Use of natural pyrophyllite as cement substitution in ultra performance polypropylene fiber concrete

Abstract

The present work investigates the use of an alumino-silicate material, the pyrophyllite as cement substitution, synthetic polypropylene fibers and binder to create an unusual ultra-performance fiber concrete; new composite, which offers a wide field of possible use in construction industry. Effect of pyrophyllite on the physical-mechanical properties is analyzed. One reference fiber concrete without pyrophyllite and three fiber concretes containing 10%, 20%, 30% of pyrophyllite were elaborated. Results show that the pyrophyllite affects the characteristics of the concrete. Indeed, in the hardened state, the density of fiber concrete decreased with pyrophyllite rate increasing. Moreover, the use of pyrophyllite slows down the hardening process of concrete, consequently producing at early ages, compressive, flexural and tensile strengths and elastic modulus of concretes approaching without exceeding those of the reference fiber concrete. The fiber concretes are also considered to be of good quality. It seems that the rate of 10 % of pyrophyllite generates the best physical-mechanical performances that approach those of the reference fiber concrete. The use of pyrophyllite as a cement substitution is beneficial since it can help to decrease the production of cement; the amount of CO2 released and protects the environment