การทดสอบเปรียบเทียบกำลังรับโมเมนต์ดัดของคานและพื้นทางเดียวที่เสริมด้วยเหล็กเส้นที่ได้มาตรฐานและไม่ได้มาตรฐาน

Abstract

Nowadays, among construction material retail stores in Thailand, there are many sizes of rebars available. For a specific size, the buyer can choose between the products that carry the standard seal or the ones that not conform with any standards. These non-standard rebars have lower mass per length than the values specified by the standard. If the contractor uses these nonstandard rebars, the structural members certainly will have less load capacities than the ones that reinforced with the standard rebars. This article presents the experimental investigation to determine the bending moment strengths of beam and one-way slab specimens. From the tests of two beam specimens, it was found that the beam reinforced with the standard DB12 rebars can carry 198% bending moment of the one calculated from the design formula while the one reinforced with the non-standard DB12 rebars can carry 118% bending moment of the calculated one. From the tests of four one-way slab specimens, the one-way slabs reinforced with the standard and non-standard RB6 rebars have the bending capacities of 101% and 78% comparing with the calculated design value respectively while the one-way slabs reinforced with the standard and non-standard RB9 rebars have the bending capacities of 121% and 73% comparing with the calculated design value respectively