360R-06 Design of Slabs-on-Ground
DESIGN OF SLABS-ON-GROUND
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- Điều hướng trang này:
- 360R-26 ACI COMMITTEE REPORT
| DESIGN OF SLABS-ON-GROUND
360R-25 are independent of load transfer requirements at joints. Further, not all joints activate uniformly, resulting in some joint opening widths that are larger than might normally be anticipated. Where aggregate interlock is anticipated as the only load-transfer mechanism in a slab-on-ground, joint spacing should be the thoughtful result of an evaluation of the anticipated, activated, joint-opening widths along with the type of wheel loadings on the slab. Furthermore, if the designer cannot be sure of positive long-term shear transfer at the joints through aggregate interlock, then positive load- transfer devices should be used at all joints subject to wheeled traffic. With respect to this issue, PCA implemented a test program to examine the effectiveness of aggregate interlock as a load-transfer mechanism (Colley and Humphrey 1967). The program tested slabs that were 7 and 9 in. (180 and 230 mm) thick. The test slabs were constructed using 1-1/2 in. (38 mm) maximum-size aggregate, were fully supported on various base materials, and loaded using repetitive applications of a 9000 lb (40 kN) and 16 in. (440 mm) diameter pads centered 9 in. (230 mm) from the joints. Among the findings were the following: Fig. 5.7—Joint details at loading dock. Fig. 5.8—Sawcut contraction joint. Fig. 5.9—Dowel basket assembly. 360R-26 ACI COMMITTEE REPORT 1. Joint effectiveness for 7 in. (180 mm) thick slabs is reduced to 60% at an opening width of 0.025 in. (0.6 mm); 2. Joint effectiveness for 9 in. (230 mm) thick slabs is reduced to 60% at an opening width of 0.035 in. (0.9 mm); 3. Three values of foundation bearing support were used. The values used were k = 89, 145, and 452 lb/in. 3 (24,200, 39,400, and 123,000 kN/m 3 ). Joint effectiveness was increased with increases in foundation bearing value k; and 4. Joint effectiveness increased with increased aggregate tải về 2.35 Mb. Chia sẻ với bạn bè của bạn:
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