Regarding the Load Capacity of the Cosinus Slide Profile

Transcription

1 Page 1 Regarding the Load Capacity of the Coinu Slide Profile Stefan Kordt and Jen Peirick Mechanim of Action of Shear Force Tranfer With common joint in concrete indutrial flooring, the load tranfer, if it i neceary, often occur through an additional arrangement of hear force dowel. For thi type of hear force tranfer, individual hear dowel that are located approximately in the middle of the lab, with a certain ditance e one below the other, will be intalled. Thi intallation require additional tructural reinforcement and from the execution of contruction work i therefore relatively time-conuming. For each dowel a hear force load will be aigned according to the ditance e and verified. To enure that the hear force load are fed into the dowel, it mut be done through an acro ditributed reinforcement. The load tranfer for thee joint type i eentially done by elective, vertical coupling that mut be verified by a correponding engineering model. The lide profile, ee fig. 1-3, can tranfer the load by itelf, through a geometric hape without additional doweling acro the concrete ection. Due to the taggered arranged, corrugated teel there are mall reinforced-concrete conole that are facing each other on the upper and lower ide, the load bearing capacity of the total joint contruction i determined by their load bearing capacity. Side view Fig. 1: Slide Profile Top view Fig. 2: Slide Profile

2 Shear Zu übertragender force to be tranferred Querkraftanteil in % in % Page 2 Sectional view Fig. 3: lide Profile A a reult of wheel load, the load tranfer occur through the ine-curved edge protection on the upper ide of the concrete bae, not abruptly a with a linear joint without profile and doweling, with hock to the joint edge, but intead it i mooth. The load that goe along the joint of the tranferred hear force, with the aumption of an elatic bedding below the concrete bae, from a ditance to the joint axi of approximately 2.20 m, a in the following diagram in fig. 4. For the determination of the hear force load, an elatic bedded beam, with a width of 1 m and a thickne of 0.20 m, wa put in and treed with ingle load of the pecified ditance. The hear force load to be tranferred, wa determined through the integration of flooring preure, with an aumption of a bedding modulu of ks= 15 MN/m³ ,0 0,5 1,0 1,5 2,0 2,5 Abtand Ditance to zum joint Fugenprofil profile in m in m Fig. 4: Shear force load for the joint with elatic bedding

3 Page 3 Deign Load The common impact on indutrial flooring arie from racking load, load from tored good, temperature tree and payload of forklift or truck traffic. The traffic load from forklift and truck traffic and load from other conveyor vehicle are particularly important for the plan of the expanion joint. The deign load model for the forklift traffic puruant to DIN : upport wheel load of 13 kn to 85 kn. Thoe mut be mathematically engraved on bedded lab on a quare ection of 0.20 m x 0.20 m, with a ditance of 0.85 m to 1.80 m. The contact area of vehicle with ynthetic tyre are generally much maller. Often, very hard tyre with very mall roll diameter are ued, with linear joint profile a hock impact on the edge protection will occur and with frequent traffic it can caue concrete palling. The planner mut provide the builder with profeional advice regarding the contruction of expanion joint and ugget correponding alternative deign. The planner cannot fall back on any et rule. Particularly with high contact preure, a in ynthetic tyre, depending on the requirement of the indoor ole, pecial meaure are required for the edge protection. At uch high local traffic impact, it i recommended to chooe a joint profile that minimize or entirely exclude a hear force crack due to hock impact olely by it geometry. Due to the inuoidal edge protection with the lide joint profile, no wear tre arie a it would with a traight edge profile. The exiting profile geometry allow for jointfree croing and thereby increae the uability. Thi wa confirmed on the bai of extenive experimental vibration meaurement. Difference of Poible Type with Expanion Joint The hear force of expanion joint can be created by different type. Here, the eential difference between the hear force i explained in the doweling with hear dowel pin and the hear force at the inu joint profile. If hear force in the joint hould be tranmitted through the hear dowel, mooth teel rod with a length of 500 mm can be ued at a ditance of about 25 cm. In order to enure the opening of the joint due to hrinkage reduction, a platic coating i applied to the anchor. The load bearing behaviour depend mainly on the hear and bending load capacity of the anchor and anchorage depth in the concrete. Therefore, it i crucial to how far the joint open. With wide open joint, greater bending load are created and the load capacity i re-

4 Page 4 duced. The hear force are electively tranferred in the dowel area, o that an acro ditributed reinforcement mut be provided. The hear force with the lide joint profile, like with other double rail, i created contant along the joint edge, jut like of a line-baed plate. Thi doe not require the acro ditributed reinforcement. The force are not tranmitted through part of the profile, but by the concrete lab itelf. Each inu haft on top correpond with a haft, located on the oppoite bottom ide, which tranfer the hear force according to the model in the chapter "engineer model". Engineer Model In determining the load capacity of the joint profile and the profile ytem, becaue of the relatively high tiffne of the profile contruction, it i aumed that a good hear ditribution i right at the wheel load in front the joint. Auming a hear ditribution of a wheel load at 45 from the rear edge of the contact area and depending on the wheel contact area, an effective tranfer width i created. From thee approache, the following impact for deign have been created: Deign hear force per wheel load: Deign hear force per inu haft: Deign moment: Moment of reitance of a inu haft: V d = V K x φ F d = V d x n M d = F d x 2.7 cm W y = b eff x h 1 ² / 6 mit b eff = 13.5 cm bzw. 7.9 cm Fig. 5: Slide profile with effective tranfer width for upper and lower curve

5 h 1 h 2 1 h Page 5 The engineering model i baed on the aumption, that the force to be tranferred create a bending tre in the pur. The bending tree reulting from thi mut be aborbed by the concrete. Puruant to DIN : , component can be carried out unreinforced, if the tenion remain under the permanent and temporary action combination of le than 1.00 N / mm ². Since indutrial flooring component are not in accordance with DIN , a 5% fractile value (fctk 0.05) of the tenile trength of C25/30 i expected, which i common for concrete floor. Under thee condition, the concrete ection remain uncracked and the tree can be determined in the linear elatic tate I. The hear force reitance of the lower pur i determined according to DIN equation (72). According to the DAfStb Directive [German Committee for Reinforced Concrete] "concrete contruction when dealing with ubtance hazardou to water", the tenile trength of the concrete i increaed by 30% with elatic bedding. f ctk Iy bw ;0,05 V Rd,ct = ( )² S c The hear force of the upper pur can be tranferred from the direct force of the compreion trut. A detailed verification can be waived. In the below engineering model, impact and the reulting tree are noticeable. The bedding tre that affect the bending and hear tree poitively are being neglected on the afe ide Fd Fd Md Md - h 2 - B1 B2 B2 B1 Fig. 6: Coinu lide profile, deign model Thi reult in the verification to

6 Height Höhe Page 6 d verification: f 1, 30 M W y ctk; 0,05 For pre-dimenioning of the joint or to etimate the neceary pur height h1 and h2, the reference value depending on the uual forklift categorie are contained in the following chart, ee figure 7 and 8. It hould be noted that the plate thickne i to be determined olely by the load on the joint. A tructural verification of the bae lab with recognition of all applied load i required in every cae. Figure 8 how reference value for the dimenion of vehicle with ynthetic tyre. Slab Plattentärke trength in depending Abhängigkeit on croing der Verkehrlat load 25,00 20,00 15,00 10,00 1 pur height top Spornhöhe oben pur height bottom Spornhöhe unten 5,00 5,00 9,00 11,00 12,00 0,00 G1 G2 G3 G4 LM 1 G5 G6 Latmodell Load model The outdated load model and SLW 60 SLW 30 are covered by the LM1. Fig. 7: Plate thickne for vehicle with pneumatic tyre.

7 Height Höhe Page 7 Slab trength Plattentärke depending on in contact Abhängigkeit preure der for Kontaktpreung vehicle with ynthetic tyre bei Hartkunttoffbereiften 5.00 Fahrzeugen N/mm² > 5,00 N/mm² 25,00 20,00 15,00 10,00 5,00 12,0013,00 14,00 9,00 10,00 10,00 pur height top pur Spornhöhe height bottom oben Spornhöhe unten 0, Contact preure in N/mm² Kontakdruck with aumption in N/mm² bei of Annahme a load area of a x b = 20 mm x 100 mm einer Latfläche (10 N/ von mm² a x = b G2; = mm N/ x mm² 100 = mm G3) (10 N/mm² = G2; 16 N/mm²= G3) Fig. 8: Plate thickne for vehicle with ynthetic tyre. Anchorage of the Profile in the Concrete To avoid a detachment of the joint profile of the concrete bae front, it mut be anchored with a uitable deign. For conventional joint profile, thi i uually done with hear tud or the imilar. The lide profile i connected with the bae to the profile by a welded patial concrete teel meh. A contant connection i created by the patially curved reinforcing teel. In thi variant, the upper a well a the lower haft are imilarly included in the plate, which lead to a homogeneou load tranfer.