grouted macadam bsuccessful technology for rehabilitationn of bituminous roads

Grouted Macadam: Successful Technology for rehabilitation of bituminous roads

V.V. Deshmukh,

Abstract

Despite the well-known disadvantages of bituminous roads it continues to be the most widely used option. In this research paper the challenge of building the most vital infrastructure of India has been addressed by ACC-RCD through the development of a technology called Grouted Macadam which meets the requirements (economic, technical and life cycle cost) better than the bituminous option. The Grouted Macadam is a composite which combines the flexibility of bituminous material with performance benefits of cementitious material. The high strength cement based grout is poured in the voids of coated aggregate layer or a high performance flexible concrete mix is prepared and laid as a pavement course.

Some of the important properties like Abrasion resistance, Marshall stability , Air voidage, Stiffness modulus and resistance to fuel spills were studied and compared with conventional bituminous pavement. It is observed that Grouted Macadam has higher stiffness modulus, lower temperature sensitivity, improved fatigue performance. These properties are used to custom design pavement structures that are comparable or better than conventional bituminous pavement.

The use of Grouted Macadam as a wearing course material in a flexible pavement construction has resulted in extended life compared to construction incorporating conventional bituminous materials. It has been extensively field tried and has gained wide market acceptance among several public/private sector organizations.

The Grouted Macadam technology offers a novel cost effective alternative in the field of road making and has the potential to significantly contribute to the country’s infrastructural needs

1 INTRODUCTION

India has a total road network of 3.35 million KMs and only about 65000KMs (2%) are the national highways which carry 40% of the traffic. Only about 2% of the total net work of roads are built with concrete as materials, the balance 98% are a combination of natural materials and bitumen.

The bituminous roads have well known disadvantages. The damage is mainly due to rutting, permanent shear strain and stiffening on account of aging. The rutting is the load-induced permanent deformation of a flexible pavement. Depending on the magnitude of the load and the relative strength of the pavement layers, permanent deformation can occur in the subgrade, the base, or the upper bituminous asphalt layers. Vulnerability of pavement layers to rutting varies at different times of the year. For example, rutting of bituminous asphalt layers is more common during summer and permanent deformation is more likely in sub-base during monsoon. The second important factor is the stress level in an individual pavement layer, which is a function of total pavement thickness and magnitude of the load. For example, application of a heavy load on a thin pavement over unstabilized sub-grade may induce excessive rutting in both the bituminous asphalt layer and the sub-grade.

An asphalt pavement that is subjected to repeated simple shear permanently deforms over time. This permanent deformation of pavement increase as the temperature of the pavement is increased. The effect is similar to what may occur at bus stops, where vehicles apply shear when they brake and shove the pavement.

Even in the absence of traffic, asphalt binder deteriorates. The stiffening of asphalt is seen to increase when the asphalt is merely exposed in a sunny, hot climate..

This research paper will illustrate how this challenge of building the most vital infrastructure of India has been addressed by the author working at ACC-RCD through the development of the technology called "Grouted Macadam" which uses high performance pavement concrete (HPPC) and meets the requirements (economy, technical and life cycle cost) better than the bituminous options.

"Grouted Macadam " consists of polymer coated aggregates with 25-30% voids in which is poured a cementitious grout. The grout is of improved cementitious binder which allows greater penetration of the void structure of polymer coated aggregate (PCA) and hence greater achievement of the theoretical packing density. The resulting material is typically used as a wearing course between 25mm and 75mm in thickness.

This type of grouted material offers the following benefits over a conventional bituminous material.

« High resistant to permanent deformation

« Fuel spill resistance

« Lower temperature susceptibility

« Higher Stiffness modulus.

1.1 Grouted Macadam Technology

« Grouted Macadam consists of an open graded coated aggregates with voids completely filled up with a special cement based grout. The grout is a dry, ready mixed which, when mixed with water, is a very light fluid material with high properties of penetration and internal cohesion.

« Grouted Macadam is laid jointless. The special coated aggregates provide the flexibility and the grout, with its characteristic dense micro structure, high wear resistance and high durability in aggressive environments.

STEP-1 STEP-3

The following methodology is used to lay grouted macadam in Bombay Municipal Corporation

The construction procedure is developed based on extensive research and data of field experience.

Grouted macadam: Methodology for application as flexible wearing course

Specifications

Wearing course for pavements

Scope of Work

The work shall consist of the general requirements for mixing and placing of coated aggregate filled with a grout. It includes the requirements for aggregate, binder, mixing at asphalt plant/ mixer, surface preparation, spreading and compacting of mix, mixing and pouring of grout

The composite shall consist entirely of aggregate coated with hot bitumen.. The voids in the finished mixture must comprise between 25 and 30 % of the total volume. The wearing course shall be laid in a thickness of 25 mm constructed of porous coated aggregates and filled with grout .

1. Coated Aggregate mixture: The mixture shall be as given in Table 1.

Table 1: Coated aggregate mix proportion

Material	Proportion
Bituminous material	3.8-4.0%
Aggregate	96-96.2 %

1. 1. Mix design shall conform with the requirement and the aggregates shall have a maximum size of 15 mm... After laying and rolling the Air Voids shall be in the range of 25-30%

2. Materials

2.1 Aggregate

The aggregates shall be chosen from basalt, granite, grit stone etc. The nominal size of the aggregates shall be as per requirement and in keeping

with the thickness of the pavement. The aggregates shall have a maximum size of 15 mm and minimum of 5mm. The property specs is attached.

Bituminous Material and Tack Coat

The bitumen shall be bitumen of 60/70 grade as per penetration test.

. The bitumen content in emulsion is measured as per IS 8887-1995.

2.2 Grouted macadam Grout:

The grout shall be made using Grouted macadam dry powder.It is cement based with mineral and chemical additives. The wet mixed grout shall be made at site in a mixer. The grout property specs is attached

3. Equipment

3.1 Mixing Plant

Aggregate coating shall be produced in a Hot Mix Asphalt mixing plant/ Mixer

3.2 Mix Transportation

Mixed bitumen coated aggregates from hot mix plant shall be transported to the site in tipper trucks constructed so as to prevent loss or undue segregation of materials after loading.

3.3 Rollers

Only steel-wheel rollers of 8-10 ton, max without vibration shall be used. Use of pneumatic rollers and vibratory rollers is prohibited.

3.4 Mixing and pouring of grout

The Grouted macadam grout shall be mixed in a mixer at brought to the site in wheel barrow/suitable equipments and laid.

4. Surface Preparation

The surface of the existing black top road shall be cleaned of all foreign material and broomed free of dust and all pot holes are repaired.

The tack coat of bitumen emulsion shall be applied at a rate of 0.5 kg/m2 as indicated in the specification.. The Tack Coat shall be evenly applied to the surface. The specs is attached

5. Mixing, Spreading and finishing

Mixing, spreading and finishing shall be a continuos operation. During the tack coating and the paving work only road roller necessary for the execution of the paving work shall be allowed on the coated aggregate course.

6. Installation of Grouted macadam grout

No traffic on the laid porous coated aggregate should be allowed before application of the grout. The porous aggregate course shall be free of any loose particles or other contaminants.

Mixing and pouring shall be a continuous operation. Not more than 3 hour shall elapse between water addition and the time of completion of grout laying.

Grouted macadam Composite

Property parameter	Method of test	Value
Compressive Strength(28days),Mpa on 4" core of composite	IS-516	4
Abrasion resistance in mm	IS-1237	4

Grouted macadam Grout

Property parameter	Method of test	Value
Density, kg/m3	IS 1528 -XII	1700-2000
Compressive strength, MPa, (3 days)	IS 516	15-20
Compressive strength,MPa, (28 days)	IS 516	50

The above does not constitute the specification of Grouted macadam. Depending on the project requirement, project specific specifications are drawn.

Specification for aggregate, bitumen content for coating and the grade of bitumen are given below:

In case of aggregate, the following is the sieve analysis

\

Sr.No.	IS sieve designation	% weight passing **
1	15-10 mm	80-100
2	10-5mm	0-20
3	0-5 mm	0-5

**The tolerance shall be +/- 5% by weight

Aggregate specification

Property parameter	Method of test	Value
Flakiness and elongation index	IS 2386	Max 30%
Aggregate Impact value	IS 2386(Part-4)	Max 30%
Los Angeles Abrasion value	IS 2386(Part-4)	Max 30%
Water absorption	IS 2386(Part-3)	Max 2%

Binder specification

Property parameter	Method of test	Value
Bitumen content in emulsion	IS-8887,1995	65%
Bitumen content in BM	IS-8887 1995	3.8-4.0%
Bitumen Grade	IS -1203-1978	60-70

Details of the jobs conducted at BMC and SMC are given below. The technology used is grouted macadam developed by the author in ACC-RCD.

ACCMARG JOBS	Month	Year	THK	AREA	REMARKS	Amount Rs.
Belapur rd/Out of Thn/BB			mm	Sq. meter
Panvel creek bridge	Sept.	2000	75	3390	5 No.Potholes repaired	528
Tolani Bridge	Nov.	2000	50	1019	O.K.	Nil
Mukund road	Dec./Jan.	2001	40	3652	Railway Bridge Work	Nil
Shapoorji-Lonawala	Dec./Jan.	2001	40	634	O.K.	Nil
MSRDC(Kon/Kalamboli)	Aug.	2001	40	9500	Gadhi river Bridge
Shirwane Road	Oct.	2001	40	4474	O.K.	Nil
L & T-Lonawala	Dec./Mar.	2002	30	65000	18.Nos.Potholes repaired	13520
Khambatki-Satara	May/Jun.	2002	40	6181	O.K.	Nil
MUMBAI-JOBS
HMP School-Andheri	Nov.	2000	40	4646	O.K.	Nil
Malad Subway	Jan.	2001	50	821	200 sqmt damaged	97884
US Club	Jan.	2001	40	1878	O.K.	Nil
LSN Ward	Mar./Sept.	2001	40	6018	O.K.	Nil
Sion Circle	Mar./Apr.	2001	50	5815	O.K.	Nil
S Ward	Apr.	2001	40	1327	13.Nos Potholes repaired	2636
Sion Station	Jun.	2001	25	711	25.Sqmt damage	6966
NM Joshi Marg	Sept.	2001	50	5812	5.Nos.potholes repaired	1200
Karani Road	Sept.	2001	40	2000	BMC replaced C. C.Road	Nil
Dadar Flyover	Oct.	2001	40	3003	2 No. potholes repaired	450
BPCL	Nov.	2001	50	2791	1 No.Pothole repaired	500
Mulund Container Yard	May	2002	35	3885	O.K.	Nil
NMMRDA	May/Apr.	2002/2003	40	6500	O.K.	Nil
Andheri Flyover	Aug.	2002	40	1793	Side edges Damaged	2700
Dahisar	Sept.	2002	40	1211	O.K.	Nil
Goregoan	Sept.	2002	40	1925	3 No. poteholes repaired	252
Borivali	Sept./Mar	2002/2003	40	1897	5 Nos.Potholes repaired	486
Tata Power	Oct./Nov.	2002	30	821	Polishing of laid ACCMarg	24000
Andheri Flyover-(E)		2003	40	1738	O.K.	Nil
M M R D A	Apr/MAY	2003	40	12035	O K.	Nil
Andheri Sub way	Feb /Mar	2003	40	3500	O.K.
Borivali	Mar/June	2003	40	6800	2 Nos.potholes repaired	225
Lonawala	Jan.	2003	40	7000	O.K.	Nil
OUT SIDE JOBS
Surat Ring road	Nov/ May	2002/03	30	92000	500sqmt repaired	85500
Tikariya Guriganj	Mar/ Jun	2003	40	11200	O.K.	Nil
Kyamur	Nov/ Jan	2002/03	40	25000	Some potholes repaired	5000
			Total	305977	Sqmt	241847

This development is reported as research paper in NCCBM international seminar .The paper has received best paper award. The Copy has been attached here with. The product properties are studied by CRRI.The report is given below

2) LABORATORY TESTING OF Grouted Macadam

The performance evaluation of Grouted Macadam overlaid road sections was certified by the Central Road Research Institute (CRRI),New Delhi.. The team of CRRI scientist visited the Grouted Macadam site in Mumbai on Aug.2002.. The periodic observations included are the evaluated performance for skid resistance measurements using British Portable Skid Resistance Tester, surface texture depth measurements and extraction of pavement cores for determination of abrasion resistance, effect of water , petroleum products and temperature on Grouted Macadam.

2.1) THE SKID RESISTANCE MEASUREMENTS

Skid resistance measurements were under taken on the representative locations under dry and wet conditions of the pavement. Skid resistance values as obtained have been given in Table 1

Table 1

Location	Skid Resistance Values				Minimum Skid Resistance Requirements	Remarks
	Dry condition		Wet condition
	*Average	Range	*Average	Range
Inner lane	92	85 - 97	53	52 - 57	55	Good surface condition with coarse surface texture
Central lane	92	86 - 96	59	55 - 64	55	Good surface condition with medium to coarse surface texture
Outer lane	91	87 - 95	55	55 - 56	55	Good surface condition with medium to coarse surface texture

*Average based on ten observations.

2.2) TEXTURE DEPTH MEASUREMENTS.

Texture depth measurements were also made at representative locations where skid resistance was measured. The standard sand of known density was used .A known volume of fine sand of uniform particle size is poured on the road surface and the sand is spread until all the cavities are filled. The mean texture depth of the surface is calculated and the results are given in Table 2.

Table 2

Lane	Mean Texture Depth (mm)		Surface Texture Classification			Remarks
	Range	Average	Coarse texture	Medium Texture	Fine Texture
Inner lane	0.37- 0.77	0.57	³0.50mm	0.50-.25mm	< 0.25 mm	Good surface condition with medium to coarse surface texture
Central lane	0.80- 1.50	1.15	³0.50 mm	0.50-.25mm	< 0.25 mm	Good surface condition with coarse surface texture
Outer lane	0.60- 0.92	0.74	³0.50 mm	0.50-.26mm	< 0.25 mm	Good surface condition with coarse surface texture

2.3) TRAFFIC VOLUME COUNTS

The daily traffic flow was assessed based on 24 hours volume count. Cars, buses, trucks, light goods and other commercial vehicles were recorded during the survey. Shown in Table 3

Table 3

24 Hours Traffic Volume Count at Sion Circle
Vehicle Type	Number of vehicles
Cars ( C )	50329
Buses ( B )	9566
Trucks ( T )	6271
*Other Goods Vehicles	5939

* Includes Tractors/Tractor trolleys etc.

2.4) ABRASION RESISTANCE

The cylindrical cores of 100mm diameter and 20-50 mm height were cut from representative locations. Core cutting was done using electrically operated (220v,1.8KW )BOSCH portable core cutting machine. These core samples were tested for abrasion as per IS 9284-1979.The abrasion test results of Grouted Macadam sample are given in table-4.

Table 4

Abrasion test results of Grouted Macadam sample
Sr. No.	Sample No.	Percent loss in weight	Tentative Suggested Maximum Value of Abrasion Loss(%)
1	11	0.25	(I) concrete pavement
2	13	0.21	(a)With mixed traffic including iron tyred traffic	= 0.16
3	14	0.21	( b) With pneumatic tyred traffic	= 0.24
4	15	0.29	(ii) Factory floors	= 0.16
Average		0.24	(iii) Dockyard	= 0.16
			(iv) Railway Platform	= 0.24
			(v) Foot- path	= 0.40

2.5) EVALUATION OF Grouted Macadam VIS-VIS DESIGNED BITUMINOUS MATERIAL.

Bituminous mixes used as surface courses of flexible pavement are visco-elastic materials and their properties are dependent upon stress, strain and temperatures. The induced strain in a bituminous material is attributable to viscous flow and increases with loading time and temperature. The other vital issue associated with failure of bituminous surfacing is loss of adhesion between binder and aggregate under the influence of water and also due to spillage of petroleum fuel from vehicles. The bituminous mixes have to fulfill a wide range of requirements to sustain traffic and environmental stresses. These are the resistance to permanent deformation and fatigue cracking, impermeable to protect lower layers of road from water, durable to resist abrasion of traffic and effects of temperature., water and oil spillage and contribute to pavement strength. It is important to study effect of water, temperature and oil on a material while comparing a new material like Grouted Macadam for its performance vis-vis bituminous material. The properties of Grouted Macadam vis-vis Bituminous concrete (BC) using 60/70 grade bitumen used for aggregate coating are given in Table 5

Table 5

Properties of Grouted Macadam vis-a-vis Bituminous Concrete using 60 / 70 grade bitumen
Properties		Values of BC using Bitumen 60 / 70	Grouted Macadam	Limits MORT & IRC specification
Bulk density, gm/cc		2.34	2.32-2.35
Marshall Stability , at 600C, kg, (ASTM D 1559)		940	2270	820 (min)
Marshall flow at 600C, mm, (ASTM D 1559)		3.2	4.2	2.0 - 4.0
Percent Air voids		4.2		3.0 - 6.0
Indirect tensile strength at 250C , kg /cm2		5.7	13.8	ASTM D 4123
Stiffness Modulus at different temperatures, kg/cm2 Poissons Ratio (m) = 0.35for bituminous materials and 0.25 for Grouted Macadam (ASTM D 4123)	150C	50920	184620	IRC - 37 - 2001 indicated value of elastic modulus of BC mix as 31260 kg / cm2 for 60/70 and 19660 kg/cm2 for 80/100 bitumen at 25oC
	250C	24990	100390
	350C	10640	79650
	450C	1920	54530
Reduction in stiffness modulus values , %, (150C - 450C )		96	71	Not specified
Retained stability at 600C immersion in water at 600C for 24 hours , % , ( ASTM D 1075)		80	93	75 (min)
Retained indirect tensile strength at 250C immersion in water at 600C for 24 hours , %, (ASTM D 4867)		85	95	80 ( min )
Loss of material in diesel oil , 7 days immersion , %		4.2	0.3	Not specified

3) PAVEMENT DESIGN CALCULATION

Having quantified the important mechanical properties of Grouted Macadam in the laboratory an analytical design approach is used to develop guidelines for the use of Grouted Macadam in certain situation. Analysis of the pavement structure performed using layered linear elastic model and design calculation are involved using a conventional bituminous asphalt wearing course material and Grouted Macadam as an alternative surface layer material.

3.1) High performance pavement concrete in the design of flexible pavements (Bituminous Roads)

The Indian Road Congress vide IRC:37-2001 lays down the following guidelines for design of flexible pavements

3.1.1) Critical locations, Relationship between number of cumulative standard axles strain values and elastic modulus of materials.

Critical locations in pavement

A and B are the critical locations for tensile strains (e₁). Maximum value of the strain is adopted for design. C is the critical location for the vertical subgrade strain (e₂) since the maximum value of the e₂ occurs mostly at C.

Fatigue criteria

Bituminous surfacing of pavements display flexural fatigue cracking if the tensile strain at the bottom of the bituminous layer is beyond certain limit. Based on the performance data of pavements of south, north, east and west zones in India collected under the research schemes of Ministry of Surface Transport Govt .of India, the relation between the fatigue life of the pavement and the tensile strain in the bottom of the bituminous layer was obtained as

N_F =221*10^-4(1/e₁) ^3.89 (1/E) ^0.854

N_F =Number of cumulative standard axles to produce 20% cracked surface area.

e₁=Tensile strain at the bottom of BC layer (micro strain)

E =Elastic modulus of bituminous surfacing(Mpa)

The values of the elastic moduli of Bituminous concrete/Dense Bituminous Macadam and Bituminous Macadam meeting the specifications of the MOST are given below.

ELASTIC MODULUS (Mpa) VALUES OF BITUMINOUS MATERIALS

Mix Type	Elastic Modulus(at 35 0 C)
BC and DBM80/100 bitumen	975
BC and DBM 60/70 bitumen	1695
BC and DBM 30/40 bitumen (75 blow compaction and 4% air void)	2944
BM 80/100 bitumen	500
BM 60/70 bitumen	700

The poisson's ratio of bituminous layer may be taken as 0.50

Rutting Criteria

As large number of data for rutting failure of pavements were obtained from the research scheme of the Ministry of Road Transport and Highways and other research investigations setting and allowable rut depth as 20mm the rutting equation was obtained as

N_R =4.1656*10^-8{1/e₂} ^4.5337

N_R =Number of cumulative standard axles to produce rutting of 20 mm

e₂= Vertical subgrade strain (micro strain)

Modulus of Elasticity of subgrade, sub-base and Base layers

Subgrade

E(Mpa)= 10*CBR for CBR £5 and

= 176*(CBR) ^0.64 for CBR ³5

Granular sub-base and Base

E2=E3*0.2*h ^0.45

E2=Composite elastic modulus of granular sub base and base (Mpa)

E3=Elastic modulus of subgrade (Mpa)

h= Thickness of granular layers (mm)

Poisson's ratio for both the granular layer as well as subgrade layer may be taken as 0.4

Substitution of Dense Bituminous Macadam (DBM)

Part of the DBM can be substituted for BM on the basis of equal flexural stiffness given as

E₁H₁³/12(1-m₁²)= E₂H₂³/12(1- m₁²)

Where

E₁ H₁ m₁ and E₂ H₂ m₂ are the parameters (Elastic modulus, Thickness and Poisson's ratio) of the DBM and BM respectively. Based on the above equation following equivalent thickness may be used

Example

180mmDBM=125MMDBM+75mm BM

240 mm DBM=185mmDBM+75mm BM

240 mm of BM=75*(700/1695)^1/3 = 55.85 mm of DBM

The equation of substitution of two different materials of Elastic modulus E1 and E2 assuming similar poisson's ratios for the two is

E₁H₁³=E₂H₂³

Which reduces to H₂=(E₁/E₂)^1/3*H₁

This implies that if a material with 8 times the elasticity of bituminous material is used then the thickness of the pavement layer for same design life could be halved. Similarly if the material has 30 times the elasticity the thickness could be one third and so on

This paper reports the development of such a material whose total cost inclusive of mixing and placing is competitive to the cost of laying bituminous macadam. Presently this technology is being used in several states of India including Maharashtra, Goa, Gujrath and Jharkhand .for wearing course, strengthening of existing road and building new road. Organizations like MSRDC, MIDC,MMRDA, CIDCO,BMC are regularly using Grouted Macadam.

The trial stretches of road have been in regular use for high density commercial vehicle traffic for several years and the benefits are quantifiable. The high performance ,low life cycle cost concrete pavement technology has the potential to contribute significantly to development of the infrastructure in our country.

The pavement with Grouted Macadam it's cost and life is compared with existing methods of pavement making. The details are given in figure below.

4) Few illustative pictures of Indian road before and after overlaying with Grouted Macadam

	A bridge deck of Mumbai-Pune Expressway after overlaying with Grouted Macadam

Typical road with potholes

Sion Circle -Mumbai after laying with Grouted Macadam

5) Discussion

The results show that using Grouted Macadam as a surfacing material can result in a saving in bituminous roadbase material .The reason is the higher stiffness modulus of Grouted Macadam compared to conventional hot rolled asphalt wearing course material. This additional stiffness helps distribute the loading applied by traffic better and as a result the expected pavement life is increased. The Grouted Macadam also showed lower temperature susceptibility compared to hot rolled asphalt.

The resistance to permanent deformation of the Grouted Macadam is high compared to a conventional hot rolled asphalt wearing course material. Consequently ,the Grouted Macadam can be used in highly stressed locations where traditional bituminous materials could rut under traffic loading. However, not all pavement rutting is confined to the wearing course. If Grouted Macadam is placed over granular or bituminous material with low deformation resistance the pavement could rut ,leading to cracking of Grouted Macadam due to loss of support.

6) Conclusion

· The Grouted Macadam pavement surface property of skid resistance and surface texture depth measured at site indicate the average skid resistance is adequate and mean texture depth data indicates the surface texture is coarse.

· The abrasion resistant of Grouted Macadam pavement surface is comparable to concrete pavement with pneumatic tyred traffic.

· The Marshall stability of cores of Grouted Macadam is 2.5 times higher than the stability of bituminous mixes used for surfacing of flexible pavement.

· Higher values of stiffness modulus indicate improved resistance to deformation for Grouted Macadam as compared to designed bituminous mix.

· Stiffness modulus values at different temperature indicate better resistance to temperature variation in case of Grouted Macadam compared to bituminous mix.

· Retained stability after immersion in water is 93 % for Grouted Macadam as compared to 80% in case of bituminous mix shows better resistant to damage by water.

· The negligible loss of material from core specimen of Grouted Macadam in diesel oil indicate resistance of Grouted Macadam against damage due to spillage of petroleum products.

· Design calculations have been performed using Grouted Macadam as a wearing course material in a flexible pavement construction.

· Grouted Macadam displays a type of performance between that of concrete and conventional bituminous materials.

7) References

1. Road Research Road Note No.27"Instruction for using British Portable Skid Resistance Tester" Department of Scientific and Industrial Research, RRL HMSO London,Year 1960

2. NCHRP Report No.37"Tentative skid resistance requirements for main rural highways, HRB" Year 1967.

3. Method of Test of Abrasion resistance of concrete as per IS 9284-1979

4. ASTM D 4867

5. ASTM D 1075 and ASTM D3637

6. ASTM D 4123 and ASTM D 1559

7. Assessment of LTPP friction Data, US Department of transportation ,FHWA March 1999

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