In-situ strength estimation of polypropylene fibre reinforced recycled aggregate concrete using Schmidt rebound hammer and point load test

Abstract

An appropriate amount of polypropylene fibre (PF) content is generally able to compensate for the low compressive strength of the recycled aggregate concrete. This mechanical strength is required to reliably estimate at the building site using partially and non-destructive testing methods. Therefore, in the present study, the compressive strength of concrete with PF at 0.1% by volume and different replacement levels of recycled coarse aggregate (RCA) was assessed using point load test (PLT) and Schmidt rebound hammer. According to the results, the sensitivity of the core specimens to the concentrated point load and the short size of PF in the failure zone of the PLT caused to appear a difference among the enhancement trends of PLI values by increasing the age. In addition, a two-variable equation between the rebound number and point load index (PLI) reliably predicted either strength of coarse natural concrete or recycled aggregate concrete or PRAC.

Preliminary evaluation of the feasibility of using polypropylene fibres from COVID-19 single-use face masks to improve the mechanical properties of concrete

“…Use of plastic fibres in concrete has attracted attention from the construction industry and academia for some time as plastic fibres hold many sustainability benefits when compared to steel reinforcement. Polypropylene fibres (PP) are widely used throughout the concrete industry due to their mechanical properties such as tensile strength and Young’s modulus as well as their ease of production and high alkaline resistance ( Yin et al, 2015 ; Kazemi et al, 2020a & b ). Islam and Gupta (2016) undertook an experiment to analyse polypropylene fibre reinforced concrete.…”

Application of Ultrasonic Measurements for the Evaluation of Steel Fiber Reinforced Concrete

“…Unlike continuous reinforcing bars, fibers are short, discontinuous, and randomly distributed throughout the concrete to produce a more ductile and crack control matrix. Fibers used in concrete [18][19][20][21] can be made of steel, glass, and polymer. Authors in [22][23] investigated the mechanical behavior of polymers by infusing machine learning algorithms and asserted the advantages of using polymers on concrete's characteristics which is applicable to real-world problems [12,18].…”

Seismic response prediction of FRC rectangular columns using intelligent fuzzy-based hybrid metaheuristic techniques

“…Fibres application in concrete can decline the requirement of transverse reinforcement in fiber-reinforced concrete (FRC) members, particularly in their seismic design (Khorami et al 2017 ; Bossio et al 2017 ; Park et al 2016 ; Ghassemieh and Bahadori 2015 ; Shahi et al 2013 ; Jalali et al 2012 ; McMullin et al 1993 ; Bahrololoumi and Dargazany 2019 ; Mohammadi et al 2019a , b ). Fibers play an important role in some critical members which require many reinforcements such as beam to column joints (Kazemi et al 2020a , b ; Afshar et al 2020 ; Sadeghian et al 2020 ). Although the mathematical modelling for the ultimate strength prediction of FRC rectangular columns subjected to simulated seismic loading is suggested in few studies (Aghakhani et al 2015 ; Thai et al 2012 ; McCulloch and Pitts 1943 ; Bahrololoumi and Dargazany 2019 ), the major objective of this research is to avoid the high nonlinearity of mathematical methods by applying soft computing methods.…”