Properties of volcanic pumice based cement and lightweight concrete
Khandaker M. Anwar Hossain
*
Department of Civil Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, Canada M5B 2K3
Received 19 November 2002; accepted 1 August 2003
Abstract
The results of investigations on the suitability of using volcanic pumice (VP) as cement replacement material and as coarse aggregate in
lightweight concrete production are reported. Tests were conducted on cement by replacing 0% to 25% of cement by weight and on concrete
by replacing 0% to 100% of coarse aggregate by volume. The physical and chemical properties of VP are critically reviewed to evaluate the
possible influence on both fresh and hardened state of cement and concrete. The standard tests on different Portland cement –volcanic pumice
powder (VPP) mixes provided encouraging results and showed good potential of manufacturing Portland volcanic pumice cement (PVPC)
with higher setting time using up to 15% of VPP. The properties of volcanic pumice concrete (VPC) using different percentages of volcanic
pumice aggregate (VPA) were evaluated by conducting comprehensive series of tests on workability, strength, drying shrinkage, surface
absorption and water permeability. It is concluded that the VPC has sufficient strength and adequate density to be accepted as structural
lightweight concrete. However, compared to control concrete, the VPC has lower modulus of elasticity and has more permeability and initial
surface absorption.
D 2003 Elsevier Ltd. All rights reserved.
Keywords: Volcanic pumice; Lightweight structural concrete; Blended cement; Shrinkage-permeability; Strength
1. Introduction
Pumice is a natural material of volcanic origin produced
by the release of gases during the solidification of lava. The
cellular structure of pumice is created by the formation of
bubbles or air voids when gases contained in the molten lava
flowing from volcanoes become trapped on cooling. The
cells are elongated and parallel to one another and are
sometimes interconnected. Volcanic pumice (VP) has been
used as aggregate in the production of lightweight concrete
in many countries of the world. So far, the use of pumice was
dependent on the availability and limited to the countries
where it is locally available or easily imported. Satisfactory
concrete [1] which is two to three times lighter than normal
concrete having good insulating characteristics with high
absorption and shrinkage can be manufactured using VP.
VP and volcanic ash (VA) like fly ash (FA) are pozzolanic
materials because of their reaction with lime liberated during
the hydration of cement [2]. Amorphous silica present in the
pozzolanic materials combines with lime (calcium hydrox-
ide) and forms cementitious materials. Jackson [2] stated that
pozzolanic cement could be made by replacing up to 40% of
cement by pozzolanic materials. These materials can also
improve the durability of concrete and the rate of gain in
strength and can also reduce the rate of liberation of heat,
which is beneficial for mass concrete. Comprehensive re-
search had been carried out in the past on the use of FA,
pulverized-fuel ash (PFA), blast furnace slag, rice husk ash,
silica fume, etc. as cement replacement material [3 –9].
Over recent decades Portland cements containing FA and
silica fume have gained increasing acceptance whilst Port-
land cement containing natural pozzolans, like rice husk ash
and burnt oil shale, are common in regions where these
materials are available. Replacement levels of Portland
cements containing blast furnace slag vary considerably
with contents of well over 50% by weight common in some
regions. FA typically replaces 10–30% of the Portland
cement although levels of 50–60% have been advocated
[8]. While silica fume is added, it commonly comprises 5–
10% of the binder. ASTM Standards [10–12] exist for the
use of natural pozzolans, FA, and silica fume and blast
furnace slag in concrete.
Researches had been conducted worldwide on a large
number of natural or artificial lightweight aggregates such
0008-8846/$ – see front matter D 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.cemconres.2003.08.004
* Tel.: +1-416-979-5000x7867; fax: +1-416-979-5122.
E-mail addresses: dr
_
k
_
m
_
hossain@hotmail.com, ahossain@ryerson.ca
(K.M. Anwar Hossain).
Cement and Concrete Research 34 (2004) 283 – 291