Horizontal/Subsurface Infrastructure & Transportation

Does anyone have any information on the mix proportions and gravel size for the precast curbstone and how it differs from the curber machine's concrete?

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Mohammed Al-Tofan Ph.D., P.E., M.ASCE
West Columbia SC
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I am not familiar with precast curb stones. Here in Michigan contractors use a curb slip form machine or handset the curb. The mix design is similar except the curb machine uses a much lower slump.

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Douglas Skylis P.E., M.ASCE
SR PROJ MANAGER
Lapeer MI
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In our region, Curbstones shall only be precast from concrete mixture contain not less 400KG/m3 of sulphat Resisting Portland cement in which the compressive strength after 28 days should achieve minimum 45 N/mm2  and the concrete produced in a fully automatic batching plant and sampling shall be done and the materials (coarse and fine aggregate , cement and water) to be are selected in compliance with suitable international standard in order to specify suitable grading, ,fine aggregate % , coarse aggregate %, water absorption, specific gravity ,elongation index, soundness, Acid soluble upper range and lower range and the combined grading shall be within appropriate specified grading limits with Max. aggregate size of 20mm. We used to  use of precast Curb  rather than curber Machin's concrete and i believe that the main differences of the concrete mix in the two methods will be on the slump range and using different type of admixtures.

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Ashraf Amin A.M.ASCE
Chief Engineer for Roads and Infrastructure
RTA- Dubai
Dubai
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