Building Materials - M-Sand

Early as 2018, the government Development Bureau - Works Division has already have documents announced that M-Sand has to be used to replace Natural Sand in Open Contracts for using as plaster and floor screeding.

The background of this announcement is originated from the decreasing of exporting natural sand from the Guang Dong Province to Hong Kong. The CIC would then start to study the possibility of using Mechanical Sand (M-Sand).Architectural Services DepartmentandHong Kong Housing Authorityconfirm that when M-Sand be used for plaster and floor screeding has no major technical problem in 2017 and 2018. After that, the Works Policies Coordination Committee has signed to execute all the open public contracts will use M-Sand for in-situ plasters and floor screeding.

The manufacturing process of M-Sand is to feed big stone into one to two crusher to make it small and finally feed into vertical shaft impact crusher and the stones are running high speed in the crushing chamber to become size of sand. The crushing action will make M-sand into rounded corner. Finally, the sand will be blown into categorizing chamber by separating into different sizes.

機砂製造流程圖
Source : internet picture

Why M-Sand? M-Sand has the following advantages:-

  1. It is well graded in the required proportion.
  2. No organic substance or water soluble compound to affect the concrete masonry characteristics hardness.
  3. No Clay, no shell etc. impurities which keep the quality of the concrete plaster.

Disadvantages of M-Sand

  1. Particle size is bigger and roundness is less than Natural Sand. As a result, more water and cement is needed in order to make to the desired applicable.
  2. Comparing to Natural Sand, M-Sand has more silt and dust. This may affect hardness of plaster or concrete or affect the workability.

The abovementioned document from Development Council stated that the pre-mixed packed plaster mixtures, no matter from China or overseas, are excluded from the Natural Sand usage restriction. Those packed plaster can be found fromOptimixorWeberproducts

If you need a bulk purchase of M-Sand, Pleasecontact us.

Reference:-

A Technical Circular (Works) No. 8/2018 for Use of Manufactured Sand in Public Works Contracts has been issued by the Development Bureau in September 2018.

A review on Technical Aspect of Aggregate Used in Concrete and Mortar Production – River Sand, Crushed Rock Fines and M-Sand

What is M-Sand?

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