Page 99 - ICJ Jan 2023

TECHNICAL PAPER COLLECTOR’S EDITION

There has been inadequate utilisation of large making effective use of the discarded crushed
quantities of crushed stone as alternative material stone dust in concrete. The test results generated
left out after crushing of rock to obtain coarse through a well planned and carefully executed
aggregate/ballast for concrete. Crushed stone dust programme indicate good prospects of utilising
does not satisfy the standard specification of fine this crushed stone dust as a partial replacement of
aggregate in cement mortar and concrete. Efforts river sand in making quality concrete.
have been made to replace river sand by rock dust.
Nagaraj et al. have studied the effect of rock dust EXPERIMENTAL PROGRAMME
1
and pebble as aggregate in cement and concrete . Materials
They found that crushed stone dust could be used
to replace the natural sand in concrete. Babu The cement used for the investigation was 43
studied the performance of quarry waste as fine grade ordinary portland cement (OPC). The initial
2
aggregate in concrete . Shukla et al. investigated and final setting times were 45 and 300 minutes
the behaviour of concrete made by partial/full respectively; the 3-day and 7-day compressive
2
2
replacement of river sand by crushed stone dust as strengths were 19.2 N /mm and 26.04 N/mm
fine aggregate and reported that 40 percent sand
can be replaced by crushed stone dust without Crushed granite aggregate having nominal size
affecting the strength of concrete . Pofale and of 20 mm was used as coarse aggregate. Sand
3
Kulkarni investigated the behaviour of concrete collected from nearby river was used without any
mixes with natural sand partially and fully replaced refinement. Crushed stone dust procured from a
by crushed stone powder (basalt) from aggregate crusher in Goramachia (Jhansi) was used.
crushing plant waste . It is reported that crushed
4
stone powder is feasible and practicable in plastic Table 1: Details of sieve analysis for natural
and cohesive mixes. Venugopal et al examined the sand and stone dust
effect of rock dust as fine aggregate in cement and IS sieve Percentage passing
concrete mixes . They have suggested a method designation River sand Stone dust River River sand
5
sand (60 (80 percent)
to proportion the concrete using rock dust as fine percent) + stone dust
aggregate. Shukla and Sachan reported results of + stone (20 percent)
dust (40
an experimental investigation in which stone dust percent)
6
is used to replace natural sand in concrete mixes . 10 mm 100.00 100.00 100.00 100.00
It was observed that 40 percent dust can be used
to replace natural sand without affecting strength 4.75 mm 100.00 99.00 99.50 99.60
of concrete mixes. 2.36 mm 98.07 97.69 97.90 98.00
1.18 mm 42.83 67.19 52.00 46.81
RESEARCH SIGNIFICANCE 600 micron 32.73 60.63 43.80 39.20

The manufacture of coarse aggregate by crushing 300 micron 4.30 30.74 14.50 11.10
rock ballast produces large amount of crushed 150 micron 0.91 11.01 4.90 2.93
stone dust as waste material. This poses a serious
Conforming Not Conforming Not
disposal problem. In many regions of India, acres to grading conforming to grading conforming
of land have become barren due to disposal of zone 1 of IS to any zone II of IS to any
383 grading 383 grading zone
crushed stone dust on it. This study is mainly zone of IS of IS 383
383
directed towards exploring the possibility of

100 The Indian Concrete Journal | November 2018