ALKALI ACTIVATED BRICK AT LOW TEMPERATURES BASED ON IRAQI ATTAPULGITE

Abstract

In this work, alkali activated brick have been synthesized from Iraqi Attapulgite clay using NaOH solution as activators. Prepared 300 brick samples have dimensions (75 x 38x 25 mm) by applied static press of (13-14 kN). In this study, two parameters with 270 samples have all, concentration of NaOH (4, 6 and 8 M) and varies curing temperatures (80, 100 and 120°C) in order to minimize firing temperature of products brick. As well, 30 samples as reference, which do not have any NaOH and fired at 1000 °C. The prepared samples subject to (water absorption, compressive strength and efflorescence) tests according to Iraqi standards [13], and rupture strength according British standard [10], in addition to SEM and EDS test was carried out. The results showed the maximum compressive strength of 13.4 MPa was obtained with 4 M of NaOH and 100 °C of curing, and the water absorption enhancing by 56.9% at 120 °C, and the increasing in term of strength rupture was 48.15% at 4 M and 80 °C. Whereas, the samples were prepared with 6 and 8 M are not holds together when immersed in water to perform tests, furthermore all brick samples exhibits high efflorescence with thick layer of NaOH salts.