In practice, slabs are the horizontal and structural components in buildings that separate storey from storey and roof. They can also be used as shallow foundation, cover or wall panels in liquidcontaining tanks, technical floors in utility stations, desk slabs in bridges, etc. Castinsitu reinforced concrete (RC) slabs supported by beams or walls, socalled slabandbeam systems, are commonly used in civil and industrial construction owing to the following advantages: (i) Good load bearing capacity; (ii) Good stiffness; (Hi) Easy for maintenance; (iv) Good fire resistance; (v) Flexible for both indoor and outdoor use purposes, etc. In terms of structural behavior, the slabandbeam system having fourside supported slab panels can be categorized into two types depending on aspect ratio, which is the ratio between the longer and the shorter sides of the rectangular slab panel. If the aspect ratio is higher than 2.0, the system can be referred to as oneway slabs, otherwise it will work as twoway slabs. This book introduces the concept, calculation procedure and an example for the design in ultimate limit states of continuous beamtype slab panels, secondary beams and main beams of castỉnsitu RC oneway slabs to current national design standard for concrete structures TCVN 5574:2012. This is a continuity of a series of text books drafted and edited under the guidance of Department of concrete structures, Faculty of Building and Industrial Construction, National University of Civil Engineering (NƯCE) and can be used for Englishsystem students (XE, CDE, MNE, etc.) as well as for students from other engineering universities who study reinforced concrete structures and the associated subject projects or conduct final year projects. The book can also be used as a reference technical material for practice engineers when establishing structural calculation sheets and design reports, for site supervisors, and for contractors working in the construction projects that require VietnameseEnglish bilingual documentation and technical communication.
NATIONAL UNIVERSITY OF CIVIL ENGINEERING (NUCE) DEPARTMENT OF CONCRETE STRUCTURES Nguyen Truong Thang DESIGN OF CAST-IN-SITU REINFORCED CONCRETE ONE - WAY SLABS THIET KE SAN SUON CO BAN MOT PHUONG BE TONG COT THEP TOAN KHOI NATIONAL UNIVERSITY OF CIVIL ENGINEERING (NUCE) DEPARTMENT OF CONCRETE STRUCTURES DESIGN OF CAST-IN-SITU REINFORCED CONCRETE ONE - WAY SLABS THIẾT KẾ SÀN SƯỜN CÓ BẢN MỘT PHƯƠNG BÊ TƠNG CỐT THÉP TỒN KHỐI Nguyen Truong Thang Dr ACPE (C&S) NHÀ XUẤT BẢN XÂY DỰNG HÀ NỘI - 2017 DESIGN OF CAST - IN - SITU REINFORCED CONCRETE ( THIET KE SAN SUONG CO BAN MOT PHUONG BE TONG COT THÉP TỒN KHĨI) Nguyen Truong Thang; NHÀ XUÁT BẢN XÂY DỰNG 37 LÊ ĐẠI HÀNH ~ QUẬN HAI BÀ TRƯNG - HÀ NỘI Điện thoại: 02437265180 Fax: 02439785233 Website: Nxbxaydung.com.vn Email: sachdientu@nxbxaydung.com.vn Văn phòng Đại diện Thành phố Hồ Chí Minh Địa chỉ: Lầu tòa nhà văn phòng 159 Điện Biên Phủ, P 15, Q Bình Thạnh, TP Hồ Chí Minh Điện thoại: 028.2241.7279 Chịu trách nhiệm phát hành xuất phẩm điện tử: Giám đốc — Tổng Biên tập: NGÔ ĐỨC VINH Chịu trách nhiệm nội dung: Giám đốc - Tổng Biên tập: NGÔ ĐỨC VINH Biên tập viên: ĐINH THỊ PHƯỢNG Thiết kế bìa: DANG HUYEN TRANG Trình bày: VU BINH MINH Xuất phẩm điện tử đăng tải địa Website Nhà nxbxaydung.com.vn Định dạng: PDF Dung lượng: 10,6 (MB) Số ĐKXB: 2273-2022/CXBIPH/97-222/XD cấp ngày 07 tháng 07 năm 2022 Mã ISBN: 978-604-82- 6759-9 QĐXB số: 371-2022/QĐ-XBSĐT-NXBXD ngày 08 tháng 07 năm 2022 QĐPH ngày 12 tháng 07 năm 2022 số: 371-2022/QĐÐ-PHSĐT-NXBXD xuất Xây dựng: PREFACE In practice, slabs are the horizontal and structural components in buildings that separate storey from storey and roof They can also be used as shallow foundation, cover or wall panels in liquid-containing tanks, technical floors in utility stations, desk slabs in bridges, etc Cast-in-situ reinforced concrete (RC) slabs supported by beams or walls, socalled slab-and-beam systems, are commonly used in civil and industrial owing construction capacity; (ii) Good to the following stiffness; (iii) advantages: Easy for (i) load Good maintenance; bearing Good fire (iv) resistance; (v) Flexible for both indoor and outdoor use purposes, etc In terms of structural behavior, the slab-and-beam system having four-side supported slab panels can be categorized into two types depending on aspect ratio, is the which ratio the between longer and the shorter sides of the rectangular slab panel If the aspect ratio is higher than 2.0, the system can be referred to as one-way slabs, otherwise it will work as two-way slabs This book introduces the concept, calculation procedure and an example for the design in ultimate limit states of continuous beam-type slab panels, secondary beams and main beams of cast-in-situ RC one-way slabs to current national design standard for concrete structures TCVN 5574:2012 This is a continuity of a series of text books drafted and edited under the guidance of Department of concrete structures, Faculty of Building and Industrial Construction, National University of Civil Engineering (NUCE) and can be used for English-system students (XE, CDE, MNE, students from other engineering universities who etc.) as well as for study reinforced concrete structures and the associated subject projects or conduct final year projects The book can also be used as a reference technical material for practice engineers when establishing structural calculation sheets and design reports, Jor site supervisors, that require and for contractors working in the construction projects Vietnamese-English bilingual documentation and technical communication We appreciate all the feedbacks from readers based on which the book contents can be continuously improved in the subsequent publications All the comments please send to our postal address at Room No.311, Al building, National University of Civil Engineering (NUCE), No.55 Giai Phong Rả, Hanoi or to our email address: bm.ctbtct(@nuce.edu.vn The author CONTENTS Page F27140 nan Chapter CONCEPT OF CAST-IN-SITU RC SLAB-AND-BEAM SYSTEMS IN Ho on ố 1.2 Components of slab-and-beam sy§SLCTS eeeheerrrrrrrtrtrtrrrrrree 10 1.3 Structural behavior of slab paneϧ ce-seeehnhhhhhhrHidrtrrierer 10 10 Hee sinh 1.3.1 Behavior of slab pan€ÌS 1.3.2 One-way and two-way slab panel§ ceeeeeehehrrrrdrrrrrrrtin 1] hưng HưhHhhhihH ác sen 1.4 Beams ín slab-and-beam syS{CIS cc: Ặ ch 1.5 Boundary walls and GOÏUTNS 12 14 hd Chapter CALCULATION OF CAST-IN-SITU RC ONE-WAY SLABS 15 2.1 StructUraÌ SVSf€IN + 22 HH tt 1442721 211e1trrrn 15 2.1.1 Sizing ofslab compOn€nfS .ccerhhehhhhhhHrerrrrrrrrrrrriidre 16 ghe Hà tt 17 HH SE 2n 2.1.2 Materlals ÍOr S{TUCTUF€S .xe enhhhHHhhhhhhhhhHge me 2.2 Calculation of one-way slab pan€Ì§ 2.2.1 Calculation điapTAI Hà Hee che 2.2.2 Loading on one-way sÍAD .c Hà HH cuc SH 2.2.3 Internal forces in beam-slab SfrID 2.2.4 Calculation Of relnÍOFC€IETE HH .ị cành sex chen Hư HH 18 1g 18 19 ig 20 kh 21 erg yscerneenrencnemmmmernnennnonennanannanancasnsatn 23 2.2.5 Detailing requiremMetitsccsssssvmsresne sc ecsecseeseceeeseseeteeeeteeeteneseeeeenscaesenersenes 25 2.3 Calculation of secondary beams 2.3.1 Calculation điagTaI .cc re 25 HH 0011401111001 2.3.2 Loading on secondary beams ccccccsescssssssessssveesesavsesessssesesesseesseseseveversees 26 2.3.3 Internal ÍOTC€S cv 21H 100111111 xe re rerse 27 2.3.4 Calculation of longitudinal reinforcement for bending .- 29 2.3.5 Strength calculation on inclined sections c c.ccccccsscsssscssssssesecsessssessseseeeeees 33 2.4 Calculation of main beams ccccscesesscsessssssvssssesssetsssavstsseareseatsrsssssseveneeeeveees 37 2.4.1 Calculation diagram wo ccccccccecesescsesssssssssssssssesessestsassssescevseavssersaveveveeses 37 2.4.2 Loading on main beams .ccccccscsesccesssscscsssescsvevessasesesesessesssvevevsceeveseeees 38 2.4.3 Internal forces of main beams c.cccececsesecssseseseesesvesssesesssvssesessesesereseess 39 2.4.4, Calculation of longitudinal reinforcement for bending - 42 2.4.5 Strength calculation on inclined sections .c.ccccscsssesscsssssscccsssssssceseesecceces 44 2.4.6 Calculation of reinforcement for breaking-off GREATEST anennnge tees iter nanncenenere 48 2.5 Detailing requirements for beams ccccccccsssssscsessssescssssscssssesesessesseeveeececees 49 2.5.1 Detailing r€quir€In€Tit§ ác cv T211 112111 se 2.5.2 Anchorage length (/„„) of reinforcement to suppoFts acc 49 50 2.5.3 Curtailment of tension longitudinal rebars - nh e - 31 2.6 Matcrial resistance enVelOpe c cv T121 1111111812111 E nu 53 2.7 Design requirement for cracks and đefromation sa Tnhh 54 Chapter DESIGN EXAMPLE ON CAST-IN-SITU RC ONE-WAY SLABS 56 Sud DROS CUA cr usassnesnesnnsnzas inanasnnennanenenenonnevenwsewerauipyemsnsstscastipitisiteemnsveoeseeseedbone 56 3.2 Design of one-way slab panels .cccccccscsscsssssssssssesessessesseseseesscssevsstessereesescesees 57 3.2.1 Analysis of the structural syS{em neo 57 3.2.2 Sizing for structural rineribors 3.2.3 Calculation đỉagram 2s 57 c1 1221 222tr 3.2.4 Design Ìoad§ HH HH2 1112111111111 3.2.5 Internal ÍOFCŒ§ cuc cv 221211 1H tre 57 eo 58 3.2.6 Calculation of reinforcement for bending nhe 3.2.7 Distribution reinforcement 58 59 62 3.3 Design of secondary beams "¬ 3.3.1 Calculation điaBFA .- St.TH HH -.312400536 T655G101EBELEEGG TOSTHOGIĐXSUDEOSI14T9911411080 63 3.3.2 Design ÏOaÔS kh Nho it 62 ố 6n 64 3.3.4 Calculation of reinforcement for bending (longitudinal rebars) 65 3.3.5 Calculation of reinforcement for shear oo cece cece eeeeeeeeeeeeneeeness 67 3.3.6 Establishing of material resistance env€ÌOD€ .ceerereereerre 71 3.3.7 Anchorage of longitudinal reDaFS cành cu 3.3.8 Distrlbution r€lnfOrC€ITTI HH HH ng nhi ret 74 3.4 Design of main beams "— 76 3.4.2 Design loads "¬ 3.4.2, Interridl ÍOTCES 76 HH K 2111101141101H4 76 cành 3.4.1 Calculation dia8rA rate teseneneeeees 74 ca 414304 77 rieri E01 G0 0011060111411411131 nenheeerieriee 3.4.4 Calculation of reinforcement for bending (longitudinal rebars) 83 3.4.5 Calculation of reinforcement for shear eee ec chen ng re 86 91 sen 3.4.6 Calculatlon of reinforcement for breaking-OfT -3.4.7 Establishing of material resistance €nVOD€ «ceeeeeeeie 92 3.4.8 Anchorage of longitudinal r€ÐATB ác nhe HH 01 111 kg tr HH HH TH cn nàn 3.4.9 Distribution reinfOTC€I€TĂ 3.5 Bill oŸ quantiEW sáx:sscnn ớt 96 96 6141881 0111818141811611101318000151111440148111014211240111110100e 98 552553 101 1/0184G165EEEET12 1553481141150 083815E10115S8400 016 168G6% APPENDIXES 113 6858550E10351508 G51 00085S039111WE0101 REFERENCES -.c+.csccssSS-vsecscc+S213288866Đ011 Chapter CONCEPT OF CAST-IN-SITU RC SLAB-AND-BEAM SYSTEMS —— 1.1 INTRODUCTION Cast-in-situ reinforced concrete (RC) slab-and-beam systems are commonly for floors of buildings, especially for spans of greater than 6m and for heavy live [7] There are various configurations of the systems such as one-way solid slabs main beams, one-way slabs with main and secondary beams, two-way slab with beams, waffle with main beams, and waffle with integral beams, which respectively shown in Figures 1.1(a, b, c, d, e) Figure 1.1, Perspective of cast-in-situ slab-and-beam systems: (a) One-way solid slabs with main beams; (b) One-way slabs with main and secondary beams; (c) Two-way slab with main beams; (d) Waffle with main beams, (e) Waffle with integral beams used loads with main are Table 3.11 Rebars schedule (continued) Structural | Label of Rebar Length (mm) (mm) 25 8000 16 128.0 493.2 28 9710 16 155.4 751.0 22 7900 16 126.4 377.2 22 5130 16 82.1 244.9 28 6990 16 111.8 540.6 Main 25 3540 16 56.6 218.6 090108 28 8120 65.0 314.0 -8 28 3620 29.0 140.0 14 4760 16 76.2 92.0 10 14 7500 32 240 290.0 11 1880 168 672 1263.4 498.5 12 350 96 384 134.4 29.8 13 10 - 1920 66 264 506.9 312.5 clement rebars (4 nos) diameter | of bar Quantity mang Weight length KG) (m n | Total AR Table 3.12 Summary of reinforcing steel Class ® (mm) CI CH § 10 12 14 16 18 M (kG) | 4680.9 | 954.9 | 312.5 | 197.3 } 382.1 | 1644.7 | 500.1 | 20 22 25 28 1324.4 | 622.1 | 711.5 | 1745.4 99 Table 3.13 Summary of materials utilization Structural element Volume of concrete (nv) Weight of rebars Ratio of rebars weight (kG) per Im’ concrete (kG/m)) Slab panel Vp=86.40 M=4498.9 Por My/Mp=52.1 Secondary Vapi =46.53; Vap2=36.59 Mgp=4274.9 Pap= Map! Vapi =91.9 Voc1=25.20; Vacgg=22.32 Mg.=4302.0 Pic=Mac! Vacv=170.7 Vo=Vot Vapot Vaco= 145.31 M =13075.8 Ps=M/V=90.0 beams Main beams All slab system Weight of reinforcing steel per 1m’ slab (4,=1080m”): =M,/A=12.2 kG/m? Notes: - Vapi, Vacit respective volumes of secondary and main beams, with cross section bxh, for calculation of the ratio of reinforcing steel weight per 1m’ volume of concrete; - Vop2, Veco: respective volumes of the webs of secondary and main beams with cross section bx(h-hy), for calculation of 1⁄2 100 APPENDIXES A.1, Initial modulus of elasticity of normal-weight concrete (E,x10°, MPa) Compressive strength class Naturally hardened Heat-treated at atmospheric B12.5 B15 21.0 230 B20 B25 B30, B35 27.0 30.0 325 345 ị ị 19.0 ị pressure : ị 20.5 : 240 25.0 31.0 325 20.0 340 35.0 355 ị ị 17.0 i Ị 29.0 i : Autoclaved | 16.0 B40 B45 B50 B55 B60 36.0 37.5 390 395 40.0 ị : 225 245 36.0 : : 26.0 270 28.0 29.0 295 300 A.2 Specified strength for Limit State - Group (Serviceability Limit States SLS) of normal-weight conerete (Ry, Rom, MPa) Compressive strength class Axial compression Rp, AxialtensionRin| B12,5 B15 B20 B25 B30 B35 B40 B45 B50 96 110 160 185 22.0 255 29.0 320360 1.0 | 1.15 1440 1.60 1.80 195 A.3 Design strength for Limit State - Group 210 i : : i : : : : : B55 B60 398 '430 220 230 240 250 (Ultimate Limit States - ULS) of normal-weight concrete (R,, Ry: MPa) Compressive strength class Axial B125: B15 : B20 j B25 B30 B35 B40 ị B45 B50: 75 8.5 ị 11.5 : 14.5 17.0 ị 19.5 22.0 | 25.0 27.5 compression Rp Axial tension Ry, | : 0.66 | 0.75 | 0.90 | 1.05 ‘ ị | 1.20 | 1.30 | 1.40 ị | 1.45 B55 B60 | 30.0 ; 33.0 ị | 1.55 ¡ 1.60 ; 1.65 10I A.4 Partial performance coefficient for concrete Partial performance coefficient Duration of loading Symbol Value Yb2 1.00 Vb2 0,90 - For cellular and aerated concrete irrespective of service condition b2 0.85 b) Including short-term (instant) loads in this combination loads not specified in item (a) for all types of concrete Yb2 1.10 a) Including constant, long-term and short-term loads except instant loads whose total action is small during service (e.g crane loads, loads from vehicles, wind loads, loads imposed by handling and erection, etc.) and special loads imposed by deformation of settling soils, swelling soils, permafrost and other similar ground - For normal-weight concrete, fine-aggregate both hardened naturally and heat treated: and light-weight concrete, + In service conditions favorable for strength gain (e.g underwater, wet soil or outdoor humidity at 75%) + In other cases or hazardous A.5 Modulus of elasticity of reinforeing steel (Esx10'', MPa) Class of Cl, A-l, Cll, Atl reinforcement Modulus of elasticity : CIll, A-Iil CIV, AV, : 21.0 A-V, As | VI 20.0 A-lllg : 19.0 18.0 A.6 Specified tensile strength of steel reinforcing bars and (R,,, MPa) and design tensile strength of steel reinforcing bars for SLS 192 Bars of classes Rsn Bars of classes Ren Cl, A-l 235 A-V 788 Cli, A-ll 295 A-VI 980 Cill, Ali 390 A;-VIl 4175 CIV, A-IV 590 A-llls _540 | A.7 Design strength of reinforcing s(cel bars for ULS (MPa) Tensile strength Transverse Bars of classes Longitudinal Compressive rebars (stirrups | strength Rsc rebars R, and bent bars) Rsw Cl, Al 225 175 225 Cll, A-H 280 225 280 diameter 6+8mm 355 285 355 | diameter 10:40mm 365 290 365 510 405 AV 680 545 | ANI 815 650 Ar-VII 980 785 500 490 390 200 450 360 200 A-lll CIH, A-lll SỐ CIV, A-IV _ A-llls With control of elongation _ 450 Si 500 ` fp 00 || and stress With control of elongation only A.8 Coefficient of working conditions of reinforcing steel bars Factors causing application of ‘ coefficient of working wee conditions of rebars Reinforcement again shear forces Presence of welded splices under shear " Description of seen Class of rebars rebar Transverse Coefficient of working 47 conditions Symbol Value Any class Ys1 0.80 Transverse CII, AIH, Ys2 0.90 rebars RB400, Ys3 TCVN rebars RB400W Repeated loading Longitudinal and transverse Any class 5574:2012 rebars 103 A.9, Limits of relative depth of compression zone of concrete when design internal forces are determined from clastic analysis (Ep) Coefficient) Class of working of sanenan | cause Rs Compressive strength class of concrete |Symbol a= B12.5, : |0796 B1S : 0.789 B20 ỹ 0.767 225 | t= | 0.689 0.681 0656 Tpz=0,9 MPa : œạ= | 0.452 0.449, 280 | MP 2| 0.746 0.728 0.432 R= | 0.667 0.658 0.633 0.608 qạ= |0.445 0.442 : 0.424 0.417 0.588 0.568 0.433 0.423 0.415 0.407 280 | ®| 366 | MP Í : |0.449 04446 : ị |0442 0.427 ị x= | 0660 0.650 œạ= 0.437 0.623 0.595 0.596 : i 0.419 0.573 ị 0.439 0.429 0.418 0.409 En= | 0.628 0.619 0.590 0.563 œạ= | 0.431 ¡0.427 0.416 0.405) 0.395 |0784 0775 0749 o= 225 | MP *| Ex= | 0.675 0.665 0.635 0.605 0582 ị qạ= | 0.447 0.444 0.433 0.422 0.412 280 | x= | 0.653 ị 0.612 0.582 : gạ= | 0.440 ; 0.436 : 0.425 365 | Er= |0621 0611 MPa œa= | 0.428 0.424 ị : 0.413 ị ị 0.388 0.379 ị 0.467 0.694 0.674 0.650 0.630 0.610 0.586 0.575 0.553 0.528 0.508 0.488 0.464 0.410 ; 0.400 ; 0.389 0.379 : ị Ệ 0.552 0.530 0.390 Ỹ j 0.369 : ị 0.356 : 0.505 0.485 0.465 0.442 0.378 0.367 0.357 : 0.344 0.453 0.434 0.411 04384 0.374 0.361 0.351 0.340 ' 0.326 0.678 0.658 0.630 0.608 0.586 0.558 0.535 0.508 : 0.402 0.392 0.379 ị 0.558 0.535 0.612 0.560 0.486 0.464 0.438 0.368 0.356 0.342 : 0.485 0.463 0.442 0.416 : 0.402 0.392 0.381 0.367 0.356 0.344 : 0.330 0.503 (0.480 0.453 0.432 0.411 0.386 0.339 0.326 0.312 0.528 0.412 0.388 0.376 Where: o=a-0.008.Rp for normal-weight concrete: «=0.85; _ Se = : 0.365 w 0.351 ; R a l+——(q—— cesar 104 0.507 0.489 0.341 0.580 0.550 0.399 0.381 | 0.370 0.362 0.353 : 0.399 0722 0700 : 0.642 0.526 0.541 0.519 0.498 0.473 Rs MPa : 0.398 0.390 0.372 ta= | 0.682 0.618 ị 0.398 0,383 225 | 0673 0645 0.549 0.530 0.512 0.490 0.436 0.392 0.758 0.734 0.714 0.612 0.475 0.457 o= | 0.790 0.782 0.401 B60 0.517 0.494 Rs 0.410 B655, 0.358 0.430 0.420 0.549 B60, 0.670 0.652 0.634 0.408 ị : B456 0.369 aạ= | 0.434 ane B40, 0.710 0692 0.627 0.601 0.576 0556 0/536 2Í : 0.631 0611 0592 0572 0.441 : B35 Ex= | 0636 MP Yo2=1.1 830 365 | MP °| MP Y2=1.0 B25 ( iP Œn=Šn.(1-0.5.ÉR) A.10 Coefficients Š, É, œm for member calculation § & ơm 0.01 0.995 0010 € Ot 026 0.870 0.226 051 0.28 0.860 0.241 0.53 0.039 0.29 0.855 0.248 - 04394 0.05 0.975 | 0.049 0.30 0/850 - 0/255 0.399 0.06 0970 0.058 0.31 0.845 : 0.262 0.07 - 0965 0.068 0.32 0/840 | 0.269 057 | 0715 ` 0408 L 0.08 ¡ 0.960 0.077 0.33 0.835 0.276 - 058 0.412 0.09 ¡ 0.955 ¡ 0.086 034 0830 0.282 — 0.89 L 0.10 0.950 ' 0.095 035 0825 0289 0.60 0.420 041 0945 - 0.104 036 0.820 : 0.295 0.82 0690 ' 0.428 002 09900020 | 003 ¡ 0.985 ˆ 0.030 004 ¡ 0.980 cô | 027 0885 0234 012 | 0.940 0.113 037 0815 0302 0122 0745 0740 0.380 0386 ị 0735 ˆ 0.390 0.56 0.720 0.403 - 0416 064 —~ 0.435 0938 0.14 i 0.930 0.130 ; 039 0805 (0314 015 0.925 0139 0.40 - 0.800 © 0.320 0.70 0650 - 0485 _ 0.16 0.920 0.147 0.41 | 0.795 0.326 (0.72 0840 - 0.461 047 ¡ 0.915 ' 0.186 042 : 0.790 0332 —074 _ 06880 0.18 0.910 — 0/182 043 ` 0.785 _ 0.338 0.19 - 0.906 0.72 044 0.780 0.20 Ì 0.900 ; 0.180 0.45 021 ' 0.895 0.188 0.890 0.196 023 0.885 0.204 S2 | ĐUẾỢ j ĐIII 0.25 ¡ 0.875 0.219 0308 | 052 ơm 049 0.22 038 0810 Eg | 0e (042| 0.68 0.466 076 0620 0.471 0343 078 | 0610 0476 0775 04349 0.80 046 - 0770 - 0354 0.85 047 | 0.765 - 0.360 0.90 0.550 ' 0.495 048 ; 0.760 0.365 095 0525 - 0.499 G5 , O00 0.750 0.375 " 0600 ˆ Bene ĐẦU 0.50 | 0.449 0.600 ' 0.480 | 0.575 ị 0.489 Relationships: C=1-0.5¢; am=€¢; (=0.5x[1+(1-2œm)°”]; £=2.(1-Ĩ 105 A.11 Coefficient for calculating envelope moment of secondary beams , with equal spans in plastic analysis Section L2 Value, for Ì"gu 04881 | : calculating Minox 0.065 |/ 78; om wm i 0.090 » 0.091 ; : 0.075 : 0.020 0,51 : : 0018, 0.058 : 0.0625 Notes: + M=0 at 0,15./ from support; + Sections of 0,425./ vu 0,5./ are distances from the left support Value of -100.£2 (2 for calculating Min) - corresponding to sections Đư/0a