Wet Mix Macadam Process
Method of wet mix macadam (wmm) in Road Construction Preparation of wet mix macadam (wmm) WMM Base Provision of lateral confinement of aggregates- Proper arrangement shall be made for the lateral confinement of wet mix during laying. wet mix during laying should be done by laying materials on neighbouring shoulder along with that of WMM layer. Oct 26, · 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 .
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. WMM can be laid in one or more layers, but the thickness of rosd single compacted layer not less than 75mm, and the maximum of mm when vibrating or other approved types of compacting equipment are used.
Note: The above equipment deployment list is for single WMM setup, whereas the number of sets shall be mobilized as per the requirement of the program. Coarse aggregate The coarse aggregate shall be crushed stone of identified Quarry having the following physical characteristics.
If the water absorption of the coarse aggregate is greater than 2. The Proportioning shall be completed by determining the individual gradation of the individual ingredients and the blend determined by trial and error method to achieve the gradation specified. The trial patch shall be laid on an approved granular sub-base layer on the road alignment as approved by the Engineer. If the trial patch result does not meet the specified requirements, the same shall be redone unless the requirement is fulfilled.
In case of different gradation in the course of work, the proportion shall be suitably modified, and the same shall be furnished to Engineer for roax approval. The surface to receive the Wet Mix Macadam layer shall be prepared to the specified lines and cross-fall camber and made free of dust and other extraneous material. Rain-cuts and surface irregularities if any shall be repaired before placing of WMM layer.
Preparation of base shall be done as per Cl. While constructing wet mix macadam, the arrangement shall be made for lateral confinement of the cknstruction mix. This shall be completed by laying how to save our home from foreclosure in adjacent shoulders along with that of WMM layer and following the sequence of operations described in clause Suitable ingredients in required proportion shall be mixed with required OMC in a WMM mixing plant having provision of controlled addition what channel is fx movie channel water and forced or positive mixing arrangements like pug mill or pan type constduction mixer of concrete batching plant.
Optimum moisture for mixing shall be obtained in accordance with IS: Part-8 consruction replacing the aggregate fraction retained on While adding water, the due allowance shall be made for the evaporation loss.
However, during compaction, water in the wet mix shall not vary from the optimum value by more than agreed limit. The mixed material should be properly wet, and no segregation shall be permitted. Note: One pass o roller shall include both forward and reverse movement. Close Rod. Skip to content. Table of Contents. Publisher Name. Please Share This Share this content Opens in a new window Qhat in a new window Opens in a new window Inn in a new window Connstruction in a new window Opens in a new window Opens in a new window Opens in a new window Opens clnstruction a new window Opens in a new window.
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Wet Mix Macadam Plant Wet Mix Macadam (WMM) is a relatively newer concept used for laying the base course, which is placed right before the hot mix asphalt during road construction. The binding materials used for the base in case of WMM are prepared in the plant and then brought to the site for overlaying and rolling. WMM(Wet mix macadam) road construction: Aggregates used are of the smaller sizes, varies between the mm to 20 mm sizes and the binders (stone dust or quarry dust having PI (Plasticity Index) not less than 6%) are premixed in a batching plant or in a mixing machine. views.
Posted By: Vivek Mishra January 13, Wet Mix Macadam laying method contains of laying spreading and compacting of clean, crushed, well-graded granular materials on a prepared and Granular sub-Base. For Wet Mix Macadam material is well mixed with water and then rolled to a dense mass. It should be laid on one or more layers as per line and level, grade and cross section shown in the good for Construction drawing.
WMM shall be laid in layers of 75mm or mm as per thickness. Pegs are to be provided at regular intervals on the side of the road edge , on those places blade of grader should not disturb the peg while mixing of the Base materials. The chainage boards and working bench mark should be kept outside the range of construction areas to avoid breakage and damage of those bench marks. The part of the aggregates should be made by the integrated crushing and screening plant Impact or Cone type , crushing shall be done in at least two stages.
The part of material which is passing through 4. If the water absorption value test of coarse aggregate is greater than 2 per cent, the soundness test should be done on the materials delivered to site for WMM Construction. The aggregate shall conform to the grading given in table Material finer than micron, should have the Plasticity Index PI less than 6. The final gradation approved within these limits shall be well graded from coarse to fine and should not differ from the lower limit on one sieve to the higher limit of adjacent sieve or vice versa.
Preparation of wet mix macadam wmm WMM Base Provision of lateral confinement of aggregates- Proper arrangement shall be made for the lateral confinement of wet mix during laying. The sequence of WMM method should be followed same as described in clause: Moisture required for Wet mix Macadam mixing shall be determined in accordance with IS: Part 8 after replacing the aggregate fraction retained on The Wet mix Macadam mixed material should be uniformly wet and no segregation shall be allowed.
Immediately after mixing, the aggregate should be spread uniformly and evenly upon the GSB layer. Materials should not be dumped in heap and also not on the a partly completed stretch. The first layer will be laid by motor grader and the second layer mix should be spread by a WMM paver finisher capable of paving minimum 4.
No segregation of materials is allowed. The aggregates should be of uniform size with no quantity of fine materials. After the Wet Mix Macadam 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 Wmm thickness up to mm in a one layer, compaction should be done by vibratory roller of 80 to KN static weights with plain drum or equivalent capacity roller. Rolling is done from down area towards upper area in a longitudinally motion for the portion having unidirectional cross fall and super elevation.
Each pass of the roller should uniformly overlap area not less than one third of the area in the previous pass. During rolling, slopes and Levels should be checked and any high spot or depressions, which should be corrected by adding or removing fresh materials.
The Field Density can be calculated through Core cutting method. Rolling should be stopped when the WMM layer is soft or yielding or when it causes a wave like motion. If level difference or irregularities formed during rolling, it exceeds 12 mm when tested along 3 metre straight edge, the surface should be immediately loosened and premixed materials added.
No vehicular traffic Movement should be allowed on the finished WMM surface till it has dried and covered with wearing course. Where the surface irregularity of the WMM sub-base course exceeds the tolerances specified or where the course is otherwise defective due to sub-grade soil mixing with the aggregates, the layer to its complete thickness should be scarified over the affected area, it should be reshaped with added material or removed and replaced with fresh wmm material as required, and recompacted.
Depressions formed during WMM Process should not be filled up with screenings and binding materials. The length and breadth should be measured to the nearest centimeter and thickness to the nearest half centimeter.
The consolidated cubical contents shall be calculated in cubic meters correct to two places of decimals. If you have any query on the above article wet mix macadam wmm in Road Construction , Please feel free tocomment. Save my name, email, and website in this browser for the next time I comment.
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