improvement and solution

8/11/2019 Improvement and Solution

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Solution And Improvement

FACTS IDEAS LEARNING ISSUES ACTION PLANS

- the roads that have

been built are often

damaged due to

vehicle load and

environment

-Single chip seal

- Reconstruction

-Double chip seal

-Stress absorbing

Membrane (SAM)

-Membrane Inter-layer

(SAMI)

-Private sector

involvement

- Technical Planning

and Supervision

-Technology Choice

-Types of chip seal

-Design of chip seal

-Aggregate for chip

seals

-Type of technology

using for upgrade rural

road

- Identified the cracks

- Propose Bill Of

Quantities to

InfraDesa or JKR

- Based on data

analysis, recommend a

design of chip seal to

repair the cracks


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Based on the destruction occurred at Jalan Parit Sempadan Laut,we conclude that the road need to

1) Reconstruction.

Reconstruction is the replacement of the entire existing pavement structure by the placement of the

equivalent or increased pavement structure. Reconstruction usually requires the complete removal and

replacement of the existing pavement structure. Reconstruction may utilize either new or recycled

materials incorporated into the materials used for the reconstruction of the complete pavement section.

Reconstruction is appropriate when a pavement has structurally failed and can no longer support the

traffic demand. Reconstruction increases the structural capacity of the pavement to a level that is

required for long term performance.

Figure 1 shows destructive road at Jalan Parit Sempadan Laut

Figure 1 shows the example of impact from road drainage structure failure in Jalan Parit

Sempadan Laut road. This problem has shortened the life span of rural roads. Normally maintenance

works are done by only resurfacing the pavement. However, this approach has not solved the

problems.The construction of the road at Jalan Parit Sempadan Laut began in 1952 and continued

through 1994. The original pavement was designed to serve for a 20- to 25-year period, and then

require an initial resurfacing. A 20-year design life is typical for pavement with an undrained base. On

average, based on historic construction data obtained from the Jabatan Kerja Raya Malaysia (Batu

Pahat), the original pavement lasted about 19 years prior to requiring a first resurfacing. Factorscontributing to the shorter than anticipated design life for the original pavement include greater than

anticipated traffic, at least, in part due to the lack of completion of the original pavement system;

greater than anticipated truck traffic volumes, weights, and axle loadings due the growth percentages of

rural area will increase every year which mean this area will continue to increase in population thus

affecting the role of the rural road


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Methods to Improve Effectiveness of Rural Road Drainage SystemGeotextiles:By using geotextiles, it can increase the soil shear strength by acting as a binding agent.Geotextiles also guard the slope from erosion by guiding the water flow in the structure as wellas water channel.

Figure 10 shows the use of geotextiles as material for slope stability (Abdul Rahim, 2005).

Combination of Geocontainers and Geotextiles:

Combination of geocontainers and geotextiles, as shown in Figure 11, will avoid soil movementthat caused by heavy load as well as to increase the soil shear strength. Geocontainers is madeby mixing sand and asphalt. In this method, the geotextiles will function as anchor togeocontainers to stabilize it. Sand will be filled underneath the geotextiles to avoid thegeocontainers settlement

Figure 11: Combination of Geocontainers and Geotextiles as Material for Slope Stability

Anchored in Soil Clay:

The easier method is to anchor the soil clay by excavating a hole to the suitable depth, put the

tendon and lay along the anchor by using tremi pipe. In order to increase the effectiveness ofthe anchor, gravel injection technique can be employed, after which a selongsang is fixed withsharp shoe is piled into the soil clay. After that, the tendon will be injected and laid into thegravel when selongsang or tube is taken

Figure 12: Anchored in Soil Clay

Soil Stabilization Using Lime:

This method is carried out by using burn lime, quick lime and hydrated lime. Hydrated lime isused because of availability and safe to use. Lime is a high alkali base that has chemistryreaction with clay soil. Calcium ion will displace cat-ion to make complex silicates or cementingmaterials


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3. Private Sector Involvement

The use of private contractors has proven to be equally successful for rural roadmaintenance as for any other works carried out in the construction industry. When designing thecontracting arrangements, it is however important to take note of the specific characteristics ofrural road maintenance, often consisting of small amounts of works dispersed over a large

geographical area. In addition, both routine and periodic maintenance of rural works in mostcases involve smaller contracts as compared with maintenance works on highways. This oftenhas the result that large contracting firms are not interested in getting involved in works on ruralroads or at best, prefer to sub-contract such works to smaller firms. This certainly applies toroutine maintenance, which involves very limited equipmentand material inputs.

For these reasons, it is important that rural road maintenance works is targeted towardsthe appropriate part of the private construction industry. With the works packaged intoappropriate size contracts, experience has shown that maintenance of rural roads can provideattractive work prospects to the local construction industry.Periodic maintenance works can beorganized into civil works contracts which in size and type of works match the capacity and

interest of small and medium size contracting firms based in the provinces not far from wherethe works are located.

Equally, routine maintenance can be organized through contracts with local communitygroups or petty contractors.Organizing the maintenance works through the involvement of theprivate sector does however require a sound local government capacity in planning andsupervision of works and contracts management. Besides allocating adequate budgets for thispurpose, the local authority in charge of providing and maintaining these roads need to beequipped with the technical and managerial skills and adequate procedures to perform theseduties in an efficient and transparent manner.


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4. Technical Planning and Supervision

Like any other civil works programme, the efficient implementation of rural roadmaintenance works, requires a sound technical organisation equipped with the necessarymanagerial and technical skills and resources. The performance of the road assets needs to becarefully monitored to ensure that they function as originally intended. When failures occur there

needs to be established procedures andresources available allowing for timely remedial action. This will ensure that access is restoredminimising the inconvenience caused to the users of the infrastructure.

All maintenance works require careful planning, supervision and control. Propermonitoring of outputs and the resources required to achieve these outputs provide the basicinformation for planning and estimating future maintenance works. However, before theseplanning and implementation activities can commence there is a need for proper and regularroad condition inspection and defects assessments, which form the basis for all consecutiveengineering inputs. The authority in charge therefore needs to be equipped with adequatemanagement tools, including:

1) Means and procedures for establishing and maintaining a road inventory,providingdetailed information about the road assets

2) Established procedures for and logistical means to carry out regular inspection of thenetwork

3) Road standards to provide guidance on how and when maintenance works should becarried out including procedures on how priorities are set for selection of wheremaintenance should first be carried out

4) Programming and budgeting procedures for the preparation of master plans,periodicplans and annual plans

5) Works implementation procedures: guidelines on choice of technology, use of the privatesector and contracting arrangements

6) Skilled staff to carry out planning and works supervision

7) Logistical means to oversee the performance of the network and inspection of works8) Financial and administrative support services to ensure effective budgetary

and expenditure control.


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5. Technology Choice

Rural road maintenance offers considerable scope for increasing efficiency by adoptingwork methods and approaches relying to a large extent on locally available resources. This notonly includes the introduction of labour-based works technology but also by involving localconstruction firms in works implementation.

A heavy reliance on the use of large and sophisticated equipment requires high initialcapital investments and in the case of rural road maintenance is not necessary.The use ofheavy equipment increases the complexity of work operations with the result that work progressbecomes more reliant on the steady supply of spare parts and repair services. Equipment alsorequires skilled operators, skilledmechanics and proper workshop facilities. If any of these items are not available,the equipmentstands idle and road maintenance is not carried out. It is not uncommon that work progress isdisrupted due to lack of simple spare parts or repair services. Moreover, due to the high initialinvestments, small-scale local contractors are barred from carrying out works contracts whichcould be possible for them to manage if alternative work methods are allowed for. Despite this,work specifications in a number of developing countries still prescribe the use of heavy

equipment for rural road maintenance.

By contrast, labour is practically always readily available and can be employed at a lowcost. Labour-based techniques are very well suited to a wide range of maintenance activities,particularly when the work force is properly managed, relying on an output-based paymentsystem. However, labour-based approaches demand proper planning and skilled supervision.Often, a combined use of labour and machines provide the most appropriate solution. Certainmaintenance tasks can be carried out more effectively using machines, while others are bestcarried out relying on manual labour. The mostappropriate technology depends on the nature of the work and the availability of labour andequipment in the area. The table below shows which activities are best suited for labour andwhich require some use of equipment.

The choice between equipment and labour-based work methods affects the basicorganisation of the road maintenance work. Relying to a high degree on the use of equipmentwill entail the involvement of larger contractors, whereas labour-based work methods favourmore decentralised solutions.In order to select the optimal approach, certain information needsto be collected and analysed. Road data relating to issues such as the function and condition ofindividual road links, traffic levels and available resources in terms of funds, labour, machinesand materials need to be clarified. This includes data on staff skills and training requirements,availability and performance of equipment, labour productivities and the effect of criticalresource requirements on general performance.In most cases, the choice between labour andmachines is not an either/or situation

It is possible to find cost-effective solutions combining the two approaches.Moreover,past experience has shown that an innovative use of intermediate equipment can be cost-effective for excavation, compaction and hauling, provided that locally available skills andmaterials are drawn upon in an imaginative way.Road maintenance is a continuous process andits employment generation potentialshould not be under-estimated. These employment opportunities, whether they are temporary oron a continuous basis may provide a significant cash injection into rural communities wheresubsistence farming constitute the mainstay of the economy.


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6. Chip Seal Design

Unquestionably, all of the design methods can effectively guide inexperienced personnel throughthe process of chip seal design. The following best practices can be drawn from a comparison of the chipseal design methodologies. To begin, the selection of the binder is a very important decision and should

be made after considering all the factors under which the chip seal is expected to perform. After all, the

primary purpose of a chip seal is to prevent water intrusion into the underlying pavement structure, andthe asphalt layer formed by the binder is the mechanism that performs this vital function.

The previously explained design methods are all based on the assumption that single-course chipseal design required the use of uniformly manner. The application rates of all methods appear to be basedon residual binder and each method has a procedure for dealing with adjustments owing to factoring the

loss of binder to absorption by the underlying pavement surface and the aggregate being used.Contemporary design practices need to determine binder application rated based on surface

characterization absorption factors, traffic condition, climate consideration, aggregate selection, and thetype of chip seal being constructed. Another important discovery is that all methods have a design

objective for embedment to be between 50% and 70% of that seals depth.

Best practices for chip seal design are difficult to isolate, because there appears to be such a largevariation in practices from agency to agency. However, the following can be identified as meeting this

projects definition for best practices:

Chip seal perform best only on roads with low underlying surface distress that will benefit from thistechnology.

The international practice is to characterize the underlying roads texture and surface hardness and

use that as a basis for developing the subsequent formal chip seal design. Where the local councilresponses indicated a routine use of qualitative characterization in the design process. Thus, the nextlogical enhancement would be to incorporate international methods to quantitatively characterize the

underlying surface in the chip seal design process.

One of those enhancements would be to try using the racked-in seal as the corrective measure forbleeding instead of spreading fine aggregate and sand on the bleeding surface


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CONCLUSION

The conclusion in this area is quite evident. First, the selection of chip seal materials is

project dependent, and the engineer in charge of design must fully understand not only the pavementand traffic conditions in which the chip seal will operate but also the climatic condition under whichthe chip seal will be applied. It appears that the widespread use of emulsion binder chip seal results

from the nation that emulsion are less sensitive to environmental conditions during construction.Additionally, as emulsions are installed at a lower binder temperature they are probably less

hazardous to the construction crew. Binder performance can be improved through the use ofmodifiers such as polymers and crumb rubber.

Next, the selection of the binder is dependent on the type of aggregate that is economicallyavailable for the chip seal project. In other way, we could to bear additional aggregate costs to ensure

the quality of their chip seals are something that should be seriously considered in this area.The aggregate should be checked to ensure that electrostatic compatibility is met with the type ofbinder specified. Also pre-coating of the aggregate appears to be required for use with hot asphaltcement binders to ensure good adhesion after application. Finally, it appears that the use of

geotextile-reinforced chip seal is promising and should be considered for those roads that have morethan normal surface distress and for which an overlay is not warranted. Therefore, several nextpractices can be extracted from the foregoing discussion:

Conduct electrostatic testing of chip seal aggregate source before chip design to ensure that thebinder selected for the project is compatible with the potential sources of aggregate.

Specify a uniformly graded high-quality aggregate.

Consider using lightweight synthetic aggregate in areas where post-construction vehicle damageis a major concern.

Use life-cycle cost analysis to determine the benefit of importing either synthetic aggregate orhigh-quality natural aggregate to areas where availability of high-quality aggregate is limited.

Use polymer-modified binders to enhance chip seal performance


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