Development Of Hybrid Cementitious Composite (HCC) For Sustainable Construction In Sea Water Environment
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Date
2016-03
Authors
Alonge, Olayiwola Richard
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
The major challenge in the construction community is to advance a new type
of fibre reinforced concrete (FRC) which possesses favourable engineering features
that yield a high flexural ability. Metakaolin (MK) display great potentials as a
supplementary cementitious material (SCM) because of its high pozzolanic reactivity
as well as reduction of Ca(OH)2 as early as one day to produce early strength.
Likewise, it intensifies the blended cement paste to undergo definite densification.
The experimental exploration involves the laboratory production of MK from raw
kaolin and characterization of MK quaternary blended cement mortar consists of
cement, colloids nanosilica (CNS) and epoxy resin. The chemical compositions and
physical properties of the MK were appraised using a laser particle size Analyzer, Xray
Fluorescence (XRF) and X-ray Diffraction (XRD). The study adopts the design
criteria and mix proportion of engineered cementitious composites standard
ECCM45 (with some modifications). A hybrid cementitious composite (HCC) was
produced, exposed to both water and sea water for ages up to 365 days. A total of
seven mixes including control were fabricated with the incorporation of 10% MK,
1% CNS, 1% of epoxy resin replacement of cement by weight. Barchip fibre,
coconut and oil palm fruit bunch fibres were incorporated at 2% each by weight of
binder. Hybridization of barchip and each of natural fibres were also incorporated.
The results showed that the MK produced has higher alumina and silica oxides and very fine particle size grading. The incorporation of MK causes an increase in water
demand of the mortar and the setting time of the quaternary cement mortar. The MK,
CNS and epoxy resin enhance the early age mechanical properties and durability
properties of the HCC even with the incorporation of the fibres and their
hybridization. Among all the fibres, the barchip fibre generated very encouraging
results while the hybridized barchip and coconut fibre likewise showed better
performance over the samples of barchip and oil palm fruit bunch. The samples
exposed in sea water revealed better performance and correlations of results than the
samples exposed in water. The HCC panels and beams fabricated exhibited better
first crack and ultimate flexural strength, multiple micro cracks width and crack
spacing than the control. However, the barchip fibre panels and beam performed
better than others.
Description
Keywords
Construction