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An assessment of the effect of grading of perlite on ultimate strength in lightweight concrete.

A RESEARCH REPORT SUBMITIED TO THE FACULTY OF ARCHITECTURE.
UNIVERSITY OF THE WITWATERSRAND, JOHANNESBURG, FOR THE DEGREE
OF MASTER OF SCIENCE IN BUILDING / This research project is an investigation into the effect of the grading of perlite
lightweight aggregates on the resultant concrete strengths.
Lightweight concretes are reviewed.
Perlite, as a lightweight aggregate, is assessed.
Grading theory for aggregates and in particular lightweight aggregate is analysed.
A series of mix designs are proposed with manipulation of the grading of the perlite as
the only variable. This is so that variations in compressive strength and density may
be assessed in terms of the grading of the perlite.
Those mixes are undertaken and tested for compressive strength and dry density.
In this research project compressive strength is considered a benefit, while mass is
considered a disadvantage.
The performance of a lightweight concrete is assessed firstly in terms of the Power
Factor. The Power Factor is the compressive strength divided by the dry density of a
concrete.
The performance of lightweight concretes produced with Perlite aggregate is assessed
secondly in terms of the Cement Content factor. The Cement Content Factor is the
Power Factor divided by the Cement Content. This factor has the effect of creating a
common denominator of the cement content.
An evaluation of the results yields the conclusions detailed in chapter Eight, the
principal two being:
• The optimal perlite grading tested was a monodisperse, single size fraction, of
between 600 and 1180 microns.
• The most practical measure for manufacturers to improve the performance of
lightweight / Andrew Chakane 2019

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/26448
Date January 1998
CreatorsWinter, Adrian Jeremy
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Formatapplication/pdf

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