The effect of polypropylene fibers on graphite-natural hydraulic lime pastes

Abstract

A reduction in greenhouse gas emissions has given rise to the search for low-embodied energy materials. Based on this assumption, natural hydraulic lime can be an alternative binder to cement, while the introduction of waste as inert material can be used to reduce the environmental impact of sand. A graphite-NHL composite had been previously analyzed but it showed both a low resistance to cracking and a brittle performance. Hence, in this paper, the effect of polypropylene fibers in this composite has been studied in order to enlarge this composite while improving its performance. Several series of natural hydraulic lime pastes based on NHL5 were prepared with a percentage of fiber ranging from 0% to 2% and graphite from 0% to 25% by weight substitution of natural hydraulic lime. Both the fresh state and the hydric, mechanical and thermal properties were analyzed. Fibers increased the ductile-like behaviour and toughness considerably, as well as its porosity. However, their combination with waste graphite and plasticizer considerably improved the properties of the plain pastes. © 2018 Elsevier Ltd