The use of wastes and industrial by-products as building materials is an important issue in order to decrease costs with waste management and the embodied energy of building products. Scrap tire rubber has been studied as aggregate for cementitious materials.
Natural hydraulic limes are natural binders with particular characteristics of both air and hydraulic binders. Their specifications became stricter with the last version of EN 459-1:2010.
In this study scrap tire rubber was used as additional aggregate of mortars, based on NHL3.5 and natural sand. Different particle size fractions and proportions of scrap tire rubber were used: a mix obtained almost directly from industry (only after sieving for preparation of particle sizes similar to mortar aggregate) and separated fine, medium and coarse fractions;
0%, 18%, 36% and 54% weight of binder, corresponding to 2.5%, 5% and 7.5% weight of
sand. The influence of the rubbers´ additions on the mortars´ fresh state, mechanical and physical performance is presented, namely by flow table consistency, water retention, fresh bulk density, dynamic elasticity modulus, flexural and compressive strength, open porosity and bulk density, capillary absorption, drying and thermal conductivity. The use of the rubber mix coming from the waste tire industry seems advantageous and may open possibilities for
use as raw material by the mortars industry
