6Chandara C, Azizli K A M, Ahmad Z A, et al. Use of waste gypsum to replace natural gypsum as set retarders in Port- land cement [ J ]. Waste Management, 2009,29 (2) : 1675 - 1679.
7Kamei T, Ahmed A, Shibi T. Effect of freeze-thaw cycles on durability and strength of very soft clay soil stabilized with recycled bassanite [ J ]. Cold Regions Science and Technolo- gy,2012,82 : 124 - 129.
8Ahmed A, Ugai K. Environmental effects on durability of soil stabilized with recycled gypsum [ J ]. Cold Regions Science and Technology,2011,66 (2) : 84 - 92.
9Kamei T, Ahmed A, Shibi T. The use of recycled bassanite and coal ash to enhance the strength of very soft clay in dry and wet environmental conditions [ J ]. Construction and Building Materials ,2013,38:224 - 235.
10Ahmed A, Ugai K, Kamei T. Investigation of recycled gyp- sum in conjunction with waste plastic trays for ground im- provement [ J ]. Construction and Building Materials, 2011, 25(1) :208 -217.