44 The Masterbuilder - October 2012 • www.masterbuilder.co.in

Possible Use of Some Waste Materials in Road Construction

Historically, naturally available materials like soil, stone aggregates, sand etc. had been used for construction of roads. For example, boulders, volcanic

tuff and lime were used for the construction of Roman roads (Barth 1990). Subsequently, as the civilization grew, some of the naturally available materials were processed further to derive new binding materials for example, bitumen, cement etc.

However, due to considerable usage of various naturally occurring materials for building road and other infrastructures, these have started depleting gradually. The cost of procure-ment and processing of such materials are increasing day by day. At the same time, large amount of industrial and domestic wastes are causing serious environmental problems in terms of disposal or safe storage. It is in this connection, road researches have been trying to find out possible ways to use some of the waste materials (after due processing) as alternative materials for road construction (Aravind and Das 2004). For success of such an initiative, the proposed material(s) should be safe, environmental friendly and cost effective. This article presents a brief review on possible use of some waste materials as reported in various literature. It may be noted that the list is no way exhaustive and the conclusions drawn may not necessarily be final. Further research is needed before such material(s) is/are finally recommended for use in road construction.

Approach to utilization

A processed waste material, which is proposed to be used for road construction, is to be assessed for its environment, health and safety hazards, physical, chemical and engineering properties, cost effectiveness, field performance etc. If environment, health and safety assessment results are negative, the candidate material is rejected as a road construction material and is recommended for safe disposal. If the material satisfies the environmental, health and safety criteria, then it is further evaluated for its physical, chemical

and engineering properties. If the chemical and physical properties of the candidate material are similar to that of traditional construction materials, then existing testing protocols may be used for evaluation of its engineering properties. Otherwise, new test procedures are to be developed. For standard materials, the testing procedures and acceptance specifications are prescribed by highway agencies or local public works departments. Further, cost evaluation needs to be performed to check the economic feasibility of using the candidate material as replacement of traditional pavement material.

Sometimes life cycle cost evaluation is conducted to study in detail the overall impact of the new material on the total cost of the road project (through out its service period, including all maintenance activities). Finally, it is important to conduct field trial with the new material to

Animesh Das, Ph.D.Professor, Department of Civil Engineering, Indian Institute of Technology Kanpur.

Aravind Krishna Swamy, Ph.D.Assistant Professor, Department of Civil Engineering, Indian Institute of Technology Delhi.

Sustainability Road Construction

Bituminous Concrete Primarily Consists of Aggregates and Binder

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1979). Some field studies have indicated increased skid resistance when bottom ash is used as top wearing course of road (Shuler 1976).

Good Quality Aggregates are Gradually Depleting

gather information on the short-term and the long-term performance of the road. Performance studies also help to develop acceptance specifications for new road materials.

Waste material used in road construction

Several researchers have tried to incorporate bottom ash and fly ash in various layers of pavement (Huang 1990). Fly ash has been used as bulk filler in construction of embankments and flyovers (Yoon et al. 2009). However, due to corrosive nature of bottom ash, its usage near metallic structures is limited (Ke 1990). Studies have indicated that bituminous concrete containing bottom ash is susceptible to rutting but more resistant to stripping (Majidzadeh et al.

Is it Possible to Have Alternative to Stone Aggregates?

Large Quantity of Stone Aggregates are Needed for Road Construction

Fly ash consists of extremely fine siliceous glass with particle size ranging from to 10 and 100 micron (FHWA 2012a). Due to its smaller particle size, fly ash has been used as mineral filler in bituminous mix. Due to increased surface area of aggregates, overall demand for binder may increase when fly ash is used as filler (FHWA 2012c). Due to pozzolonic nature, fly ash with lime has been widely used in base/sub-base courses as binder (Wen et al. 2011). Lack of homogeneity, sulphates, and slow strength development are some of the issues in using fly ash in road construction (Sherwood 1995).

Waste glass has been used as bulk filler in layers beneath bituminous layers (Ahmed 1991). Due to the presence

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Pavement Needs to Perform Well Under Various Climatic Conditions

46 The Masterbuilder - October 2012 • www.masterbuilder.co.in

of inherent porosity in usual stone aggregates, bitumen adheres to the surface strongly, compared to broken glass pieces used as substitute for aggregates. Thus, the strength of bituminous mix with glass as aggregates are found to show lower strength than normal bituminous mix (Su and Chen 2002). It has been also observed that glass particles break under traffic and finally leads to raveling (Larsen 1989). Some studies indicated that resilient modulus and indirect tensile strength of bituminous concrete containing glass are unaffected up to 15% of glass (Sultan 1990).

Construction and demolition wastes has been used as

bulk filling material in road structure, well as in recycled aggregate concrete (Rao 2005). In fine powder form, it can also be used as fillers in bituminous mixes (Chen et al. 2011). Some studies have indicate that performance of construction and demolition waste as sub-base material is comparable to the conventional material (Rao et al. 2007).

Colliery spoil has been used in bulk fill in pavement layers (Sherwood 1995). Presence of combustible matter sometimes makes this material unsuitable for direct use (Sherwood 1995). Thus, it is recommended to incinerate the waste material before being used in construction. Colliery spoil contains some amount of sulphates. Under presence of water, compounds containing suplhates tend to leach out and react with the cement (Sherwood 1995).

Air cooled blast furnace slag has been used in making concrete, road base material. Also, fine ground slag has been used as filler material as well as soil stabilizer (Mroueh and Wahlström 2002). Due to high metallic content that is fused at high temperature, steel slag has been observed to show high skid resistance property (Asi 2007).

Attempts have also been made to use foundry sand in highway construction (Kleven et al. 2000, Javed et al. 1994). Since the particle size ranges from sand to fine dust, it makes a suitable candidate for filler cement concrete (Javed et al. 1994). Also it can be used as filler in granular subgrade material. Previous research has found that bitumen has less affinity to foundry sand making bituminous concrete susceptible to stripping (FHWA 2012b).

Past researchers have explored various other waste materials for their potential as alternative road construction materials, for example, spent oil shale (Gromko 1975), cement kiln dust (Hawkins et al. 2003), marble dust (Okagbue and Onyeobi 1999), incinerated residue of domestic wastes (Ciesielski 1980), sewage sludge (Lin et al. 2006), roofing shingles (Foxlow et al. 2011), polyethylene waste (Hınıslıoğlu and Ağar 2004, Punith and Veeraragavan 2011) etc. The list is definitely not exhaustive and the research is still ongoing.

Conclusion

Available literature points out that there is ample scope for utilization of waste materials for road construction. However, one needs to proceed cautiously, because of possible environmental, health and safety concerns associated with the usage of some of the waste materials. Thus, further research is needed before any specific waste material is finally approved as an alternative road construction material. It is hoped that availability of suitable technology, appropriate legislation and awareness among all stake holders would widen the possibilities of using some of the waste materials for sustainable road construction.

Building of Highway Infrastructure Requires Resources and Time

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Pavement Construction is a Challenging Task Under Extreme Weather Conditions

48 The Masterbuilder - October 2012 • www.masterbuilder.co.in

References

- Ahmed, I. (1991) Use of Waste Materials in Highway Construction. Publication FHWA/IN/JHRP-91/03. Joint Highway Research Project, Indiana Department of Transportation and Purdue University, West Lafayette, Indiana.

- Aravind, K. and Das, A., (2004) Industrial waste in highway construction, Pebbles, 1st issue, Society of Civil Engineers, IIT Kanpur.

- Asi, I.M. (2007). “Evaluating skid resistance of different asphalt concrete mixes.” Building and Environment, 42(1), 325-329.

- Barth, E.F. (1990). “An overview of the history, present status, and future direction of solidification/stabilization technologies for hazardous waste treatment.” Journal of Hazardous Materials, 24(2-3), 103-109.

- Ciesielski, S.K. (1980) “Incinerator residues as aggregates in asphaltic concrete wearing mixes.” Asphalt Pavement Construction: New Materials & Techniques, ASTM STP 724, American Society for Testing and Materials, 79-92.

- Chen, M., Lin, J., and Wu, S., (2011) “Potential of recycled fine aggregates powder as filler in asphalt mixture.” Construction and Building Materials, Vol. 25, pp.3909-3914.

- Foxlow, J.J., Daniel, J.S., and Swamy, A.K. (2011) “RAP or RAS? The differences in performance of HMA containing reclaimed asphalt pavement and reclaimed asphalt shingles.” Journal of the Association of Asphalt Paving Technologists, 80, 347-376.

- Gromko, G J. (1975). “A preliminary investigation of the feasibility of spent oil shale as road construction material.” Transportation Research Record, TRB, National Research Council, Washignton, D. C., 549, 47-54.

- Hawkins, G. J., Bhatty, J. I and O’Hare, A. T., (2003) Cement kiln dust production, management and disposal, Portland Cement Association, PCA, R&D No. 2737.

- Hınıslıoğlu, S. and Ağar, E. (2004) “Use of waste high density polyethylene as bitumen modifier in asphalt concrete mix.” Materials Letters, 58 (3-4), 267-271.

- http://www.fhwa.dot.gov/pavement/recycling/fach01.cfm (2012a) (last accessed 10/June/2012).

- http://www.fhwa.dot.gov/publications/research/infrastructure/structures/97148/fs2.cfm (2012b) (last accessed 05/June/2012).

- ht tp: / /www.fhwa.dot .gov/publ icat ions/research/ . . . /pavements/.../research/infrastructure/structures/97148/cfa52.cfm (2012c) (last accessed 05/June/2012).

- Huang, W., (1990). The use of bottom ash in highway embankments, subgrades, and subbases. Publication FHWA/IN/JHRP-90/04., Indiana Department of Transportation and Purdue University, West Lafayette, Indiana.

- Javed, S., Lovell, C.W., Leonard and Wood, W. (1994). “Waste foundry sand in asphalt concrete,” Transportation Research Record, TRB, National Research Council, Washignton, D. C., 1437, 27-34.

- Ke, T. (1990) The Physical Durability and Electrical Resistivity of Indiana Bottom Ash : Executive Summary. FHWA/IN/JHRP-90/06-2. Joint Highway Research Project, Indiana Department

of Transportation and Purdue University, West Lafayette, Indiana.

- Kleven, J.R,, Edil, T.B., and Benson, C.H. (2000) “Evaluation of excess foundry system sands for use as sub base material.” Transportation Research Record, TRB, National Research Council, Washignton, D. C., 1714, 40–48.

- Larsen, D.A. (1989). Feasibility of utilizing waste glass in pavements. Connecticut Department of Transportation, Report No. 343-21-89-6.

- Lin, C.F., Wu, C. H., and Ho, H. M. (2006) “Recovery of municipal waste incineration bottom ash and water treatment sludge to water permeable pavement materials.” Waste Management, 26(9), 970-978.

- Majidzadeh, K., El-Mitiny, R.N., and Bokowski, G. (1979). Power plant bottom ash in black base and bituminous surfacing, Federal Highway Administration. Materials Division, USA.

- Mroueh, U.M. and Wahlström, M. (2002). “By-products and recycled materials in earth construction in Finland—an assessment of applicability.” Resources, Conservation and Recycling, 35, 117–129.

- Okagbue, C.O., and Onyeobi, T.U.S. (1999) “Potential of marble dust to stablize red tropical soils for road construction,” Engineering Geology, 53, 371-380.

- Punith, V. S., and Veeraragavan, A., (2011) “Behavior of reclaimed polyethylene modified asphalt cement for paving purposes,” Journal of Materials in Civil Engineering, Vol.23(6), pp.833-845.

- Rao A. (2005). Experimental investigation on use of recycled aggregates in mortar and concrete. Master’s Thesis, Department of Civil Engineering, Indian Institute of Technology Kanpur.

- Rao, A., Jha, K.N., Misra, S. (2007). “Use of aggregates from recycled construction and demolition waste in concrete.” Resources, Conservation and Recycling, 50(1), 71-81.

- Sherwood, P. T. (1995). Alternative materials in road construction, Thomas Telford Publications, London.

- Shuler, T.S. (1976). The effects of bottom ash upon bituminous sand mixtures. Publication FHWA/IN/JHRP-76/11. Joint Highway Research Project, Indiana Department of Transportation and Purdue University, West Lafayette, Indiana.

- Su, N., and Chen, J.S., (2002). “Engineering properties of asphalt concrete made with recycled glass.” Resources, Conservation and Recycling, 35(4), 259-274.

- Sultan, H.A. (1979). “Stabilized copper mill tailings for highway construction.” Transportation Research Record, TRB, National Research Council, Washignton, D. C., 734, 1-7.

- Wen, H., Baugh, J., Edil, T., and Wang, J., (2011) “Cementitious high-carbon fly ash used to stabilize recycled pavement materials as base course.” Transportation Research Record, TRB, National Research Council, Washignton, D. C., 2204, 110–113.

- Yoon, S., Balunaini, U., Yildirim, I., Prezzi, M., and Siddiki, N., (2009) “Construction of an Embankment with a Fly and Bottom Ash Mixture: Field Performance Study,” Journal of Materials in Civil Engineering, Vol 21(6), pp. 271–278.

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