Rheological and mechanical properties of concrete containing crushed granite fine aggregate

摘要

The influence of crushed granite fine aggregate (CGA) on the rheological and mechanical properties of concrete is reported in this work. Concretes were produced with 10, 30, and 50% (in volume of fine aggregates) of CGA, with respect to a reference mixture, which contained a regular siliceous river sand. The reference was designed for a 28-day compressive strength of 50 MPa and a slump ranging from 200 to 220 mm. All concrete mixtures had 20% of rice husk ash as the volume of cementitious materials from the rheological (Brookfield viscometer), and 28-day compressive strength tests of cement-based pastes. The concrete rheology was measured using a BTRHEOM parallel plate rheometer. Experiments were also performed to investigate the concrete air content, compressive strength (at 7 and 28 days), Young's modulus (at 28 days), and water absorption. The results showed that the Herschel-Bulkley model adequately fit the rheology data, and high superplasticizer dosages in CGA concretes inhibited the negative influence of CGA on the plastic viscosity. The compressive strength was not negatively affected, and no significant change was observed in Young's modulus for up to a 50% CGA content. Moreover, water absorption was reduced for concretes containing 30 and 50% of CGA. (C) 2016 Elsevier Ltd. All rights reserved.