Initial setting time of cement for asbestos cement products should be not less than

Initial Setting Time refers to the period after water is added to cement during which the mixture remains workable before it begins to stiffen.

For asbestos cement products such as roofing sheets and pipes, a longer setting time is essential to allow for proper mixing, molding, and compaction.

According to standard requirements, the minimum initial setting time should be 90 minutes to ensure sufficient workability.

Other options like 30, 50, and 75 minutes are too short and do not provide adequate time for the manufacturing process of asbestos cement products.