What Is Wet Mix Macadam In Road Construction?

What Is Wet Mix Macadam In Road Construction
Wet Mix Macadam consist of laying spreading and compacting of clean, crushed, well-graded granular materials on a prepared and approved Granular sub-Base. The material is well mixed with water and rolled to a dense mass. It shall be laid on one or more layers as per line and level, grade and cross section shown in the drawing or as directed by the Engineer.

The thickness of single compacted Wet Mixed Macadam (WMM) Base shall not be less than 75 mm. Maximum thickness of single compacted layer base can be up to 250 mm upon approval of Engineer.1. Reference 2. Setting Out.3. Selection of Material.4. Equipments.5. Methods of Operation.6. Quality Control.7. Work Safety.8.

Environmental Safety.1.0 Reference Reference Documents:- I) Ministry of Road Transport& Highways Specifications II) Technical Specifications III) Relevant Drawings. IV) IS 2720 Codes.2.0 Setting Out After the layer of GSB Sub-Base has been approved, then line and level are carried out to fix the Wet Mix Macadam base layer (herein after called WMM Base).

  • Pegs are fixed at regular intervals on the safe side of the road edge where blade of grader should not disturb the peg while blending of the Base materials.
  • On each peg’s top level of Base layer is marked.
  • The chainage boards and working bench mark shall be set out side the limits of construction areas.3.0 Selection of Material 3.1 Aggregate Coarse aggregate shall be crushed stone or crusher run as per IRC 109 or clause 406.2.1 of MORT&H specification.3.2 Physical requirement The constituents of the aggregates shall be produced by integrated crushing and screening plant (Impact or Cone type) and, unless otherwise instructed by the Engineer, crushing shall be carried out in at least two stages.

The fraction of material passing through 4.75mm sieve shall also be crusher run screening only. The aggregate shall conform to the physical requirements set forth in Table 400-12 of MORT&H. or IRC 109 clause 3.1.1 If the water absorption value test of coarse aggregate is greater than 2 per cent, the soundness test shall be carried out on the materials delivered to site.3.3 Grading Requirement The aggregate shall conform to the grading given in table 406.2.1.2 of technical specification or IRC 109 -2015.

  1. Material finer than 425 micron, shall have Plasticity Index (PI) less than 6.
  2. The final gradation approved within these limits shall be well graded from coarse to fine and shall not vary from low limit on one sieve to high limit of adjacent sieve or vice versa.4.0 Equipments The following equipments shall be carried out for the WMM 1.

Wet Mix Macadam Plant 2. Dumper / Tippers.3. Vibro Roller (80 to 100 KN) 4. Water Tanker 5. Paver capable of paving more than 9 meter width.6. Survey kit / instrument 5.0 Method of Operation 5.1 Preparation of WMM Base (As per clause 406.3.1): 5.1.a Provision of lateral confinement of aggregates Proper arrangement shall be made for the lateral confinement of wet mix during laying.

This shall be done by laying materials on adjoining shoulder along with that of WMM layer. The preparation of mix, spreading of mix and compaction are done sequentially. The sequence of operation shall be followed as described in clause: 406.3.3 of MORT&H.5.2 Preparation of mix Wet mix Macadam shall be prepared in an approved WMM mixing plant having provision for controlled addition of water and forced/positive mixing arrangement.

Optimum moisture for mixing shall be determined in accordance with IS: 2720 (Part 8) after replacing the aggregate fraction retained on 22.4 mm sieve with materials of passing from 22.4 and retained on 4.75 mm. While adding water, evaporation loss shall also be taken into account.

The mixed material should be uniformly wet and no segregation shall be permitted.5.3 Spreading of mix Immediately after mixing, the aggregate shall be spread uniformly and evenly upon the approved GSB layer. Materials should neither be dumped in heap nor their hauling over a partly completed stretch.

The first layer will be laid by motor grader and the second layer mix shall be spread by a WMM paver finisher capable of paving minimum 4.5m to 9.0m width. The layer may be tested by depth block during construction. No segregation of materials are allowed.

The aggregates should be of uniform gradation with no pockets of fine materials.5.4 Compaction After the mix has been laid on site to the required thickness, grade and camber, then compaction is carried out with suitable roller to the full depth. For a thickness up to 200mm in a single layer, compaction shall be done with vibratory roller of 80 to 100 KN static weights with plain drum or equivalent capacity roller.

Rolling is done from lower edge towards upper edge longitudinally for the portion having unidirectional cross fall and super elevation. Each pass of the roller shall uniformly overlap not less than one third of the track made in the previous pass. During rolling, grade and cross fall shall be checked and any high spot or depressions, which become apparent, corrected by adding or removing fresh materials.

  • The speed of roller shall not exceed 5km/h.
  • Rolling shall be continued till the density of the layer is achieved 98% of the Maximum Dry Density.
  • Rolling should not be done when the WMM layer is soft or yielding or when it causes a wave like motion.
  • If level difference or irregularities develop during rolling which exceeds 12 mm when tested with 3 metre straight edge, the surface should be loosened and premixed materials added or removed as required before rolling again.

In no case the unmixed material be permitted to make up the depressions.5.5 Opening to traffic After testing the compaction & level of WMM course the road shall be allowed to dry for 24 hours. Preferably no vehicular traffic should be allowed on the finished WMM surface till it has dried and covered with wearing course.6.0 Quality Control Table 400-12 Physical Requirement of coarse aggregate for Wet Mix Macadam for Sub-base /Base Courses 406 WET MIX MACADAM SUB BASE /BASE Table 400- 13: Grading Requirement of Aggregate for Wet Mix Macadam

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Control Tests for Granular WMM Base: Post Construction Tolerance in Surface Level : +10 mm permissible undulation (with 3 m straight edge) : 8 mm no. of undulations permitted in any 300 m length, exceeding 12 mm: 20 Control on quality of materials and works shall be in accordance to section 900 of MORT&H.

7.0 Work Safety 1.Safety will be provided location specific safety plan.8.0 Environmental Safety 1.Nearby Streams, water courses, lakes, reservoir shall be protected from contamination by the soil erosion from areas exposed during excavation by constructing temporary berms, dykes, sediment Basins, slopes, drains & by the use of temporary mulches, seeding or other control devices.2.Vehicles tracks shall be kept moist to prevent flying of dust particles with the vehicle movement.

What is the use of WMM in road construction?

Finishing and Opening to Traffic: –

After the final compaction of Wet Mix Macadam, the same shall be allowed to dry for 24 Hours.The surface of Wet Mix Macadam shall have a suitable cross fall to enable efficient surface drainage. The finished WMM top surface level shall be within the tolerance limits specified in Table 900-1. (i.e +10 mm to –10mm).Vehicular traffic or heavy movement should not be allowed on the finished WMM top surface until it has dried and the wearing course is laid.During the construction period, the traffic arrangement shall be made as per clause 112 of MORTH technical specification.

Summary What Is Wet Mix Macadam In Road Construction Article Name Wet Mix Macadam Construction and Quality Control Description Wet Mix Macadam(WMM) work includes laying and compacting clean, crushed, graded aggregate and granular material, premixed with water, to a dense mass on a prepared GSB layer or existing pavement as per the requirement of the project. Author WhiteHelmet Publisher Name Construction Civil Publisher Logo What Is Wet Mix Macadam In Road Construction

Why WMM is required?

Wet Mix Macadam (WMM) construction is an improvement upon the conventional WBM and is intended to be as an alternative and more durable pavement layer. It consists of clean, crushed, graded aggregates premixed with other granular materials and water and rolled to a dense mass on a prepared surface. Secretary, IRC (S.C.

What is difference between GSB and WMM?

The prime work of GSB is drainage system and secondary to support the load transfer to the sub-grade. WMM is a part of designed road section, thickness arrived from design calculations to withstand design load and ultimate transfer to sub0grade.

What is the thickness of WMM?

The material shall be laid in one or more layers such that the thickness of a single compacted Wet Mix Macadam layer shall not be less than 75mm.

Is cement used in WMM?

Components of Wet Mix Plants – Atlas make wmm plant is manufactured for tough conditions. The components of the are very heavily designed. In fact, the pug mill mixer which is the mixing unit is very strong. It is designed to take heavy loads with ease and perform smoothly.

Aggregate feeding system: Standard bins come with 4 feeders. Each bins have individual gates for controlled floe of aggregates. The number and size of bins can be customized. Each bin is provided with a gate for manual adjustment and individual belt beneath equipped with variable speed drive motors. There is a bigger gathering conveyor below each bins. These belts discharge materials into the gathering conveyor. Vibrating screen: Aggregates from the gathering conveyor are transferred to the charging conveyor belt. While passing through the two belts they have to pass through a single deck vibrating screen. The screen is provided with a vibrator and prevents oversized material to reach the mixer. Charging conveyor: The aggregates are transferred to the pug mill mixing unit by a charging conveyor. This conveyor is fitted with a load cell. Load cell will weigh the aggregates. It will then send a signal to the control panel. This helps the panel to synchronize the addition of cement and water into the mixing unit. Mixing unit: Mixing unit is built on a rugged structure. It is a continuous pug mill mixer. All the liner plates, arms and tips are easy replaceable. It’s a sturdy mixer with easy to maintain design. This mixing unit consists of two shafts. These shafts have arms fitted on them parallel to each other. Water tank: Water tank of suitable capacity is supplied. It is connected to the pug mill mixer with the help of a pipe and the plant comes with water pump for transfer of water to the mixer. Depending on the input from the load cell, the flow of water is controlled. Control cabin and panel: Control cabin houses the control panel. Control panel is microprocess or PLC type depending on the choice of the customers. The easy to use software allows easy learning of the same. Storage silo: Suitable sized storage silos are available. They help in storage of the material before discharge of the material into the trucks. Silo is on a heavy structure with hydraulically operated gates for open-close mechanism. Cement addition: Cement addition is possible with the help of cement silo or hopper. A screw conveyor is equipped for addition of cement into the mixing unit.

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What Is Wet Mix Macadam In Road Construction How do you make a wet mix? Wet mix macadam is made by use of stone aggregates, water, cement and or emulsion. All these items are mixed in desired proportions and then laid for a granular sub-base. Why is wmm used? Wet mix macadam method includes spreading of well mix material prepared for sub-base.

Where is wet mix macadam used?

All You Need to Know About Wet Mix Macadam While constructing a road, there needs to lay down the base course material right before hot mix asphalt is laid, and that process done through the Wet Mix Macadam. The materials used for the sub-base, base or existing pavement are prepared in a plant as per the specifications provided. What Is Wet Mix Macadam In Road Construction The WMM process is a newly developed concept. Earlier it was done through the WBM (water bound macadam) process. Though WBM process is cheaper than the WMM, the later gives plenty of benefits. In short, the outputs of WMM pay you of the debt. So, let’s find out the benefits we get from the WMM process.

  • The roads constructed through WMM process are durable
  • The WMM roads get dry sooner as compared to that of WBM
  • The WMM process allows constructing road faster than other processes
  • Roads can be ready in no time and can be applied or topped with Bituminous layers soon after the laying process done
  • WMM process saves plenty of water
  • Apart from that, the WMM machines are easily operated and give a bunch of benefits.
  • Similarly, there are so many additional benefits which can compensate you well if you use this wet mix plant to construct the road.
  • Here’s the list of components which set the Wet Mix Macadam plant apart from others.
  • Feeders
  • Vibrating Screen
  • Conveyor
  • Pug Mill mixer
  • Conveyor
  • Silo or Hopper
  • Water tank
  • Control Panel

Aggregate Feeders: It’s a four-bin aggregate with a manually adjustable gate in each to store four types of aggregates. It helps to discharge the materials and smoothens wet mix process. Vibrating Screen: It works to filter the oversized aggregates and deliver it to the charging conveyor belt.

  1. The pug mill mixer consists liner plates, arms, and tips and spreads materials when comes in contact with water.
  2. And at last, the loadout conveyor transfers the mixer to the storage which later transmitted to other truck for further process.
  3. All components used during the process to simplify the mixing process and help achieve the highest goal.
  4. The wet mix plant is very much in trend for its friendly features including ease of operation, providing high-quality services and giving a satisfactory result to the builder.

Last but not the least, in the fast developing world, people demand quick and reliable services and Wet Mix Plant will meet such a challenge for sure. A builder has to go through many uninvited challenges while constructing roads. Hence, the WMM plants will help in tackling all the challenges occur during the course. : All You Need to Know About Wet Mix Macadam

Does WMM affect speed?

Disabling WMM causes Wi-Fi Speeds to drop to 14Mbps is the default setting of most modems and should be left enabled. While WMM is, indeed, designed to give priority to multimedia traffic, it is also required in order to use the high throughput link rates.

When WMM is disabled, only 54 Mbps is possible. WMM is required by 802.11n and 802.11ac for link speeds above 54 Mbps, so disabling it can affect your overall Internet speed. If your Internet speed is 20 Mbps or less, then you maybe could get away with disabling WMM, but WiFi is going to be terrible. You could also try playing around with Dynamic QoS, if supported by the router.

Dynamic QoS works on top of WMM and may be able to re-prioritize your gaming traffic. I suggest finding a better solution than disabling WMM. If your phone has difficulties with it, find other ways of dealing with the problem. : Disabling WMM causes Wi-Fi Speeds to drop to 14Mbps

Which is better WMM or WBM?

Difference Between WMM and WBM Road – Here are the differences between WMM (Wet Mix Macadam) and WBM (Water Bound Macadam) roads.

WMM Road WBM Road
WMM roads are more durable. WBM roads are less durable.
WMM roads get dry very fast WBM roads take time to get dry.
It can be constructed at a faster pace. It took more time to construct.
It consumes less water. It consumes more water.
In WMM roads stone aggregates and binders are used. In WBM roads stone aggregates, screenings, and binder material (Stone dust with water) is used.

Water Bound Macadam Road

What is the CBR value of GSB?

MDD of the GSB material is found to be 2.1 g/cc at an OMC of 3.3%. CBR Value: To know the strength of GSB, CBR test is conducted on GSB granular mix as per IS 2720-pt 16 under soaked conditions. The CBR value at 2.5 mm penetration level is found out to be 31%.

What is the thickness of GSB?

As per IRC: 37-2001, the minimum thickness of granular base Free 10 Questions 10 Marks 10 Mins The minimum thickness of granular base course depends on traffic intensity. The recommended minimum thickness of granular base is 225 mm for traffic upto 2 msa (million standard axles) and 250 mm for traffic exceeding 2 msa.

What is the density of DBM?

Dense Bituminous Macadam is a close-graded premix material with a void content of 5-10 per cent, working as a binder course used for road construction. DBM design should be according to the standard method considering heavy commercial vehicles. The full-scale laying and compaction of Dense Bituminous Macadam shall be carried out with the help of approved material and mix design proposed for the permanent works using the Plants, Equipment, Machinery and approved methodology. What Is Wet Mix Macadam In Road Construction Dense Bituminous Macadam (DBM) Construction Also, Read: Wet Mix Macadam Construction and Quality Control

What is meant by GSB?

Gaud Saraswat Brahmin

Parshurama with Saraswat Brahmin settlers, commanding Varuna to make the seas recede in order to create the Konkan Region
Regions with significant populations
Primary populations in Karnataka, Goa, Maharashtra and Kerala
Languages
Konkani
Religion
Hinduism
Related ethnic groups
Saraswat Brahmins

Gaud Saraswat Brahmins (GSB) (also Goud or Gawd) are a Hindu Brahmin community of the north. The Konkani speaking Gaud Saraswat of Goa and southern India claim to be descendents of these Gaud Saraswat Brahmins of the north that migrated to Konkan from Gaud, as per the Skanda Purana, Their traditional occupation was trading.

Is Wmm a base course?

Answer (Detailed Solution Below) – Option 4 : Well graded hard crushed aggregates and adequate proportion of water mixed thoroughly in a mixing plant Free RSMSSB JE General Knowledge Free Mock Test 10 Questions 10 Marks 8 Mins Last updated on Sep 22, 2022 The DV Dates for the RSMSSB JE (Agriculture) have been announced.

The DV will be conducted on the 9th and 10th of November 2022. Earlier, the RSMSSB JE Result, Final Answer Key, Cut Off were released for written examination on 14th October 2022. The candidates who have cleared the cut off have been shortlisted for the document verification. The Rajasthan Subordinate & Ministerial Services Selection Board had announced a total of 189 vacancies for RSMSSB JE (Agriculture).

The finally appointed candidates will be entitled to Pay Matrix Level 10.

What is GSB road work?

Construction Methodology of Granular Sub base(GSB) – CivilYard Granular Sub Base (GSB) shall consist of laying and compacting well-graded material on prepared and approved in accordance with clause 401 of MORT&H specification. In other words, GSB is laid in between the subgrade and the base course of all highway pavements. The primary functions of GSB are:

  1. Serves as an effective drainage layer to drain off the water entering into the pavement layers.
  2. In flexible pavement, Distributes the wheel load stresses transmitted through the surface course and granular base course. however, in the case of rigid pavement, the GSB layer only serves as an effective drainage layer.

Which cement is used for leakage?

Hydraulic Cement is a product used to stop water and leaks in concrete and masonry structures. It is a type of cement, similar to mortar, that sets extremely fast and hardens after it has been mixed with water. Hydraulic cement is used widely in the construction industry sealing structures below grade and in situations where structures can be affected or submerged in water.

Which mix is used for slab?

A concrete mix of 1 part cement : 2 parts sand : 4 parts coarse aggregate should be used for a concrete slab.

Where is wet mix macadam used?

All You Need to Know About Wet Mix Macadam While constructing a road, there needs to lay down the base course material right before hot mix asphalt is laid, and that process done through the Wet Mix Macadam. The materials used for the sub-base, base or existing pavement are prepared in a plant as per the specifications provided. What Is Wet Mix Macadam In Road Construction The WMM process is a newly developed concept. Earlier it was done through the WBM (water bound macadam) process. Though WBM process is cheaper than the WMM, the later gives plenty of benefits. In short, the outputs of WMM pay you of the debt. So, let’s find out the benefits we get from the WMM process.

  • The roads constructed through WMM process are durable
  • The WMM roads get dry sooner as compared to that of WBM
  • The WMM process allows constructing road faster than other processes
  • Roads can be ready in no time and can be applied or topped with Bituminous layers soon after the laying process done
  • WMM process saves plenty of water
  • Apart from that, the WMM machines are easily operated and give a bunch of benefits.
  • Similarly, there are so many additional benefits which can compensate you well if you use this wet mix plant to construct the road.
  • Here’s the list of components which set the Wet Mix Macadam plant apart from others.
  • Feeders
  • Vibrating Screen
  • Conveyor
  • Pug Mill mixer
  • Conveyor
  • Silo or Hopper
  • Water tank
  • Control Panel

Aggregate Feeders: It’s a four-bin aggregate with a manually adjustable gate in each to store four types of aggregates. It helps to discharge the materials and smoothens wet mix process. Vibrating Screen: It works to filter the oversized aggregates and deliver it to the charging conveyor belt.

  1. The pug mill mixer consists liner plates, arms, and tips and spreads materials when comes in contact with water.
  2. And at last, the loadout conveyor transfers the mixer to the storage which later transmitted to other truck for further process.
  3. All components used during the process to simplify the mixing process and help achieve the highest goal.
  4. The wet mix plant is very much in trend for its friendly features including ease of operation, providing high-quality services and giving a satisfactory result to the builder.

Last but not the least, in the fast developing world, people demand quick and reliable services and Wet Mix Plant will meet such a challenge for sure. A builder has to go through many uninvited challenges while constructing roads. Hence, the WMM plants will help in tackling all the challenges occur during the course. : All You Need to Know About Wet Mix Macadam

Why we use water bound macadam?

Advantages of Water Bound Macadam –

Water bound macadam is superior in quality because the materials are carefully graded and the resulting mass is almost void less compacted mass. The interlocking of aggregate particles imparts adequate strength of the materials selected for filling the voids. These ensure non-entry of the plastic materials of the sub-grade into the voids. Water bound macadam is less costly as compared to bituminous base course.