Extensive amounts of waste materials from excavation waste, modern
industrial waste and development construction squander are being produced. The
utilization of waste materials in highway construction in Oman and uses of
chose waste materials are talked about. An assessment in view of specialized,
natural and financial components has been required. The fundamental target of
this paper is to exhibit the outcomes on the utilization of steel slags and concrete
block waste in the development of road bases and sub-bases. Additionally,
utilizing the marble powder squander as added substance in expanding the
quality of subbase material. Physical properties were resolved. All materials
were examined as per Oman development particulars. Results can possibly swap
ordinary materials for different applications in thruway development and ought
to be anticipated for future development. The properties of tried waste
materials demonstrated that it is attainable to utilize these materials in the
blend of road sub-bases. The materials meet Oman standards, for example, liquid
limit, plasticity index and sieve analysis results.
Key words: Waste, Road, Construction,
Enormous amounts of local, modern industrial, and mining waste are
created in Oman. There are three procedures for transfer of these waste
materials: (a) reusing, (b) cremation with or without generation of energy, and
(c) internment. The distributed information on current practice show that the
bulk of household reject is either burned or land filled.
Waste materials are generally utilized as a part of development
extends so as to spare regular assets. Using these materials in unbound
base/sub-base development will give reasonable improvement in a nation by
sparing virgin materials, preserving vitality and occupying materials from
landfills 1. Reused materials utilized as a part of black-top asphalts and unbound
base/sub-base applications for the most part originate from pulverization waste
and results from mechanical procedures. Most normally utilized ones incorporate
coarse and fine aggregates, tiles, blocks, coal fly fiery remains, impact
heater slag, boiler slag, steel slag, base cinder, glass waste, reclaimed
paving materials and elastic tires 2.
In some countries where aggregate and sand resources are limited
and more expensive, these wastes are usually used for other construction purposes.
The materials are formed due to construction work and industrial processes
consists of some other materials that can be used in strengthen the main
Population development in Oman will create expanding measures of
waste materials that must be discarded. As the volume of squanders keeps on
developing, the endorsement and accessibility of offices for waste handling and
appropriate transfer will turn out to be more hard to acquire. Oman produces
huge amounts of building, development and modern industrial waste which could
be reused in road development.
In the choice of a stabilizer, the elements that must be considered
are the sort of soil to be balanced out, the reason for which the settled layer
will be utilized, the kind of soil change, the required quality and solidness
of the settled layer, and the cost and ecological conditions.
The principle target of this research was to research the potential
for utilizing some waste materials created in Sohar territory in Oman in
developing road bases and subbases. To meet this target, physical properties of
concrete block waste and mining slags were resolved. Results were contrasted
with Oman specifications 1 with build up the feasibility of utilizing such
materials in the base and sub-base structure. Likewise, the accessibility of
marble powder squander in expanding the quality of base and subbase material.
In flexible pavement, Wheel loading is firstly met with wearing
course in flexible pavements. The magnitude of load is uniformly transmitted to
lower layers and to subgrade lastly. Flexible pavements must also carry the
axle loading of vehicles as safety and economically. Layered flexible pavements
are designed by considering criteria as design life, traffic volume and the
strength of the subgrade. The flexible pavements are composed of wearing
course, base course, subbase and subgrade layers.
For many designs, the main
function of the subbase of a flexible pavement is to reduce the building cost.
The objective is to achieve required pavement thickness with the possible economic
materials. The entire thickness could be constructed with a highly quality
material such as that used in the base course. However, it is generally
preferred to make the base thinner and substitute a subbase layer of poorer
quality material, although the total pavement thickness may have to be
increased. The poorer the quality of the material that is used, the greater
will be the thickness required to tolerate and transmit the stresses. Another
function of subbase is to provide a transition layer between the material of
base course, which is generally coarse-grained, and that of the subgrade, which
is usually much finer. The subbase also serves to absorb detrimental
deformations in the subgrade such as volume changes associated with variations
in water content, which might eventually be reflected in the pavement surface.
Another function of the subbase is to drain off any water that infiltrates from
the surface and to prevent water from the fill from rising towards the base
course due to capillarity 10.
Three waste materials, namely marble waste, slag and concrete block
waste were collected from several locations around Sohar industrial area. No
pre-treatment was done to the materials of this study. A total of 15 buckets
for each type of waste material were sampled from stockpiles and brought to
laboratories in Sohar university for physical testing. The following tests were
conducted on the three waste materials in accordance with British
specifications (Standard – BS EN 1463-2:2000).
analysis (ASTM C 136).
density, specific gravity and absorption (ASTM C 127 and ASTM C 128).
Anglos abrasion (ASTM C 131)
limit and plasticity index tests (BS 1377).
Bearing Ratio (CBR) test (ASTM D 698 and ASTM D 1883).
Results and Discussion
Physical properties of each of the three materials were determined
in the laboratory. A summary of test results for these waste materials are
presented in Table 1. Table 1 indicates that slag and concrete block wastes met
the maximum 45% LA Abrasion criteria in British standard BS.
Also, Table 1 indicates that liquid limit and plasticity index
results obtained for slag and concrete block wastes met BS standards. However
marble waste was slightly higher than the BS requirements of a maximum 25 and 6
for liquid limit and plastic index respectively.
In order to determine the grain size distribution of materials
collected from the field, sample sizes were reduced using a crusher to collect
enough material to run the sieve analysis test according to ASTM C 136 4.
Figure 1 shows the sieve analysis results for slag and concrete block waste
along with the upper and lower limits for sub-base layer given in BS. Figure 2
shows the sieve analysis results for slag and concrete block waste along with
the upper and lower limits for Class A base coarse. Figure 3 shows the sieve
analysis results for slag and concrete block waste along with the upper and
lower limits for Class B base coarse. These figures show that % passing amount
for all sieve sizes are in the range between upper and lower limits based on
sub-base specifications and thus meet the specification requirements.
All sieve analysis results for the three materials and % passing
requirements for two types of bases (classes A and B) and one type of sub-base given
in BS are presented in Table 2. The results indicate that slag can meet the
requirements for a sub-base material type, but not those of Class A base and
Class B base material. On the other hand, the results indicate that concrete
block waste cannot meet the requirement for base or sub-base material where the
distribution is out of the range for upper and lower limits for all types. Marble
waste is mixed with original aggregate to show the effect of marble powder on
the strength of the material. California Beating Ratio test was done for two
sample, one without marble and one with marble, the results shows that the CBR
value of the mix with marble is higher than CBR value for the mix without
marble. The CBR value for the original aggregate is 90% but the CBR value for
the mix with marble is 130. As a result, the marble powder can be used in the
base and subbase as stabilizing agent material to strength these layers.
Table 1 Physical properties of
used waste materials
Concrete block waste
Los Angles abrasion (%)
Water absorption (%)
Sieve analysis results and gradation limits
Conclusion and Recommendations
Three different waste materials collected from different locations
in Sohar, Oman were investigated for possible use in road base and sub-base in
Oman. Physical tests were conducted for all materials to determine their
sustainability according to BS. Based on the data obtained from laboratory
test, the following conclusion can be made:
Concrete block waste and slag can satisfy the Los Angles Abrasion,
liquid limit, plasticity index for unbound materials specified in BS.
Marble waste did not satisfy all standard requirements to be used
as base or sub-base.
Marble powder waster can be used as stabilizing agent instead of
Portland cement to increase the strength of the layer.
slag material is suitable in their current conditions for road sub-base
construction in Oman.
Concrete block waste is not suitable in its current condition for
road bases and sub-bases construction in Oman.
Figure 1: Sieve
analysis results for slag and concrete block waste compared with sub-base upper
and lower limits
Figure 2: Sieve
analysis results for slag and concrete block waste compared with Class A base
upper and lower limits
Figure 3: Sieve
analysis results for slag and concrete block waste compared with Class B base
upper and lower limits
Recommendations for future work should focus on:
Stabilization of such materials with Portland cement combined with
marble powder waste to improve their strength.
Blending the concrete waste material with other virgin aggregates
such as gravel or limestone to meet the requirements.
Mixing with discarded aggregate generated in Oman such as aluminium
dross, glass waste and others.
Changing the percentage of marble powder waste to get the best
percentage can be used to increase the strength of base and subbase layers.
Comparing economically between the virgin aggregates by mixing with
cement and marble.
This publication was made possible by a grant from Sohar university
under the fund of undergraduate final year project. Its contents are solely the
responsibility of the authors and do not necessarily represent the official
views of Sohar university research fund.
1- El-Assaly A,
Ellis R (2001) Evaluation of recycling waste materials and by-products in
highway construction. Int. Journal of Sustainable Development and World Ecology
2- Horvath A
(2003) Life-Cycle Environmental and Economic Assessment of Using Recycled
Materials for Asphalt Pavements. Technical Report, University of
3- BS 1377-1 (2000)
methods of test for soils for civil engineering purposes. General requirements
and sample preparation. Standard Publication by BSI Group.
C136-06, Standard Test Method for Sieve analysis of fine and coarse aggregates.
5- I.Ahmed. Use
of Waste Materials in Highway Construction. Report FHWA/IN/JHRP-91/3. School of
Civil Engineering, Purdu University, West Lafayette, Ind., 1991.
6- J. Paul
Guyer, P.E., R.A., Fellow ASCE, Fellow AEI, Introduction to Soil Stabilization
in Pavement, Continuing Education and Development (CED), 2011
7- Tahs R,
sirin O, Sadek H (2014) Evaluation of combined Excavation Waste and reclaimed
Asphalt Pavement Aggregates for Use in road Bases and Sub-bases. J Civil
Environ Eng 4: 141. Doi: 10.4172/2165-784X. 1000141.
Ebrahim, Evaluation of Steel slag and crushed limestone mixtures as subbase
material in flexible pavement, Ein Shams Engineering Journal, 2012.
Mehmet, Selcan Findik F. Stabilization of subbase layer materials with waste
pumice in flexible pavement. Build Environ 2008; 43:415-21.
Mahmoud, Behnood Ali. Laboratory studies to investigate the properties of CIR
mixes containing steel slag as a substitute for virgin aggregates. Constr.
Build Mater 2012;26:475-80.