Mechanical Properties of Lightweight Concrete Containing Andesite-Dusty Rock

Abstract

This paper presented the study results of the use of andesite-dusty rock (ADR) in the productionof lightweight concrete. This rock dust was used for partially replacing river sand and being used as afine aggregate. The studied parametric included the fineness moduli (FM) of ADR (2.0, 2.5 or 3.0), andthe replacement ratios of ADR in river sand by weight (0% (control), 25%, 50%, 75% and 100%) and awater-to-binder (cement and fly ash) ratio by mass (w/b = 0.52). The tested physical properties were unitweight, flow slump, air content and setting time. The mechanical properties were compressive and splittingtensile strengths, and elastic modulus.

Through the test results, it was found that andesite-dusty rock (ADR) has silicon dioxide (SiO2)as a main component. Their particles have an irregular shape with smooth and rough surface. Whereasthe gradation of ADR as cumulative passing percentages, they were close to the lower bound as specifiedin the ASTM C33 standard. Lightweight concretes mixed with ADR, the increased FM of ADR from 2.0up to 2.5 resulted in an increase of air content. On the other hand, the setting times were decreased withincreasing the FM of ADR from 2.0 up to 2.5, and they were increased with increasing the FM up to 3.0.Whereas the lightweight concrete containing ADR that having a 2.0 FM and a 50%-ADR replacement inriver sand was the highest compressive and splitting tensile strengths and elastic modulus.

Keywords : Andesite-dusty Rock / Lightweight Concrete / Mechanical properties