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TECHNICAL PAPER

table 1: Chemical oxide composition of OPC and FCA (by % weight)

cOnstitUEnts caO Al O 3 fe O 3 siO 2 MgO na O K O sO 3 cr O 3 lOi
2
2
2
2
2
OPC 59.53 9.12 3.52 20.34 2.02 0.19 0.42 2.39 - 1.4
FCA 4.20 11.21 6.15 19.62 15.61 1.34 14.51 - 12.44 4.1
C - Coesite
Cr - Chromite
S - Spinal
J - Jadeite
Ca - Argaonite

(a) (b)

α - CH
β - CC

(c) (d)

Figure 1 (a): SEM image of spherical FCA particles, (b) mineralogical phases of FCA, (c) SEM image of lime, and (d) XRD pattern of lime (CH - calcium
hydroxide, CC - calcium carbonate).

2.2 Ferrochrome Ash Figure 1 (d) shows mineralogical composition of lime, which
mainly consists of calcium hydroxide (CH) and calcium carbonate
Ferrochrome ash (FCA) was supplied from M/s Balasore alloys (CC).
Ltd., Balasore, Odissa, India. Chemical oxide composition of
FCA is presented in Table 1. Figure 1(a) presents SEM image of
spherical FCA particles. X-ray Diffraction (XRD) pattern of FCA 2.4 Natural Fine Aggregate
is shown in Figure 1(b). FCA is composed of calcium, aluminum, Locally available saturated surface dry (SSD) and clean natural
silica, iron, magnesium, sodium and chromium rich minerals like siliceous sand, having 4.75 mm maximum size, was used as
coesite (SiO ), chromite (FeOCr O ), spinal (MgAl O ), jadeite
2 2 3 2 4 natural fine aggregate in the preparation of mortar mixtures. The
(NaAlSi O ), and aragonite (CaCO ).
2 6 3 gradation of sand used conformed to zone II as per [11] grading
requirement. The specific gravity, fineness modulus, water
2.3 Lime
absorption value and compacted bulk density of sand were 2.54,
Lime used in the experiments was procured from local market. 2.59, 0.9%, and 1681 kg/m , respectively. Table 2 presents the
3
Figure 1(c) shows SEM image of lime, which is irregular in shape. results of sieve analysis, of the fine aggregate.

The IndIan ConCreTe Journal | oCToBer 2019 15