What is the difference between wbm and wmm?

Answer 1

WBM (Water Bound Macadam) and WMM (Wet Mix Macadam) are used for Road construction in Base course layer. WMM is a new technology. difference between WBM and WMM can be summarized as below:

• Stone aggregate used in WBM is larger in size compared to WMM. In case of WBM its size varies between 45 mm to 90 mm depending upon the grade while in case of WMM aggregate size varies between 4.75 mm to 20 mm
• In case of WBM stone aggregate, screening material and binders are overlaid one after another respectively at the time of construction. But in case of WMM, aggregate and binding materials are premixed in a batching plant or concrete mixing machine and then brought to site for overlaying and rolling.
• Materials used in WBM are stone aggregate, screening material (Kankar or murrum or smaller stone aggregate for filling up the voids ) and/or binding material (stone dust or Quary dust of PI not less than 6). materials used in WMM are Stone aggregate and binders (Stone dust or Quary dust of PI not less than 6)
• Quantity of WBM is generally measured in Cubic Meter while quantity of WMM is measured in Square Meter.

WMM HAS MANY ADVANTAGES OVER WBM CONSTRUCTION

1. SUPERIOR GRADATION OF AGGREGATES

2.FASTER RATE OF CONSTRUCTION

3.HIGHER STANDARD OF DENSIFICATION

4.LESS CONSUMPTION OF WATER

5. STRICTER STANDARD OF QUALITY ACHIEVABLE