Comparative Evaluation of 100% Recycled and Virgin PP Fibre Reinforced Concretes
Cement matrix is highly alkaline with pH value of around 13, thus durability of the plastic fibre in concrete alkaline environment is an important factor that needs proper consideration. This chapter assessed alkali resistance of 100% recycled PP fibre in four different alkaline solutions with pH value ranging from 12.3 to 13.5, and compared with virgin PP fibre.
Performance of the 100% recycled PP fibre was then studied in different grades of concrete and was compared with the virgin PP fibre. Two volume percentages of fibres were chosen to reinforce 40 and 25 MPa concrete, which are the standard grades of concrete used in precast panels and concrete footpaths, respectively. Through crack mouth opening displacement (CMOD) test and round determinate panel test (RDPT), this chapter proved the industrial feasibility of using 100% recycled PP fibre to replace virgin PP fibre. After proving the feasibility of using 100% recycled PP fibre in different construction applications in this chapter, the reinforcement of newly developed various recycled PP fibres described in Chap. 3 will be studied in next chapter (Chap. 5).