed to the decrease in porosity. e bulk density of AAS mortar decreased slightly with the increase of the content of PPF which is due to the low specific gravity of PPF compared with the AAS paste [61,62]. is is consistent with the findings of Ranjbar et al [59].…”

Comparative Overview of the Performance of Cementitious and Non-Cementitious Nanomaterials in Mortar at Normal and Elevated Temperatures

“…The binder/sand ratio is generally kept between 1:2 and 1:4 [ 36 , 78 , 86 , 87 ]. ASTM C-778 is used to identify the grading curve of a fine aggregate [ 84 ].…”

“…Following the procedures for ASTM C-109 and ASTM C-39, respectively, the compressive strength for the mortar is determined using cube sizes of 50 or 40 mm and cylinders of 100 mm diameter and 200 mm height for a required number of days [ 84 , 123 , 124 , 125 ]. The load is applied using a hydraulic press at a rate of 0.25 MPa/s and an average compressive strength of 3 samples is considered [ 31 , 73 , 87 ].…”

“…The flexural strength (FS) of a mortar is determined by the 3-point bending method, with a displacement rate of 0.5 mm/min on a specimen measuring 40 × 40 × 160 mm 3 in, accordance with ASTM C-348 [ 84 , 124 ]. The split tensile strength is carried out in accordance with ASTM C-496, using a cylindrical specimen measuring 100 mm in diameter and 200 mm in height [ 29 ].…”

Effect of Nano-Silica on the Autogenous Shrinkage, Strength, and Hydration Heat of Ultra-High Strength Concrete

“…They also found that in early-age shrinkage, nS plays a more active effect than silica fume. Chen et al [18] found that nS effectively improved the mechanical properties of mortars mixed with recycling plastic waste, but also increased the self-shrinkage.…”