APPLICATION OF QUARRY ROCK DUST AS FINE AGGREGATE
IN CONCRETE CONSTRUCTION
R.ILANGOVAN
DR.K.NAGAMANI
Common river sand is expensive due to excessive cost of transportation from
natural sources. Also large-scale depletion of these sources creates environmental
problems. In such a situation the quarry rock dust can be an economical
alternative to the river sand. Quarry rock dust can be defined as residue,
tailing or other non-valuable material after the extraction and processing of
rocks to form fine particles less than 4.75mm. Usually, Quarry rock dust is
used in a large scale for highways as a surface finishing material and also
used for manufacturing of hollow blocks and lightweight concrete prefabricated
elements. Use of quarry rock dust as a fine aggregate in concrete and mortar
draws serious attention of researchers and investigators.
This paper presents the feasibility of the usage of quarry rock dust as a
complete substitute for natural sand in plain concrete. Mix design has been
developed for M30 grade concrete using three different sizes of coarse aggregates
for both conventional concrete and quarry dust concrete. Tests were conducted
on cubes, beams and cylinders to study the strength of concrete made of
quarry rock dust and the results were compared with the natural sand concrete.
An attempt has also been made to establish durability studies on quarry rock
dust when compared with the natural sand concrete. It is found that the
compressive, flexural and split tensile strength and Durability Studies of
concrete made of quarry rock dust are nearly 10% more than the conventional
concrete.
River sand Substitute- Quarry Rock Dust-Concrete mixes- Compressive Strength-
Flexural Strength- split tensile strength - gain in strength and shrinkage.
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Research Articles
FACTORS CAUSING CONSTRUCTION DELAYS: A SURVEY OF
LARGE HOUSING PROJECTS IN INDIA
B UMASANKAR, S CHATTOPADHYAY, B K SENGUPTA
This paper presents the results of a survey conducted by the researcher to
determine the relative significance of principal factors causing construction
delays in large group housing projects in India. Questionnaire survey was
the primary methodology for the study. The questionnaire consisted of 50
previously identified delay factors, grouped under 10 factor categories. The
survey was conducted among two groups – consultants and contractors. The
first part of this paper deals with a brief literature review on related studies,
the factors considered for the questionnaire design and with the methods of
data analysis adopted in this study. The second part dwells upon the analysis
of the data collected. According to the consultants, slow decision making by
the client, late release of interim payments, contractor’s low overall productivity,
subcontractor’s delays and insufficient working capital were the top five
delay causing factors. The contractors ranked late release of interim payments,
late release of drawings / details, contractor’s low overall productivity,
insufficient working capital and poor resource allocation as the key factors
resulting in construction delays. Relative agreement between the two groups
was analyzed and a comparison of rankings for each of the factor categories
is presented in the final part.
Large housing projects, construction delays, questionnaire surveys.
Research & Publications Department 