Effects of Polypropylene Fibre and Strain Rate on Dynamic Compressive Behaviour of Concrete

• Published in: Materials Vol. 12; no. 11; p. 1797
• Main Authors: Chen, Meng, Ren, Chenhui, Liu, Yangbo, Yang, Yubo, Wang, Erlei, Liang, Xiaolong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 03.06.2019; MDPI
• Subjects: Aggregates; Cement; Compressive properties; Compressive strength; Concrete mixing; constitutive model; Corrosion resistance; Density; Energy; Energy absorption; failure mode; Fiber reinforced concretes; Fiber reinforced polymers; Fibre reinforced concrete; impact loading; Polypropylene; Reduction; Reinforced concrete; Split Hopkinson pressure bars; Strain rate; Stress-strain relationships; Workability; Beijing China; China; polypropylene; impact loading; Fibre reinforced concrete; failure mode; constitutive model
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12111797

This paper presents an experimental study on the dynamic compressive behaviour of polypropylene (PP) fibre reinforced concrete under various strain rates using split Hopkinson pressure bar (SHPB) equipment. The effects of PP fibre content and strain rate on the dynamic compressive stress-strain relationship and failure patterns were estimated. The results indicated that the addition of PP fibre enhanced the dynamic compressive properties of concrete mixtures although it resulted in a significant reduction in workability and a slight decrease in static compressive strength. Considering the workability, static compressive strength and dynamic compressive behaviour, the optimal PP fibre content was found to be 0.9 kg/m as the mixture exhibited the highest increase in dynamic compressive strength of 5.6%, 40.3% in fracture energy absorption and 11.1% in total energy absorption; further, it showed the least reduction (only 5.8%) in static compressive strength among all mixtures compared to the reference mixture without fibre. For all mixtures, the dynamic compressive properties, energy absorption capacity, strain at peak stress, ultimate strain and dynamic increase factor (DIF) were significantly influenced by strain rate, i.e., strain rate effect. When the strain rate was relatively low, PP fibres were effective in controlling the cracking, and the dynamic compressive properties of PP fibre reinforced mixtures were improved accordingly.