iop
1.What was the total cost in Ringgit Malaysia (RM) or USD of PLUS (Project Lebuhraya Utara Selatan Berhad) highway of length 772 km during its construction period.
North south interurban toll expressway: Johor Bahru to Bukit Kayu Hitam: 791.2 (772) km. cost: USD 2.6 billion —– or RM 6.6 billion (Straits times, world bank report on 30, 09, 1993)
2.Why PMS is needed for existing pavements?
In the past, pavement were maintained but not managed. The pavement engineer’s experience tended to dictate the selection of maintenance and rehabilitation (M&R) techniques with little regard given to life-cycle costing or to priority as compared to other pavement requirements in the network. In today’s economic environment, as the pavement infrastructure has aged, a more systematic approach to determining M & R needs and priorities is necessary. Pavement networks must now be managed, not simply maintained.
3.What are types of recycling and explain them in brief?
1.cold in place recycling of pavements with cement or emulsion or foamed bitumen (CIPR) >50mm
2.Hot in place recycling or hot plant mix recycling (HIPR) <50mm, thin and non structural: heading, scarifying, remixing and repaving. Compaction within 2/3 minutes, heating converts to 140ºc.
3.Hot mix asphalt recycling in plant, defined as the process in which all or some portion of the pavement structure is removed, reduced to desired size, mixed hot with additional asphalt cement at a central plant.
4.What are the detrimental effects of cracks?
i)Loss of water-proofing of the pavement layers.
ii)Loss of load spreading ability of the cracked material.
iii)Pumping and loss of fines from the base course.
iv)Loss of riding quality through loss of surfacing.
v)Loss of appearance.
5.What are the possible causes of cracks?
i)Depression.
ii)Fatigue life of the surfacing being exceeded.
iii)Age embrittlement of the surfacing.
iv)Reflection of cracks in underlying layers.
v)Shrinkage.
vi)Poor construction joints.
6.Draw a typical pavement section and show the location of fatigue and rutting?
7.Draw a tentative graph showing proctor values and explain MDD and OMC?
8.What is the major difference between California Bearing Ratio (CBR) and Plate Load Test?
CBR test assesses the strength of soil, whereas, plate load test is used to evaluate the support capability.
9.Draw a curve of pavement deterioration with age and show the trigger values in terms of pavement condition indices (PCI).
10.What are the principal causes of asphalt hardening?
Oxidation
Loss of volatiles
Physical hardening
Exudative hardening
11.What are the fields falls under restoration?
–Pothole patching
–Grooving/cold milling
–Crack sealing
–Application of pavement rejuvenating agent
–Slurry seal
–Thin hot mix overlay
–Surface dressing
–Resurfacing with gap graded mix
–Resurfacing with porous asphalt
12.What are the criteria used to address the structural and functional failures of flexible pavement?
Pavement is considered fail if it exhibit a rut depth 20mm
Pavement is considered fail if 20% of surface area has cracked
13.What is the pavement preservation?
Pavement preservation is the sum of all activities under taken to provide and maintain serviceable road ways, including preservation the investment, extending service life, enhancing performance, ensuring cost effectiveness and reducing user delays.
14.Show a prediction model of flexible pavement with a simple graph?
15.What are the elements in network level?
–It deals with the pavement network as a whole
–It’s related with high level decision, relating to network wide planning, policy and budget
–Mangers at this level might compare the benefits and cost for several alternatives
–They will also identify on greatest network benefit-cost ratio over the analysis period.
16.Write down the five most common type of flexible pavement distress.
Bleeding – Cracking – Rutting – Fatigue – Drainage Problem
17.Draw a graph to show projected condition of roadway with a treatment and without treatment?
18.What are the basic affecting factors for pavement, needed to address for all pavement design procedures?
–Classification of the road
–Traffic
–Available material
–Geometry
–Type of pavement
–Drainage
–Subgrade quality
–climate
19.What problems are needed to address during a project level evaluation, answer to the point?
–Distress
–Roughness
–Friction
–rutting
20.What is the rehabilitation processes involved for pavements?
–Restoration
–Structural resurfacing
–Full depth reconstruction
–Partial depth reconstruction
–Recycling
21.What are the major difference between California bearing ratio (CBR) and Resilient Modulus (Mr) of subgrade soil.
Whereas CBR test evaluates the potential strength of geometrical resilient modulus is a stiffness property obtained under repeated/cyclic load test. The determination of resilient modulus requires sophisticated equipment and skilled personnel for laboratory and field testing. Therefore, some agencies continue to use CBR to estimate resilient modulus for flexible pavement design.
22.What are the differences between maintenance works and rehabilitation works for flexible pavements?
–Maintenance: Pavement maintenance corrective (reactive) maintenance
–Rehabilitation: Major maintenance
23.What is the difference between preventive maintenance and corrective maintenance?
Preventive maintenance is a planned strategy of cost-effective treatments to an existing road way system but corrective maintenance activities are performed in response to the development of deficiencies that negatively input the safe, efficient operations of the facility and future integrity of the pavement section.
24.What is the main objective functions used in optimization model?
Optimization model is to find best function among other alternatives
25.What is the main use of cold mixture asphalt?
For patching pothole for small project or
Mainly pothole repairing
26.What are the main destructive factors for a flexible pavement?
–Penetration water in pavement layers
–Aging
–Hardening
–cracking
27.What are the factors used to priority rank projects?
–Pavement distress
–Ride or pavement roughness
–Traffic
–Economic factors
–Functional class
–Accidents
–Friction and skid resistance
–Geometric deficiencies
–Structural capacity
–Engineering judgment
–Age and location
28.What functional conditional conditions are used for network level consideration?
–Riding surface is smooth in the longitudinal and transverse direction (<IRI 6)
–Surface distress are within tolerable limits (<30% area)
–Riding surface process adequate skid – resistance properties
–Rutting is not excessive (12 – 15 mm)
29.What are the factors needed to consider in selecting rehabilitation methodology?
–Structural
–Surface distresses
–Drainage
–Materials
–traffic
30.What are the structural responses for a flexible pavement, and depends on which layer of pavement?
Pavement structural response depends on the support of the subgrade layer. Surface deflection is highly dependent on subgrade support.
31.What are the desirable properties of subgrade?
–Adequate shear strength
–Adequate permeability
–Ease and permanency of compaction
–Volume stability
32.What is the strength tests needed for subgrade evaluation?
CBR – resilient modulus – Dcp – plate load test – haveem – resistance value – triaxial test
33.Define structural number and how you determine the remaining life of flexible pavement?
SN=a1D1+a2D2+a3D3
Where: a1, a2, a3 are the layer thickness so structural number is a function of layer thickness layer coefficient and drainage coefficient.
34.Define the following terms in brief?
a.Permeability:
Is the degree to with these void spaces are interconnected
b.Porosity:
Is the amount of void space between the particles that makeup a soil or rock
c.Emulsified asphalt and cutback asphalt:
Emulsified asphalt and cutback asphalt use emulsifying agent and water or petroleum solvents, respectively, to liquefy the asphalt for use in roads or other construction projects.
35.What are the factors involved in drain ability of subgrade?
–Grain size
–Depth of water table
–Soil plasticity
–topography
36.Define resilient modulus and why resilient modulus is important in pavement design?
Resilient modulus (Mr) is the elastic modulus based on the recoverable strain under repeated load, and is defined as Mr=MR=sd/εr
Mr is used to determine stress, strain and deflection in pavement design as input parameter.
37.What are the different types of surface courses used in flexible pavement, in general?
·Hot Mix Asphalt (HMA)
·Highly Compacted Mixture (HMA)
·Cold asphalt (CMA)
·Porous asphalt
·Stone Mastic Asphalt (SMA)
·Fiber Mastic Asphalt (FMA)
·Novachip
38.What is the demarcation line in consideration of thickness in cold and hot in-place recycling?
CIPR>50mm
HIPR<50mm
39.What is the rut depth in consideration for selecting structural failure of flexible pavement?
20 mm
40.What are the stabilizing agents used for asphalt pavement recycling?
–Lime
–Cement
–emulsions