USE STUDY ON SLIGHT BEAM REINFORCED CONCRETE FLOOR PLATE IN LIEU OF SCONDARY BEAM Hery Riyanto, Sugito, Liies Widodjoko, Sjamsu Iskandar Master of Civi Engineering, Graduate Schoo, University of Bandar Lampung, J. Zaena Abidin Pagar Aam 26 Bandar Lampung, 35142, Indonesia Abstract-Use of fase beams on reinforced concrete sab instead of the joist is an innovation in the construction of reinforced concrete sab. Where the study was made by using 4 sampes of precast concrete sab specimens (PBP). Ie: P1 type - pate ony, type P2 - pate with joists, type P3 - sma pates with sight beams, type P4 - pate with big apparent beam. The fourth specimen sampes made using the Batu Raja cement, sand from Gunung Sugih, and oca spit Bandar Lampung in the Civi Engineering Laboratory of UBL. The fourth test specimen sampes was conducted at the Laboratory of Civi Engineering Unia using method one point oad that is paced in the center - the center span in order to get the oad and the maximum defection and crack patterns. The data obtained are used to verify the theoretica cacuations. Concusions wi be given at the end of writing. Keywords: artificia beam, maximum oad, maximum defection, crack patterns. 399
h Z d 2 nd Internationa Conference on Engineering and Technoogy Deveopment INTRODUCTION In the modern era many young architects to design buidings with a minimaist stye that minima design but most notaby on the function of the ower eve foor (spit eve). In this case the Civi Engineer must be abe to toerate the design of the architect, of course, within imits - imits the rues of civi engineering criteria. The case that the joists shoud be discarded because they interfere with the aesthetic design of the ceiing. To anticipate that it is made apparent as the study of beam repacement joist with experimenta methods carried out in the aboratory of civi engineering. As for making fase beams can aso be beneficia in terms of economics, time, construction of buidings (buiding height may be ower due to the ower foor eve). The purpose of this paper to obtain data on the extent to which the apparent beam reinforced concrete construction can be used. LITERATURE REVIEW 1.Formua Speciment Panning Anaysis In panning specimen authors use the basic formua cacuation of reinforced concrete beams without taking into account the conversion factors Whitney votage bock as shown in Figure 1 C c to the resutant force on the tensie stee. H = 0 C c = T y where T y = A s ς y Cacuation appies to the cacuation of the coapse of state panning baanced, then appyt y = A s f y 2. Externa moments must be equa to the moment interna. M ext = M int = M utimat M u = A s f y Z where Z = ( 0, 0,9 ) d A s = M u f y Z ρ = A s b d Requirement : ρ min < ρ < ρ max 2.Testing the formua In this experiment the specimen is paced on two simpe pacement foowing the 1.20 m ong with a center to center distance of 1 m pedesta, then given the gradua oading (incrementa oad) through the actuator oad to the crack that is paced on the center span as shown in thefigure 2.. ς c 10 cm 10 cm A s ϵ y ς y T y L : cm Figure 1: The diagram of distribution of strain and stress Baance equation the horizonta force and moments: 1. The resutant compression force concrete the magnitude must be equa Figure 2. schematic of oading Based on Figure 2, the oad ine can be considered as a concentrated oad as the specimen just riveted on the two sides so that it can be considered as engineering 400
mechanics cacuations beam. Engineering mechanics cacuations: (See figure 3) Figure 4.formwork and reinforcement -M LL = 1 P L 4 -M DL = 1 L + + M LL Figure 3: Moment diagram Q L2 So M u = M LL + M DL = 1 4 P L + 1 Q L2 3. Studi EksperimenModu Benda Uji Specimens were made with severa types, namey: P1 type - pate ony, type P2 - pate with joists, type P3 - pates with sma apparent beams, type P4 - pate with big apparent beam. Each - each specimen using pain reinforcement (BJTP) Ø mm in diameter and quaity of stee fy: 2400 kg/cm2, wherein each - each rebars paced 2 cm from the outermost ayer of concrete. Modue wi test object given in tabe 1. Tabe 1: Modue test specimens Tipe Jenis Ukuran Peat ( cm ) Ukuran Baok P1 peat saja 120 60 12 _ P2 peat dengan baok anak 120 60 12 12 17 P3 peat dengan baok semu keci 120 60 12 12 12 P4 peat dengan baok semu besar 120 60 12 21,5 12 Figure 4 shows the images - photos of the four types of the test specimens (formwork and reinforcement). M DL specimen Tangga Pengecoran Tangga Pengujian Berat Jenis ( kg/m 3 ) Kuat Tekan ( kg/cm 2 ) 11/11/200 10/12/200 2321,302 11,17 11/11/200 15/12/200 2192,593 177,7 11/11/200 15/12/200 223,557 220,1 11/11/200 15/12/200 2251,52 12,22 4. Concrete Process Manufacture of concrete for test specimens conducted at the Laboratory of Civi Engineering UBL according to Procedure of Making Pans Mixed Concrete Norma accordance with SNI 03-234 -2000. The use of cement in making concrete the King Stone, Sand Gunung Sugih, and oca spit Bandar Lampung. Manufacture of fresh concrete mixtures with compressive strength fc pan: 225 kg/cm2 for 1 m3 of fresh concrete required: - Cement = 323 kg - Sand ( keadaan SSD ) = 11,14 kg - Spit = 92 kg - Watter = 153,6 tr 5. Concrete Compressive Strength Test Resuts Compressive strength testing of concrete cubes for the four specimens hed after the age of concrete at 2 days. Tests carried out at LTS - UBL and data testing resuts are shown in Tabe 2. Tabe 2 : concrete compressive strength test resuts P1 RESULTS AND DISCUSSION 1. Anaysis of Specimens P3 401
2 nd Internationa Conference on Engineering and Technoogy Deveopment 6 Ø 6 Ø = 4 9151,47 = 3674,05 kg 4 Ø 5 cm 6 Ø P3 6 Ø P4 21 cm 6 Ø Cacuation pate with sma apparent beam Figure 5: section of the test specimen Cacuations for the pate ony M u = n π r 2 f y 0,9d = 6 3,14 0,4 2 2400 0,9(9,6) M u = 62506,60 kgcm M DL = 1 Q 2 = 1 1,73 2 = 2162,50 kgcm = 62506,60 2162,50 = 60344,10 kgcm = 4 60344,10 = 2413,76 kg Cacuation pate with scondary beam M u = M u1 + M u2 = n 1 π r 2 f y 0,9d 1 + n 2 π r 2 f y 0,9d 2 M u = 6 3,14 0,4 2 2400 0,9 9,6 + 2 3,14 0,4 2 M u = 94193,97 kgcm 2400 0,9 14,6 M DL = 1 Q 2 = 1 1,73 + 0,144 2 = 2342,50 kgcm = 94193,97 2342,50 = 9151,47 kgcm M u = n π r 2 f y 0,9d = 3,14 0,4 2 2400 0,9(9,6) M u = 3342,13 kgcm M DL = 1 Q 2 = 1 1,73 2 = 2162,50 kgcm = 3342,13 2162,50 = 1179,63 kgcm = 4 1179,63 = 3247,1 kg Cacuation of the pate with arge apparent beams M u = n π r 2 f y 0,9d = 10 3,14 0,4 2 2400 0,9(9,6) M u = 104177,66 kgcm M DL = 1 Q 2 = 1 1,73 2 = 2162,50 kgcm = 104177,66 2162,50 = 102015,16 kgcm = 4 102015,16 = 400,60 kg 2 Testing Anaysis Test Specimen 402
Specimens were concentrated on two simpe pedesta pressure graduay unti the cracks with hydrauic jack in tengah2 span stee through soid concrete sab width of a rigid specimens. Any increase in the burden of proving ring reading on mounted on hydrauic jacks and any defection that occurs is read on the dia gauge mounted in the bottom center specimens. Load and defection resuts are shown in Figure 6. Figure. Graph shows the moment vs. defection reationship of each specimen Cracking pattern of each specimen is shown in Figure 9. Figure 6. Load vs. defection graph P1 Based on the anaysis of the oad vs. defection reationship, then substantia rigidity of each specimens can be seen in Figure 7. Stiffness = oad is achieved when specimens divided by the crack defection occurs. P2 Figure 7 Graph shows the stiffness of each specimen. P3 403
Figure 9: crack pattern test specimens CONCLUSION 1. Of the four specimens used in this study, a concrete sab with beams apparent 21.5 (P4) is most effectivey used as an aternative in the panning of a concrete sab. Specimen P4 abe to bear the oad of 4061 kg before the coapse. The maximum moment capacity reached 103,67.5 kgcm, whie the nomina moment capacity is ony 101 525 kgcm. 2. In the chart 4.2: Reationship oad - defection for specimens P1, P2, P3, P4 on the inear ine P2 has seen test specimen stiffness k2 = 1237.3 kg / mm which means much more rigid than the P4 specimens having rigidity k4 = 634.5 kg / mm, but specimens P4 is abe to bear the greatest burden before deveoping cracks. So a rigid structure that can not be said to be as strong as the test specimen P2. In other words specimen P4 is more ductie than the specimen so that the specimen P2 P4 stronger withstand impact oads and oad creep. P4 2. Kh Sunggono (194) "Civi Engineering Books", pubisher Nova. 3. Nationa Agency for Standardization (2002) "Panning Procedures Concrete Structures for Buidings" Nationa Standardization Agency. 4. Nationa Agency for Standardization (2002) "Cacuation Procedure for Concrete Structures for Buidings" Nationa Standardization Agency. 5. Reno Widodo (1993), "Coefficient Tabes and Graphs for Panning Pates Concrete Beams", the Foundation Board of Pubic Works Pubisher. 6. Sage R. and P. Koe and Kusuma Gideon (1994), "Guideines for Concrete Work", Erangga. 7. Schodek Danie (199), "Structure", Refika Aditama.. Vis W.C. and Kusuma Gideon (1993), "Panning Basics Reinforced Concrete, Erangga. 9. Vis W.C. and Kusuma Gideon (1993), "Graphs and Tabe Cacuation Reinforced Concrete, Erangga. 10. Vierck Robert (1995) "Vibration Anaysis, Eresco. REFERENCES 1. Department of Pubic Works (197) "Guideines for the Imposition of Panning and Buiding Houses", the Foundation Board of Pubic Works Pubisher. 404