Concrete by Preplaced Aggregate Method Using Silica Fume and Polypropylene Fibres

Farooq Azam Khanzada; Kashif Nazir; Muhammad Ishtiaq; Muhammad Faisal Javed; Sardar Kashif-Ur-Rehman; Fahid Aslam; Muhammad Ali Musarat; Kseniia Iurevna Usanova

doi:10.3390/ma15061997

Concrete by Preplaced Aggregate Method Using Silica Fume and Polypropylene Fibres

Materials (Basel). 2022 Mar 8;15(6):1997. doi: 10.3390/ma15061997.

Authors

Farooq Azam Khanzada¹, Kashif Nazir², Muhammad Ishtiaq³, Muhammad Faisal Javed⁴, Sardar Kashif-Ur-Rehman⁴, Fahid Aslam⁵, Muhammad Ali Musarat⁶, Kseniia Iurevna Usanova⁷

Affiliations

¹ Department of Transportation Engineering (SCEE), National University of Sciences and Technology, Islamabad 44000, Pakistan.
² Department of Civil Engineering, School of Engineering, Nazabayev University, Astana 010000, Kazakhstan.
³ Department of Civil Engineering, Capital University of Science & Technology, Islamabad 44000, Pakistan.
⁴ Department of Civil Engineering, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22060, Pakistan.
⁵ Department of Civil Engineering, College of Engineering in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia.
⁶ Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar 32610, Perak, Malaysia.
⁷ Peter the Great St. Petersburg Polytechnic University, 195291 St. Petersburg, Russia.

Abstract

Preplaced aggregate concrete (PAC) is prepared in two steps, with the coarse aggregate being initially laid down in the formwork, after which a specialised grout is injected into it. To enhance the properties of concrete and to reduce the emission of CO₂ produced during the production of cement, supplementary cementitious materials (SCMs) are used to partially substitute ordinary Portland cement (OPC). In this study, 100 mm × 200 mm (diameter x height) PAC cylinders were cast with 10 per cent of cement being substituted with silica fume; along with that, 1.5% dosage of Macro polypropylene fibres were also introduced into the coarse aggregate matrix. Compressive strength test, splitting tensile strength test, mass loss at 250 °C, and compressive strength at 250 °C were performed on the samples. PAC samples with 10% of cement replaced with Silica Fume (SPAC) were used as control samples. The primary objective of this study was to observe the effect of the addition of Polypropylene fibres to PAC having Silica fume as SCM (FRPAC). The aforementioned tests showed that FRPAC had a lower compressive strength than that of the control mix (SPAC). FRPAC had greater tensile strength than that of NPAC and SPAC. Mass loss at 250 °C was greater in SPAC compared to FRPAC. The compressive strength loss at 250 °C was significantly greater in FRPAC compared to SPAC. FRPAC exhibited a greater strain for the applied stress, and their stress-strain curve showed that FRPAC was more ductile than SPAC.

Keywords: concrete; mass loss; polypropylene fibres; preplaced aggregate; silica fume.