International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 3, March 2014)
Suitability of Crushed Stone Dust as Fine Aggregate in
Mortars
S. P. S. Rajput1, M. S. Chauhan2
1
Assistant professor, 2Professor, Department of Civil Engineering, Maulana Azad National Institute of Technology Bhopal462051 (India)
1. Physical properties like bulk density, fineness
modulus etc., grain size distribution for Crushed stone
dust and natural river sand
2. Mortar and masonry characteristics using Crushed
stone dust and river sand
a. Compressive strength of mortar
b. Flow/workability
c. Compressive strength for mortar and masonry
using 1:4 and 1:6 Cement: Sand ratio
The test programme for mortar is shown in Tables 1.
Two cement mortars (1:6 and 1:4, cement: sand by
volume) were used in this study and tested for strength,
Flow/ workability, water absorption, masonry
compressive strength.
Abstract--The present investigation shows that the
characteristics of mortars and concrete using Crushed stone
dust as fine aggregate are superior when compared to the
natural river sand as fine aggregate. The results pertain to
the most commonly used grading zone – II sand. Crushed
stone dust falling within the grading Zone II sand, grading
limits specified by IS 383 code and manufactured from the
hard rock is suitable as fine aggregate in masonry mortars.
Also, IS-2116 and IS 383 codes permit the use of crushed
stone fine aggregate in masonry mortars.
Keywords: Crushed stone dust, Mortar, River sand
I. INTRODUCTION
In India, river sand is used as fine aggregate in mortar
over a period of millions of years. In general, the demand
of river sand is very high in developing countries to
satisfy the rapid infrastructure growth. In this situation
developing country like India facing shortage in good
quality of river sand (Amnon and Hadassa 2006).
Properties of sand affect the durability and
performance of mortar, so fine aggregate is an
essential component of cement mortar.
Now a day’s sand is becoming a very costly
material, in this situation research began for cheep
and easily available alternative material than river
sand.
Thus Manufactured sand (Crushed stone dust), as a
fine aggregate, is an attractive alternative of river sand
for cement mortars. It is purpose made fine aggregate
produced by crushing and screening or further processing
i.e. washing, grading, classifying of quarried rock,
cobbles, boulders or gravels from which natural fine
aggregate had been removed.
The present study has been attempted to evaluate the
characteristics of cement mortar using Crushed stone dust
as fine aggregate and its compare with river sand.
Table 1
Test Programme For Mortars Using River Sand And Crushed
Stone Dust
Mortar and
masonry
property
1:6 Cement Mortar
1:4 Cement
Mortar
River
Sand
Crushed
stone dust
River
Sand
Compressive
strength at
85% flow
√
√
√
Crushed
stone
dust
√
Compressive
strength for
masonry
√
√
----
----
Material Properties
(A) Physical Properties Of Crushed Stone Dust And
River Sand
The physical properties of fine aggregates are given in
Table 2.
II. EXPERIMENTAL P ROGRAMME
The main objective of the study was to examine the
suitability of Crushed stone dust as fine aggregate in
Mortars. Apart from characterizing the properties of
Crushed stone dust, tests were performed on the mortars
using Crushed stone dust as well as natural river sand.
The following tests were performed:
87
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 3, March 2014)
Table: 2
Physical Properties Of Fine Aggregates
Properties
Type of Sand
Crushed stone dust
Natural
Sand
Bulk density (kg/cm3)
18.18
15.3
Specific gravity
2.8
2.73
Bulking of sand (%)
4.91
5.55
Fineness Modulus
2.49
2.10
Water absorption (%)
6.2
9.4
Crushed stone dust contains elements of Si, Al, Ca, Mg,
Na, K, Fe, etc.
(B) Sieve Analysis
Sieve analysis (or gradation test) is a practice or
procedure used to assess the particle size distribution for
sand. Gradation affects many properties of a fine
aggregate. With careful selection of the gradation, it is
possible to achieve high bulk density, and low
permeability. Sieve analysis of fine aggregates
determined as per IS: 383 (1970) given in Table 3.
Fig. 1 Crushed stone dust mortar at 85% flow (no segregation)
Mortar composition as well as water-cement ratio
affects the workability. Workability of the fresh mortar
can be measured by conducting a flow table test
following the BS – 4551 code guidelines. Workability of
fresh mortar is expressed as flow value. Fig. 1 shows
mortar flow at 85% using Crushed stone dust in 1:6
cement mortar.
(b) Compressive strength for mortar: Compressive
strength values given in Table 4 represent mean of three
specimens. Considerable increase in compressive
strength of mortars between 3 and 7 days curing
irrespective of flow value for 85% and sand type for both
the mortars.
(c) Compressive strength of masonry: Compressive
strength of masonry was examined by testing five brick
high stack bonded masonry prisms. Prisms (size: 105 x
225 x 445 mm, having height to width ratio of 4.23) were
prepared using burnt clay bricks having compressive
strength of 9.8 MPa (mean value) and using 1:6 cement
mortar with river sand and Crushed stone dust.
Compressive strength of the masonry prisms was 3.15
MPa and 4.08 MPa for mortar with river sand and
crushed stone dust respectively. These are the mean
values of six prisms. Nearly 30% increase in masonry
strength due to the use of mortar with Crushed stone dust
was observed. Fig. 2 shows the masonry prism failure
(typical vertical splitting cracks) using mortar with
Crushed stone dust.
Table 3
Details Of Sieve Analysis Of Natural Sand And Manufactured Sand
Natural
Sand
Crushed
stone
dust
Grading
Limits for
Zone II
Sand (IS
383)
4.75 mm (No.4)
100
100
90-100
2.36 mm (No. 8)
99.3
94.5
75-100
1.18 mm (No.16)
97.1
69.2
55-90
600 micron (No.30)
89
49.8
35-59
300 micron (No.50)
2.7
21.4
08 - 30
150 micron (No.100)
1
6.1
0-10
Percentage Passing
Sieve Designation
III. T EST RESULTS AND D ISCUSSION
(a) Mortar characteristics using Crushed stone dust and
river sand Flow/workability: Workability of the mortar
should be such that it allows the mason to spread the
mortar easily and adheres well to the masonry units.
88
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 3, March 2014)
Table 4
Compressive Strength Mortars
Mortar
Proportion
(by volume)
Cement : Sand
Flow
Water – cement ratio
Compressive strength (MPa)
(%)
River sand
1:6
85
1.72
Crushed
stone dust
1.30
1:4
85
1.13
0.84
River sand
3 days
7 days
Crushed stone dust
3 days
7 days
3.10
5.03
4.80
7.20
4.89
8.35
10.8
14.0
Fig. 2 (A) Typical Failure Pattern
Fig. 2 (B) Prism With Strain Gauge
REFERENCES
IV. CONCLUSIONS
[1]
Based on the study following conclusion has been
drawn:
1. Grading limits of Crushed stone dust lies in the
grading Zone-II sand, grading limits specified by IS
383 code.
2. Bulk density and specific gravity of Crushed stone
dust are comparable to those of river sand.
3. Mortars with Crushed stone dust show better
workability and to achieve a specific flow value
when compared to mortars with river sand.
4. Compressive strength of mortar with Crushed stone
dust is higher than that of the mortar with river sand
for mortar flow in the range of 85%.
5. Crushed stone dust mortar shows higher
compressive strength and modulus for masonry
when compared with the values for masonry using
river sand.
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
89
Amnon K., and Hadassa B., (2006), “Effect of high levels of
fines content on concrete properties”, ACI Material Journal,
103, pp 474-481.
BS: 4551 - 1980, "British standard methods of testing mortars,
screeds and plasters", British Standards Institution, U. K.
IS: 456 – 2000, “Plain and reinforced concrete – code of
practice”, Bureau of India Standards, New Delhi, India.
IS: 383 – 1970 (2002), “Specification for coarse and fine
aggregates from natural sources for concrete”, Bureau of Indian
Standards, New Delhi, India.
IS: 2116 – 1980 (1998), “Specification for sand for masonry
mortars”, Bureau of Indian Standards, New Delhi, India.
IS: 2250 – 1981 (2000), "Indian Standard Code of Practice for
Preparation and Use of Masonry Mortars", Bureau of Indian
Standards, New Delhi.
IS: 1905 - 1987, "Code of Practice for Structural Use of Un
reinforced Masonry", Bureau of Indian Standards, New Delhi
IS: 1199 – 1959 (2004), “Methods of sampling and analysis of
concrete” Bureau of Indian Standards, New Delhi, India.
IS: 516 – 1959 (2004), “Methods of tests for strength of
concrete”, Bureau of Indian Standards, New Delhi, India.